Heavy transition metal complexes of biologically important molecules. I. The crystal and molecular structure of trans-dichloro(bis(isopropyl)-sulfoxide-S)(1-methylcytosine-N)platinum(II)

1976 ◽  
Vol 54 (1) ◽  
pp. 53-58 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Robert Anthony Speranzini ◽  
John Powell

The crystal and molecular structure of trans-dichloro(bis(isopropyl)sulfoxide-S)(1-methylcytosine-N)platinum(II) has been determined by single crystal X-ray diffraction. The crystals are triclinic with a = 16.205(5), b = 8.078(2), c = 6.776(2) Å, α = 106.53(2), β = 96.35(2), γ = 98.54(2)°. The space group is [Formula: see text] and there are two molecules per unit cell. A total of 2294 independent reflections, of which 2023 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares analysis to an R2 value of 0.0427. The ligands form a rough square around the platinum atom with Pt—Cl(1), 2.304(3), Pt—Cl(2), 2.287(4), Pt—S, 2.232(2), Pt—N, 2.058(7). Distances within the ligands are normal. The plane of the cytosine ring is at 84.4° to the plane formed by the ligands around platinum.

1974 ◽  
Vol 52 (9) ◽  
pp. 1704-1708 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan

A compound, obtained in large yields from the reaction of acetylacetone and oxodichloroethoxobis(triphenylphosphine)rhenium(V) in benzene, has been shown by single crystal X-ray diffraction to be cis-dichloropentane-2,4-dionato-trans-bis(triphenylphosphine)rhenium(III). The crystals are monoclinic with a = 13.06(1), b = 18.30(1), c = 16.55(1) Å, and β = 112.7(2)°. The space group is P21/c and there are four molecules per unit cell. A total of 3841 independent reflections, of which 2686 were observed, were examined by film methods, the intensities being measured with a microdensitometer. The structure was refined by full matrix least-squares analysis to an R2 value of 0.068. The ligands are arranged around the rhenium atom in the manner described by the compound name to give a rough octahedron of nearest neighbours and the Re—Cl (2.369 Å av.), Re—O (2.02 Å av.), and Re—P (2.474 Å av.) distances are as expected.


1977 ◽  
Vol 55 (2) ◽  
pp. 333-339 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Graham Turner

The crystal and molecular structure of the title compound has been examined by single crystal X-ray diffraction. The crystals are monoclinic with a = 28.045(10), b = 8.766(3), c = 12.376(5) Å, β = 91.14(3)°. The space group is C2/c and there are eight molecules per unit cell. A total of 5053 independent reflections, of which 2860 were observed, were examined on a Syntex [Formula: see text] diffractometer. The structure was refined by full matrix least squares to an R2 value of 0.0449. The ligands form a very rough octahedron around the rhenium atom with Re—Cl(1), 2.441(3); Re—Cl(2), 2.366(3), Re—O(1), 1.684(7); Re—O(2), 1.896(6); Re—N(1), 2.144(7); Re—N(2), 2.132(7) Å. The pyridine rings are a dominant factor in determining the details of the molecular structure.


1988 ◽  
Vol 41 (5) ◽  
pp. 641 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker

The structure of mer-(Pme2Ph)3Cl-cis-H2IrIII (1) has been determined by single-crystal X-ray and neutron diffraction analyses. Crystals are monoclinic, space group P21, with a 11.476(4), b 14.069(5), c 8.286(3)Ǻ, β 92.45(1)° and Z 2. Full-matrix least-squares analyses converged 0.022 for 7773 X-ray data and R(F2) = 0.062 for 1538 neutron data. Ir -H [1.557(11)Ǻ trans to Cl, 1.603(10) Ǻ trans to P] and Ir -P distances [2.292(1)Ǻ trans to P, 2.328(1)Ǻ trans to H] both exhibit trans lengthening effects. Consistent with the increased hydride content the Ir -P distances in (1) are c. 0.04 Ǻ shorter than for the corresponding bonds in its dichloro monohydrido analogues and c. 0.08 Ǻ shorter than those in the trichloride . In contrast Ir-Cl [2.505(1)Ǻ] is not significantly different to the corresponding distance (2.504 Ǻ av.) in mer -(PMe2Ph)3-cis-Cl2HIrIII.


1977 ◽  
Vol 30 (5) ◽  
pp. 1007 ◽  
Author(s):  
GR Scollary

A structural analysis of the platinum-silatrane complex, PtCl [Si(OCH2CH2)3N] [PMe2Ph]2, has been carried out by X-ray diffraction. Crystals are monoclinic, space group P21/c, a 6.630(4), b 17.465(6), c 22.297(6) Ǻ, β 97.4(2)�, Z 4. The structure has been refined by a full- matrix least-squares procedure to R 0.048 for 2165 reflections. Basic geometries are square (platinum), tetrahedral (silicon) and trigonal (nitrogen). Within the silatrane ligand, the Si-N non-bonding distance is 2.89(1) Ǻ.


1995 ◽  
Vol 48 (7) ◽  
pp. 1277 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson

The structure of mer-trans-(PPri3)2(PH3)H-trans-Cl2IrIII (1) (Pri = isopropyl), the second third-row transition-metal-PH3 complex to be so characterized, has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group C 2/c with a 21.701(2), b 8.735(1), c 15.594(1) Ǻ, β 119.57(1)° and Z 4. Structure refinement by full-matrix least-squares analysis (2811 reflections, 113 parameters) converged with R = 0.016 and Rw = 0.022. Molecules exhibit crystallographically imposed C2 symmetry. The C2 axis passes through the iridium, hydride and PH3 phosphorus atoms, and requires the PH3 hydrogen atoms to be disordered. Important molecular dimensions are Ir-PPri3 2.371(1) Ǻ, Ir-PH3 2.362(1) Ǻ, Ir-Cl 2.374(1) Ǻ and P- Ir -P(trans) 163.21(3)°.


1996 ◽  
Vol 49 (11) ◽  
pp. 1253 ◽  
Author(s):  
EJ Ditzel ◽  
KD Griffiths ◽  
GB Robertson

The structure of mer-cis-(PEt2Ph)2(PPri3)H-trans-Cl2IrIII (4) has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group P21/c, with a 11.607(1), b 21.553(1), c 14.066(1) Ǻ, β 109.04(1)? and Z 4. Structure refinement by full-matrix least-squares analysis (3244 unique reflections, 316 parameters) converged with R 0.034 and Rw 0.041. The PEt2Ph ligands are similarly disposed to their PMe2Ph counterparts in mer-cis-(PEt2Ph)2(PPri3)H-trans-Cl2IrIII (2) but the PPri3 ligands are differently oriented and differently configured. Metal-ligand distances [ Ir -P(1,2,3) 2.333(2), 2.404(2), 2.368(2) Ǻ; Ir-Cl (1,2) 2.388(2), 2.400(2) Ǻ] are all within c. 0.02 Ǻ of those in (2). The P-Ir -P(trans) angle is 155.3(1)°.


1978 ◽  
Vol 56 (2) ◽  
pp. 179-188 ◽  
Author(s):  
Colin James Lyne Lock ◽  
Graham Turner

The crystal structure of µ-oxobis(cis-dichloro-cis-di(pyridine)-trans-oxorhenium(V)), ORe(C5H5N)2Cl2•O•Re(C5H5N)2Cl2O bas been studied by single crystal X-ray methods. The crystals were orthorhombic with lattice parameters a = 15.367(2), b = 10.283(2), c = 16.685(2) Å. The space group was Pna21 and there were four formula weights per unit cell. A total of 3339 reflections, of which 2990 were observed, were examined, and the structure refined by full matrix least squares (treating the pyridine rings as groups) to an R2 value of 0.0449. The dimer had a roughly rectilinear O—Re—O—Re—O backbone with pairs of chlorine atoms and pyridine molecules arranged cis in each half of the dimer. The two halves of the dimer were arranged such that the pairs of cis atoms in one half were rotated about the Re(1)–Re(2) axis almost 113 ° when compared to the corresponding pair in the other half. Important bond lengths (Re—O(terminal), 1.715(16), 1.764(16); Re—O(bridging), 1.943(16), 1.903(16); Re—Cl, 2.356(5)–2.390(5); Re—N, 2.116(16)–2.180(16)) were close to previously observed values. The molecule was markedly disturbed from the idealized structure and this was caused by intramolecular non-bonded interactions.


1993 ◽  
Vol 48 (11) ◽  
pp. 1635-1650 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Wolfgang Conrad ◽  
Reiner Exner

Photochemical reactions of hexacarbonyl-μ-η5:5-fulvalene-dimolybdenum (1) with 1,3-butadiene (a), 2-methyl-1,3-butadiene (b), E-1,3-pentadiene (c), 2,3-dimethyl-1,3-butadiene (d), and E-3-methyl-1,3-pentadiene (e) yield the corresponding tetracarbonyl-η4-s-cisdiene-μ-η5:5-fulvalene-dimolybdenum complexes 3a-3e. In addition to 3a also η4-s-trans1,3-butadiene-tetracarbonyl-μ-η5:5-fulvalene-dimolybdenum (4) is formed. Similarily hexacarbonyl-μ-η5:5-fulvalene-ditungsten (2) forms with a and b tetracarbonyl-η4-s-cis-diene-μ-η5:5-fulvalene-ditungsten (5a, 5b) and bis(η4-s-cis-1,3-butadiene)-dicarbonyl-μ-η5:5-fulvalene-ditungsten (6). The complexes 3b —3e and also 5b are obtained as mixtures of the o- and u-isomers. Only for tetracarbonyl-η4-cis-2,3-dimethyl-1,3-butadiene-μ-η5:5-fulvalene-dimolybdenum (3d) an interconversion of the o- and u-isomers is observed with an energy barrier of ΔG183# = 73.9 kJ/mol. Both isomers of 3d show hindered inversions with energy barriers of ΔG#313 = 66.1 kJ/mol (u-3d) and ΔG183# = 36.4 kJ/mol (o-3d). For o-3d the crystal and molecular structure was determined by an X-ray diffraction analysis. Hexacarbonylµ — η5:5-bis(cyclopentadiendiyl)methane-dimolybdenum (7), hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)ethane-dimolybdenum and hexacarbonyl-μ-η5:5-bis(cyclopentadiendiyl)propane-dimolybdenum do not react with conjugated dienes. Upon UV irradiation 7 looses CO and forms by dimerization octacarbonyl-bis(μ-η5:5-(cyclopentadiendiyl-cyclopentadien-triyl)methane)-dihydrido-tetramolybdenum (8).


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