Weak interactions observed in ruthenium and iridium complexes containing hydride, amine, and bulky phospyhine ligands

1997 ◽  
Vol 75 (5) ◽  
pp. 475-482 ◽  
Author(s):  
Wei Xu ◽  
Alan J. Lough ◽  
Robert H. Morris

New amineruthenium and amineiridium hydride derivatives have been synthesized and characterized with the objective of observing intramolecular [Formula: see text] or [Formula: see text] interactions. These include RuHCl(CO)(L)(PPri3)2 (1a, L = NH2NH2; 1b, L = NH3) and IrCl2(L)(H)(PCy3)2 (2a, L = SC(NH2)2; 2b, L = NH3; 2c, L = NH2NH2; 2d, L = NH2(CH2)3NH2; 2e, L = NH2OH). Instead, weak [Formula: see text] van der Waals contacts have been detected in the solid state by X-ray analysis and in solution by NMR T1 measurements and nOe techniques. Both X-ray crystal structure analysis and minimum T1 measurements indicate that the [Formula: see text] distances in the [Formula: see text] interactions are ca•2.0–2.2 Å. The weak interactions might influence the course of deuteration of these complexes under D2 gas. The crystal and molecular structure of IrCl2(NH3)(H)(PCy3)22a has been determined by X-ray diffraction at 173 K: monoclinic, space group P21/n, a = 14.859(2) Å, b = 18.579(3) Å, c = 18.548(3) Å, β = 97.29(1)°, V = 5079.1(13) Å3, Z = 4, full-matrix least-squares refinement on F2 for 10 953 independent reflections; R[F2 > 4σ(F2)] = 0.0283, wR(F2) = 0.0704. Keywords: ruthenium, iridium, hydride, dihydrogen, complexes, hydrogen bond, NMR, X-ray.

1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley

The crystal structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, (PhPSi2Me4)2, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P21/c, with a = 9.866(1), b = 11.921(1), and c = 11.324(2) Å, β = 104.31(1)°, Z = 2, and ρcalcd = 1.15 g/cm3. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.060 and Rw of 0.078, for 1173 reflections with intensities greater than 3σ. The (PhPSi2Me4)2 molecule lies on a crystallographic centre of symmetry, and the six-membered P2Si4 ring has a chair conformation with equatorial phenyl groups. The endocyclic angles at P (104.4(1)°) and Si (104.9(2)°) are intermediate between those found in cyclic hexaphosphine and hexasilane molecules, and the Si—Si and P—Si distances of 2.345(3) and 2.252(4) Å, respectively, correspond to single bond lengths, with no appreciable evidence for secondary pπ → dπ bonding between phosphorus and silicon. The Si—C (1.867(8) Å) and P—C (1.828(7) Å) bond lengths are also normal. The variations in the Si—P—C (101.6(2)°, 108.6(2)°), P—Si—C (range 106.2(3)–120.0(3)°), and Si—Si—C (range 105.8(3)–113.7(3)°) angles indicate that the positions of the exocyclic methyl and phenyl groups are influenced by both intra- and intermolecular steric forces.


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)°.


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.


1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.


1972 ◽  
Vol 50 (6) ◽  
pp. 912-916 ◽  
Author(s):  
P.-T. Cheng ◽  
S. C. Nyburg

The X-ray crystal structure analysis of the triphenyl–phosphine platinum ethylene complex (PPh3)2PtC2H4 is reported. The crystals belong to the monoclinic system a = 16.46(3), b = 10.85(2), c = 17.85(3) Å, β = 100.5(1)°, space group P21/a, Z = 4 molecules per cell.The ethylene C—C distance of 1.434(13) Å is in accord with that found when other transition elements form metallo-cyclopropanes. The structure has been refined by anisotropic full-matrix least-squares, the final R-factor being 0.043 for 4174 observed reflections.


1975 ◽  
Vol 53 (18) ◽  
pp. 2707-2713 ◽  
Author(s):  
Debbie Allen ◽  
Colin James Lyne Lock ◽  
Graham Turner ◽  
John Powell

The crystal and molecular structures of pentane-2,4-dionato-(2,3,5,6-tetrahapto-2,3-dicarbomethoxo[2.2.1]bicycloheptadienerhodium(I), Rh(C5H7O2)(C7H6(CO2CH3)2), have been measured by single crystal X-ray diffraction. The orange crystals are monoclinic, space group P21/c, Z = 4, a = 9.245(4), b = 9.003(4), c = 21.680(15) Å, β = 113.41(5)°. The calculated and observed densities are 1.645 and 1.642(5) respectively. Intensity data were collected on a Syntex [Formula: see text] diffractometer and a full matrix least squares refinement on 3010 observed reflections leads to a conventional R = 0.0660. The structure can be considered as a roughly square planar arrangement of ligands around the rhodium atom composed of two β-ketoenolate oxygen atoms (Rh—O, 2.037(5) and 2.025(5) Å ) and the centers of the two ethylenic groups. The Rh—C distances for the olefin group attached to the two carbomethoxo groups, 2.117(8), 2.108(8) Å, appear to be slightly larger than those for the other olefinic group, 2.087(7), 2.082(6), and the corresponding C=C distances of 1.375(10) and 1.410(9) Å are different at the 95% confidence level.


1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.


1989 ◽  
Vol 44 (1) ◽  
pp. 5-8
Author(s):  
Michel Mégnamisi-Bélombé

Abstract trans-Dichloro(ethanedial-dioximato)(ethanediaI-dioxime)rhodium (III), RhCl2(GH)(GH2), has been synthesized and its structure determined by single crystal X-ray diffraction at room temperature. C4H7Cl2N4O4Rh, Mr = 348.94. monoclinic space group P21/ɑ; a = 10.543(3), b = 8.363(2), c = 11.512(3)Å ; β = 92.79(2)°; V = 1024Å3; Z = 4; Dc = 2.26 Mg m-3. Final Rw = 0.075 for 2035 reflections and 139 parameters. The coordination geometry around Rh is a dis­torted (4+2) octahedron, with four chelating N atoms lying in the equatorial plane and the two Cl atoms in the apical positions. The H atoms of the oxime groups are involved in relatively weak intramolecular O-H-O bridgings, as well as in very strong intermolecular bridgings which extend throughout the crystal structure and propagate nearly parallel to the [101] crystallographic direction.


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