@article {2542, title = {Paclitaxel incorporated in hydrophobically derivatized hyperbranched polyglycerols for intravesical bladder cancer therapy}, journal = {Bju International}, volume = {103}, number = {7}, year = {2009}, note = {ISI Document Delivery No.: 417GSTimes Cited: 6Cited Reference Count: 37Mugabe, Clement Hadaschik, Boris A. Kainthan, Rajesh K. Brooks, Donald E. So, Alan I. Gleave, Martin E. Burt, Helen M.}, month = {Apr}, pages = {978-986}, type = {Article}, abstract = {To develop paclitaxel incorporated into unimolecular micelles based on hydrophobically derivatized hyperbranched polyglycerols (dHPGs) for use as mucoadhesive intravesical agents against non-muscle-invasive bladder cancer. Two different types of dHPGs (HPG- C10-polyethylene glycol (PEG) and polyethyleneimine (PEI)-C18-HPG) were synthesized and paclitaxel was loaded into these using a solvent evaporation method. After physicochemical characterization of the resulting nanoparticles, four human bladder cancer cell lines were incubated with various concentrations of paclitaxel incorporated in dHPGs and the results were compared with those of paclitaxel formulated in Cremophor-EL (Taxol (R), Bristol-Myers-Squibb). In vivo, nude mice with orthotopic KU7-luc tumours were intravesically instilled with phosphate buffered saline, Taxol, or paclitaxel/HPG-C10-PEG. dHPGs are mucoadhesive nanoparticles with hydrodynamic radii of < 10 nm and incorporation of paclitaxel did not affect their size. The release profiles of paclitaxel from dHPGs were characterized by a rapid-release phase followed by a slower sustained-release phase. While the PEI-C18-HPG formulation released only approximate to 40\% of the initially incorporated paclitaxel, up to 80\% was released from HPG-C10-PEG. Moreover, only paclitaxel/HPG-C10-PEG was stable in acidic urine. In vitro, all paclitaxel formulations potently decreased bladder cancer proliferation although paclitaxel/HPG-C10-PEG was slightly less cytotoxic than standard Taxol. By contrast, in vivo, the mucoadhesive HPG-C10-PEG formulation of paclitaxel was significantly more effective in reducing orthotopic tumour growth than Taxol and was well tolerated. Intravesical administration of mucoadhesive nanoparticulate formulations of paclitaxel might be a promising approach for instillation therapy of patients with non-muscle-invasive bladder cancer.}, keywords = {ARCHITECTURES, bladder cancer, chemotherapy, DESIGN, DRUG-DELIVERY, hyperbranched polyglycerols, intravesical therapy, MANAGEMENT, MICROSPHERES, MUCOADHESION, orthotopic mouse model, PACLITAXEL, pharmacokinetics, POLYMERS, unimolecular micelles}, isbn = {1464-4096}, url = {://000264065100022}, author = {Mugabe, C. and Hadaschik, B. A. and Kainthan, R. K. and Brooks, D. E. and So, A. I. and Gleave, M. E. and Burt, H. M.} } @article {2473, title = {Poly(oligo(ethylene glycol)acrylamide) Brushes by Surface Initiated Polymerization: Effect of Macromonomer Chain Length on Brush Growth and Protein Adsorption from Blood Plasma}, journal = {Langmuir}, volume = {25}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 418JRTimes Cited: 12Cited Reference Count: 45Kizhakkedathu, Jayachandran N. Janzen, Johan Le, Yevgeniya Kainthan, Rajesh K. Brooks, Donald E.}, month = {Mar}, pages = {3794-3801}, type = {Article}, abstract = {Three hydrolytically stable polyethyleneglycol (PEG)-based N-substituted acrylamide macromonomers, methoxypolyethyleneglycol (350) acrylamide (MPEG(350)Am) methoxypolyethyleneglycol (750) acrylamide(MPEG(750)Am) and methoxypolyethyleneglycol (2000)acrylamide (MPEG(2000)Am) with increasing PEG chain length were synthesized. Surface-initiated aqueous atom transfer radical polymerization (ATRP) using CuCl/1,1,4,7,10,10-hexamethyl triethylene tetramine (HMTETA) catalyst was utilized to generate dense polymer brushes from these monomers via an ester linker group on the surface of model polystyrene (PS) particles. The molecular weight, hydrodynamic thickness, and graft densities of the grafted polymer layers were controlled by changing the reaction parameters of monomer concentration, addition of Cu(II)Cl-2, and sodium chloride. The graft densities of surface-grafted brushes decreased with increasing PEG macromonomer chain length, 350 > 750 >> 2000, under similar experimental conditions. The molecular weight of grafts increased with increase in monomer concentration, and only selected conditions produced narrow distributed polymer chains. The molecular weight of grafted polymer chains differs significantly to those formed in solution. The hydrodynamic thicknesses of the grafted polymer layers were fitted to the Daoud and Cotton model (DCM) for brush height on spherical surfaces. The results show that the size of the pendent groups on the polymer chains has a profound effect on the hydrodynamic thickness of the brush for a given degree of polymerization. The new PEG-based surfaces show good protection against nonspecific protein adsorption from blood plasma compared to the bare surface. Protein adsorption decreased with increasing surface density of grafted polymer chains. Poly(MPEG(750)Am) brushes were more effective in preventing protein adsorption than poly(MPEG(350)Am) even at low graft densities, presumably due to the increase in PEG content in the grafted layer.}, keywords = {AQUEOUS ATRP, COPOLYMER BRUSHES, density, METHYL-METHACRYLATE, MODEL, N-DIMETHYLACRYLAMIDE), OLIGO(ETHYLENE GLYCOL) METHACRYLATE, PHOSPHORYLCHOLINE, POLY(N, POLYMERS, TRANSFER RADICAL POLYMERIZATION}, isbn = {0743-7463}, url = {://000264145000068}, author = {Kizhakkedathu, J. N. and Janzen, J. and Le, Y. and Kainthan, R. K. and Brooks, D. E.} } @article {2220, title = {Nonlinear optical properties of Schiff-Base-containing conductive polymer films electro-deposited in microgravity}, journal = {Advanced Materials}, volume = {20}, number = {12}, year = {2008}, note = {ISI Document Delivery No.: 320XMTimes Cited: 5Cited Reference Count: 41Pietrangelo, Agostino Sih, Bryan C. Boden, Britta N. Wang, Zhenwei Li, Qifeng Chou, Keng C. MacLachlan, Mark J. Wolf, Michael O.}, month = {Jun}, pages = {2280-+}, type = {Article}, abstract = {Organic-inorganic hybrid films prepared from copper(II)-containing Schiff base complexes bearing long alkoxy chains grown under microgravity conditions show enhanced third-order NLO susceptibilities relative to films grown at 1 g.}, keywords = {2ND-ORDER, BOND-LENGTH ALTERNATION, CHAIN, CONJUGATED, COPPER(II), ENVIRONMENT, GENERATION, GRAVITY, HYBRID, PHTHALOCYANINE THIN-FILMS, POLYMERS}, isbn = {0935-9648}, url = {://000257268500006}, author = {Pietrangelo, A. and Sih, B. C. and Boden, B. N. and Wang, Z. W. and Li, Q. F. and Chou, K. C. and MacLachlan, M. J. and Wolf,Michael O.} } @article {2342, title = {A novel functional polymer with tunable LCST}, journal = {Macromolecules}, volume = {41}, number = {14}, year = {2008}, note = {ISI Document Delivery No.: 326NJTimes Cited: 13Cited Reference Count: 44Zou, Yuquan Brooks, Donald E. Kizhakkedathu, Jayachandran N.}, month = {Jul}, pages = {5393-5405}, type = {Article}, abstract = {Poly(N-[(2,2-dimethyl-1,3-dioxolane)methyl]acrylamide) (PDMDOMA), a novel thermo-responsive polymer containing pendant dioxolane groups was synthesized via atom transfer radical polymerization (ATRP). Water soluble PDMDOMAs with controlled molecular weight and narrow molecular weight distribution were obtained. GPC-MALLS and MALDI-TOF-MS analysis verified the controlled nature of polymerization. It was found that an aqueous solution of PDMDOMA has a lower critical solution temperature (LCST) around 23 degrees C. The LCST of PDMDOMA was finely tuned over a wide temperature range by the partial hydrolysis of the acid labile dioxolane side group to form diol moieties (PDMDOMA diols). Unlike the traditional way of controlling LCST by copolymerization, the advantage of this method is that a series of thermo-responsive polymers with different LCST can be prepared from a single batch of polymer with comparable molecular weight profiles. The LCST of the resulting PDMDOMA diols increased almost linearly up to 28 mol \% of diol in the copolymer and the LCST disappeared above 43 mol \% diol content. The diol moiety generated during the hydrolysis was further oxidized to create aldehyde functionalities along the polymer backbone (PDMDOMA-aldehyde). The NMR analysis indicates that the aldehyde groups in the polymer exist in equilibrium with their covalent hydrates in water. The presence and reactivity of aldehyde groups on the PDMDOMA-aldehyde was verified by reaction with propylamine and aniline. The LCST of PDMDOMA-aldehyde did not change significantly compared to the precursor diol polymer. However, the propylamine or aniline derivatives showed a dramatic decrease in the LSCT possibly due to an increase in the hydrophobic character. The LCST of PDMDOMA-propylamine and PDMDOMA-aniline derivatives depends on the composition and nature of the attached groups. The structure of PDMDOMA and its derivatives were fully characterized by H-1, C-13, and 2D HMQC NMR, GPC-MALLS, and MALDI-TOF-MS.}, keywords = {2-(2-METHOXYETHOXY)ETHYL METHACRYLATE, AQUEOUS-SOLUTIONS, N-ISOPROPYLACRYLAMIDE, OLIGO(ETHYLENE GLYCOL) METHACRYLATE, POLYMERS, PROTEINS, SMART, SOLID TUMORS, STIMULI-RESPONSIVE POLYMERS, TEMPERATURE, TRANSFER RADICAL POLYMERIZATION}, isbn = {0024-9297}, url = {://000257665900045}, author = {Zou, Y. Q. and Brooks, D. E. and Kizhakkedathu, J. N.} } @article {2209, title = {Phosphorus-containing block copolymer templates can control the size and shape of gold nanostructures}, journal = {Journal of the American Chemical Society}, volume = {130}, number = {39}, year = {2008}, note = {ISI Document Delivery No.: 353GITimes Cited: 17Cited Reference Count: 31Noonan, Kevin J. T. Gillon, Bronwyn H. Cappello, Vittorio Gates, Derek P.}, month = {Oct}, pages = {12876-+}, type = {Article}, abstract = {{Amphiphilic block copolymers containing phosphine moieties in the main chain are employed as macromolecular ligands for gold (1). The sequential living anionic copolymerization of isoprene (1) and the phosphaalkene}, keywords = {ARCHITECTURE, CROSS-LINKING, DIBLOCK COPOLYMER, HOMOPOLYMERS, LIVING ANIONIC-POLYMERIZATION, micelles, MORPHOLOGIES, multiple, NANOPARTICLES, nanotechnology, POLYMERS}, isbn = {0002-7863}, url = {://000259553700020}, author = {Noonan, K. J. T. and Gillon, B. H. and Cappello, V. and Gates, D. P.} } @article {2118, title = {Unimolecular Micelles based on Hydrophobically Derivatized Hyperbranched Polyglycerols: Biodistribution Studies}, journal = {Bioconjugate Chemistry}, volume = {19}, number = {11}, year = {2008}, note = {ISI Document Delivery No.: 373VOTimes Cited: 7Cited Reference Count: 31Kainthan, Rajesh Kumar Brooks, Donald E.}, month = {Nov}, pages = {2231-2238}, type = {Article}, abstract = {We recently reported the synthesis and testing of a new class of unimolecular micelles based on hyperbranched polyglycerols as second generation synthetic plasma expanders and as general drug delivery vehicles. A detailed biodistribution study of two derivatized hyperbranched polyglycerols of different molecular weights derivatized with hydrophobic groups and short poly(ethylene glycol) chains is reported in this article. In mice, these materials are nontoxic with circulation half-lives as high as 31 h, controllable by manipulating the molecular weight and the degree of PEG derivatization. Organ accumulation is low, presumably due to the "pegylation" effect. Thermal degradation and hydrolysis data suggest that these polymers are highly stable with a long shelf life, a major advantage for a pharmaceutical product. Degradation under acidic conditions has been observed for these polymers.}, keywords = {ALBUMIN, BIOLOGICAL EVALUATION, DENDRIMERS, IMMUNOGENICITY, IN-VIVO, LIPOSOMES, MOLECULAR-WEIGHT, POLYETHYLENE-GLYCOL DEGRADATION, POLYMERS, STARCH}, isbn = {1043-1802}, url = {://000261001800018}, author = {Kainthan, R. K. and Brooks, D. E.} } @article {1161, title = {Comparison of hyperbranched and linear polyglycidol unimolecular reverse micelles as nanoreactors and nanocapsules}, journal = {Macromolecular Rapid Communications}, volume = {26}, number = {3}, year = {2005}, note = {ISI Document Delivery No.: 897MDTimes Cited: 28Cited Reference Count: 20}, month = {Feb}, pages = {155-159}, type = {Article}, abstract = {Amphiphilic-hyperbranched polyglycidols and a linear analogue were tested for the unimolecular elimination (E1) reactions of tert-alkyl iodides. Their encapsulation properties were also compared. The linear polymer was found to have very good "unimolecular reverse micellar" characteristics as well, even though the results showed the advantages of a hyperbranched nature over a one linear one. Our results showed the need for a direct comparison of branched and linear polymers for any application.}, keywords = {CATALYSIS, host-guest systems, hyperbranched, LIGHT-SCATTERING, MOLECULAR NANOCAPSULES, POLYGLYCEROLS, polyglycidol, POLYMERIZATION, POLYMERS, unimolecular reverse micelle}, isbn = {1022-1336}, url = {://000227007400005}, author = {Kumar, K. R. and Brooks, D. E.} } @article {607, title = {Analysis of electron spectra of carbon allotropes (diamond, graphite, fullerene) by density functional theory calculations using the model molecules}, journal = {Journal of Physical Chemistry A}, volume = {107}, number = {44}, year = {2003}, note = {ISI Document Delivery No.: 738HWTimes Cited: 2Cited Reference Count: 30}, month = {Nov}, pages = {9403-9408}, type = {Article}, abstract = {X-ray photoelectron, emission, and Auger electron spectra of diamond, graphite, and fullerene have been analyzed by deMon density-functional theory (DFT) calculations using the model molecules adamantane derivative (C10H12(CH3)(4)), pyrene (C16H10), and C-60, respectively. The theoretical valence photoelectron, C Kalpha X-ray emission, and Auger electron spectra for the allotropes are in good accordance with the experimental ones. The combination analysis of the valence X-ray photoelectron and C Kalpha X emission spectra enables us to divide the valence electronic distribution in the individual contributions for psigma- and ppi-bonding MOs of the carbon allotropes, respectively. The experimental Auger electron spectra of the allotropes can be classified in each range of 1s-2p2p, 1s-2s2p, and 1s-2s2s transitions for C KVV spectra, and in individual contributions of the chemically different carbon atoms from the theoretical analysis.}, keywords = {APPROXIMATION, AUGER LINE-SHAPES, C-60, ENERGY, POLYMERS, RAY PHOTOELECTRON-SPECTRA, SILICON, SIO2, XPS}, isbn = {1089-5639}, url = {://000186282000019}, author = {Endo, K. and Koizumi, S. and Otsuka, T. and Ida, T. and Morohashi, T. and Onoe, J. and Nakao, A. and Kurmaev, E. Z. and Moewes, A. and Chong, D. P.} } @inbook {654, title = {Synthesis of poly(N,N-dimethylacrylamide) brushes from functionalized latex surfaces by aqueous atom transfer radical polymerization}, booktitle = {Advances in Controlled/Living Radical Polymerization}, series = {Acs Symposium Series}, volume = {854}, year = {2003}, note = {ISI Document Delivery No.: BW85KTimes Cited: 7Cited Reference Count: 30Proceedings Paper224th National Meeting of the American-Chemical-SocietyAUG 17-22, 2002BOSTON, MASSACHUSETTSAmer Chem Soc1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA}, pages = {316-330}, publisher = {Amer Chemical Soc}, organization = {Amer Chemical Soc}, address = {Washington}, abstract = {Negatively charged, ATRP initiator functionalized polystyrene latexes were synthesized and N,N-dimethylacrylamide was polymerized from their surfaces by aqueous ATRP using several catalyst combinations. Very high grafting densities and molecular weights were achieved with good polydispersities. The brushes exhibited a strong repulsive force that increased with molecular weight in atomic force microscopy measurements. Hydrodynamic thicknesses were consistent with theory. Polymerization from these surfaces is very different from ATRP in solution and depends on monomer concentration in solution, type of catalyst, and surface initiator concentration. The observations were explained with an electrostatic model of the surface region that predicts an increase in the local concentration of Cu(I) and Cu(II) catalyst complexes.}, keywords = {ADSORPTION, BLOCK-COPOLYMERS, density, FORCE MICROSCOPE, INITIATED POLYMERIZATIONS, LAYER, MEDIA, POLYMERS, SELF-ASSEMBLED MONOLAYERS}, isbn = {0097-61560-8412-3854-5}, url = {://000183406500022}, author = {Kizhakkedathu, J. N. and Goodman, D. and Brooks, D. E.}, editor = {Matyjaszewski, K.} } @article {517, title = {Analysis of X-ray photoelectron spectra of electrochemically prepared polyaniline by DFT calculations using model molecules}, journal = {Journal of Molecular Structure}, volume = {608}, number = {2-3}, year = {2002}, note = {ISI Document Delivery No.: 536ABTimes Cited: 1Cited Reference Count: 44}, month = {May}, pages = {175-182}, type = {Article}, abstract = {In order to clarify the electronic state of polyaniline synthesized electrochemically, we analyzed valence X-ray photoelectron spectra (XPS) and core-electron binding energies of N,N{\textquoteright}-Diphenyl-1,4-phenylenediamine and polyaniline by deMon density-functional theory calculations (DFT) using the molecule and model molecule, respectively. Polyaniline has been synthesized electrochemically from two different thin films on platinum plates in oxidation and reduction states, respectively. Valence XPS of the conductive polymers were analyzed by deMon DFT calculations using model tetramers of the four chemical structural formulae (1S, 2S, 1A, and 2A) which MacDiarmid and co-workers proposed. We can conclude that the oxidized polyanililine corresponds to the 2A type, while the reduction form approximated the 1S type. (C) 2002 Elsevier Science B.V. All rights reserved.}, keywords = {APPROXIMATION, C1S SPECTRA, CONTAINING, deMon DFT calculations, DENSITY-FUNCTIONAL CALCULATIONS, ELECTRON BINDING-ENERGIES, electronic state, interconversion, OLIGOMERS, polyaniline, POLYMERIZATION, POLYMERS, SPECTROSCOPY, XPS}, isbn = {0022-2860}, url = {://000174677600008}, author = {Takaoka, K. and Otsuka, T. and Naka, K. and Niwa, A. and Suzuki, T. and Bureau, C. and Maeda, S. and Hyodo, K. and Endo, K. and Chong, D. P.} } @article {469, title = {Theoretical Auger electron and X-ray emission spectra of CO and H2O by density functional theory calculations}, journal = {Chemical Physics Letters}, volume = {352}, number = {5-6}, year = {2002}, note = {ISI Document Delivery No.: 521CHTimes Cited: 3Cited Reference Count: 33}, month = {Feb}, pages = {511-520}, type = {Article}, abstract = {We propose a new method for analysis of X-ray emission and Auger electron spectra (XES and AES) of molecules involving the valence spectra using density functional theory (DFT) calculations. To obtain the more accurate transition energies and the relative intensities, we use the total-energy difference procedure (DeltaE-KS) for all transition energies, and transform the coefficients in the LCGTO-MO scheme in the DFT to those for the linear combination of the LCGTO-AO scheme. The method is applied to the analysis of valence spectra, XES and AES for CO and H2O molecules. The simulated spectra are in a good agreement with the experimental results. (C) 20021 Published by Elsevier Science B.V.}, keywords = {ACCURATE, APPROXIMATION, BINDING-ENERGIES, MODEL, PHOTOELECTRON-SPECTRA, POLYMERS}, isbn = {0009-2614}, url = {://000173820900032}, author = {Otsuka, T. and Chong, D. P. and Maki, J. and Kawabe, H. and Endo, K.} } @article {5058, title = {Analysis of XPS and XES of diamond and graphite by DFT calculations using model molecules}, journal = {Journal of Computational Chemistry}, volume = {22}, number = {1}, year = {2001}, note = {ISI Document Delivery No.: 384EGTimes Cited: 6Cited Reference Count: 31}, month = {Jan}, pages = {102-108}, type = {Article}, abstract = {X-ray photoelectron and emission spectra (XPS and XES) of diamond and graphite have been analyzed by deMon density-functional theory (DFT) calculations using the model adamantane derivative (C10H12(CH3)(4)) and pyrene (C16H10) molecules, respectively. The theoretical valence photoelectron and C K alpha X-ray emission spectra for the allotrope are in good accordance with the experimental ones. The combined analysis of the valence XPS and C K alpha XES enables us to divide the valence electronic distribution into the individual contributions for p sigma-, and p pi -bonding MOs of the diamond and graphite, respectively. (C) 2000 John Wiley \& Sons, Inc.}, keywords = {APPROXIMATION, carbon allotrope, combined analysis of XPS and XES, DENSITY-FUNCTIONAL CALCULATION, DFT calculations, ELECTRON BINDING-ENERGIES, POLYMERS, RAY PHOTOELECTRON-SPECTRA, SILICON}, isbn = {0192-8651}, url = {://000165929000009}, author = {Endo, K. and Koizumi, S. and Otsuka, T. and Suhara, M. and Morohasi, T. and Kurmaev, E. Z. and Chong, D. P.} } @article {5160, title = {Polybis(pyrazolato)iron(II) and poly-2,2 {\textquoteright} bipyridinetetrakis(imidazolato)-diiron(II) and -dicobalt(II): from short-range magnetic interactions in the pyrazolate to long-range ferromagnetic ordering in the imidazolates}, journal = {Polyhedron}, volume = {20}, number = {11-14}, year = {2001}, note = {ISI Document Delivery No.: 451LWTimes Cited: 11Cited Reference Count: 307th International Conference on Molecule-Base Magnets (ICMM 2000)SEP 16-21, 2000SAN ANTONIO, TEXAS}, month = {May}, pages = {1577-1585}, type = {Proceedings Paper}, abstract = {Polybis(pyrazolato)iron(II), [Fe(pz)(2)](x) (1) has an extended chain ID structure in which iron ions are doubly bridged by pyrazolate ligands. The compound exhibits weak antiferromagnetic interactions. The magnetic susceptibility data were fit to a Heisenberg model for chains of antiferromagnetically coupled S= 2 metal centers, yielding the magnetic parameters -J= 0.59 cm(-1) and g = 2.01. Poly-2,2{\textquoteright}-bipyridinetetrakis(imidazolato)diiron(II), [Fe-2(imid)(3)(bipy)](x) (2) and the isomorphous cobalt compound, 3, have 2D extended structures in which double layered sheets of alternating tetrahedrally and octahedrally coordinated metal ions are linked by single bridging imidazolates. The octahedral metal centers are additionally coordinated by 2,2{\textquoteright}-bipyridine ligands, which occupy positions between the sheets, isolating the sheets from each other. The presence of the two different iron centers in 2 is confirmed by ambient temperature Mossbauer studies. The magnetic properties of these materials reveal a transition to long-range ferromagnetic order below 11 K for 2 and below 13 K for 3. Both materials reveal magnetic hysteresis at 4.8 K. Analysis of the data yield, for 2 and 3, respectively, coercive fields of 15 and 125 G and remanent magnetizations of 200 and 1900 cm(3) G mol(-1). (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {antiferromagenetism, COMPLEXES, COORDINATION CHEMISTRY, crystal structures, ferromagnetic ordering, iron(II) and cobalt(II) imidazolates, iron(II) pyrazolate, LIGANDS, LOW-TEMPERATURES, METALLOCENES, MOSSBAUER, POLYMERS, SERIES, SYSTEMS}, isbn = {0277-5387}, url = {://000169804400076}, author = {Patrick, B. O. and Reiff, W. M. and Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {5160, title = {Polybis(pyrazolato)iron(II) and poly-2,2 {\textquoteright} bipyridinetetrakis(imidazolato)-diiron(II) and -dicobalt(II): from short-range magnetic interactions in the pyrazolate to long-range ferromagnetic ordering in the imidazolates}, journal = {Polyhedron}, volume = {20}, number = {11-14}, year = {2001}, note = {ISI Document Delivery No.: 451LWTimes Cited: 11Cited Reference Count: 307th International Conference on Molecule-Base Magnets (ICMM 2000)SEP 16-21, 2000SAN ANTONIO, TEXAS}, month = {May}, pages = {1577-1585}, type = {Proceedings Paper}, abstract = {Polybis(pyrazolato)iron(II), [Fe(pz)(2)](x) (1) has an extended chain ID structure in which iron ions are doubly bridged by pyrazolate ligands. The compound exhibits weak antiferromagnetic interactions. The magnetic susceptibility data were fit to a Heisenberg model for chains of antiferromagnetically coupled S= 2 metal centers, yielding the magnetic parameters -J= 0.59 cm(-1) and g = 2.01. Poly-2,2{\textquoteright}-bipyridinetetrakis(imidazolato)diiron(II), [Fe-2(imid)(3)(bipy)](x) (2) and the isomorphous cobalt compound, 3, have 2D extended structures in which double layered sheets of alternating tetrahedrally and octahedrally coordinated metal ions are linked by single bridging imidazolates. The octahedral metal centers are additionally coordinated by 2,2{\textquoteright}-bipyridine ligands, which occupy positions between the sheets, isolating the sheets from each other. The presence of the two different iron centers in 2 is confirmed by ambient temperature Mossbauer studies. The magnetic properties of these materials reveal a transition to long-range ferromagnetic order below 11 K for 2 and below 13 K for 3. Both materials reveal magnetic hysteresis at 4.8 K. Analysis of the data yield, for 2 and 3, respectively, coercive fields of 15 and 125 G and remanent magnetizations of 200 and 1900 cm(3) G mol(-1). (C) 2001 Elsevier Science Ltd. All rights reserved.}, keywords = {antiferromagenetism, COMPLEXES, COORDINATION CHEMISTRY, crystal structures, ferromagnetic ordering, iron(II) and cobalt(II) imidazolates, iron(II) pyrazolate, LIGANDS, LOW-TEMPERATURES, METALLOCENES, MOSSBAUER, POLYMERS, SERIES, SYSTEMS}, isbn = {0277-5387}, url = {://000169804400076}, author = {Patrick, B. O. and Reiff, W. M. and Sanchez, V. and Storr, A. and Thompson, R. C.} } @article {5059, title = {Theoretical X-ray photoelectron and emission spectra of Si- and S-containing polymers by density-functional theory calculations using model molecules}, journal = {Journal of Molecular Structure}, volume = {561}, number = {1-3}, year = {2001}, note = {ISI Document Delivery No.: 420KQTimes Cited: 5Cited Reference Count: 29}, month = {Apr}, pages = {17-28}, type = {Article}, abstract = {The X-ray photoelectron and emission spectra (XPS and XES) of Si- and S-containing polymers [(-Si{-CH2-}(3))(n) (PCS), (-Si(CH3)(OH)-O-)(n) (PMHSO), (-Si(C6H5)(OH)-O-)(n) (PTES), (-Si(C6H5)(OH)-O-Si(CH3)(OH)-O-)(n) (PPMHSO), (-C6H4-O-C6H4-SO2-)(n) (PES)] were simulated by the deMon density-functional theory (DFT) calculations using the model molecules. The theoretical valence photoelectron and C K alpha X-ray emission spectra showed good accordance with some experimental ones. The combined analysis of the valence XPS and C and O K alpha XES enables us to divide the observed valence electronic distribution into the individual contributions for p sigma-, p pi- and non-bonding MOs of the polymers. (C) 2001 Elsevier Science B.V. All rights reserved.}, keywords = {APPROXIMATION, C1S SPECTRA, CK alpha XES, DFT calculations, ELECTRONIC STATES, ENERGY, FILMS, FLUORESCENCE, OLIGOMERS, POLYMERS, SPECTROSCOPY, XPS}, isbn = {0022-2860}, url = {://000168004500002}, author = {Endo, K. and Shimada, S. and Ida, T. and Suhara, M. and Kurmaev, E. Z. and Moewes, A. and Chong, D. P.} } @article {4748, title = {Structure and scattering in colloidal ferrofluids}, journal = {Physical Review E}, volume = {62}, number = {4}, year = {2000}, note = {ISI Document Delivery No.: 365YATimes Cited: 67Cited Reference Count: 32Part B}, month = {Oct}, pages = {5403-5408}, type = {Article}, abstract = {The structure of a model colloidal ferrofluid, the dipolar hard-sphere fluid, at low temperature has been investigated using Monte Carlo simulations. Extensive particle association into chainlike and ringlike clusters is observed at low density. The structure factors have been calculated, and are analyzed with the aid of simple scaling arguments. We describe the progression of fluid structures from the low-density associated phase, to the high-density liquid phase. This paper may he of help in obtaining an experimental observation of a fluid-fluid transition in colloidal ferrofluids.}, keywords = {DIPOLAR HARD-SPHERES, FLUIDS, LIQUID, LIVING, LOW-DENSITIES, MODEL POLAR CLUSTERS, MONTE-CARLO, orientational order, PHASES, POLYMERS, SYSTEMS}, isbn = {1063-651X}, url = {://000089977000025}, author = {Camp, P. J. and Patey, G. N.} } @article {4947, title = {Theoretical valence photoelectron and UV-visible absorption spectra of four stable conductive molecules obtained by MO calculations}, journal = {Bulletin of the Chemical Society of Japan}, volume = {73}, number = {1}, year = {2000}, note = {ISI Document Delivery No.: 284WKTimes Cited: 4Cited Reference Count: 31}, month = {Jan}, pages = {43-51}, type = {Article}, abstract = {Theoretical valence photoelectron and UV-visible absorption spectra of four stable conductive molecules (N, N{\textquoteright}-diphenyl-1,4-phenylenediamine (DPPD), p-quaterphenyl (PQP), 2, 3, 7, 8, 12, 13, 17, 18-octaethyl-21H, 23H-porphyrin (OEP), and 29H, 31H-phthalocyanine (PC)) have been obtained by semiempirical HAM/3 and ZINDO MO calculations, respectively. The Al K alpha photoelectron spectra were simulated using Gaussian lineshape functions of an approximate linewidth 0.10 E-k (E-k = E-k{\textquoteright} - WD), where E-k{\textquoteright} is the vertical ionization potential (VIP) of each MO and WD is a shift to account for sample work function and other energy effects, as stated in previous studies. The theoretical valence spectra of the four conductive compounds are in good accordance with the observed ones. The theoretical UV-visible absorption curves of DPPD, PQP, OEP, and PC were obtained after AM1 calculations with COSMO option to reflect solvent effects. The absorption curves as simulated with Gaussian lineshape functions of a constant linewidth of 0.003 eV. Correspond well to the observed spectra. For PC, the simulated spectrum which consists of 0.5 inner protonation (IP) and 0.5 outer protonation (OP) types for PC-ring shows much better agreement with the experimental spectrum in H2SO4 than the spectrum of either TP or OP type alone.}, keywords = {HAM-3, MODEL, OLIGOMERS, PHTHALOCYANINES, POLYMERS, STATES, XPS}, isbn = {0009-2673}, url = {://000085355700005}, author = {Takaoka, K. and Maeda, S. and Miura, H. and Otsuka, T. and Endo, K. and Chong, D. P.} } @article {4894, title = {Theoretical X-ray photoelectron spectra of polymers by deMon DFT calculations using the model dimers}, journal = {Journal of Molecular Structure}, volume = {522}, year = {2000}, note = {ISI Document Delivery No.: 305GFTimes Cited: 12Cited Reference Count: 60}, month = {Apr}, pages = {47-60}, type = {Article}, abstract = {Core-electron spectra of 15 polymers [(CH2CH2)(n) (PE), (CH2CH(CH3))(n) (PP), (CH2CH2NH)(n) (PEI), (CH2CH2O)(n) (PEG), (CH2CH(OCH3))(n) (PVME), (CH2CHF)(n) (PVF), (CH2CF2)(n) (PVDF), (CF2CF2)(n) (PTFE), (CH2CH(CN))(n) (PAN), (CH2C(CH3)(CN))(n) (PMAN), (CH2CH2S)(n) (PETHS), (CH2CHCl)(n) (PVC), (CH2CCl2)(n) (PVDC), (Si(CH3)(2))(n) (PDMS), (Si(CH3)(2)O)(n) (PDMSO)], and valence photoelectron spectra (XPS) of the six polymers (PP, PEI, PAN, PMAN, PVME, PTFE) were obtained by deMon density-functional theory (DFT) calculations using the model dimers. The core-electron spectra were simulated with the Gaussian lineshape functions with fixed linewidths of 0.5, and 1.0 eV for each C1sd, and (N1s, O1s, F1s) MO value, respectively, and calculated Al-K alpha Valence photoelectron spectra were obtained using Gaussian lineshape functions of an approximate linewidth (0.08I(k)): I-k(I-FL) = I-k{\textquoteright} - WD, as indicated in previous works. The vertical ionization potential I-k{\textquoteright} and each core-electron binding energy (CEBE) were calculated by restricted generalized diffuse ionization (rGDI) and unrestricted generalized transition-state (uGTS) models, respectively. The theoretical core-electron spectra showed better agreement with the experimental ones of the polymers than those due to Koopmans{\textquoteright} theorem. The difference between the calculated and the experimental CEBEs reflected the reasonable WDs of the polymers. (C) 2000 Elsevier Science B.V. All rights reserved.}, keywords = {C1S SPECTRA, core-electron spectra, deMon DFT calculations, DENSITY-FUNCTIONAL CALCULATION, ELECTRON-BINDING-ENERGIES, LOCAL-DENSITY, MOLECULES, POLY(METHYL METHACRYLATE), POLY(VINYL ALCOHOL), POLYMERS, SEMIEMPIRICAL MO THEORY, VALENCE-BAND, XPS CORE}, isbn = {0022-2860}, url = {://000086530500004}, author = {Otsuka, T. and Endo, K. and Suhara, M. and Chong, D. P.} } @article {4541, title = {Chemistry of the Ag-2(dmb)(2)(2+) template (dmb=1,8-diisocyano-p-menthane). Preparation, characterization, and x-ray structures of the Ag-2(dmb)(2)Y-2 dimers (Y = NO3-, ClO4-, CH3CO2-) and the paramagnetic [Ag-4(dmb)(4)(TCNQ)(3)]TCNQ complex (TCNQ=7,7,8,8}, journal = {Inorganic Chemistry}, volume = {38}, number = {6}, year = {1999}, note = {ISI Document Delivery No.: 180DKTimes Cited: 17Cited Reference Count: 43}, month = {Mar}, pages = {1253-1260}, type = {Article}, abstract = {{Direct reactions of the AgY salts with dmb (1,8-diisocyano-p-menthane) in a 1:1 stoichiometric amount generate the binuclear Ag-2(dmb)(2)Y-2 complexes. The X-ray crystallography establishes that the structure consists of two Ag+ atoms bridged by two dmb ligands forming a 20-membered ring and by two counteranions via one of the O-atoms, forming a four-membered ring (local symmetry D-2h) The Ag-I... Ag-I separations are 3.909(1) and 3.6831(8) Angstrom for Y = NO3- and CH3CO2-, respectively. Reactions of Ag-2(dmb)(2)Y-2 (Y = NO3-, ClO4-) with LiTCNQ lead to the paramagnetic tetranuclear species [Ag-4(dmb)(4)(TCNQ)(3)]TCNQ. The structure at 180 K consists of two Ag-2(dmb)(2)(2+) species (d(Ag ... Ag) = 4.113(1) Angstrom held together by three parallel TCNQ(-{\textquoteright})s, with Ag+... N=C distances ranging from 2.359(5) to 2.787(5) Angstrom. Two of the Ag+ atoms are tricoordinated, and the other two are tetracoordinated placed within in a centrosymmetric geometry. The three bridging TCNQ-{\textquoteright}s exhibit interplanar distances of 3.333(1) Angstrom, and the Ag-4 species are packed side-by-side with two adjacent TCNQ-{\textquoteright}s face-to-face (separation 3.372(1) Angstrom) forming an infinite pi-stacked chain TCNQ(-{\textquoteright})s. The TCNQ(-) counteranion also exhibits weak pi-contacts via the -CN groups with other counteranions. The magnetic susceptibilities, EPR spectra, and unit cell parameters have been measured as a function of temperature. The magnetic data are best explained by extended chains of anti Ferromagnetically coupled S = 3/2 and S = 1/2 centers for the [Ag-4(dmb)(4)-(TCNQ)(3)](+) and TCNQ(-) moieties, respectively. No hyperfine structure has been observed between 106 and 290 K, indicating the presence of rapid exchange in the paramagnetic system. Crystal data: Ag-2(dmb)(2)(NO3)(2), crystal system, orthorhombic, space group = C-cmb}, keywords = {1, 7, 7{\textquoteright}, 8, 8-DIISOCYANO-P-MENTHANE, 8-TETRACYANOQUINODIMETHANE, 8{\textquoteright}-TETRACYANOQUINODIMETHANE, CRYSTAL-STRUCTURE, MAGNETIC-PROPERTIES, NICKEL(II), POLYMERS, SPECTROSCOPY, SYSTEMS, TCNQ}, isbn = {0020-1669}, url = {://000079370000030}, author = {Fortin, D. and Drouin, M. and Harvey, P. D. and Herring, F. G. and Summers, D. A. and Thompson, R. C.} } @article {4541, title = {Chemistry of the Ag-2(dmb)(2)(2+) template (dmb=1,8-diisocyano-p-menthane). Preparation, characterization, and x-ray structures of the Ag-2(dmb)(2)Y-2 dimers (Y = NO3-, ClO4-, CH3CO2-) and the paramagnetic [Ag-4(dmb)(4)(TCNQ)(3)]TCNQ complex (TCNQ=7,7,8,8}, journal = {Inorganic Chemistry}, volume = {38}, number = {6}, year = {1999}, note = {ISI Document Delivery No.: 180DKTimes Cited: 17Cited Reference Count: 43}, month = {Mar}, pages = {1253-1260}, type = {Article}, abstract = {{Direct reactions of the AgY salts with dmb (1,8-diisocyano-p-menthane) in a 1:1 stoichiometric amount generate the binuclear Ag-2(dmb)(2)Y-2 complexes. The X-ray crystallography establishes that the structure consists of two Ag+ atoms bridged by two dmb ligands forming a 20-membered ring and by two counteranions via one of the O-atoms, forming a four-membered ring (local symmetry D-2h) The Ag-I... Ag-I separations are 3.909(1) and 3.6831(8) Angstrom for Y = NO3- and CH3CO2-, respectively. Reactions of Ag-2(dmb)(2)Y-2 (Y = NO3-, ClO4-) with LiTCNQ lead to the paramagnetic tetranuclear species [Ag-4(dmb)(4)(TCNQ)(3)]TCNQ. The structure at 180 K consists of two Ag-2(dmb)(2)(2+) species (d(Ag ... Ag) = 4.113(1) Angstrom held together by three parallel TCNQ(-{\textquoteright})s, with Ag+... N=C distances ranging from 2.359(5) to 2.787(5) Angstrom. Two of the Ag+ atoms are tricoordinated, and the other two are tetracoordinated placed within in a centrosymmetric geometry. The three bridging TCNQ-{\textquoteright}s exhibit interplanar distances of 3.333(1) Angstrom, and the Ag-4 species are packed side-by-side with two adjacent TCNQ-{\textquoteright}s face-to-face (separation 3.372(1) Angstrom) forming an infinite pi-stacked chain TCNQ(-{\textquoteright})s. The TCNQ(-) counteranion also exhibits weak pi-contacts via the -CN groups with other counteranions. The magnetic susceptibilities, EPR spectra, and unit cell parameters have been measured as a function of temperature. The magnetic data are best explained by extended chains of anti Ferromagnetically coupled S = 3/2 and S = 1/2 centers for the [Ag-4(dmb)(4)-(TCNQ)(3)](+) and TCNQ(-) moieties, respectively. No hyperfine structure has been observed between 106 and 290 K, indicating the presence of rapid exchange in the paramagnetic system. Crystal data: Ag-2(dmb)(2)(NO3)(2), crystal system, orthorhombic, space group = C-cmb}, keywords = {1, 7, 7{\textquoteright}, 8, 8-DIISOCYANO-P-MENTHANE, 8-TETRACYANOQUINODIMETHANE, 8{\textquoteright}-TETRACYANOQUINODIMETHANE, CRYSTAL-STRUCTURE, MAGNETIC-PROPERTIES, NICKEL(II), POLYMERS, SPECTROSCOPY, SYSTEMS, TCNQ}, isbn = {0020-1669}, url = {://000079370000030}, author = {Fortin, D. and Drouin, M. and Harvey, P. D. and Herring, F. G. and Summers, D. A. and Thompson, R. C.} } @article {4415, title = {Theoretical valence XPS and UV-visible absorption spectra of four leucodyes using MO calculations}, journal = {Bulletin of the Chemical Society of Japan}, volume = {71}, number = {4}, year = {1998}, note = {ISI Document Delivery No.: ZP865Times Cited: 8Cited Reference Count: 26}, month = {Apr}, pages = {807-816}, type = {Article}, abstract = {Semiempirical HAM/3 MO program was used to obtain the theoretical valence X-ray photoelectron spectra (XPS) of the two leuco dyes (2{\textquoteright}-anilino-6{\textquoteright}-diethylamino-3{\textquoteright}-methylspiro[isobenzofuran-1(3H),9{\textquoteright}-[9H] xanthene]-3-one (DEAMAF) and 3,3-bis(4-dimethylaminophenyl)-6-dimethylamino-1(3H)-isobenzofuranone (CVL)) and UV-visible adsorption spectra of the four leuco dyes (DEAMAF, CVL, 2{\textquoteright}-chloro-6{\textquoteright}-diethylamino-3{\textquoteright}-methylspiro[isobenzofuran-1 (3H),9{\textquoteright}-[9H]xanthene]3-one (DEAMCF), and 3{\textquoteright},6{\textquoteright}-bis(diethylamino)-spiro [isobenzofuran-1 (3H),9{\textquoteright}-[9H]]xanthene]-3-one (Rhodamine B base). The calculated Al K alpha photoelectron spectra were obtained using Gaussian lineshape functions of an approximate linewidth 0.10E(k) (E-k = E{\textquoteright}(k) -WD), where E{\textquoteright}(k) is the vertical ionization potential (VIP) of each MO and WD is a shift to account for sample work function, polarization energy and other energy effects. On the other hand, the absorption curves were simulated with Gaussian lineshape functions of a constant linewidth of 0.02 eV. The theoretical valence energy levels corresponded well to the spectra of two leuco dyes observed 0-40 eV, while the simulated adsorption spectra were shifted for a good fit with the experimental solution spectra in the range of 250-700 nm.}, keywords = {HAM-3, MODEL, POLYMERS, RAY PHOTOELECTRON-SPECTRA}, isbn = {0009-2673}, url = {://000073796400006}, author = {Takaoka, K. and Maeda, S. and Miura, H. and Endo, K. and Chong, D. P.} } @article {4252, title = {Use of NMR imaging in the optimization of a compression-coated regulated release system}, journal = {Journal of Controlled Release}, volume = {51}, number = {2-3}, year = {1998}, note = {ISI Document Delivery No.: ZA955Times Cited: 22Cited Reference Count: 15}, month = {Feb}, pages = {179-184}, type = {Article}, abstract = {Nuclear magnetic resonance (NMR) imaging is routinely used to detect the protons of mobile water molecules within samples. In this investigation, this non-destructive, non-invasive technique was used to determine the cause for faster than predicted drug release from a dissolution-based regulated-release tablet. The NMR images of tablets, from mio different formulations, taken at various intervals of time while immersed in static USP dissolution medium showed that the tablet with faster than predicted drug release had a porous coating. The porous coat exposed more of the core surface area to the dissolution medium than desired and this caused an increase in the rate of dissolution of the core. The data presented in this paper demonstrate the usefulness of NMR imaging in solid dosage form development. (C) 1998 Elsevier Science B.V.}, keywords = {compression coating, DIFFUSION, formulation optimization, modified-release tablet, NMR imaging, POLYMERS, regulated-release tablet, RODS}, isbn = {0168-3659}, url = {://000072419400009}, author = {Fahie, B. J. and Nangia, A. and Chopra, S. K. and Fyfe, C. A. and Grondey, H. and Blazek, A.} } @article {4117, title = {Transition metal azolates from metallocenes .1. Dimetallic and trimetallic cyclopentadienyl nickel pyrazolates, synthesis and structural studies}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {75}, number = {7}, year = {1997}, note = {ISI Document Delivery No.: XR886Times Cited: 10Cited Reference Count: 23}, month = {Jul}, pages = {949-958}, type = {Article}, abstract = {{The reactions of nickelocene with pyrazoles in benzene solution have resulted in the isolation of either dimeric compounds, [CpNi(mu-pz{\textquoteright})](2), (room temperature conditions) or trimetallic complexes, [CpNi(mu-pz {\textquoteright}{\textquoteright})(2)](2)Ni, (elevated temperature conditions). Both dimeric and trimetallic species were obtained as red crystalline materials and X-ray structural investigations are reported for representative samples of each type. Structural features are interpreted and compared with similar, previously reported, nickel pyrazolate structures. Crystals of [CpNi(3,5-diMepz)](2) (C20H24N4Ni2), 1, are orthorhombic}, keywords = {3, 5-DIMETHYLPYRAZOLATE COMPLEXES, BR, CH3, CRYSTAL, crystal structures, CYCLOPENTADIENYL, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURES, NICKEL, nickelocene, POLYMERS, pyrazolates}, isbn = {0008-4042}, url = {://A1997XR88600004}, author = {Rettig, S. J. and Storr, A. and Summers, D. A. and Thompson, R. C. and Trotter, J.} } @article {4117, title = {Transition metal azolates from metallocenes .1. Dimetallic and trimetallic cyclopentadienyl nickel pyrazolates, synthesis and structural studies}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {75}, number = {7}, year = {1997}, note = {ISI Document Delivery No.: XR886Times Cited: 10Cited Reference Count: 23}, month = {Jul}, pages = {949-958}, type = {Article}, abstract = {{The reactions of nickelocene with pyrazoles in benzene solution have resulted in the isolation of either dimeric compounds, [CpNi(mu-pz{\textquoteright})](2), (room temperature conditions) or trimetallic complexes, [CpNi(mu-pz {\textquoteright}{\textquoteright})(2)](2)Ni, (elevated temperature conditions). Both dimeric and trimetallic species were obtained as red crystalline materials and X-ray structural investigations are reported for representative samples of each type. Structural features are interpreted and compared with similar, previously reported, nickel pyrazolate structures. Crystals of [CpNi(3,5-diMepz)](2) (C20H24N4Ni2), 1, are orthorhombic}, keywords = {3, 5-DIMETHYLPYRAZOLATE COMPLEXES, BR, CH3, CRYSTAL, crystal structures, CYCLOPENTADIENYL, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURES, NICKEL, nickelocene, POLYMERS, pyrazolates}, isbn = {0008-4042}, url = {://A1997XR88600004}, author = {Rettig, S. J. and Storr, A. and Summers, D. A. and Thompson, R. C. and Trotter, J.} } @article {4117, title = {Transition metal azolates from metallocenes .1. Dimetallic and trimetallic cyclopentadienyl nickel pyrazolates, synthesis and structural studies}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {75}, number = {7}, year = {1997}, note = {ISI Document Delivery No.: XR886Times Cited: 10Cited Reference Count: 23}, month = {Jul}, pages = {949-958}, type = {Article}, abstract = {{The reactions of nickelocene with pyrazoles in benzene solution have resulted in the isolation of either dimeric compounds, [CpNi(mu-pz{\textquoteright})](2), (room temperature conditions) or trimetallic complexes, [CpNi(mu-pz {\textquoteright}{\textquoteright})(2)](2)Ni, (elevated temperature conditions). Both dimeric and trimetallic species were obtained as red crystalline materials and X-ray structural investigations are reported for representative samples of each type. Structural features are interpreted and compared with similar, previously reported, nickel pyrazolate structures. Crystals of [CpNi(3,5-diMepz)](2) (C20H24N4Ni2), 1, are orthorhombic}, keywords = {3, 5-DIMETHYLPYRAZOLATE COMPLEXES, BR, CH3, CRYSTAL, crystal structures, CYCLOPENTADIENYL, MAGNETIC-PROPERTIES, MOLECULAR-STRUCTURES, NICKEL, nickelocene, POLYMERS, pyrazolates}, isbn = {0008-4042}, url = {://A1997XR88600004}, author = {Rettig, S. J. and Storr, A. and Summers, D. A. and Thompson, R. C. and Trotter, J.} } @article {3313, title = {ANALYSIS OF VALENCE XPS OF (CH2-CHR)(N) (R=H, CH3, OH AND F), (CH2-CH2-NH)(N) AND (CH2-CH2-O)(N) POLYMERS BY THE SEMIEMPIRICAL HAM/3 MO METHOD USING THE N-MER (N=2, 3, 4, 5) MODEL}, journal = {Journal of Physics and Chemistry of Solids}, volume = {56}, number = {8}, year = {1995}, note = {ISI Document Delivery No.: RF331Times Cited: 26Cited Reference Count: 50}, month = {Aug}, pages = {1131-1140}, type = {Article}, abstract = {The valence X-ray photoelectron spectra (XPS) of six representative polymers [CH2-CHR)(n) (R = H, CH3, OH, F), (CH2-CH2-NH)(n), and (CH2-CH2-O)(n)] were analysed by a semi empirical HAM/3 MO method using model molecules [H-(CH2-CHR)(n)-H, (R = H, CH3, OH, F), H2N-(CH2-CH2-NH)(n)-H, and HO-(CH2-CH2-O)(n)-H] with n = 2 to 5. The calculated AlK alpha photo electron spectra were obtained using Gaussian functions of an approximate linewidth (0.10I(k)); I-k = I{\textquoteright}(k) - WD, where I{\textquoteright}(k); is the vertical ionization potential (VIP) of each MO and WD is a shift to account for sample work function, polarization energy and other effects. To explain the broader linewidth for the inner valence spectra, we propose that the lifetime of the 2s hole states are shorter because the holes can be filled by 2p electrons in ultra-violet emission or radiationless transition. The theoretical spectra showed good agreement with the observed spectra of the polymers between 0-40 eV. The present results suggest that the spectra can be analysed by the calculations for model trimers.}, keywords = {BAND, CLUSTER-EXPANSION, Electronic Structure, ELECTRONIC-STRUCTURE, ENERGY-LEVELS, ESCA, IONIZATION, photoelectron spectroscopy, POLYETHYLENE, POLYMERS, POLYOXYMETHYLENE, RAY PHOTOELECTRON-SPECTROSCOPY, SPECTRA, WAVEFUNCTION}, isbn = {0022-3697}, url = {://A1995RF33100017}, author = {Endo, K. and Kaneda, Y. and Aida, M. and Chong, D. P.} } @article {3278, title = {TEMPLATION EFFECTS ON FORMATION OF A HEMICARCEPLEX}, journal = {Supramolecular Chemistry}, volume = {5}, number = {1}, year = {1995}, note = {ISI Document Delivery No.: RX096Times Cited: 15Cited Reference Count: 36}, pages = {31-37}, type = {Article}, abstract = {We have shown previously that the reaction to form carceplex 3 . guest has dramatic templation requirements where the best template molecule studied is one million times more effective at bridging the two bowl-shaped precursors than the poorest template. Here, we investigate the template requirements for the formation of hemicarceplex 4 . guest which is similar to carceplex 3 . guest in cavity size and shape. The two compounds differ in that 4 . guest lacks one of the four inter-bowl methylene bridges and thus has a portal and reduced symmetry relative to carceplex 3 . guest (C-2v vs D-4h). Thus, the template requirements for hemicarceplex 4 . guest are more stringent because the two howls can, in principle, misalign. We have found that despite these differences, the same template effect holds. We conclude that the same forces are at play in each reaction. These forces include 1) favorable van der Waals interactions between the template molecule and the forming cavity of the carceplex or hemicarceplex 2) unfavorable steric strain being imparted to the complex and 3) hydrogen bonds between the bowls. We also demonstrate the utility of matrix-assisted laser desorption ionization (MALDI) as a mild mass spectrometric technique for non-volatile organic compounds and complexes.}, keywords = {4 PORTALS, BINDING, CAPTURE, CARCERANDS, CONSTRICTIVE, HOST-GUEST COMPLEXATION, LASER DESORPTION IONIZATION, MASS-SPECTROMETRY, POLYMERS, RECOGNITION, RELEASE}, isbn = {1061-0278}, url = {://A1995RX09600007}, author = {Chopra, N. and Sherman, J. C.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {2790, title = {OCTAMOLYBDENUM OXO-PYRAZOLATE CLUSTERS - SYNTHESES, CHARACTERIZATION, AND CRYSTAL AND MOLECULAR-STRUCTURES OF THE MO(V)/MO(VI) AND MO(VI) OCTAMOLYBDENUM CLUSTERS MO8(PZ)6O18(PZH)6 AND MO8(PZ)6O21(PZH)6}, journal = {Inorganic Chemistry}, volume = {32}, number = {23}, year = {1993}, note = {ISI Document Delivery No.: MG613Times Cited: 20Cited Reference Count: 36}, month = {Nov}, pages = {5176-5182}, type = {Article}, abstract = {{Two octamolybdenum compounds, containing both bridging pyrazolate and terminal pyrazole ligands, have been prepared by the reaction of molten pyrazole with molybdenum oxides, and their structures have been determined by single-crystal X-ray diffraction. Crystals of Mo8(pz)6O18(pzH)6.2pzH (1;pzH=pyrazole, C3H4N2; pz = pyrazolate anion, C3H3N2) are monoclinic, space group C2/c, with a = 23.026(3) angstrom}, keywords = {3, 5-DIMETHYLPYRAZOLATE, CATALYSIS, CHEMISTRY, COMPLEXES, HETEROPOLY, MAGNETIC-PROPERTIES, MOLYBDATES, MOLYBDENUM, OXYGEN, POLYMERS}, isbn = {0020-1669}, url = {://A1993MG61300039}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {7241, title = {OBSERVATION OF HETEROGENEOUS TRACE (0.4-PERCENT W/W) WATER-UPTAKE IN BISPHENOL A POLYCARBONATE BY NMR IMAGING}, journal = {Chemistry of Materials}, volume = {4}, number = {2}, year = {1992}, note = {ISI Document Delivery No.: HL702Times Cited: 6Cited Reference Count: 17}, month = {Mar-Apr}, pages = {267-271}, type = {Article}, abstract = {The uptake of water by injection-molded bars of bisphenol A polycarbonate (Lexan 121 resin) has been monitored by a combination of one-dimensional proton NMR spectroscopy, relaxation time (T1 and T2) measurements, and microscopic imaging techniques. The bulk of the water absorbed in the initial stages (20-24 h) of 100-degrees-C water exposure is uniformly distributed throughout the polymer with a trace amount of the water found in clusters of 200-300-mu-m in size. The water that has aggregated to form these clusters is more mobile, having a T2 relaxation time 20 times longer than that found for the uniformly distributed water. At longer exposure times (30-40 days) the number of clusters is observed to increase. Although the total amount of water adsorbed is considerably less than 1 \% w/w, good-quality images are obtained, demonstrating that the NMR microimaging technique can successfully monitor even trace levels of solvent if the molecules are relatively mobile.}, keywords = {DIFFUSION, mobility, NUCLEAR MAGNETIC-RESONANCE, POLYMERS}, isbn = {0897-4756}, url = {://A1992HL70200010}, author = {Fyfe, C. A. and Randall, L. H. and Burlinson, N. E.} } @article {7224, title = {{POLYNUCLEAR PYRAZOLATE COMPLEXES OF COPPER - CRYSTAL AND MOLECULAR-STRUCTURES OF [CU(TMPZ)]3, [CU(3-CO2DMPZ)(TMPZH)]2CU, AND [CU(4-BR-3-CO2MEPZ)(4-BR-DMPZH)2]2 (WHERE MEPZ = METHYLPYRAZOLATE}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {70}, number = {8}, year = {1992}, note = {ISI Document Delivery No.: JW564Times Cited: 55Cited Reference Count: 17}, month = {Aug}, pages = {2161-2173}, type = {Article}, abstract = {{The reaction of molten trimethylpyrazole (tmpzH) with copper metal shot in air yields a mixture of the trinuclear copper(I) complex [Cu(tmpz)]3, 1, and the trinuclear copper(I/II) complex [Cu(3-CO2dmpz)(tmpzH)]2Cu, 2 (where dmpz is dimethylpyrazolate). Crystals of 1 are monoclinic}, keywords = {POLYMERS}, isbn = {0008-4042}, url = {://A1992JW56400005}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {7224, title = {{POLYNUCLEAR PYRAZOLATE COMPLEXES OF COPPER - CRYSTAL AND MOLECULAR-STRUCTURES OF [CU(TMPZ)]3, [CU(3-CO2DMPZ)(TMPZH)]2CU, AND [CU(4-BR-3-CO2MEPZ)(4-BR-DMPZH)2]2 (WHERE MEPZ = METHYLPYRAZOLATE}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {70}, number = {8}, year = {1992}, note = {ISI Document Delivery No.: JW564Times Cited: 55Cited Reference Count: 17}, month = {Aug}, pages = {2161-2173}, type = {Article}, abstract = {{The reaction of molten trimethylpyrazole (tmpzH) with copper metal shot in air yields a mixture of the trinuclear copper(I) complex [Cu(tmpz)]3, 1, and the trinuclear copper(I/II) complex [Cu(3-CO2dmpz)(tmpzH)]2Cu, 2 (where dmpz is dimethylpyrazolate). Crystals of 1 are monoclinic}, keywords = {POLYMERS}, isbn = {0008-4042}, url = {://A1992JW56400005}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} } @article {7224, title = {{POLYNUCLEAR PYRAZOLATE COMPLEXES OF COPPER - CRYSTAL AND MOLECULAR-STRUCTURES OF [CU(TMPZ)]3, [CU(3-CO2DMPZ)(TMPZH)]2CU, AND [CU(4-BR-3-CO2MEPZ)(4-BR-DMPZH)2]2 (WHERE MEPZ = METHYLPYRAZOLATE}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {70}, number = {8}, year = {1992}, note = {ISI Document Delivery No.: JW564Times Cited: 55Cited Reference Count: 17}, month = {Aug}, pages = {2161-2173}, type = {Article}, abstract = {{The reaction of molten trimethylpyrazole (tmpzH) with copper metal shot in air yields a mixture of the trinuclear copper(I) complex [Cu(tmpz)]3, 1, and the trinuclear copper(I/II) complex [Cu(3-CO2dmpz)(tmpzH)]2Cu, 2 (where dmpz is dimethylpyrazolate). Crystals of 1 are monoclinic}, keywords = {POLYMERS}, isbn = {0008-4042}, url = {://A1992JW56400005}, author = {Ehlert, M. K. and Rettig, S. J. and Storr, A. and Thompson, R. C. and Trotter, J.} }