Synthesis, spectroscopic and structural characterisation of copper, silver and gold complexes of the mixed P/O-donor ligand Ph2P(CH2)(2)O(CH2)(2)O(CH2)(2)PPh2

摘要

Reaction of L-1 (L-1 = Ph2P(CH2)(2)O( CH2)(2)O(CH2)(2)PPh2) with [Cu(MeCN)(4)]PF6 or AgBF4 in CH2Cl2 solution yields the complexes [Cu(L-1)]PF6 and [Ag(L-1)]BF4 respectively as white solids. Spectroscopic measurements are consistent with coordination via the P-donors and the crystal structure of [Ag(L-1)]BF4 confirms that L-1 acts as a rrans-chelate giving an unusual example of approximately linear P-2-coordination at Ag(I) (angle P-Ag-P = 164.66(4)degrees) and, despite the availability and proximity of the ether O atoms, these remain essentially uncoordinated (Ag ... O = 2.95 Angstrom) thus reflecting the low affinity of the soft Ag(I) ion for hard O-donor ligands. [AuCl(tht)], L-1 and TIPF6 react in a 1:1:1 molar ratio in MeCN solution to yield the analogous Au(I) species [Au(L-1)]PF6, the structure of which also shows linear P-2-coordination and once again the O-donors are non-coordinating, at a distance of ca. 3.16 Angstrom from Au(I). The neutral dinuclear species [(AuCl)(2)(L-1) ] is readily formed by reaction of [AuCl(tht)] with L-1 in a 2:1 molar ratio in MeCN. Confirmation of the coordinated Cl ligands comes from IR spectroscopy, nu(Au-Cl) = 324 cm(-1), and delta((31)p) which is indicative of a PCl donor set at Au(I). This arrangement is confirmed in the solid state from the crystal structure. The related phosphathia complex [(AuBr)(2)(L-2)] (L-2 = Ph2P(CH2)(2)S(o-C6H4)S(CH2)(2)PPh2) is prepared similarly from [AuBr(tht)] and L-2 in MeCN solution and its structure reveals the AuBr units each coordinated to one P-donor and directed to the same side as the o-C6H4 unit. (C) 2000 Elsevier Science Ltd All rights reserved. [References: 23]