Theoretical study on the interaction of neutral and charged Tin (n = 1-7) clusters with one nitrogen molecule

The interactions of neutral and charged (−2, −1, +1, and +2) Tin clusters (n = 1-7) with one N2 molecule were investigated by density functional theory. For neutral TinN2 clusters, the nitrogen molecule is geometrically dissociative and each separated N atoms is favored to bind at the threefold hollow site for n ⩾ 3. The adsorption energies of neutral TinN2 clusters which increase monotonously from n = 1 to 4 and then oscillate from n = 4 to 7, are all energetically favorable, suggesting the higher stability of large-sized neutral TinN2 clusters. The detachment of Tix (1 ⩽ x ⩽ n − 1, n = 2-7) sub-unit from neutral TinN2 (n = 2-7) clusters are energetically unfavorable, further suggesting their thermodynamic stability. The addition of different charges (−2, −1, +1, +2) on the most stable neutral TinN2 (n = 1-7) clusters would induce their geometrical perturbations. The stabilities of neutral TinN2 systems are enhanced by adding −1 e, while would be reduced by −2, +1, and +2 e. The calculated adsorption energies of charged TinN2 clusters have the following order: TinN22+>TinN21+>TinN22->TinN21-.