15min:

ANDREW R. CONRAD, NATHAN Z. BAREFOOT AND MICHAEL J. TUBERGEN, Department of Chemistry, Kent State University, Kent, Ohio 44242.

Rotational spectra of p -, m -, and o -cyanophenol have been measured in the range of 10.5 - 21 GHz and fit using Watson's A-reduction Hamiltonian coupled with nuclear quadrupole coupling interaction terms for the ¹⁴N nuclei. Ab initio calculations at the MP2/6-311++G** level predict the cis conformers of m - and o -cyanophenol to be more stable due to the intramolecular hydrogen bonding interaction between the hydroxyl hydrogen and the cyano nitrogen. We recorded 14 a- and b-type rotational transitions for cis m -cyanophenol and 16 a- and b-type rotational transitions for trans m -cyanophenol. The rotational constants are A=3408.9200(2) MHz, B=1205.8269(2) MHz, and C=890.6672(1) MHz and A=3403.1196(3) MHz, B=1208.4903(2) MHz, and C=891.7241(2) MHz for the cis and trans species respectivly. We recorded 25 a- and b-type rotational transitions for cis o -cyanophenol; the rotational constants are A=3053.758(2) MHz, B=1511.2760(3) MHz, and C=1010.7989(2) MHz. The trans conformer of o -cyanophenol was not observed. Rotational transitions of the p -cyanophenol monomer are split due to the symmetric internal rotation of the hydroxyl group with respect to the aromatic ring. We recorded 25 a- and b-type rotational transitions for p -cyanophenol; the b-type transitions are split by 40 MHz. The rotational constants are A=5612.96(2) MHz, B=990.4283(6) MHz, and C=841.9364(6) MHz and the ground state spitting E is 20.1608(6) MHz.