Synthesis and characterization of group 11 1,1,3,3-tetraalkylguanidinate (TAG) clusters: [M2(mu-TAG){mu-N(SiMe3)2}]2 (M = Cu, Ag, and Au).

The addition of diethylcyanamide to a tetrahydrofuran solution of lithium dialkylamide {LiN(CH(3))(2) or LiN[upper bond 1 start]CH(2)CH(2)C[upper bond 1 end]H(2) CH(2), Li(PYR)} results in the corresponding lithium 1,1,3,3-tetraalkylguanidinate, Li(TAG). Two equivalents of Li(TAG) and 2 equiv of lithium bistrimethylsilylamide, LiN(SiMe(3))(2), were subsequently reacted with 4 equiv of Group 11 halide (CuCl, AgBr, and AuCl) to generate tetranuclear complexes with the general formula [M(2)(mu-TAG){mu-N(SiMe(3))(2)}](2) where M and TAG = {Cu, DEDMG, (1)}, {Ag, DEDMG, (2)}, {Au, DEDMG, (3)}, {Cu, DEPYRG, (4)}, {Ag, DEPYRG, (5)}, and {Au, DEPYRG, (6)}. Compounds 1-6 were characterized by single-crystal X-ray diffraction. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FT-IR spectroscopy, (1)H and (13)C NMR studies.