15min:

PARAGRANJITA BHOWMIK, SHENGGANG LI, BRADFORD R. SOHNLEIN, JASON F. FULLER, XU WANG AND DONG-SHENG YANG, Department of Chemistry, University of Kentucky, Lexington, KY 40506.

The Al and Ga complexes were produced by reactions of laser-vaporized metal atoms with piperidine (C₅H₁₁N) and characterized by pulsed field ionization-zero electron kinetic energy (PFI-ZEKE) spectroscopy. For Al-C₅H₁₁N, the adiabatic ionization potential was measured to be 37060 cm^-1, and vibrational frequencies were determined for the Al⁺-N stretching (238 cm^-1), Al⁺/Al-N-C bending (84/105 cm^-1) and piperidine-based vibrations (300 and 464 cm^-1). By comparing the ZEKE measurements with ab initio calculations, the neutral and ionic aluminum complexes were determined to be in C_s symmetry with Al binding to the nitrogen of the chair-like piperidine ring. For the gallium complex, the ZEKE spectrum shows an ionization potential of 37529 cm^-1, a Ga⁺-N stretching frequency of 176 cm^-1 and a Ga⁺-N-C bending frequency of 70 cm^-1.