Klaus von Deuten

The coordinative properties of the ligands Ph2ECH2EPh2 (E = P, As, Sb) in carbonylvanadium complexes, and the molecular structure of η5-C5H5V(CO)3As2Ph4

Abstract Photo-reaction between the ligands Ph2ECH2EPh2 (E = P: dppm, E = As: dpam, E = Sb: dpsm), L, and the vanadium complexes η5-C5H5V(CO)4 and [Et4N][V(CO)6] yields monosubstituted mononuclear (dpsm) and dinuclear, ligand-bridged complexes (dpam, dpsm). With dppm, the final products are disubstituted chelate complexes, but monosubstituted mono- and dinuclear species are formed as intermediates. The shielding of the 51V nucleus decreases in the series dpsm > dppm > dpam and {M(CO)n} > {M(CO)n−1} L > {M(CO)n−1}2μ-L > {M(CO)n−2}dppm ({M(CO)n}[V(CO)6]−, η5-C5H5V(CO)4). The half-widths of the NMR signals are greater for dinuclear than for mononuclear complexes. The crystal and molecular structures of η5-C5H5V(CO)3As2Ph4 have been determined. The compound crystallizes in the space group P21/c with a = 1347.8, b = 1020.0, c = 2085.2 pm and β = 82.3°. Due to steric crowding, the 51V shielding is low composed to that of {η5-C5H5V(CO)3}2μ-dpam.

Cyclometallation reactions inortho-methyl substituted iridium arylsvia CO insertion and oxidative C-H addition. Characterization of the reported IrH[C6H2Me2-(4,6)-CH2-(2)][P(OMe)3]3 as the internally metallated benzoyl complexfac-IrH[C(O)C6H2Me2-(4,6)-H2(2)]-[P(OMe)3]3 by X-Ray diffraction(1)

SummaryThe title compound, previously reported as , has been characterized as by x-ray analysis. The complex crystallizes in the triclinic space group P1 witha = 1029.2(4),b = 1192.7(7),c = 1216.6(7) pm, α = 105.42(4), β = 105.95(4), γ = 95.45(4)°, and Z = 2. With 3909 independent reflections for which F0 > 3 σ(F0,), the structure has been refined anisotropically to R = 0.048. The molecular geometry corresponds to a distorted octahedron with the phosphite ligands infac positions. The complex contains a five-membered metallocycle of the iridaindanone type,, in which the metal deviates slightly from the plane defined by the carbon atoms. Important bond distances are Ir-P = 230.1(3), 230.6(4), and 228.0(3) pm, Ir-C(O) = 207(1) pm, and Ir-CH2 = 213(1) pm. On the basis of the x-ray results and further i.r. and13C n.m.r. data, the structures of a series of related complexes, previously regarded as, have also been reformulated as.

Carbonyl-η5-cyclopentadienyl(1,1,4,7,7-pentaphenyl-1,4,7-triphosphaheptane)vanadium(I), η5-C5H5V(CO)PPh(CH2CH2PPH2)2

Abstract The molecular structure and spectroscopic properties of the title compound are reported. The complex crystallizes in the space group P 2 1 / c with a 1807.1, b 1088.7, c 3461.6 pm and β 94.3°. The vanadium atom is centered between the two best planes spanned by the cyclopentadienyl ring and the three phosphorus atoms plus the CO ligand. The angle between the two planes is 10.5°; bond angles at the vanadium are around 77°. In solution, 31 P NMR, 51 V NMR and IR data indicate fluxional behaviour down to 200 K.

Crystal and molecule structure of 1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantane

Abstract The colourless crystals of the title compound are monoclinic, a = 679.0(10), b = 1003.0(9), c = 1191.4(8) pm, β = 105.14(8)°, space group P2 1 /c. A three dimensional X-ray analysis of the structure was made with counter data (1903 unique reflections with | F o | > 3σ). The structure was determined by direct methods and refined anistropically by full matrix least squares methods to a conventional unweighted R of 0.059. The structure consist of discrete molecules As 4 O 4 (CH 2 ) 2 which can be described as penetrating distorted As 4 -tetrahedra and trans -O 4 C 2 -octahedra. The mean bond lengths and angles are: AsO = 179.5, AsC = 196.2 pm, OAsO = 101.8, CAsO = 99.3, AsOAs = 129.0, AsCAs = 119.4°.

CHALCOGENOLATES AND THEIR DERIVATIVES, IX1 CRYSTAL AND MOLECULAR STRUCTURE OF CHLORO-TRIS(DIETHYLDITHIOCARBAMATO-S,S')-TELLURIUM (IV) - DIOXANE (1/1)

Abstract The reaction of sodium N,N-diethyldithiocarbamate with tellurium (IV) chloride in 2:1 molar ratio in dioxane yields the title compound [Cl(Et2NCS2)3Te]·C4H8O2(5), the X-ray crystal structure of which has been determined. Tellurium has a distorted pentagonal-bipyramidal coordination with the lone pair showing only slight stereochemical activity.

CHALCOGENOLATES AND THEIR DERIVATIVES, XIII1 COMPLEXES OF TELLURIUM WITH HALIDE AND DITHIO LIGANDS. Crystal and Molecular Structure of Bromo-Bis(Dimethyldithiocarbamato-S,S′)Tellurium(IV) Tetrabromo-(Dimethyldithiocarbamato-S,S′) Tellurate(IV) Dioxane Solvate

Abstract Starting from tellurium(IV) chloride and bromide the mixed ligand complexes cis-[TeCl2(S2CNMe2)2] (8), cis-[TeBr2(S2CNEt 2)2] (11), [TeCl(S2CNEt 2)3] (10), [TeBr(S2CNMe2)2][TeBr4(S2CNMe2)] (9), [TeBr(S2COEt)]2 (12) and [TeCl(S2CPh)]2 (13) are formed by reaction with the corresponding dithio ligands in dioxane or ethanol as solvents. The X-ray crystal structure of 9 has been determined and shows the lone pair of tellurium(IV) to be stereochemically active in both ions of the compound. The structures of the cation and the anion of 9 can be derived from octahedral and pentagonal bipyramidal coordinations respectively.

X-Ray Crystal Structure Analysis of Factor A (2-Methyladeninyl-cyanocobamide), a Native Vitamin B12-Analogue

Abstract Vitamin B12-factor A (2-Methyladeninyl-cyanocobamide), Vitamin B12, X-Ray Crystal Structure Analysis The crystal and molecular structure of 2-methyladeninyl-cyanocobamide (factor A) has been determined. This compound crystallizes in space group P21212, with a = 2630.6 (15), b = 2210.6 (13) and c = 1592.1 (9) pm. The structure has been solved by the heavy-atom method and refined by least-squares methods on the basis of 3682 X-ray counter data to R = 0.166 and R w = 0.148. As far as we know, this is the first X-ray-investigation of a purine-corrinoid, which differs from cyanocobalamin (vitamin B12) by containing a purine base instead of 5,6-dimethylbenz-imidazole. The structure analysis of 2-methyladeninyl-cyanocobamide shows unambiguously, that the purine base coordinates with cobalt via N B9. The choice of N B9 as coordinative atom can be ascribed partly (or mainly?) to steric influences, since coordination via N B3, which was also discussed, would presumably lead to severe distortion of the nucleotide loop.

Chalkogenolat-Ionen und ihre Derivate, V Kristall- und Molekülstruktur von 2.8-Dimethyldibenzo [c.g] [1.2.5.6] tetrathiacyclooktadien, einem Oxidationsprodukt von 4-Methylbenzol-1.2-dithiol/Chalcogenolates and their Derivatives, V Crystal and Molecular Structure of 2.8-Dimethyldibenzo[c,g][1,2,5,6]tetrathiaocin, an Oxidation Product of 4-Methylbenzene-1,2-dithiol

Abstract The structure of 2,8-dimethyldibenzo[c,g][1,2,5,6]tetrathiaocin (1b) has been determined by X-ray methods and discussed in connection with the preferred conformations of diaryl disulfides. The compound has the anti-form I. The SS-distance is 205.8 pm, the mean CSS-angle 104.1°, and the CSS/SSC-dihedral angle 111.1°.