A matrix isolation and ab initio study of the C2H2MeOH complex

Hydrogen-bonded complexes of C2H2MeOH were studied using matrix isolation infrared spectroscopy and computational methods. Our computations at the B3LYP/6-31++G∗∗ level located two minima on the potential surface. The global minimum corresponded to a n–σ complex, where C2H2 serves as the proton donor to MeOH. The second minimum corresponded to a weaker H–π complex, where MeOH was the proton donor to the π cloud of C2H2. The stronger n–σ complex appeared in both Ar and N2 matrixes, whereas the weaker H–π complex was observed only in a N2 matrix at temperatures below 20 K. AIM analysis was also performed to understand the nature of the interactions in these complexes.