@article {4730, title = {The tetrakis(carbonyl)dioxoosmium(VI) cation: trans-[OsO2(CO)(4)](2+)}, journal = {Angewandte Chemie-International Edition}, volume = {39}, number = {1}, year = {2000}, note = {ISI Document Delivery No.: 273GWTimes Cited: 5Cited Reference Count: 34}, pages = {168-+}, type = {Article}, keywords = {C-13, carbonyl complexes, CATIONS, COMPLEXES, CRYSTAL-STRUCTURE, density functional calculations, MAS-NMR-SPECTRA, MOLECULAR-STRUCTURE, superacidic systems, UNDECAFLUORODIANTIMONATE(V), vibrational spectroscopy}, isbn = {1433-7851}, url = {://000084700400017}, author = {Bernhardt, E. and Willner, H. and Jonas, V. and Thiel, W. and Aubke, F.} } @article {4473, title = {Hexakis(carbonyl)iron(II) undecafluorodiantimonate(V), [Fe(CO)(6)][Sb2F11](2), and -hexafluoroantimonate(V), [Fe(CO)(6)][SbF6](2), their syntheses, and spectroscopic and structural characterization by single crystal X-ray diffraction and normal coordinate}, journal = {Journal of the American Chemical Society}, volume = {121}, number = {31}, year = {1999}, note = {ISI Document Delivery No.: 227UKTimes Cited: 32Cited Reference Count: 109}, month = {Aug}, pages = {7188-7200}, type = {Review}, abstract = {Hexakis/carbonyl iron(LI) undecafluorodiantimonate(V), [Fe(CO)(6)][Sb2F11](2) is conveniently prepared by the oxidative carbonylation of Fe(CO)(5) with XeF2 as external oxidizer in the conjugate Br phi nsted-Lewis superacid HF-SbF5. The colorless compound crystallizes from the reaction medium in high purity. The molecular structure is obtained by single-crystal X-ray diffraction. The cation is a regular octahedron, while the vertex-shared di-octahedral [Sb2F11](-) anion is distorted from D-4h symmetry by bending and rotational processes, due to significant interionic interactions, primarily of the FC type. Washing of [Fe(CO)(6)][Sb2F11](2) with anhydrous HF results in an unusual elution of SbF5 and the quantitative conversion to hexakis(carbonyl)iron(II) hexafluoroantimonate;(V) [Fe(CO)(6)][SbF6](2) The molecular structure of the salt shows octahedral ions with slight tetragonal distortions for the cation (elongation) and the anion (comprsssion). Both salts are thermally stable up to 150 degrees C, The averaged bond distances and the vibrational wavenumbers of [Fe(CO)(6)](2+) are nearly identical in both compounds. The [Fe(CO)(6)](2+) cation, the first and so far only isolated and structurally characterized dipositive, superelectrophilic carbonyl cation formed by a 3d-metal, is further characterized by a normal coordinate analysis (NCA). The obtained force constants are compared to those of the isoelectronic molecule Cr(CO)6. Changes in pi-back-bonding affect the F-CO/CO and F-CO/MC interaction force constants more strongly than the stretching force constants F-CO and F-MC All 13 fundamentals of [Fe(CO)(6)](2+) are detected and assigned with the help of the data obtained from the normal coordinate analysis and density functional calculations published previously. The electronic ground state (1)A(1g), of the [Fe(CO)(6)](2+) cation is established by magnetic susceptibility measurements of polycrystalline [Fe(CO)(6)][SbF6](2) and [Fe(CO)(6)][Sb2F11](2) between and 300 K. The magnetic impurity formed during synthesis is identified as Fe[SbF6](2) which has iron(II) in high spin (T-5(2g)) ground state. Consistent with a diamagnetic ground state are the single line in the Fe-57 Mossbauer spectrum (i.s. = -0.003(8) mm s(-1) relative to alpha-Fe), obtained on polycrystalline samples and the single sharp line in the C-13 NMR spectrum in DF solution at 178 ppm with J (Fe-57-C-13) of 19.2 Hz.}, keywords = {C-13, COMPLEXES, CONSTANTS, IRON PENTACARBONYL, MAS-NMR-SPECTRA, METAL-CARBONYL CATIONS, MO, MOLECULAR-STRUCTURE, MONOXIDE, VIBRATIONAL-SPECTRA}, isbn = {0002-7863}, url = {://000082098200003}, author = {Bernhardt, E. and Bley, B. and Wartchow, R. and Willner, H. and Bill, E. and Kuhn, P. and Sham, I. H. T. and Bodenbinder, M. and Brochler, R. and Aubke, F.} } @article {4080, title = {Specific N-15,NH correlations for residues in N-15,C-13 and fractionally deuterated proteins that immediately follow methyl-containing amino acids}, journal = {Journal of Biomolecular Nmr}, volume = {10}, number = {3}, year = {1997}, note = {ISI Document Delivery No.: YG934Times Cited: 10Cited Reference Count: 47}, month = {Oct}, pages = {283-288}, type = {Article}, abstract = {A triple-resonance pulse scheme is described which records N-15, NH correlations of residues that immediately follow a methyl-containing amino acid. The experiment makes use of a N-15, C-13 and fractionally deuterated protein sample and selects for CH2D methyl types. The experiment is thus useful in the early stages of the sequential assignment process as well as for the confirmation of backbone N-15, NH chemical shift assignments at later stages of data analysis. A simple modification of the sequence also allows the measurement of methyl side-chain dynamics. This is particularly useful for studying side-chain dynamic properties in partially unfolded and unfolded proteins where the resolution of aliphatic carbon and proton chemical shifts is limited compared to that of amide nitrogens.}, keywords = {C-13, C-13/N-15-ENRICHED PROTEINS, CELLULOSE-BINDING DOMAIN, correlations, H-2 spin relaxation, H-2-labeled proteins, ISOTOPICALLY-ENRICHED PROTEINS, LABELED PROTEINS, N-15, NH, NMR EXPERIMENTS, PERDEUTERATED PROTEINS, RELAXATION-TIMES, SEQUENTIAL ASSIGNMENT, SIDE-CHAIN, TRIPLE-RESONANCE EXPERIMENTS}, isbn = {0925-2738}, url = {://A1997YG93400009}, author = {Muhandiram, D. R. and Johnson, P. E. and Yang, D. W. and Zhang, O. W. and McIntosh, L. P. and Kay, L. E.} } @article {3657, title = {Solution structure of the ETS domain from murine Ets-1: A winged helix-turn-helix DNA binding motif}, journal = {Embo Journal}, volume = {15}, number = {1}, year = {1996}, note = {ISI Document Delivery No.: TQ160Times Cited: 113Cited Reference Count: 68}, month = {Jan}, pages = {125-134}, type = {Article}, abstract = {Ets-1 is the prototypic member of the ets family of transcription factors, This family is characterized by the conserved ETS domain that mediates specific DNA binding, Using NMR methods, we have determined the structure of a fragment of murine Ets-1 composed of the 85 residue ETS domain and a 25 amino acid extension that ends at its native C-terminus. The ETS domain folds into a helix-turn-helix moth on a four-stranded anti-parallel beta-sheet scaffold. This structure places Ets-1 in the winged helix-turn-helix (wHTH) family of DNA binding proteins and provides a model for interpreting the sequence conservation of the ETS domain and the specific interaction of Ets-1 with DNA. The C-terminal sequence of Ets-1, which is mutated in the v-Ets oncoprotein, forms an alpha-helix that packs anti-parallel to the N-terminal helix of the ETS domain, In this position, the C-terminal helix is poised to interact directly with an N-terminal inhibitory region in Ets-1 as well as the wHTH motif. This explains structurally the concerted role of residues flanking the ETS domain in the intramolecular inhibition of Ets-1 DNA binding.}, keywords = {AMINO-ACID SUBSTITUTION, C-13, C-ETS-1, COUPLING-CONSTANTS, CRYSTAL-STRUCTURE, DNA binding, ERYTHROBLASTOSIS, FACTORS, GENE FAMILY, intramolecular inhibition, protein NMR structure, PROTEINS, selective labelling, transcription, V-ETS, winged helix-turn-helix}, isbn = {0261-4189}, url = {://A1996TQ16000013}, author = {Donaldson, L. W. and Petersen, J. M. and Graves, B. J. and McIntosh, L. P.} }