TiN12团簇的合成研究

以高纯氮气为载气,通过532nm的激光轰击由Ti、BN粉末混合压制成的样品,生成了钛氮团簇,确定了最稳定钛氮团簇的组成为TiN12。以四氟化钛和三甲基叠氮硅烷为原料,在液氮冷却下开展了钛氮团簇的化学法合成,对所得产物进行了IR、NMR表征,确定其结构为Ti(N3)4。用密度泛函理论(DFT)对TiN12的结构进行了优化,发现存在一种Ti(N3)4形式的具有对称的正四面体结构的稳定构型,这与化学法合成的TiN12的IR和NMR谱相符。不过,仍需进一步确定激光轰击法和化学合成法产生的TiN12是否具有相似的结构。

Preparation Study ofCluster TiN12

With N2 as carrier gas, the Ti-N clusters were generated by laser ablation (532 nm) of Ti/BN mixture target. According to mass spectra, TiN12 was found to be the most stable one. The chemical synthesis of Ti-N clusters was attempted by TiF4 and azidotrimethylsilane under the liquid nitrogen cooling condition. The only product was characterized by IR and NMR spectra and was proved to be Ti(N3)4. The structure of TiN12 was optimized by DFT and the results show that Ti(N3)4 is a stable configuration. This was consistent with the result of chemical synthesis. Ti(N3)4 exhibits tetrahedral structures with unique linear M-N-NN bond angles, which was considered to be the reason of its relatively high stability. Further studies on whether the TiN12 produced by laser ablation have similar structure as that from chemical synthesis are in progress.