A comparison of hydrogen-bonded and van der Waals isomers of phenol centerdot center dot nitrogen and phenol center dot center dot carbon monoxide: An ab initio study

The hydrogen-bonded and van der Waals isomers of phenol .. nitrogen and phe nol .. carbon monoxide in their neutral electronic (S-0) and cation ground state (D-0) were studied using ab initio HF/6-31G*, MP2/6-31G*, and B3LYP/6 -31G* methods. The hydrogen-bonded isomers have the ligand bound via the hy droxyl group of the phenol ring, while the van der Waals isomers studied ha ve the ligand located above the aromatic ring. For both complexes, the hydr ogen-bonded isomer was found to be the most stable form for both the S-0 an d the D-0 states. For phenol .. carbon monoxide, twice as many isomers as c ompared to phenol .. nitrogen were found. The hydrogen-bonded isomer with t he carbon end bonded to the hydroxyl group was the most stable structure fo r both the S-0 and the D-0 states. (C) 1999 American Institute of Physics. [S0021-9606(99)01628-1].