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Notes: The square-planar RhI complex, [Rh(trop)(PFcPh2)(CO)] (tropH = 2-hydroxy-2,4,6-cycloheptatrienone, C7H6O2, and PFcPh2 = ferrocenyldiphenylphosphine, C22H19FeP), contains a five-membered chelate ring. The most important bond lengths and angles include Rh—O 2.0838 (14) Å (trans to P) and Rh—O 2.0487 (14) Å (trans to CO), Rh—P 2.2395 (5) Å, Rh—C 1.803 (2) Å, and O—Rh—O 77.56 (6)° and P—Rh—C 89.73 (7)°.

Notes: A series of structures of trans-dichlorobis(triphenylarsine)platinum(II), recrystallized from four different solvents, have been characterized by X-ray crystallography and were shown to crystallize as different solvates (same metal complex, different crystallization solvents). Their geometric differences induced by packing and solvent molecules were analysed with half-normal probability plots and root-mean-square deviations. The recrystallization solvents used in the investigation were 1,1,1-trichloroethane, dichloromethane, 1,2-dichloroethane and benzene, and the following crystallization modes were obtained. From 1,1,1-trichloroethane the metal complex crystallizes without solvent as trans-[PtCl2(AsPh3)2] in P21/n with Z = 2, a = 9.271 (2), b = 19.726 (4), c = 9.830 (2) Å, β = 111.83 (3)°, V = 1668.8 (6) Å3, R = 0.0262, and from dichloromethane with two solvent molecules as trans-[PtCl2(AsPh3)2]·2CH2Cl2 in Pbca with Z = 4, a = 20.582 (4), b = 8.146 (2), c = 23.491 (5) Å, V = 3938.5 (14) Å3 and R = 0.0316. From dichloroethane it crystallizes with one solvent molecule as trans-[PtCl2(AsPh3)2]·C2H4Cl2 in P\overline 1 with Z = 1, a = 9.390 (2), b = 9.548 (2), c = 11.931 (2) Å, α = 109.70 (3), β = 108.26 (3), γ = 98.77 (3)°, V = 915.6 (3) Å3, R = 0.0390, and from benzene with half a solvent molecule as trans-[PtCl2(AsPh3)2]·0.5C6H6 in P21/n with Z = 4, a = 11.778 (2), b = 18.712 (4), c = 16.647 (3) Å, β = 104.78 (3)°, V = 3547.3 (12) Å3 and R = 0.0303. In all four compounds platinum(II) coordinates to triphenylarsine and chloride in a pseudo-square-planar trans configuration. The Pt—As distances are in the range 2.4104 (4)–2.3923 (4) Å and the Pt—Cl distances are in the range 2.309 (2)–2.2839 (9) Å. The solvents have a large influence on the packing, resulting in different space groups or different occupancies in the same space group. Half-normal probability plots show that the largest geometric differences, within the metal complex, are in the bond and torsion angles around the As—C bonds. Very similar torsion angles were observed around the Pt—As bond for all the structures, except for one AsPh3 ligand in the benzene solvate, which differs by about 10° from the others. The metal–donor bond distance varies by as much as 0.019 and 0.025 Å (95% confidence interval) for Pt—As and Pt—Cl, respectively. The variations are essentially caused by intermolecular interactions. Packing efficiency is expressed as the volume filled by each metal complex in the unit cell and is calculated by subtracting the sum of the solvent molecule volumes from the total volume of the unit cell and then dividing by Z. The efficiency is largest in the dichloroethane solvate and smallest in the non-solvated compound, with a difference of approximately 22 Å3 per metal complex.

Notes: Two different crystals (A and B) were used to structurally characterize trans-[PtCl2(PPh3)2] and to study random and systematic errors in derived parameters. The compound is isomorphous with trans-[PdCl2(PPh3)2] and with one of the polymorphs of trans-[PtMeCl(PPh3)2] reported previously. Half-normal probability plot analyses based on A and B show realistic s.u.'s and negligible systematic errors. R.m.s. calculations give very good agreement between A and B, 0.0088 Å. Important geometrical parameters are Pt—P = 2.3163 (11) Å, Pt—Cl = 2.2997 (11) Å, P—Pt—Cl = 87.88 (4) and 92.12 (4)°. Half-normal probability plots and r.m.s. calculations were also used to compare the title compound with the palladium analogue, showing small systematic differences between the compounds. The torsion angles around the Pt—P bond were found to be very similar to those reported for isomorphous complexes, as well as to the torsion angles around the Pt—As bond in trans-[PtCl2(AsPh3)2]. The NMR coupling constants for the title compound are similar to Pt—P coupling constants reported for analogous trans complexes.

Notes: The crystal structure of the title compound, [PtCl(CH3)(C18H33P)2], is isostructural with various platinum(II) and palladium(II) complexes containing two bulky tricyclohexylphosphine ligands in a trans orientation. The Pt atom resides on an inversion centre, resulting in a 50% statistical disorder in the chloro and methyl positions. The most significant geometrical parameters are Pt—P 2.3431 (8), Pt—Cl 2.440 (4) and Pt—C1 2.179 (13) Å, and P—Pt—P 180, P—Pt—Cl 89.15 (12) and 90.85 (12), and C—Pt—Cl 172.7 (5)°. The effective and Tolman cone angles for the tricyclohexylphosphine ligands were calculated as 160 and 162°, respectively.

Notes: The crystal structure of cis-[PtCl2(C6H15As)2], (I), is isostructural with a previously reported structure of cis-[PtCl2(C6H15P)2], (II). A new polymorph of (II) is also reported here. Selected geometrical parameters in the arsine complex are Pt—Cl 2.3412 (12) and 2.3498 (13), Pt—As 2.3563 (6) and 2.3630 (6) Å, Cl—Pt—Cl 88.74 (5), As—Pt—As 97.85 (2), and Cl—Pt—As 171.37 (4) and 177.45 (4)°. Corresponding parameters in the phosphine complex are Pt—Cl 2.364 (2) and 2.374 (2), Pt—P 2.264 (2) and 2.262 (2) Å, Cl—Pt—Cl 85.66 (9), P—Pt—P 98.39 (7), and Cl—Pt—P 170.26 (7) and 176.82 (8)°.

Notes: The crystal structure of the title compound, trans-[PdCl(CH3)(C18H15P)2], was found to be isomorphous with several related platinum(II) and palladium(II) complexes. The Pd atom has a slightly distorted square-planar geometry, with most important bond lengths and angles of Pd—P = 2.3289 (7) and 2.3224 (7) Å, Pd—Cl = 2.4227 (6) Å and Pd—C = 2.054 (2) Å, and P—Pd—P = 177.38 (2)°, P—Pd—Cl = 88.97 (2) and 89.03 (2)°, and C—Pd—Cl = 175.23 (8)°.

Notes: The crystal structure of the title compound, trans-[PtI2(C6H12N3P)2], describes one of the few platinum(II) complexes containing two of the water-soluble 1,3,5-triaza-7-phosphaadamantane ligands reported to date. The complex crystallizes on an inversion centre with the most important bond lengths and angles being Pt—P 2.3128 (12) Å, Pt—I 2.6022 (6) Å, P—Pt—I 90.94 (3)° and P′—Pt—I 89.06 (3)°.