ИСТИНА

The 1,2-diphosphacyclopentadienide anion, an isolobal analogue of the Cp- and pyrazolate anion, has received significant interest as ligand in coordination chemistry due to the possibility of realizing various coordination modes with metal atoms[1]. Unfortunately, nowadays the chemistry of the 1,2-diphosphacyclopentadienide anion is limited to triphenyl-substituted derivatives. Recently, we have found that the structure of the product of the reaction between sodium 1,2-diphospholide and Mn(CO)5Br is depending on the nature of the substituents at the carbon atoms. The formation of exclusively 1,2-diphosphacymanthrene was observed in the reaction of 3,4,5-tris(diethylamino)-1,2-diphospholide containing electron donating groups with Mn(CO)5Br in THF. The formation of a binuclear manganese(I) carbonyl complex with bridging coordination mode of the 1,2-diphosphacyclopentadienyl ligand as in the case of aryl-substituted 1,2-diphospholide was not observed [2]. At the same time, the synthesis and investigation of novel 1,2-diphospholide derivatives facilitated the investigation of similarities and differences in the chemical behavior of these compounds.