15min:

KARISSA UTZAT, ROBERT K. BOHN AND EMILY CHU, Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060.

Benzyl compounds (C₆H₅C_ H₂X), generally fall into two conformational classes. With X=CH₃, C₂H₅, F, or Cl, the C-C-C_ -X dihedral angle is 90^\circ; with X=CN and CCH, the dihedral angle is 0^\circ; however, benzyl alcohol (C₆H₅CH₂OH) and benzyl amine (C₆H₅CH₂NH₂) have asymmetric structures. Two conformers of benzyl amine have been observed, one with a dihedral angle approximately 50^\circ and a higher energy form with dihedral angle 90^\circ. Benzyl alcohol has a single asymmetric conformation with dihedral, C-C-C_ -O about 60^\circ . The microwave rotational spectrum displays tunneling doublets for all transitions indicating a low barrier path between two of the four equivalent energy minima. These splittings are significantly smaller in the C₆H₅CH₂OD spectrum. The rotational spectrum of sec-phenethanol, (C₆H₅C_ H(C_ H₃)OH), displays a single conformation with C-C-C_ -C_ dihedral angle approximately 90^\circ and the C-C-C_ -O dihedral angle approximately 30^\circ, and no tunneling split transitions. ab initio calculations on sec-phenethanol and benzyl alcohol will also be discussed.