Conformation and stereodynamics of 2-dialkylamino-1,3-dimethyl-2,3-dihydro-1H-1,3,2-benzodiazaphospholes. An experimental nuclear magnetic resonance, ultraviolet photoelectron, and theoretical MNDO investigation

Abstract

Conformational information on the title compounds obtained from low temperature ¹³C and ¹H n.m.r. studies is in agreement with the geometry calculated by the MNDO SCF molecular orbital procedure. The barriers to rotation about the exocyclic P–N bond have been measured and the rotational transition state has been investigated by MNDO. Some u.v. photoelectron and ¹⁵N n.m.r. data are reported and the possibility of enhanced π-bonding in the exocyclic PN bond is discussed.