Binuclear Macrocyclic Silver(I) Complex of a Bis(carbone) Pincer Ligand: Synthesis and Application as a Carbone-Transfer Agent.

A facile synthesis of a binuclear Ag I complex 2 of a bis(carbone) ligand L and its application as a carbone-transfer agent for the generation of other transition-metal complexes of Au I ( 3 ), Ni II ( 4 ), and Pd II ( 5 ) is presented. Complex 2 was synthesized through multiple synthetic routes under mild reaction conditions using the tetracationic [ L H 4 ][OTf·Cl] 2 precursor salt, the dicationic [ L H 2 ][OTf] 2 ylide salt, and the free ligand L . The first two synthesis routes require no prior isolation of the air-, moisture-, and temperature-sensitive free ligand L , thus affording complex 2 with high yield and purity. Multinuclear NMR techniques, high-resolution mass spectrometry, and single-crystal X-ray diffraction analysis confirmed the identity of complex 2 as a binuclear Ag I complex of L with a molecular formula of [ L 2 Ag 2 ][OTf] 2 and a 16-membered-ring metallomacrocyclic structure. During the transmetalation reaction with Au I , the binuclear nature of complex 2 remains intact to give analogous complex 3 ([ L 2 Au 2 ][OTf] 2 ). However, the dimeric structure was disrupted upon the carbone-transfer reaction with Ni II and Pd II , yielding mononuclear C-N-C pincer-type complexes 4 ([ L NiCl][OTf]) and 5 ([ L PdCl][OTf]), respectively. These results demonstrated the versatile use of complex 2 as a carbone-transfer agent to other transition metals regardless of the type or size of the metals or the geometry they prefer.