Recent advances in the chemistry of carborane metal complexes incorporating d- and f-block elements

Structure and decomposition of [HFe(CO)4(B2H5)], a revised behavior of an old uncharacterized complex

“…In our case, the interaction between (m 3 -H) and the iron centre is partially covalent and Table 2). Nevertheless, the bond length FeeB which is about 2.53 A is higher than the observed longest one (2.36 A) [51,62]. This does not support the existence of any interaction between iron and boron atoms in this structure.…”

From nonpeptide toward noncarbon protease inhibitors: Metallacarboranes as specific and potent inhibitors of HIV protease

“…Among other transition metal metallacarboranes (22), cobalt bis(1,2-dicarbollide) ion (23) shows certain unique features: synthetic availability, wide possibilities of exo-skeletal modifications, high stability, charge delocalization, low nucleophilicity, strong acidity of conjugated acids, and high hydrophobicity. These properties are reflected in unique solution properties and ion-pairing behavior of this ion, which in turn led to its known applications in extraction chemistry (24,25) and in the development of lowest coordinating anions (26) and compounds for radioimaging (14).…”

Metal complexes of monocarbon carboranes bearing C-amine or -amino substituents

“…We anticipated that we might prepare an analogous dianionic monocarbollide species [1-NHBu t -2-(g 3 -C 3 H 5 )-2,2-(CO) 2 -closo-2,1-MoCB 10 H 10 ] 2À by deprotonating 7-NH 2 Bu t -nido-7-CB 10 H 12 [30] with 3 equivalents of LiBu n to generate [7-NHBu t -nido-7-CB 10 It was subsequently found that 15a could be more straightforwardly prepared and in better yield by the interaction of the lithium salt of the monoanionic species [7-NHBu t -nido-7-CB 10 H 12 ] À [24] with [Mo(CO) 6 ] in refluxing NCMe, followed by addition of [N(PPh 3 ) 2 ]Cl [31]. In the synthesis the two face-bridging protons of the carborane are reduced and eliminated as dihydrogen with a concomitant two-electron oxidation of the molybdenum.…”

“…Evidently two molecules of the neutral complex The compound 24a can be obtained by two different routes. It can be isolated either from the reaction between the carborane trianion [7-NH 2 -nido-7-CB 10 H 10 ] 3À and [Mo(CO) 3 (NCMe) 3 ] in thf/NCMe at room temperature, followed by oxidation with CH 2 ‚CHCH 2 Br, or from the reaction between the monoanionic carborane [7-NH 2 -nido-7-CB 10 H 12 ] À with [Mo(CO) 6 ] in refluxing NCMe. In both cases [N(PPh 3 ) 2 ]Cl is added to isolate the salt.…”

“…However, until recent times compounds based on {closo-3,1,2-MC 2 B 9 } structures have largely dominated the field. Now there is a growing interest in metallacarboranes with polyhedral structures other than those that are icosahedral, and also interest in species with more than two carbon atoms in the cage [4][5][6]. Surprisingly the study of species with only one carbon atom in the polyhedral framework has been largely neglected.…”