tailieunhanh - Mass-selected photodissociation of V19+

The fluence-dependent photodissociation experiments show that the V19+ clusters prefer the evaporation of vanadium dimers rather than monomers. This finding is in line with dissociation energies extracted from early collision-induced dissociation data. | Mass-selected photodissociation of V19+ Nghiên cứu khoa học công nghệ MASS-SELECTED PHOTODISSOCIATION OF V19+ Nguyen Thanh Tung1,2* Abstract: We experimentally investigate the dissociation behavior of V19+ clusters by means of photodissociation spectrometry. Vanadium clusters of several atoms are produced in gas phase using pulsed laser vaporization technique, mass- selected in a dual-reflection time-of-flight mass spectrometer, and photodissociated by using a powerful 532 nm laser light. The fluence-dependent photodissociation experiments show that the V19+ clusters prefer the evaporation of vanadium dimers rather than monomers. This finding is in line with dissociation energies extracted from early collision-induced dissociation data. Keywords: Vanadium, Gas phase clusters, Photodissociation. 1. INTRODUCTION Transition metal and their oxides have attracted significant interest in physics, chemistry, and material science due to their great potential for applications in catalysis, electronics, and magnetic materials [1-5]. Since 1980s, clusters of transition metal atoms have been investigated extensively in the gas phase, showing a strongly size-dependent behavior, which results in intriguing chemical and physical properties. Among them, vanadium clusters have been of particular interest because of their pronounced reactivity and potential nano magnetic properties. For example, vanadium cluster ions Vn+ (n=3–5) were investigated in the IR–UV region by measuring photodissociation action spectra of their argon–atom complexes [6]. Meanwhile, the water absorption on vanadium cluster cations was examined by the infrared photodissociation spectroscopy in the region of the bending mode of water [7]. Engeser and coworkers reported ion-cyclotron resonance mass-spectrometric experiments to examine the reactions of small cationic vanadium clusters Vn+ (n ≤ 5) with molecular oxygen [8]. On the other hand, Walther and .