Infrared (IR) spectra of methanol clusters in helium nanodroplets are reported in the OH stretching region for the first time. A simple series of intense bands are seen which almost perfectly match previous gas phase studies of these clusters and which are consistent with cyclic structures for the trimer and larger clusters. This finding differs from an earlier report of (CHOH) clusters in helium nanodroplets, which focused on the CO stretching region and concluded that while the trimer was cyclic, the tetramer and pentamer adopted branched structures based on a cyclic trimer core. We also present preliminary data for small (CHOH)(HO) clusters, and in particular, we report the first IR spectra for (CHOH)(HO) and (CHOH)(HO). Supporting ab initio calculations suggest that, like the pure methanol clusters, cyclic structures are adopted by these mixed solvent clusters in helium droplets.

Theoretical calculations are reported to predict the geometrical structures and IR vibrational frequencies of entrance channel of C2H2+Cl interaction in the ground state. The calculations are performed via Ab initio calculations at perturbation theory (MP2) with Dunning correction-consistent basis set (aug-cc-pVDZ). The results show that attaching acetylene molecule with radical chlorine via van der Walls bonds has two equilibrium structures. These structures have IR active of harmonic vibrational frequencies. In one of these structures; Cl atom bonded to a particular H atom which has a single IR active of C-H asymmetric stretching vibration at 3428 cm-1. The other structure, in which Cl atom attached to both of H atoms (T- shape), predicted harmonic vibration at 3424 cm-1 for asymmetric C-H stretch. The rear geometrical structure is lower minimum energy than the former one by 11.78 KJ/mol. Finally, the barrier for the interconversion from one minimum to the other is also computed in this study.

IR spectra of entrance and exit channels of methane and radical oxygen reaction are predicted in the ground state energy. Ab initio calculations at perturbation theory (MP2) with Dunning correction- consistent basis set (aug-cc-pVDZ) have been used. The calculations predicted structures, vibrational frequencies and potential energy surface. Three van der Waals minima from three adiabatic potential energy surfaces have been predicted in entrance and exit channels. Vibration frequency of 3209 cm-1 and 3212 cm-1 of C-H stretching in entrance structures are predicted while O-H vibrational frequency is predicted to be at 3673 cm-1 in the other channel. The lowest energy structure in entrance channel has - 0.18 kJ/ mol minimum energy.