Synthesis and crystal structures of five new rhenium acetamidate complexes

Syntheses are reported of five rhenium(m) cluster complexes with acetamidat e ligands: [(C4H9)(4)N](2)[{Re2Cl6(mu-1,2-NHCOCH3)}(2)] (1), [(C2H5)(4)N] [ Re3Cl8(mu-1,2-NHCOCH3)(mu-2,3-NHCOCH3)] . 2.5(C4H10O) (2), [(C4H9)(4)N](2)[ Re3Cl10(mu-1,2-NHCOCH3)] (3), [(C4H9)(4)N]2[{Re3Cl8(mu-1,2-NHCOCH3)(OH)}2]. 1.7(C4H10O) (4), and (C4H9),N[Re3Cl9(H2O)(mu-1,2-NHCOCH3)] . C3H6O (5). Th e acetamidate ligands in these complexes arise via reactions of acetonitril e-rhenium halide species (either dirhenium or trirhenium chloride clusters) and water. Coordination activates the nitrile to hydrolysis; proton loss a nd chelation of the acetamidate ligand with displacement of chloride ion le ads to the products. Initial formation of a rhenium(III) acetonitrile compl ex can be assisted using a halide acceptor, Ag+, to generate an open coordi nation site on the metal. The reaction with K4Mo2Cl8 and Ag+ ion in acetoni trile gives Mo2Cl4(NCCH3)(4) (6)The use of MALDI mass spectrometry in suppo rt of synthetic efforts and as a characterization tool is described, and th e molecular structures of 1-6 were established using X-ray crystallography. (C)2000 Elsevier Science Ltd All rights reserved.