Mono- and bimetallic silver(I) complexes with bridging and terminal-bound organic chelating ligands

The synthesis of the mononuclear and homobimetallic silver(I) complexes [P(C6H4CH2NMe2-2)3]AgL2 [L2=acetylacetonate, acac (5a); tropolonate, trop (5b); 3-hydroxy-2-methyl-γ-pyranoate, pyro (5c)], [P(C6H4CH2NMe2-2)3]AgOC(O)Me (8) and [P(C6H4CH2NMe2-2)3]AgL4Ag[P(C6H4CH2NMe2-2)3] [L4=2,5-dihydroxy-p-benzochinoate, benz (6a); 1,4-dihydroxy-anthrachinoate, anthra (6b)] can be achieved by the reaction of the silver(I) salts [AgL2] [L2=acac (3a), trop (3b), pyro (3c)], [Ag2L4] [L4=benz (3d), anthra (3e)] or [AgCO2Me] (7) with P(C6H4CH2NMe2-2)3 (4) in a 1:1 or 1:2 molar ratio. The respective silver(I) salts 3a–3e are accessible by treatment of [AgNO3] (1) with HL2 or H2L4 (2a–2d), respectively. In 5a–5c, 6a and 6b the silver atom possesses a pseudotetrahedral environment caused by the chelate-bound ligands acac, trop, pyro, benz or anthra and the bidentate coordinated phosphane 4. In homobimetallic 6a and 6b the appropriate transition metals are spanned by the benz or anthra units, respectively. While in 5a–5c, 6a and 6b the silver metal possesses the coordination number 4, in 8 a T-shaped arrangement is set-up with a linear PAgO unit. The chemical and physical behaviour of complexes 5a–5c, 6a, 6b and 8 is reported. Spectroscopic studies reveal that on the NMR time-scale the phosphane group with its Me2NCH2 built-in arms is dynamic.