X-Ray photoelectron spectroscopic characterization of [{Pt(PPh3)2(μ3-S)}2PtCl 2], [{Pt2(PPh3)4(μ3-S) 2Cu}2(μ-dppf)][PF6]2 [dppf = Fe (C5H4PPh2)2] and other heterometallic aggregates derived from...

Abstract

Title full: X-Ray photoelectron spectroscopic characterization of [{Pt(PPh3)2(μ3-S)}2PtCl 2], [{Pt2(PPh3)4(μ3-S) 2Cu}2(μ-dppf)][PF6]2 [dppf = Fe (C5H4PPh2)2] and other heterometallic aggregates derived from [{Pt(PPh3)2(μ-S)}2]. Lewis acid-base reactions between [{Pt(PPH3)2(μ-S)}2] and [{Cu(NO3)(μ-dppf)}2]-NH4PF6 [dppf = Fe(C5H4PPh2)2] and [PtCl2(NCMe)2] gave hexanuclear [{Pt2(PPh3)4(μ3-S) 2Cu}2(μ-dppf)][PF6]2 and trinuclear [{Pt(PPh3)2(μ3-S)}2PtCl 2] respectively. X-Ray photoelectron spectroscopic (XPS) studies of these sulfur aggregates were made together with other known alkylated complexes [Pt2(PPh3)4(μ-S)(μ-SR)]X (R = Me, X = 1; R = CH2Cl, X = Cl; R = CHCl2, X = PF6; R = CH2Ph, X = PF6) and metallated complexes [{Pt2(PPh3)4(μ-S)2} xML]n+nX- [M = Ni, L = Ph2PCH2CH2PPh2 (dppe), X = PF6, x = 1; M = Pd2, L = (μ-Cl)2, X = PF6, x = 2; M = Ag2, X = NO3, x = 2; M = Au, L = PPh3, X = PF6, x = 1; M = Hg, X = PF6, x = 2; M = Hg, L = dppe, X = PF6, x = 1; n = 2 for all M except Au where n = 1]. The observed binding energies are related to the charge distribution and nucleophilicity of the sulfur centres. The possibility of using multinuclear XPS [S(2p), P(2p), Cl(2p), Pt(4f)] to distinguish chemically inequivalent nuclei is examined.