Ab Initio and Topological Study of Interactions between SiH4-nXn(n= 0−3, X = F and Cl) and BH3

Theoretically, silane and its derivatives (SiH 4 - n X n, n = 0−3, X = F and Cl) are found to form hydrogen-bridged complex with borane (BH 3 ) at gas phase. High level ab initio calculations at the MP2/aug-cc-pVTZ level show that the interaction energies ( D e ) between SiH 4 - n X n and BH 3 are −6.43 ∼ −12.06 kcal/mol corrected by zero-point energy and the basis set superposition error, whereas without the corrections, the D e values are −14.73 ∼ −21.65 kcal/mol. The SiH 4 - n X n −BH 3 complexes can be regarded as analogues of B 2 H 6 with one monomer BH 3 replaced by SiH 4 - n X n although only one bridged bond Si−H−B is definitely located via topological analyses of the electron density. Upon bonding, boron becomes four coordinated by receiving a hydrogen atom from SiH 4 - n X n . In contrast to the compact hydrogen-bridged complexes, the electron donor−acceptor conformers with a bridged halogen atom are only loosely bound ( D e < 2 kcal/mol). The results indicate that BH 3 is a better hydrogen attractor in these interactions. The predicted SiH 4 - n X n −BH 3 complexation and hydrogen transfer from SiH 4 - n X n to BH 3 may help to understand the initial stage reactions in producing boron doped silicon films by chemical vapor deposition.