Complexes of the dicyclohexylphosphinodithioformate anion involving the nickel triad metals: the crystal and molecular structures of the platinum(II) and palladium(II) derivatives

1984 ◽  
Vol 37 (1) ◽  
pp. 197 ◽  
Author(s):  
D Dakternieks ◽  
BF Hoskins ◽  
ERT Tiekink

The crystal and molecular structures of bis (dicyclohexylphosphinodithioformato-S,P)M, M[S2CP-(C6Hl1)2]2 where M = Pt (1) and Pd (2), have been determined by single-crystal three-dimensional X-ray diffraction methods. The isomorphous crystals are monoclinic, of space group P21/c with four molecules per unit cell which has dimensions for (1) a 14.732(4), b 15.11 8(4), c 16.000(3) � and β 120.90(2)� and for (2) a 14.721(2), b 15.142(2), c 15.986(2) � and β 120.80(1)�. The structures were solved by normal Fourier methods and were refined with anisotropic thermal parameters. A full-matrix least-squares method was used, involving 3454 and 5052 statistically significant reflections for (1) and (2) respectively with final R and Rw values of 0.058 and 0.055 for (1) and 0.038 and 0.039 for (2). The complexes are isostructural. The ligand coordinates in a bidentate manner to the central atom through the phosphorus atom and one of the sulfur atoms with the metal atom in a cis-planar environment.

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.


1986 ◽  
Vol 39 (4) ◽  
pp. 713 ◽  
Author(s):  
D Dakternieks ◽  
BF Hoskins ◽  
CL Rolls ◽  
ERT Tiekink

The crystal and molecular structure of bis ( tricyclohexylphosphine )cadmium(II) nitrate as its dichloromethane solvate, Cd [P(c-C6H11)3]2(NO3)2.CH2Cl2, has been determined by single- crystal, three-dimensional X-ray diffraction methods. The crystals of the cadmium(II) complex are monoclinic with space group C2/c, a 20.880(6), b 12.775(3), c 17.075(5) Ǻ and β 106.38(2)°, Z 4. The structure was solved by normal Fourier methods and refined by a full-matrix least-squares procedure. The refinement used the 2169 statistically independent reflections for which I ≥ 2σ(I) converged with R and Rw of 0.065 and 0.067 respectively. The crystals consist of discrete Cd [P(c-C6H11)3]2(NO3)2 molecules and CH2Cl2 in the ratio 1 : 1. There is a distorted tetrahedral environment around the cadmium atom formed from the coordination of the two phosphines and two nitrates with each nitrate essentially occupying one stereochemical position. The two markedly different Cd -O bond lengths of 2.405(9) and 2.575(8) Ǻ show gross asymmetry in the coordination of the nitrate.


1976 ◽  
Vol 29 (11) ◽  
pp. 2337 ◽  
Author(s):  
BF Hoskins ◽  
CD Pannan

The crystal structure of tetraethylammonium tris(O-ethylxanthato) tellurate(11), [Et4N] [Te(S2COEt)3], has been determined by single-crystal three-dimensional X-ray diffraction methods. Crystals are monoclinic of space group P21/c with four cation-anion pairs per unit cell which has the dimensions a 8.121(1), b 18.858(2), c 19.260(2) � and β 105.22(2)�. The structure was solved by the normal Fourier methods and was refined with anisotropic thermal parameters by a full-matrix least-squares method converging with R and Rw values of 0.061 and 0.082 for the 2404 independent statistically significant reflections collected by counter methods. The tris(ethylxanthato)tellurate(11) anion has a novel five-coordinate pentagonal-planar structure with only two of the xanthato ligands bidentate and with the Te-S bond distances having values in the range 2.503(4)-3.059(3)�. The TeS5 atoms are coplanar, the maximum deviation from the plane being 0.122 �. This, together with the intra-planar S...S distances of 3.340-3.661 �, indicates that the ligand atoms of the pentagonal plane are not over-crowded. The geometry of the anion configuration can be explained in terms of the VSEPR theory using a pentagonal-bipyramidal arrangement of the seven electron pairs in the valence shell of the tellurium.


1975 ◽  
Vol 28 (8) ◽  
pp. 1663 ◽  
Author(s):  
CJ Commons ◽  
BF Hoskins

The crystal structure of the solvated complex Mn2(CO)5(dpm)2,CH2Cl3,C6H14 (where dpm = Ph2PCH2PPh2) has been determined by three-dimensional X-ray diffraction methods. The crystals are monoclinic, of space group Cc, with a 19.650(3), b 16.908(2), c 22.253(4) Ǻ and β 130.89(1)�, containing four molecules per unit cell. The structure, solved by conventional Patterson and Fourier methods, was refined by a least- squares method, using individual isotropic temperature factors, to R and Rw of 0.105 and 0.125 respectively, for 1893 independent statistically significant reflections collected by counter methods. The crystals are molecular, being composed of discrete molecules of complex and solvent. The principal feature of interest in the binuclear manganese complex is the presence of a carbonyl ligand simultaneously bonded to both manganese atoms in a manner quite different from the normal symmetrical bridging mode. This novel arrangement, which seems to involve a metal-carbonyl bond analogous to that found for many metal-olefin complexes, accounts for the anomalously low carbonyl stretching frequency observed at 1645 cm-1. The Mn-Mn distance is 2.934(6) Ǻ.


1982 ◽  
Vol 35 (7) ◽  
pp. 1311 ◽  
Author(s):  
MA Bennett ◽  
K Ho ◽  
JC Jeffery ◽  
GM Mclaughlin ◽  
GB Robertson

Crystal and molecular structures of the title compounds have been determined from three dimensional X-ray diffraction data recorded on a four-circle diffractometer. Crystals of the acetyl complex, trans-PtCl(COMe)(PMePh2)2,(1), are monoclinic, space group P2,1/c, with a 12.9709(5), b 11.1024(5), c 277535(9) Ǻ, β 94.75(1)° and Z 6. Crystals of the trifluoroacetyl complex, trans-PtCl(COCF3)- (PMePh2)2, (2), are monoclinic, space group P21/n (non-standard setting of P21c), with a 11.4246(7), b 15.5750(7), c 15.4200(8) Ǻ, β 90.54(1)° and Z 4. For (I), with Z 6, the unit cell contains one set of four equivalent molecules in the general equipoint and one set of two equivalent (disordered) molecules located at inversion centres. The four molecules in (2) comprise a single equivalent set in the general equipoint. Least-squares analyses converge with R 0.042 for (1) (5696 unique data) and R 0.025 for (2) (3933 unique data). Molecules of both complexes exhibit small deformations from planar towards tetrahedral platinum geometry; the acyl and coordination planes are approximately orthogonal. The phosphine substituents in (2) and in the 'general' molecules in (1) are approximately eclipsed, and approximately eclipse the Pt-C (acetyl) bonds. In the 'special' molecules in (1) the phosphines are constrained to adopt the mutually staggered conformation found in the alkyl analogues trans-PtClR(PMePhM2)2 (R = Me, CF3, C2F2). Important comparative lengths in (1) (general molecule) and in (2) (in square brackets) are: Pt-C 2.028(6) [1.960(4)] A, Pt-Cl 2.430(2) [2.390(1)] Ǻ, Pt-P 2.301(2), 2.297(2) [2.316(1), 2.321(1)] A, C-O 1.182(8) [1.210(5)] 8, and C C (acetyl) 1.488(10) [1.547(6)] A. The trifluoroacetyl ligand forms a shorter and presumably stronger bond with platinum, and exerts a larger cis- and a smaller trans-influence than the acyl ligand. The smaller trans-influence of the trifluoroacetyl ligand is consistent with the expectation from platinum-chlorine stretching frequencies (v(Pt-Cl)).


1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.


1990 ◽  
Vol 45 (10) ◽  
pp. 1369-1382 ◽  
Author(s):  
Heindirk tom Dieck ◽  
Lutz Stamp

Diazadienes RN = CR′-CR′ = NR (DAD) form molecular complexes with copper(I) halides of composition (DAD)CuX, the structures of which vary from [(DAD)2Cu]+(CuCl2)⁻ with a non-tetrahedral bis(chelated) cation, over [(DAD)CuCl]2 with asymmetrically bridging chloro ligands to planar three-coordinate (DAD)CuCl. The composition of the isolated complexes depends on the relative concentrations or on the solvent. The “soft” coordination geometry of copper is underlined by the structure of the coordination polymer of composition (DAD)2Cu5Cl5, in which Cu atoms of coordination number 2, 3 and 4 and very irregular geometries are encountered and where the DAD ligands are exclusively bridging. Halide ions and sp2-nitrogen donors are very competitive. Bridging DAD ligands are also encountered in (DAD)Cu-Y with the less nucleophilic anions trifluoromethane-sulphonate or perchlorate. Crystal and molecular structures are established for all these coordination geometries and the causes are discussed for the coordination flexibility of copper(I)


1986 ◽  
Vol 41 (5) ◽  
pp. 581-586 ◽  
Author(s):  
Konrad Holl ◽  
Ulf Thewalt

Among the reaction products of S4N4 with SnCl4 in chloroform, that contains acetic acid and small amounts of water, there are two salts S4N4H+[SnCl5(H2O)]- (A) and (S3N2NH2+)2[SnCl6]2- (B), both containing protonated SnNm units. The crystal and molecular structures of A and B have been determined by X-ray diffraction. A: monoclinic, P21/c, a = 9.084(2), b - 23.758(4), c = 6.587(1) Å , β = 101.86(3)°, Dc = 2.383 g·cm-3 and Z = 4. B: monoclinic, P21/n, a = 9.882(3), b = 12.873(4), c = 6.807(2) Å , β = 93.77(5)°, Dc = 2.352 g·cm-3 and Z = 2. The structures of the cations in both compounds agree well with those found of other salts containing these cations.


1966 ◽  
Vol 44 (8) ◽  
pp. 939-943 ◽  
Author(s):  
A. K. Das ◽  
I. D. Brown

(NH4)2TeBr6 and Cs2TeBr6 crystals have the cubic K2PtCl6 structure with space group: [Formula: see text] with a0 = 10.728 ± 0.003 Å and 10.918 ± 0.002 Å respectively. The positional coordinate of the bromine atom, and the anisotropic temperature factors of all atoms in the unit cell, have been refined for both crystals by a full matrix least-squares analysis of the three dimensional X-ray diffraction data (R = 0.08). The Te—Br distance, corrected for probable thermal motions of atoms forming the bond, is 2.70 ± 0.01 Å in both crystals.


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