Biomedical subjects

G M Rosair

Publications and source records attributed to G M Rosair.

4 recordsLinked to original sources

PubMed2001

Are halocarboranes suitable for substitution reactions? The case for 3-I-1,2-closo-C(2)B(10)H(11): molecular orbital calculations, aryldehalogenation reactions, (11)B NMR interpretation of closo-carboranes, and molecular structures of 1-Ph-3-Br-1,2-closo-C(2)B(10)H(10) and 3-Ph-1,2-closo-C(2)B(10)H(11).

In this paper, the chemistry of 3-X-1,2-closo-C(2)B(10)H(11) (X = halogen) derivatives is extended. Molecular orbital and (11)B and (13)C NMR calculations on these species are presented. A qualitative interpretation of the (11)B NMR spectra of closo o-carborane derivatives is also provided. The synthesis of 3-X-1-R-o-carborane (X = I, Br and R = Me, Ph) derivatives is reported, and aryldehalogenation at the B3 position is reported for the first time. The molecular and crystal structures of 1-phenyl-3-bromo-1,2-dicarba-closo-dodecaborane and 3-phenyl-1,2-dicarba-closo-dodecaborane are described.

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PubMed2001

Crystal engineering with heteroboranes. I. 1-Carboxy-1,2-dicarba-closo-dodecaborane(11).

The title compound, C(3)H(12)B(10)O(2) or 1-COOH-1,2-closo-C(2)B(10)H(11), forms centrosymmetric dimers through intermolecular hydrogen bonding between the carboxylic acid groups, resulting in the formation of an eight-membered ring [R(2)(2)(8)]. The C==O bond of the carboxylic acid group almost eclipses the unsubstituted cage C atom, with a C-C-C-O torsion angle of 2.6 (2) degrees.

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PubMed2001

Sodium phenoxyacetate hemihydrate.

The structure of the hemihydrate of sodium phenoxyacetate, Na(+) x C(8)H(7)O(3)(-) x 0.5H(2)O, has been redetermined at low temperature (160 K). The structure consists of ribbons containing octahedral NaO(6) units, and half of the Na(2)O(2) squares within the ribbon are bridged by water molecules which lie across twofold rotation axes in C2/c. The phenyl substituents lie on the outside of the ribbon.

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PubMed2000

7,8-Diphenyl-9-dimethylsulfido-10,11-mu-hydro-7, 8-dicarba-nido-undecaborane(9).

In the title compound, C(16)H(25)B(9)S, there are two crystallographically independent molecules, and the conformations of the phenyl and SMe(2) substituents indicate some intramolecular steric crowding. The bridging H atom is asymmetrically disposed. The title compound is a precursor to a crowded vertex-labelled nido carborane ligand important in establishing the mechanism of isomerization of icosahedral heteroboranes.

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