@article {2344,
	title = {Tuning Gold Nanoparticle Self-Assembly for Optimum Coherent Anti-Stokes Raman Scattering and Second Harmonic Generation Response},
	journal = {Journal of Physical Chemistry C},
	volume = {113},
	number = {9},
	year = {2009},
	note = {ISI Document Delivery No.: 412ODTimes Cited: 3Cited Reference Count: 66Addison, Christopher J. Konorov, Stanislav O. Brolo, Alexandre G. Blades, Michael W. Turner, Robin F. B.},
	month = {Mar},
	pages = {3586-3592},
	type = {Article},
	abstract = {The research and development of new substrates for use in surface-enhanced spectroscopy is primarily motivated by the ability to tune such substrates to provide maximum signal enhancement and therefore lower detection limits. We examined a series of multilayer nanoparticle (NP) arrays with between 1 and 17 NP layers using two nonlinear optical (NLO) techniques: Coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG). The CARS signal of oxazine 720 was monitored at 1600 cm(-1) using a 709-nm pump beam and an 800-nm stokes beam. Maximum signal was observed for 11 NP layers and is attributed to the matching of the CARS signal and the substrate surface plasmon excitation at 637 nm. The CARS signal for the 3000-cm(-1) C-H stretching vibration showed maximum enhancement at 13 NP layers. The maximum SHG signal enhancement occurred at 13 NP layers, with a 50-fold overall enhancement of the SHG signal. We demonstrate that the NP-containing substrates can be tuned to provide maximum NLO response based on the number of NP depositions and the wavelength(s) involved in the NLO experiments. These multilayer NP arrays yield a stable and modular spectroscopic substrate advantageous for a variety of surface-enhanced spectroscopic techniques.},
	keywords = {ABSORPTION, ARRAYS, AU-COLLOID, BROKEN SYMMETRY, ENHANCEMENT, FILMS, HARMONIC-GENERATION, MONOLAYERS, NONLINEAR-OPTICAL RESPONSES, SPECTROSCOPY, SURFACE-PLASMON RESONANCE},
	isbn = {1932-7447},
	url = {<Go to ISI>://000263733200034},
	author = {Addison, C. J. and Konorov, S. O. and Brolo, A. G. and Blades, M. W. and Turner, R. F. B.}
}
@article {2344,
	title = {Tuning Gold Nanoparticle Self-Assembly for Optimum Coherent Anti-Stokes Raman Scattering and Second Harmonic Generation Response},
	journal = {Journal of Physical Chemistry C},
	volume = {113},
	number = {9},
	year = {2009},
	note = {ISI Document Delivery No.: 412ODTimes Cited: 3Cited Reference Count: 66Addison, Christopher J. Konorov, Stanislav O. Brolo, Alexandre G. Blades, Michael W. Turner, Robin F. B.},
	month = {Mar},
	pages = {3586-3592},
	type = {Article},
	abstract = {The research and development of new substrates for use in surface-enhanced spectroscopy is primarily motivated by the ability to tune such substrates to provide maximum signal enhancement and therefore lower detection limits. We examined a series of multilayer nanoparticle (NP) arrays with between 1 and 17 NP layers using two nonlinear optical (NLO) techniques: Coherent anti-Stokes Raman scattering (CARS) and second harmonic generation (SHG). The CARS signal of oxazine 720 was monitored at 1600 cm(-1) using a 709-nm pump beam and an 800-nm stokes beam. Maximum signal was observed for 11 NP layers and is attributed to the matching of the CARS signal and the substrate surface plasmon excitation at 637 nm. The CARS signal for the 3000-cm(-1) C-H stretching vibration showed maximum enhancement at 13 NP layers. The maximum SHG signal enhancement occurred at 13 NP layers, with a 50-fold overall enhancement of the SHG signal. We demonstrate that the NP-containing substrates can be tuned to provide maximum NLO response based on the number of NP depositions and the wavelength(s) involved in the NLO experiments. These multilayer NP arrays yield a stable and modular spectroscopic substrate advantageous for a variety of surface-enhanced spectroscopic techniques.},
	keywords = {ABSORPTION, ARRAYS, AU-COLLOID, BROKEN SYMMETRY, ENHANCEMENT, FILMS, HARMONIC-GENERATION, MONOLAYERS, NONLINEAR-OPTICAL RESPONSES, SPECTROSCOPY, SURFACE-PLASMON RESONANCE},
	isbn = {1932-7447},
	url = {<Go to ISI>://000263733200034},
	author = {Addison, C. J. and Konorov, S. O. and Brolo, A. G. and Blades, M. W. and Turner, R. F. B.}
}
@article {1548,
	title = {Density functional theory calculation of 2p core-electron binding energies of Si, P, S, Cl, and Ar in gas-phase molecules},
	journal = {Journal of Electron Spectroscopy and Related Phenomena},
	volume = {151},
	number = {1},
	year = {2006},
	note = {ISI Document Delivery No.: 017GXTimes Cited: 12Cited Reference Count: 40},
	month = {Mar},
	pages = {9-13},
	type = {Article},
	abstract = {Density functional theory (DFT) calculations have been performed on the gas-phase 2p core-electron binding energies (CEBEs) of Si and Ar in 145 cases using the following procedure: AEKS (scalar-ZORA + E-xc)/TZP//HF/6-31G(d). Delta E-KS is the difference in the total Kohn-Sham energies of the 2p-ionized cation and the neutral parent molecule calculated by DFT using different exchange-correlation functionals E-xc with triple-zeta polarized basis set, at molecular geometry optimized by HF/6-31G(d), and relativistic effects have been estimated by scalar zeroth-order regular approximation. Among the 26 functionals tested, the form of E-xc giving the best overall performance was found to be the combination of OPTX exchange and LYP correlation functionals. For that functional, the average absolute deviation (AAD) of the 145 calculated CEBEs from experiment is 0.26 cV. There are seven other exchange-correlation functionals that led to AADs of less than 0.30 eV. Some functionals give lower AADs than E-xc=OPTX-LYP for some individual elements. In the case of Si, for example, the combination of either mPW91-PBE or Becke88-Perdew86 led to an AAD of only 0.10 eV for 56 silicon-containing molecules. Another example is the case of the argon atom, for which the choice of E-xc=OPTX-Perdew86 yields a value for CEBE equal to the experimental value. (c) 2005 Elsevier B.V. All rights reserved.},
	keywords = {ABSORPTION, ACCURATE, Ar(2p), ARGON, BEHAVIOR, Cl(2p), emission, ESCA, EXCHANGE-ENERGY, GENERALIZED GRADIENT APPROXIMATION, L-shell ionization, P(2p), POTENTIALS, RAY PHOTOELECTRON-SPECTROSCOPY, S(2p), Si(2p), SILICON, XPS},
	isbn = {0368-2048},
	url = {<Go to ISI>://000235683200003},
	author = {Segala, M. and Takahata, Y. and Chong, D. P.}
}
@article {1011,
	title = {Comparison of anti-hyperglycemic effect amongst vanadium, molybdenum and other metal maltol complexes},
	journal = {Journal of Inorganic Biochemistry},
	volume = {98},
	number = {5},
	year = {2004},
	note = {ISI Document Delivery No.: 824HVTimes Cited: 37Cited Reference Count: 7411th International Conference on Biological Inorganic ChemistryJUL 19-23, 2003Cairns, AUSTRALIA},
	month = {May},
	pages = {683-690},
	type = {Proceedings Paper},
	abstract = {A wide variety of vanadium-containing complexes have been tested, both in vivo and in vitro, as possible therapeutic agents for the oral treatment of type 2 diabetes mellitus. None so far has surpassed bis(maltolato)oxovanadium(IV) (BMOV) for glucose- and lipid-lowering in an orally available formulation. Ligand choice is clearly an important factor in pharmacological efficacy of vanadium compounds as insulin enhancing agents. In this study, we kept the ligand and dose the same, varying instead the metal ion bound to the maltolato ligand in a series of binary complexes of neutral charge. A requirement for vanadyl ion as the metal ion of choice was apparent; no other metal ion tested served as a suitable substitute. Amongst [MoO2](2+), Co(II), Cu(II), Cr(III), and Zn(II), only [MoO2](2+) and Co(II) showed any hypoglycemic activity at the ED50 dose for bis(maltolato)oxovanadium(IV), 0.6 mmol kg(-1) by oral gavage in streptozotocin (STZ)-diabetic rats within 72 It of administration of compound. (C) 2004 Elsevier Inc. All rights reserved.},
	keywords = {ABSORPTION, CHROMIUM, cobalt, COORDINATION MODE, copper, DEPENDENT DIABETES-MELLITUS, GLUCOSE-METABOLISM, IN-VIVO, INSULIN, LIPID-METABOLISM, MOLYBDENUM, RATS, VANADIUM, zinc, ZINC SUPPLEMENTATION},
	isbn = {0162-0134},
	url = {<Go to ISI>://000221678300004},
	author = {Thompson, K. H. and Chiles, J. and Yuen, V. G. and Tse, J. and McNeill, J. H. and Orvig, Chris}
}
@article {757,
	title = {Preparation and characterization of vanadyl complexes with bidentate maltol-type ligands; in vivo comparisons of anti-diabetic therapeutic potential},
	journal = {Journal of Biological Inorganic Chemistry},
	volume = {8},
	number = {1-2},
	year = {2003},
	note = {ISI Document Delivery No.: 638ACTimes Cited: 62Cited Reference Count: 52},
	month = {Jan},
	pages = {66-74},
	type = {Article},
	abstract = {A series of 2-alkyl-3-hydroxy-4-pyrone oxovanadium(IV) compounds has been synthesized, characterized, and tested for bioactivity as potential insulin-enhancing agents. The vanadyl complexes, bis(maltolato)oxovanadium(IV), BMOV, bis(ethylmaltolato)oxovanadium(IV), BEOV, and bis(isopropylmaltolato) oxovanadium(IV), BIOV, were compared against vanadyl sulfate for glucose-lowering ability, when administered i.p. to STZ-diabetic rats, at a one-time dose of 0.1 mmol kg(-1) body weight. Blood levels of vanadium were determined at regular intervals, to 72 h, following i.p. injection. All complexes tested exceeded vanadyl sulfate in glucose-lowering ability; this effect was not correlated, however, with blood vanadium levels. Analysis of the pharmacokinetics of the disappearance of [ethyl-1-C-14]BEOV after an oral gavage dose (50 mg kg(-1), 0.144 mmol kg(-1), in a 10 mL kg(-1) volume of 1\% CMC solution) indicated clearly that metal ion-ligand dissociation took place relatively soon after oral ingestion of the complex. Half-lives of fast phase uptake and slow phase disappearance for C-14 and V were calculated from a two-compartment model for whole blood, plasma, liver, kidney, bone, small intestine, and lung, ranging from 17 min (t(1/2)alpha for C-14, liver) to 30 days (t(1/2)beta for V, bone). Curves of disappearance of plasma and whole blood C-14 and V diverged dramatically within the first hour after administration of the vanadium complex.},
	keywords = {ABSORPTION, BIS(MALTOLATO)OXOVANADIUM(IV) BMOV, CHEMISTRY, COORDINATION MODE, ETHYL MALTOL, IN-VITRO, INSULIN MIMETIC AGENT, insulin-enhancing activity, pharmacokinetics, PHOSPHATIDYLINOSITOL 3-KINASE, POLYMORPHIC FORMS, RATS, STZ-diabetic rat, vanadyl pyrone complexes},
	isbn = {0949-8257},
	url = {<Go to ISI>://000180545000008},
	author = {Thompson, K. H. and Liboiron, B. D. and Bellman, Yskdd and Setyawati, I. A. and Patrick, B. O. and Karunaratne, V. and Rawji, G. and Wheeler, J. and Sutton, K. and Bhanot, S. and Cassidy, C. and McNeill, J. H. and Yuen, V. G. and Orvig, Chris}
}
@article {524,
	title = {Influence of chelation and oxidation state on vanadium bioavailability, and their effects on tissue concentrations of zinc, copper, and iron},
	journal = {Biological Trace Element Research},
	volume = {86},
	number = {1},
	year = {2002},
	note = {ISI Document Delivery No.: 541ZTTimes Cited: 27Cited Reference Count: 45},
	month = {Apr},
	pages = {31-44},
	type = {Article},
	abstract = {Today, vanadium compounds are frequently included in nutritional supplements and are also being developed for therapeutic use in diabetes mellitus. Previously, tissue uptake of vanadium from bis(maltolato)oxovanadium(IV) (BMOV) was shown to be increased compared to its uptake from vanadyl sulfate (VS). Our primary objective was to test the hypothesis that complexation increases vanadium uptake and that this effect is independent of oxidation state. A secondary objective was to compare the effects of vanadium complexation and oxidation state on tissue iron, copper, and zinc. Wistar rats were fed either ammonium metavanadate (AMV), VS, or BMOV (1.2 mM each in the drinking water). Tissue uptake of V following 12 wk of BMOV or AMV was higher than that from VS (p < 0.05). BMOV led to decreased tissue Zn and increased bone Fe content. The same three compounds were compared in a cellular model of absorption (Caco-2 cells). Vanadium uptake from VS was higher than that from BMOV or AMV at 10 min, but from BMOV (250 \&mu;M only, 60 min), uptake was far greater than from AMV or VS. These results show that neither complexation nor oxidation state alone are adequate predictors of relative absorption, tissue accumulation, or trace element interactions.},
	keywords = {ABSORPTION, BIS(MALTOLATO)OXOVANADIUM(IV), bone, CACO-2, Caco-2 cells, COMPLEXES, DIABETIC RATS, GLUCOSE-METABOLISM, IN-VITRO, INSULIN, kidney, ORTHO-VANADATE, skeletal muscle, SULFATE, VANADIUM, zinc},
	isbn = {0163-4984},
	url = {<Go to ISI>://000175018100004},
	author = {Thompson, K. H. and Tsukada, Y. and Xu, Z. M. and Battell, M. and McNeill, J. H. and Orvig, Chris}
}
@article {4834,
	title = {High-resolution spectroscopy of jet-cooled (SO2)-S-32 and (SO2)-S-34: The (a)over-tilde(3)B(1)-(X)over-tilde(1)A(1), 2(0)(1) and 1(0)(1) bands},
	journal = {Journal of Molecular Spectroscopy},
	volume = {203},
	number = {1},
	year = {2000},
	note = {ISI Document Delivery No.: 347WMTimes Cited: 5Cited Reference Count: 20},
	month = {Sep},
	pages = {151-157},
	type = {Article},
	abstract = {Laser-induced excitation spectra of the two bands (a) over tilde(3)B(1)-(X) over tilde(1)A(1), 2(0)(1) and 1(0)(1) of (SO2)-S-32 and (SO2)-S-34 have been recorded in a supersonic jet at a resolution of 0.015 cm(-1). The rotational and electron-spin fine structure has been analyzed for both isotopic species. Analysis of the rotational and electron-spin fine structure yields precise values of the rotational constants A, B, and C and the spin constants alpha and beta for both (SO2)-S-32 and (SO2)-S-34 in the states (a) over tilde(3)B(1) (010) and (100). No interaction between these two vibrational States with any nearby triplet state is observed for rotational levels with J less than or equal to 8 and K less than or equal to 2. (C) 2000 Academic Press.},
	keywords = {ABSORPTION, AMPLIFIED SPONTANEOUS EMISSION, ROTATIONAL STRUCTURE, SO2, SPECTRUM, STATE, STIMULATED BRILLOUIN-SCATTERING, sulfur dioxide, SULFUR-DIOXIDE, SYSTEM},
	isbn = {0022-2852},
	url = {<Go to ISI>://000088952200018},
	author = {Huang, C. L. and Ju, S. S. and Chen, I. C. and Merer, A. J. and Ni, C. K. and Kung, A. H.}
}
@article {4991,
	title = {Laser-induced phosphorescence of SO2 in solid neon: Direct observation of the (b)over-tilde(3)A(2) state in the (OSO)-O-16-O-18 molecule},
	journal = {Journal of Physical Chemistry A},
	volume = {104},
	number = {4},
	year = {2000},
	note = {ISI Document Delivery No.: 280WFTimes Cited: 13Cited Reference Count: 41},
	month = {Feb},
	pages = {771-776},
	type = {Article},
	abstract = {Laser excitation of isotopically labeled SO2 molecules in a neon matrix has allowed the measurement of dispersed phosphorescence spectra ((a) over tilde(3)B(1)-(X) over tilde(1)A(1)) in the wavelength region 387.5-526.3 nm (19 000-25 800 cm(-1)). The origin of the (a) over tilde-(X) over tilde transition lies at 25 747 cm(-1) in (OSO)-O-16-O-16, shifted 18 cm(-1) to the red from the gas phase; the three vibrational frequencies of the (X) over tilde state are nearly unperturbed in the neon matrix (1149, 520, and 1362 cm(-1)). As the zero-phonon lines are sharp and well resolved, it has been possible to monitor emission from a specific isotopomer to obtain its excitation spectrum. The excitation spectra of matrix-isolated (OSO)-O-16-O-16 and (OSO)-O-18-O-18 in the region 350.9-388.5 nm (25 740-28 500 cm(-1)) are similar to those previously observed in the gas phase, with strong perturbations affecting all vibrational levels above a(3)B(1)(110) at 27 005 cm(-1) (370 nm). Two additional groups of bands are observed for the unsymmetrical isotopomer (OSO)-O-18-O-16; they are identified as transitions to levels of the (a) over tilde(3)B(1) state with v(3) = 1 and as direct transitions to the (b) over tilde(3)A(2) state, which both become allowed in the lower symmetry. The v(3) frequency of the (a) over tilde(3)B(1) state of (OSO)-O-18-O-16 is 922 cm(-1); for the (b) over tilde(3)A(2) state, v(1) similar or equal to 791 cm(-1) and v(2) similar or equal to 315 cm(-1), while the (b) over tilde (001) level lies 26 653 cm(-1) above the (X) over tilde (000) level.},
	keywords = {ABSORPTION, BAND SYSTEM, FLUORESCENCE, INDUCED EMISSION, MATRICES, REGION, ROTATIONAL, SPECTRA, STRUCTURE, SULFUR-DIOXIDE, VIBRATIONAL STRUCTURE},
	isbn = {1089-5639},
	url = {<Go to ISI>://000085126200014},
	author = {Zen, C. C. and Chen, I. C. and Lee, Y. P. and Merer, A. J.}
}
@article {4534,
	title = {Methylated bismuth in the environment},
	journal = {Applied Organometallic Chemistry},
	volume = {13},
	number = {10},
	year = {1999},
	note = {ISI Document Delivery No.: 243BTTimes Cited: 24Cited Reference Count: 424th International Conference on Biological and Environmental Aspects of Main Group OrganometallicsJUN, 1998ODENSE, DENMARK},
	month = {Oct},
	pages = {739-748},
	type = {Proceedings Paper},
	abstract = {Biomethylation of metals and metalloids of Group 14 and 15 metals such as tin, lead and arsenic takes place in the environment, but information about methylated bismuth compounds is rather limited, although bismuth compounds are used widely in alloys, cosmetics and pharmaceutical products, Cryotrapping gas chromatography and hydride generation gas chromatography coupled with an ICP-MS as a bismuth-selective detector were used to determine volatile bismuth compounds in landfill and in sewage gas, as well as non-volatile methylated compounds in water and sediment samples, One volatile bismuth compound could be determined in gaseous samples; it was identified as Me3Bi (TMB) by element-specific detection (ICP-MS, m/z 209), matching the retention time with a TMB standard. The molecular structure was recently confirmed by gas-chromatographic fractionation with MS-ion trap detection (electron impact), Among other volatile metal compounds, TMB is a major component in the gases of sewage sludge digesters: concentrations of up to 25 mu g m(-3) have been measured at eight sewage treatment plants, The concentration in landfill gas was approximately one order of magnitude lower. In laboratory experiments, fermenters containing an anaerobic culture from a clean pond sludge were mixed with contaminated soil from four different industrial areas, After an incubation time of two weeks at 30 degrees C in the dark, TMB was detected in the headspace of all the samples, The volatilization rate of bismuth did mot correlate with the total amount of bismuth: in the sediments or with the available fraction after acid digestion following hydride generation. Some evidence was obtained for the occurrence of methylated bismuth compounds in water samples and in sediments, Copyright (C) 1999 John Wiley \& Sons, Ltd.},
	keywords = {ABSORPTION, BIOMETHYLATION, BISMUTH, deposits, GAS-CHROMATOGRAPHY, ICP-MS, landfill gas, PLASMA-MASS SPECTROMETRY, sewage gas, SPECIATION, VOLATILE METAL, WASTE},
	isbn = {0268-2605},
	url = {<Go to ISI>://000082977800010},
	author = {Feldmann, J. and Krupp, E. M. and Glindemann, D. and Hirner, A. V. and Cullen, W. R.}
}
@article {3978,
	title = {Investigation of hydrogel formation from hydroxypropylmethylcellulose (HPMC) by NMR spectroscopy and NMR imaging techniques},
	journal = {Macromolecules},
	volume = {30},
	number = {20},
	year = {1997},
	note = {ISI Document Delivery No.: YA289Times Cited: 54Cited Reference Count: 21},
	month = {Oct},
	pages = {6230-6237},
	type = {Article},
	abstract = {NMR imaging has been used to investigate the in situ swelling behavior of 2-hydroxypropylmethylcellulose (HPMC) tablets in a sample geometry chosen for the simplicity of its diffusion behavior. Preliminary H-1 NMR spectroscopy experiments were performed on equilibrated mixtures of HPMC and water. From these, the dependence of the H-1 T-1 and T-2 relaxation parameters of the water protons with respect to HPMC weight percent were obtained. Further analysis of the T-2 values and H-1 z-spectroscopic data revealed that as the polymer concentration was increased from 10\% to 20\% w/w HPMC, the polymer mobility decreased substantially. One-dimensional NMR imaging of H-1 in the swelling tablet system was used to monitor the movement of water into the polymer and to calculate the T-2 parameters across the system. HPMC weight percents were calculated from these T-2 values using the previously determined calibration. HPMC distributions were determined for two tablet thicknesses. Similar swelling behavior was observed for both thicknesses at early times prior to the thinner tablet becoming completely hydrated.},
	keywords = {ABSORPTION, BEHAVIOR, DIFFUSION, DRUG-RELEASE, GEL LAYER, MECHANISMS, microscopy, PENETRATION, RELEASE DOSAGE FORMS, TABLETS},
	isbn = {0024-9297},
	url = {<Go to ISI>://A1997YA28900036},
	author = {Fyfe, C. A. and Blazek, A. I.}
}
@article {4047,
	title = {Spatial and temporal profiles of indium in a furnace atomization plasma excitation spectrometry source},
	journal = {Applied Spectroscopy},
	volume = {51},
	number = {11},
	year = {1997},
	note = {ISI Document Delivery No.: YP332Times Cited: 5Cited Reference Count: 39},
	month = {Nov},
	pages = {1715-1721},
	type = {Article},
	abstract = {Spatially resolved emission and absorption intensities from the indium 303.93-nm resonance line were measured in a furnace atomization plasma excitation spectrometry (FAPES) source. These measurements show that the spatial structure observed in the analyte emission is due to two effects, The first is the spatial distribution of analyte atoms in the source. The absorption measurements show that this spatial distribution is fairly uniform. There is a slight gradient, with analyte concentrations increasing from the cuvette wall to the center electrode. The fine structure in the emission intensity profiles must therefore be caused by the dependence of the degree of analyte excitation on position within the cuvette. This structure suggests that the FAPES source operates as an atmospheric-pressure radio-frequency glow discharge. Negative glows are seen adjacent to the graphite cuvette wall and center electrode.},
	keywords = {ABSORPTION, aluminum, ANALYTE, ATOMIC-ABSORPTION, CCD, DYNAMICS, emission, EMISSION-SPECTROMETRY, FAPES, FURNACE ATOMIZATION PLASMA EXCITATION SPECTROMETRY, GRAPHITE-FURNACE, indium, INVESTIGATING ELECTROTHERMAL ATOMIZATION, LEAD, profile, SPATIAL, SPECTROSCOPY},
	isbn = {0003-7028},
	url = {<Go to ISI>://000071266300022},
	author = {LeBlanc, C. W. and Blades, M. W.}
}
@article {7244,
	title = {PROTOTROPIC CONTROL OF ORGANIC-PHOTOCHEMISTRY - HYDROGEN-BONDING EFFECTS ON THE DI-PI-METHANE PHOTOREARRANGEMENT},
	journal = {Journal of Organic Chemistry},
	volume = {57},
	number = {1},
	year = {1992},
	note = {ISI Document Delivery No.: GY184Times Cited: 6Cited Reference Count: 54},
	month = {Jan},
	pages = {241-247},
	type = {Article},
	abstract = {The IR and UV spectra as well as the photochemistry of the isopropyl monoester of dibenzobarrelene dicarboxylic acid 2 were analyzed in detail in several media. A correlation was found between the photochemical results and the spectroscopically detected hydrogen-bonded structures of 2. An equilibrium between dimeric (2-HD) and intramolecularly hydrogen bonded (2-HI) structures was detected by IR spectroscopy in nonpolar solvents having weak hydrogen-bond-accepting capabilities. The ratio of the two regioisomeric dibenzosemibullvalene products 3 and 4 formed in the di-pi-methane photorearrangement of 2 was found to correlate with such an equilibrium, and it was concluded that intramolecular (2-HI) and dimeric (2-HD) hydrogen-bonded structures display significantly different photochemical reactivity. The infrared spectra and the photoproduct ratio in polar solvents possessing hydrogen-bond-accepting capabilities (e.g., acetonitrile), on the other hand, turned out to be concentration independent. High regioselectivity was found in the solid state where the dimer 2-HD is the only species, leading to 4 as the major product. In contrast, 3 was obtained preferentially in aqueous sodium bicarbonate solutions where 2 exists as the carboxylate anion. Supporting evidence regarding the different hydrogen bonding arrangements in 2 was found in the solvent effects on its UV spectra.},
	keywords = {ABSORPTION, DIBENZOBARRELENES, EXCITED-STATE, LASER EXCITATION FLUORESCENCE, METHYL SALICYLATE, ORTHO-HYDROXYBENZALDEHYDE, PHOTOISOMERIZATION, REARRANGEMENTS, SOLID-STATE, STATE PROTON-TRANSFER},
	isbn = {0022-3263},
	url = {<Go to ISI>://A1992GY18400043},
	author = {Garciagaribay, M. A. and Scheffer, J. R. and Watson, D. G.}
}
