The structure of boranes B:one sp3 orbital from each boron overlaps a hydrogen's 1s orbital to give a three center bond to which two electrons are assigned(三中心两电子键).(B-H-B bridge) H H H Sp3 p denote: B B H SD 1s 要点：B的杂化方式， 三中心两电子键、氢桥。• The structure of boranes B: one sp3 orbital from each boron overlaps a hydrogen’s 1s orbital to give a three center bond to which two electrons are assigned (三中心两电子键). (B-H-B bridge) denote： H H B B H H H H 要点：B的杂化方式， 三中心两电子键、氢桥