Diphenylmethane and diphenyl ether — experimental conformations and torsional surfaces calculated with AM1, MNDO, PM3, and density functional theory (Becke3LYP)

Abstract

The complete energy surfaces of the torsion around the central C—O or C—CH2 bonds in diphenyl ether (DPE) and diphenylmethane (DPM) are calculated with semiempirical methods (AM1, MNDO, PM3) and density functional theory (Becke3LYP/3-21G). Stationary points are optimized at the Becke3LYP/6-31G(d) level of theory. The geometry of a very recently published X-ray structure of 4,4′-bis[N-(2,4,6-trimethyl)benzenesulfonamide]diphenylmethane (1), as well as the solid state structures of many other diphenyl ethers and diphenylmethanes, is found in the low-energy regions of the AM1 surfaces of the parent compounds. Keywords: Conformational analysis, diphenyl ether, diphenylmethane, quantum chemistry (AM1, MNDO, PM3), density functional theory (Becke3LYP).