Growth Pattern of WSinHx+ (n = 1 ~ 5, x = 0 ~ 4) Originated from W+ + SiH₄
邱珮盈(Pei-Ying Chiu)1*, 洪祐明 (Yu-Ming Hung)1
1Master Program of Applied Chemistry, Department of Chemistry, Chinese Culture University, Taipei, Taiwan
* presenting author:邱珮盈,
Hiura et. al. observed the reactions of SiH4 with the W+ obtained by hot tungsten wire1. Their time-lapsed mass spectroscopy showed that WSinHx+ (x = 0 ~ 4) reacted with SiH4 step by step and terminated at WSi12+. It was believed that in WSi12+ the cation was completely encapsulated, hence could not react with the next silane. Their work has inspired us to investigate the growth pattern of WSinHx+ at each step, starting from W+ + SiH4. Here, arrangements of a new silane around the most stable previous WSin-1Hx+ was structurally optimized by the DFT method implemented in the Material Studio DMOL3 software; spin polarization was set to obtain the optimal multiplicities of WSinHx+. The relative stability among different dehydrogenation products was determined by the mean binding energies (MBE) defined as MBE = -[E(WSinHx+) – E(W+) – nE(Si) – xE(H)]/(1 + n + x)]. For bonding properties, the Hirshfeld charges, which was believed to reflect the trend of elemental electronegativites better than the Mulliken charges, were calculated to reveal electron redistribution in the products of each step. Mayer bond orders were used to analyze the bond types between W-Si and W-H, e.g., single bonds, double bonds or partial bonds, etc.
1.H. Hiura, T. Miyazaki, T. Kanayama, Phys. Rev. Lett. 86 (2001) 1733.

Keywords: WSinHx+, Metal encapsulating clusters, Hirshfeld charges, Mayer bond orders, Mayer total valences