本文用Ab initio法对B_3H_7,B_3H_8~-和B_3H_9等三个硼烷分子作了深入讨论,从而揭示了这些分子中的化学键性质.因B—H_b、—B三中心桥键与B—B—B三中心键的相互作用,在B_3H_7中融合为一个四中心键;B_3H_(?)~-中则融合成一个五中心键;可是在B_3H_9中由于不具备两种三中心键相互作用的条件,故仍然是三个彼此独立的B—H_b—B三中心键 Ab initio method was used to investigate three Borane molecules such as B_3H_7, B_3H_8 ~ - and B_3H_9, which revealed the chemical bond properties of these molecules.Because of B-H_b, -B three-center bridge bonds and B-B- B three central bond interactions in the B_3H_7 fused to a four-center bond; B_3H _ (?) ~ - are fused into a five-center bond; but in the B_3H_9 due to the lack of two three-center key interaction conditions, So it is still three independent B-H_b-B three center keys