Progress of structure characteristics on several kinds of low-valent aluminum cluster complexes

The low-valent aluminum cluster complexes with abundant Al-Al bonds and Al-R bonds is reviewed in order to provide a new way to synthesize novel metal-rich materials with special properties. The average oxidation number of aluminum cluster is between zero and three. The preparation of the predecessor of aluminum cluster complexes AlX (X=F, Cl, Br, I) were introduced, and the recent advances in the low-valent aluminum cluster complexes were reviewed, containing organometallic cluster complexes, metalloid aluminum cluster complexes and Al_n^m- aluminum cluster complexes with jellium model. The structure characteristics of the low-valent aluminum cluster complexes were analyzed including formation mechanism, coordination mode, performance characteristic, atom and so on. Finally, the suggestions on further study of the low-valent aluminum cluster complexes are presented. The novel metal-rich materials have vast potential for future development in many fields such as energetic materials, heat conducted materials and superconducting materials, which could be prepared by reacting between appropriate ligand and predecessor.