Boron-nitrogen-hydrogen compounds have been investigated and developed very fast in last decades caused by its excellent hydrogen-storage performances.The bottleneck problem hindering its application is the irreversibility after its dehydrogenation.However,the traditional B-N (or B-P) bond can be hindered by connecting with large steric hindrances,which results in the possible reversible hydrogenationdehydrogenation properties.In this research,we analyse the structural characters based on the experiments to obtain the required electronic structure properties for realizing the reversibility of FLPs in the hydrogenation (or dehydrogenation).