Identification of octahedral coordinated ZrN12+ cationic clusters by mass spectrometry and structure searches

Abstract

Cationic zirconium-doped nitrogen clusters were produced by laser ablation of a Zr : BN mixture target and were detected by TOF mass spectrometry. It is found that the mass peak of the ZrN₁₂⁺ cluster is dominant in the spectrum. The ZrN₁₂⁺ cluster was further dissociated with 266 nm photons. Extensive structure searches of a cationic ZrN₁₂⁺ cluster indicate that the ground state structure of ZrN₁₂⁺ consists of a central Zr atom and six N₂ pairs with O_h symmetry. The calculated binding energy of the ZrN₁₂⁺ cluster is about 0.96 eV, which is in accordance with the result of the photodissociation experiment. The neutral ZrN₁₂ cluster has almost the same geometry, but with D_3h symmetry. NBO analysis showed that the molecular orbitals of ZrN₁₂^+/0 clusters are mainly composed of Zr 4d and N 2p orbitals. These findings provide rich information for understanding the geometries and the electronic properties of zirconium-doped N clusters, which will offer valuable guidance for the exploration of other metal doped nitrogen clusters.