Synthesis and structure of complexes of phosphorus pentachloride with 4-dimethylaminopyridine and n-methylimidazole

Article abstract of DOI:10.1002/hc.20392

Complexes of phosphorus pentachloride with 4-dimethylaminopyridine and N-methylimidazole were synthesized. The molecular structure of the phosphorus pentachloride complex with N-methylimidazole was determined by single-crystal X-ray diffraction. In the cationic part of the complex, the phosphorus atom possesses four P - Cl bonds within the range 2.109-2.148 A and two cis-P-N bonds (1.811 and 1.832 A) with N-methylimidazole and exhibits slightly distorted octahedral coordination with angles at phosphorus atom in the range 87.57°-91.50°. The relative stability of the cis and trans conformations of the complex was studied by DFT calculations. The chemical properties and reactivity of the compounds obtained are determined; their utility as condensing agents in the synthesis of amides from acids and amines was shown.