Synthesis, characterization and dynamic behavior of mono- and dinuclear palladium(II) carbene complexes derived from 1,1′-methylenebis(4-alkyl-1,2,4-triazolium) diiodides

Mononuclear palladium carbene complexes 2a-c and 3 derived from 1,1'-methylenebis(4-alkyl-4,5-dilhydro-1H- 1,2,4-triazole-5-ylidene) have been obtained by the reaction of 1,1'-methylenebis(4-alkyl-1,2,4-triazolium) diiotides 1a-d with palladium acetate under mild conditions. The mononuclear complexes 2a-c have been transformed into their corresponding trans-binuclear complexes 4a-c. All compounds were characterized by spectroscopic techniques and the dynamic behavior of 2a-c and 4a-c has been studied. The X-ray structures of 2a and 4c are reported.