Realization of an Al≡Al Triple Bond in the Gas-Phase Na Al Cluster via Double Electronic Transmutation.

The discovery of homodinuclear multiple bonds composed of Group 13 elements represents one of the most challenging frontiers in modern chemistry. A classical triple bond such as N≡N and HC≡CH contains one σ bond and two π bonds constructed from the p orbitals perpendicular to the σ bond. However, the traditional textbook triple bond between two Al atoms has remained elusive.

Electronic Transmutation (ET): Chemically Turning One Element into Another.

The concept of electronic transmutation (ET) depicts the processes that by acquiring an extra electron, an element with the atomic number Z begins to have properties that were known to only belong to its neighboring element with the atomic number Z+1. Based on ET, signature compounds and chemical bonds that are composed of certain elements can now be designed and formed by other electronically transmutated elements. This Minireview summarizes the recent developments and applications of ET on both the theoretical and experimental fronts.

The Existence of a Designer Al=Al Double Bond in the LiAl H Cluster Formed by Electronic Transmutation.

The Al=Al double bond is elusive in chemistry. Herein we report the results obtained via combined photoelectron spectroscopy and ab initio studies of the LiAl H cluster that confirm the formation of a conventional Al=Al double bond. Comprehensive searches for the most stable structures of the LiAl H cluster have shown that the global minimum isomer I possesses a geometric structure which resembles that of Si H , demonstrating a successful example of the transmutation of Al atoms into Si atoms by electron donation.