Cationic bis-diphosphaferrocene copper and gold complexesElectronic supplementary information (ESI) available: Cartesian coordinates and optimized geometries for copper, nickel and palladium complexes. See http://www.rsc.org/suppdata/nj/b3/b301408h/
- 20 June 2003
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in New Journal of Chemistry
- Vol. 27 (8) , 1233-1239
- https://doi.org/10.1039/b301408h
Abstract
The octa(ethyl)diphosphaferrocene 1 reacts with half an equivalent of [Cu(MeCN)4][PF6] to afford the corresponding [Cu(1)2][PF6] complex 2 in which 1 behaves as a chelate ligand. An X-ray crystal structural analysis reveals that the overall arrangement of the four phosphorus atoms around the Cu cation is distorted tetrahedral. The same strategy was applied to the synthesis of gold(I) complexes. Ligands 1 and the octa(n-propyl)diphosphaferrocene 4 react with two equivalents of [AuCl(SMe2)] to yield the expected bimetallic complexes [Au2Cl2(1)] 3 and [Au2Cl2(4)] 5 respectively. In these two complexes, each phospholide unit is coordinated to an AuCl fragment. Surprisingly, crystallization of 5 affords the bis-chelate [Au(4)2][FeCl4] derivative. A mechanism involving oxidation of the diphosphaferrocene ligand followed by nucleophilic attack of one chloride anion has been tentatively proposed. Complexes [Au(1)2][GaCl4] 7 and [Au(4)2][GaCl4] 8 can be conventionally prepared by the direct reaction of the two ligands with [AuCl(SMe2)] in the presence of GaCl3 as chloride abstractor. A DFT study, coupled with a Charge Decomposition Analysis (CDA), performed on the [Cu(dpf)2] and [Cu(dpe)2] model complexes (dpf = C8H8P2Fe, dpe = H2PCH2CH2PH2) indicates that σ-donation dominates in the two complexes. In homoleptic [M(dpf)2] and [M(dpe)2] complexes (M = Ni, Pd), dpf and dpe exhibit a stronger π-accepting capacity. A comparison between theoretical structures of the bis-carbonyl complexes [NiL(CO)2] (L = dpf or dpe or Me2PCH2CH2PMe2) indicates that dpf and dpe display a similar π-accepting capacity.Keywords
This publication has 0 references indexed in Scilit: