This award in the Inorganic, Bioinorganic, and Organometallic Program supports research by Dr. John A. Morrison of the Chemistry Department, University of Illinois at Chicago, concerning polyhedral boron halide clusters. Divalent anions with equivalent numbers (n) of boron and halide atoms (including n = 7, 8, 10, 11, 12) will be synthesized and their reactivities and structures characterized using PES, XPS, NMR, and X-ray crystallography. Diboron tetrahalides and tetraboron tetrahalides and B(14)Cl(18) will also be studied. Substituents will not be limited to halides, but also will include alkyl, alkoxide, and amide groups. The goal of the research is to investigate the bonding modes of these electron deficient compounds which are expected to exhibit structures not previously observed in boron clusters. Molecular orbital calculations will facilitate the interpretation of spectra and bonding. %%% Large regular polyhedral clusters containing up to 12 boron atoms are well known. Each boron is typically bound also to a hydrogen or halide atom. The number of "framework" electrons required to hold the cluster together is usually 2n+2, where n is the number of boron atoms in the cluster. Morrison will synthesize novel species which contain only 2n electrons and observe the effects on the shape and reactivity of the cluster and its bonding characteristics. Although the research is fundamental, it may be applicable to clusters of other elements, particularly those containing metals which are found in many catalytic and electronic materials.
