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.
Hawthorne
M Frederick
MF
Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA. mfh@chem.ucla.edu
Shelly
Kenneth
K
Li
Fangbiao
F
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