The versatile chemistry of the [B20H18]2- ions: novel reactions and structural motifs.
Among the polyhedral [closo-BnHn]2- ion series (n = 5-12 inclusive) the aromatic [closo-B10H10]2- ion is both readily available and quite reactive. Among its many reactions which retain its cage structure one finds the oxidative dimerization reaction in which two [closo-B10H12]2- ions each formally lose a hydride ion and undergo dimerization of the resulting [closo-B10H9]- ions to produce the [trans-B20H18]2- ion. The two-component [closo-B10H9]- ions of the latter are linked together by a pair of unique B-B-B bonds which provide unprecedented reactivity to the structure. Among these reactions are the two-electron reduction to a set of three interconvertible [B20H18]4- ions having intercage B-B bonds and the related reductive substitution reaction in which [trans-B20H18]2- undergoes attack by nucleophile, L, to produce [B20H18L]2-. The latter species is formally a substituted [B20H19]3- (L = H) ion formed by B-B bond protonation of one of the isomeric [B20H18]4- ions. These and a variety of novel reactions are described here along with interrelated reaction mechanisms considered for the first time.
Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA. mfh@chem.ucla.edu
M Frederick
MF
Hawthorne
Kenneth
K
Shelly
Fangbiao
F
Li
D001880:Boranes / Q000737:chemistry* / Q000493:pharmacokinetics / Q000627:therapeutic use; D001896:Boron Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000627:therapeutic use; D016754:Boron Neutron Capture Therapy; D006801:Humans; D015394:Molecular Structure; D013237:Stereoisomerism
D001880:Boranes; D001896:Boron Compounds