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

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 Oh 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 D3h 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.