Structure, stability and spectral signatures of monoprotic carborane acid–waterclusters (CBWn, where n = 1–6)

Abstract

The gas phase structure, stability, spectra, and proton transfer properties of monoprotic carborane acid–water clusters [CB₁₁F_mH_11−m(OH₂)₁]–(H₂O)_n (where m = 0, 5, and 10; n = 1–6) have been calculated using density functional theory (DFT) with the Becke's three-parameter hybrid exchange functional and Lee–Yang–Parr correlation functional (B3LYP) using 6-31+G* basis set. Results reveal that Eigen cation defects are found in CBW_n (where n = 2–6) clusters and these clusters are significantly more stable than the non-Eigen geometry. In addition to the conventional hydrogen bond (H-bond) the role of dihydrogen bond (DHB) and halogen bond (XB) in the stabilization of these clusters can be observed from the molecular graphs derived from the atoms in molecules (AIM) analysis. Spectral information shows the features of Eigen cation and proton oscillation involved in the proton transfer process. The dissociation of proton from the perfluoro derivatives with two water molecules is more favorable when compared to the other derivatives.