Detection of OH Stretching Mode of CH₃OH Chemisorbed on Ni₃⁺ and Ni₄⁺ by Infrared Photodissociation Spectroscopy

Abstract

Structures of nickel cluster ions adsorbed with methanol, Ni3+ (CH3OH)m (m = 1-3) and Ni4+ (CH3OH)m (m = 1-4) were investigated by using infrared photodissociation (IR-PD) spectroscopy based on a tandem-type mass spectrometer, where they were produced by passing Ni3,4+ through methanol vapor under a multiple collision condition. The IR-PD spectra were measured in the wavenumber region between 3100 and 3900 cm-1. In each IR-PD spectrum, a single peak was observed at a wavenumber lower by approximately 40 cm-1 than that of the OH stretching vibration of a free methanol molecule and was assigned to the OH stretching vibrations of the methanol molecules in Ni3,4+ (CH3OH)m. The photodissociation was analyzed by assuming that Ni3,4+ (CH3OH)m dissociate unimolecularly after the photon energy absorbed by them is statistically distributed among the accessible modes of Ni3,4+ (CH3OH)m. In comparison with the calculations performed by the density functional theory, it is concluded that (1) the oxygen atom of each methanol molecule is bound to one of the nickel atoms in Ni3,4+ (defined as molecular chemisorption), (2) the methanol molecules in Ni3,4+ (CH3OH)m do not form any hydrogen bonds, and (3) the cross section for demethanation [CH4 detachment from Nin+ (CH3OH)] is related to the electron density distribution inside the methanol molecule.

Infrared consequence spectroscopy of gaseous protonated and metal ion cationized complexes

“…The IRMPD spectra of the metal cluster cations, Ni þ 3 and Ni þ 4 , solvated with up to three methanol molecules were very simple with a single absorption feature. It was concluded that each methanol is on a different Ni atom and there is no methanol-methanol hydrogen bonding (Hirabayashi et al, 2007). Recent thermochemical studies of hydrated Ca 2þ ions using threshold CID (Carl, Moision, & Armentrout, 2007) concluded that six water molecules bind directly to the calcium ion closing the first solvation shell and forcing further water molecules to bind to inner shell waters.…”

Comparative Study of Methanol Activation by Different Small Mixed Silicon Clusters Si2M with M = H, Li, Na, Cu, and Ag

“…Nonetheless, cleavage of these strong organic bonds is still a major challenge for any efficient chemical process and thereby continues to receive widespread attention of both academic and industrial experts alike. In fact, experimental and theoretical studies on the selective breaking of both O–H and C–H bonds of methanol have been carried out with the assistance of a wide range of compounds, such as bioinspired metal compounds, transition-metal (TM) surfaces, − metal oxides, − metal clusters, − and so forth.…”

Observation of the Reaction Intermediates of Methanol Dehydrogenation by Cationic Vanadium Clusters

“…[16] In contrast, the study on the reactions of pure metal clusters with methanol molecules is relatively limited. [17] In this work, we report amass spectrometric study on the reaction of cationic vanadium and cobalt clusters M n + (M = V, Co; n = 6-30) with methanol in al ow-pressure collision cell. Va nadium and cobalt were chosen for acomparative study of the early (V: [Ar]3d 3 4s 2 )a nd late (Co:[ Ar]3d 7 4s 2 )3 d transition metals.T he M n + clusters were generated via am odified Smalley type laser ablation cluster source (see experimental details in Supporting Information).…”