Structural Evolution of Carbon-Doped Aluminum Clusters Al<sub><i>n</i></sub>C<sup>–</sup> (<i>n</i> = 6–15): Anion Photoelectron Spectroscopy and Theoretical Calculations
Chao-Jiang Zhang, Wenshuai Dai, Hong‐Guang Xu, Xi‐Ling Xu, Wei‐Jun Zheng
Abstract
Carbon-doped aluminum cluster anions, AlnC– (n = 6–15), were generated by laser vaporization and investigated by mass-selected anion photoelectron spectroscopy. The geometric structures of AlnC– (n = 6–15) anions were determined by the comparison of theoretical calculations with the experimental results. It is found that the most stable structure of Al6C– is a carbon endohedral triangular prism. The Al7C– anion is a magic cluster with high stability. The structures of Al7-9C– can be viewed as the additional aluminum atoms attached around the triangular prism Al6C–. Two isomers of Al10C– have been detected in the experiments. The most stable one has a planar tetracoordinate carbon structure. The second one derives from Al9C– with the carbon atom located in a pentagonal bipyramid. The Al11C– anion has a bilayer structure composed of one planar tetracoordinate carbon and one aluminum-centered hexagon, in which the major interactions between two layers are multicenter bonds. The structures of Al12-14C– can be viewed as evolving from Al11C– by adding aluminum atoms to interact with the carbon atom. In Al15C–, the carbon atom stays at the surface with a tetracoordinate structure, and an icosahedral Al13 unit can be identified as a part of the geometric structure of Al15C–.