Bis(carbonyl)platinum(II) Derivatives: Molecular Structure of <i>cis</i>-Pt(CO)₂(SO₃F)₂, Complete Vibrational Analysis of <i>cis</i>-Pt(CO)₂Cl₂, and Attempted Synthesis of <i>cis</i>-Pt(CO)₂F₂

As part of a comprehensive study of square planar palladium(II) and platinum(II) carbonyl derivatives, the molecular structure of cis-Pt(CO)2(SO3F)2, the complete vibrational spectra of cis-Pt(CO)2Cl2, and the attempted synthesis of cis-Pt(CO)2F2 are reported. cis-Pt(CO)2(SO3F)2 is isostructural with cis-Pd(CO)2(SO3F)2 and crystallizes in the monoclinic space group P21/n (no. 14). Crystal data: a = 7.419(1) Å; b = 14.751(2) Å; c = 8.634(1) Å; β = 89.95(1)°; V = 944.9(2) Å3; Z = 4; T = 300 K; R [Fo > 4σ(Fo)] = 0.0447 and wR2 = 0.1097. The internal bond parameters of the cis-Pt(CO)2(SO3F)2 are compared to those of cis-Pd(CO)2(SO3F)2, cis-Pt(CO)2Cl2, and [M(CO)4]2+, M = Pd, Pt. Solid cis-Pt(CO)2Cl2 is studied by IR and Raman spectroscopy, and the data are compared to those of the matrix-isolated complex by IR spectroscopy. Vibrational assignments are supported by DFT calculations, which provide, in addition to vibrational wavenumbers, estimates of IR and Raman band intensities. The positions of 12 of the expected 15 fundamentals of cis-Pt(CO)2Cl2 are obtained experimentally. Attempts to synthesize cis-Pt(CO)2F2, using, in addition to cis-Pt(CO)2X2, X = Cl or SO3F, [Pt(CO)4][Sb2F11]2 or PtF6 as starting material and toluene or anhydrous hydrogen fluoride as the reaction medium, are unsuccessful. There are however two interesting results: The reductive carbonylation of PtF6 in HF produces with [Pt(CO)4][PtF6] the first carbonyl fluoride of platinum, and the reaction of [Pt(CO)4][Sb2F11]2 and CsF in HF results in the formation of the previously reported anionic cluster complex Cs2[Pt3(CO)6]n≈10. The inclusion of [M(CO)4]2+, M = Pd, Pt, provides new insights into the nature of the Pd(II)−CO and Pt(II)−CO bonds.