[Fluorescence spectroscopic study on the biointeraction of new organometallic carborane derivatives with bovine serum albumin].

The biointeractions between a series of new organometallic carborane derivatives and model protein bovine serum albumin (BSA) were investigated by means of fluorescence and synchronous spectroscopy. The observations demonstrate that the ferrocene-carborane conjugates (FcSB1, FcSB2 and FcSBCO) and the ruthenium(II)-arene carborane complexes (RuBFc and RuBCOOH) can form a steady complex with BSA and statically quench its fluorescence. The ferrocene-carborane conjugates could remarkably affect the tertiary structure of BSA and induce the microenvironment changes of Trp and Tyr residues from hydrophilic to hydrophobic environment. But the effect of the ruthenium(II)-arene carborane complexes on the tertiary structure of BSA is much less. This study would give meaningful insights into the evaluation of the promising biomedical applications of the new carborane derivatives and benefit the development of potential multifunctional metallodrugs.

Reactivity of the 16e Cp*Co half-sandwich complex containing a chelating 1,2-dicarba-closo-dodecaborane-1,2-dithiolate ligand towards alkynes.

The 16e half-sandwich complex Cp*Co(S(2)C(2)B(10)H(10))(1, Cp* = pentamethylcyclopentadienyl) reacts with N-1-naphthylpropargylamide to afford two 18e complexes (2) and (3). 2 is a 1 : 1 adduct containing a four-membered metallacycle. In 3 the alkyne is twofold inserted into one Co-S bond in a head-head mode. Reactions of 1 with 1-(2-furyl)-2-propyn-1-one and 1-ferrocenyl-2-propyn-1-one lead to two types of alkyne twofold inserted products (4)/(5) and (6)/(7), respectively. The reaction of 1 with phenylacetylene gives rise to the sole complex (8) of the same structural type as 3, 4 and 6, whereas the reaction of 1 with dimethyl acetylene dicarboxylate affords the sole 1 : 1 adduct (9). Complexes 2-9 have been characterized by IR, NMR, elemental analysis and mass spectrometry, and 3-9 have also been determined by single-crystal X-ray diffraction analysis.