title: Identification of multiple transition structures on the potential energy hypersurface for [2+2] electrocyclization of the pentadienyl cation bearing a phosphorus in the 3-position.
abstract: Ab initio molecular orbital investigations of the [2+2] electrocyclization of 3-substituted pentadienyl cations, where the substituents are BH2, AlH2, OH, SH, NH2, PH2, or H, show significant substituent effects on the ground state conformations, transition structures, and energies of activation. Locating the transition structure for the cyclization of the PH2-substituted system was particularly troublesome due to the tendency of the phosphorus group to undergo inversion. The AVS Chemistry Viewer, a data flow environment-based application for the analysis, visualization, and animation of molecular modeling results, proved useful in mapping the potential energy hypersurface and understanding the transition structures for this system.
authors.affiliation: Concurrent Technologies Corporation, Johnstown, Pennsylvania 15904, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Smith
authors.forename: C W
authors.initials: CW
authors.lastname: Ulmer
mesh_terms: D002412:Cations / Q000737:chemistry*; D003196:Computer Graphics; D003626:Data Display; D001330:Electronic Data Processing; D008958:Models, Molecular; D015394:Molecular Structure; D010758:Phosphorus / Q000737:chemistry*; D012984:Software; D013816:Thermodynamics
chemical_list: D002412:Cations; D010758:Phosphorus