Conformational analysis of an arylazo phosphate dimer by molecular and quantum mechanics approaches [articol]

Abstract

The phosphorous, halogen and nitrogen-containing polymers have excellent thermal stability and good flame retardant properties. In this paper the structure of a diarylazo phosphate was simulated by molecular mechanics methods using the MM+, AMBER and MMFF94s force fields included in the Hyperchem, respectively Omega software. Structures of minimum energy were generated using the RMS gradient value of 0.01 kcal/Å· mol as criterion to choose an optimized conformation, in case of the Hyperchem program and a RMSD deviation value of 2.0 Å for the duplicate removal, in case of the Omega software. The conformations of minimum energy obtained by Omega were further minimized by the semiempirical RM1 method included in the MOPAC 2009 software. Structural dimer features which characterize the most stable energetically conformations obtained by molecular and quantum mechanics methods were compared, yielding a unified dimer structure.