Synthesis And Structural Characterization Of Metal Complexes Bearing1,2,4-diazaphospholide Ligands

Five-membered1,2,4-diazaphospholide compounds are a kind ofunique aromatic heterocyclic ligands with lone pair electrons, πelectronics, and low-valent phosphorus. In this paper, a series ofmetal complexes with1,2,4-diazaphospholide lignads have beenprepared, which contain calcium, barium, erbium and cobalt ions,respectively. In addition, a pentamethylcyclopentadienyl cobalt-base1,2,4-diazaphospholide compound was also successfully synthesized.All of the structures have been characterized by X-ray single crystaldiffraction analysis, NMR, IR, and EPR.1. Two homoleptic1,2,4-diazaphospholide calcium and bariumcomplexes were prepared by the reaction of metallic calcium andbarium with3,5-di-tert-butyl-1,2,4-diazaphosphole.2.3,5-Di-tert-butyl-1,2,4-diazaphospholide erbium and cobaltcomplexes were prepared by the reaction of3,5-di-tert-butyl-1,2,4-diazaphospholide potassium and ErCl3andCoCl2, respectively.3.3,5-Di-pheny-1,2,4-diazaphospholide cobalt was prepared by thereaction of3,5-di-pheny-1,2,4-diazaphospholide potassium andCoCl2. A novel tetrameric cobalt1,2,4-diazaphospholide wasprepared by the reaction of3,5-di-pheny-1,2,4-diazaphospholide potassium with pentamethylcyclopentadienyl cobalt chloride.4. Cobalt2,6-(1,2,4-diazaphosphol-1-yl)pyridine dichloride wasprepared by the reaction of2,6-(1,2,4-diazaphosphol-1-yl)pyridine(bdppy) and CoCl2.