Carbonyl halides of the Group VIII transition metals. VII. Reactions of palladium(I) halocarbonyls with Bis(diphenylphosphino)methane and Bis(diphenylarsino)methane and the crystal and molecular structures of these derivatives

1978 ◽  
Vol 31 (7) ◽  
pp. 1425 ◽  
Author(s):  
R Colton ◽  
MJ McCormick ◽  
CD Pannan

The reactions of Pd(CO)X (X = Cl, Br) with bis(diphenylphosphino)methane (dpm) and its arsenic analogue, dam, have been investigated. The iodo complexes were prepared indirectly. Ligand dpm gives complexes of the formula [Pd(dpm)X]2. With dam, the nature of the product depends upon the identity of the halogen; with X = Cl, Br the products are [Pd(dam)X]2CO, but the iodo derivative is [Pd(dam)I]2. N.m.r. spectroscopy suggests that [Pd(dam)I]2 has a structure different to the dpm complexes. ��� [Pd(dam)Cl]2CO,3C6H14 is tetragonal, space group P4I, a 22.0458(1), c 14.4345(1) Ǻ containing four dimer units per unit cell. The structure was refined to R 0.096 and Rw 0.097 for 1698 independent reflections. The crystals are molecular being composed of discrete dimeric molecules of the complex and solvent. The palladium coordination is approximately square planar with two trans arsenic atoms, terminal halogen and the bridging carbonyl group which is common to both metal environments. There is no twist about the Pd-Pd axis so the Pd,As, unit is planar. The Pd-Pd distance of 3.274(8) Ǻ is too long for a direct metal-metal bond. However, the compound is diamagnetic so spin pairing must occur through the unusual carbonyl bridge.

1990 ◽  
Vol 45 (8) ◽  
pp. 1167-1176 ◽  
Author(s):  
Alfons Möhlenkamp ◽  
Rainer Mattes

The reaction of NaReO4 with thiobenzoylhydrazine yields Re(NHNC(S)Ph)3- DMF (1). With ReOCl3(PPh3)2 thiobenzoylhydrazine reacts to give Re(NHNC(S)Ph)3 · OPPh3 (2) and in the presence of HCl to yield [Re(NHNC(S)Ph)(NHNHC(S)Ph),]Cl · 1/3 C2H5OH -1 /3 H2O (3). The structures of 1-3 have been determined. 1: monoclinic, space group P2,/c, a = 1150.1(9), b = 2050.0(9), c = 1181.0(8) pm, β = 109.62(5)°, Z = 4, 2980 reflections, R = 0.055; 2: trigonal, space group R 3, a = 1399.8(1), c = 1684.0(1) pm, Z = 3, 1419 reflections, R = 0.033; 3: monoclinic, space group P2,/c, a = 1446.8(3), b = 3220.7(5), c = 1727.1(4) pm, β = 108.42(2)°, Z = 12, 6112 reflections, R = 0.062. In 1 and 2 three N,S-chelating ligands NHNR (R = C(S)Ph) are coordinated to the central rhenium atom. The ligand structure is intermediate between a diazene and a hydrazido(2–) structure. In 3 each rhenium atom is coordinated by one NHNR and two NHNHR ligands, all N,S-chelating. The latter can be considered as protonated diazene ligands. The unit cell contains three isomeric coordination polyhedra.


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.


1987 ◽  
Vol 40 (5) ◽  
pp. 907 ◽  
Author(s):  
GB Deacon ◽  
BM Gatehouse ◽  
SN Platts ◽  
DL Wilkinson

The crystal structures of tris (η5-cyclopentadienyl) (pyridine) samarium(III), monoclinic, space group P21/c, a 10.906(4), b 8.636(2), c 17.825(3) �, β 96.44(2)�, Z 4, R 0.027 and Rw 0.032 for 3619 'observed' reflections, and tris (η5-cyclopentadienyl)(pyridine)neodymium(III), monoclinic, space group P21 / c, a 14-206(4), b 8.619(2), c 15.190(7) �, β 107.38(2)�, Z 4, R 0.035 and R, 0.039 for 2677 'observed' reflections have been determined. Both compounds have pseudotetrahedral geometry with a coordination number of 10 for the lanthanoid metal but there is a difference in the coordination of pyridine and in unit cell packing between the two structures.


1975 ◽  
Vol 28 (11) ◽  
pp. 2377 ◽  
Author(s):  
M Corbett ◽  
BF Hoskins ◽  
NJ McLeod ◽  
BP O'Day

The crystal and molecular structures have been determined, by single-crystal X-ray methods, for each of the isomorphous set of divalent binuclear metal derivatives of 1,3-diphenyltriazene, abbreviated as dptH, [M(dpt)2]2 where M = Ni, Pd, and Cu. The crystals are composed of discrete molecular units, of composition M2(dpt)4, which have a syn-syn structure analogous to that of copper(II) acetate monohydrate with pairs of closely separated metal atoms held together by the terminal nitrogen atoms of four ligand groups in such a way that the environment of each metal atom is almost square-planar. The interatomic distances between the pairs of metal atoms, 2.395(3), 2563(1), and 2.441(2) Ǻ for the Ni, Pd, and Cu compounds, are strongly suggestive of metal-metal bonding. The two N4-planes are almost parallel but the two sets of coordinating nitrogen atoms are twisted markedly from the eclipsed configuration, the average angle of rotation being about 15°. Crystals of each complex are triclinic with space group P 1. The unit cell parameters in the order of a, b, c, α, β, and γ are 10.335(3), 15.84(1), 13.546(3)& 100.48(5), 94.47(2), 102.57(3)° for Ni2(dpt)4; 10.486(1), 15.791(2), 13.751(1)Ǻ, 99.48(1), 93.61(1), 104.37(1)° for Pd2(dpt)4; 10.373(3), 15.916(5), 13.612(3) Ǻ, 99.51(2), 94.85(3), 102.33(2)° for Cu2(dpt)4. The structure of the nickel complex was solved by the Patterson-Fourier method and the atomic parameters found for this structure were used as the basis of the structure determinations of the isomorphous copper and palladium compounds. All three structures were refined by a block-diagonal least-squares method using 3300 (photographic data) 4065 (counter) and 2753 (counter) independent non-zero terms for the nickel(II), palladium(II) and copper(II) compounds respectively, converging with R values 0.13 (isotropic), 0.056 (anisotropic) and 0.069 (isotropic) respectively.


1994 ◽  
Vol 1 (4) ◽  
pp. 321-328 ◽  
Author(s):  
Kevin B. Nolan ◽  
Leo P. Ryan ◽  
Colm J. Campbell ◽  
Patrick McArdle ◽  
Desmond Cunningham ◽  
...  

The synthesis and crystal and molecular structures of the platinum(II) complex Pt(HL)Cl where H2L is the diacid diamide –[CH2N(CH2COOH)CH2CONH2]2, a hydrolytic metabolite of an antitumour active bis(3,5-dioxopiperazin-1-yl)alkane are reported. The complex is square planar and contains HL− as a tridentate 2N (amino), O (carboxylate) donor. The metal to ligand bond distances are Pt-Cl 2.287(1) Å, Pt-O 2.002 (1) Å, Pt-Ntrans Cl 2.014(1) Å and Pt-Ntrans O 2.073 Å. There is extensive hydrogen bonding, each molecule of Pt(HL)Cl being intermolecularly hydrogen bonded to ten others giving a 3-dimensional network. There is also one intramolecular H-bond.


1983 ◽  
Vol 61 (6) ◽  
pp. 1132-1141 ◽  
Author(s):  
Gordon William Bushnell ◽  
Roderick James Densmore ◽  
Keith Roger Dixon ◽  
Arthur Charles Ralfs

Synthesis and 31P nmr spectra of the complex cations, cis-[PtCl(L)(PEt3)2]+, L= theophylline, caffeine, or isocaffeine, and cis[Pt(isocaff)2(PEt3)2]2+ are reported. The crystal structure of cis-[PtCl(caffeine)(PEt3)2][BF4] is determined, space group [Formula: see text], a = 1.1766(6), b = 1.4428(5), c = 0.9002(4) nm, α = 97.28(4)°, β = 97.69(4)°, γ = 100.96(5)°, Dm = 1.649 g cm−1, the bond lengths are Pt—Cl= 233.4(4) pm, Pt—N = 215(1) pm, Pt—P = 225.4(5) pm (mean), and the residual R = 0.071. The crystal structure of cis-[Pt(isocaffeine)2(PEt3)2][BF4]2 is orthorhombic, space group Pbca, a = 2.317(3), b = 1.717(3), c = 2.130(3) nm, Dm = 1.574 g cm−3, with an opposing isocaffeine conformation, bond lengths Pt—N = 211(2) pm, Pt—P = 227.6(9) pm (mean), and R = 0.073. Both crystal structures contain approximately square planar Pt(II) coordination with the purine coordinated via an imidazole nitrogen. The structures are discussed as models for the possible involvement of [Formula: see text] chelation of guanine to platinum when platinum drugs act as antitumour agents, but there is no evidence that isocaffeine acts as an [Formula: see text] chelate.


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