Chemical Reactivity of Ti+ Ion within Ti+(CH2FCH2OH)n Clusters

Abstract

The ion-molecule reactions that proceed inside Ti+(CH2FCH2OH)(n) heterocluster ions were studied using a laser ablation-molecular beam/reflectron time-of-flight mass spectrometric technique. The mass spectra exhibit a major sequence of cluster ions with the formula Ti+(OCH2CH2F)(m)(CH2FCH2OH)(n) (m = 1, 2), which is attributed to sequential insertions of Ti+ into the O-H bond of ethanol molecules within the heteroclusters, followed by H elimination. The TiO+ and TiFOH+ ions produced from the reactions of Ti+ with CH2FCH2OH are interpreted as arising from insertion of Ti+ into the C-O bond, followed by C2H5F and C2H4+ elimination, respectively. The observation of Ti+(H2O)(CH2FCH2OH)(n) ions is attributed to the insertion of Ti+ ions into the C-O bond in the ethanol molecules, leading to a beta-H atom transfer and CH2CHF elimination. This reaction pathway presumably plays an important role as the cluster size increases. A initio calculations on the complexes of Ti+ with CH2FCH2OH molecules show that the minimum energy structure is that in which Ti+ is attached to the O and F atoms of fluorinated ethanol, forming a five-membered ring. The formation mechanisms and reaction energetics of the observed heterocluster ions are discussed.