It has been shown by IR and NMR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4-Hg)3 (1) is capable of binding closo-[B10H10]2- and closo-[B12H12]2- anions to form complexes [[(o-C6F4Hg)3](B10-H10)]2- (2), [[(o-C6F4Hg)3]2(B10H10)]2-(3), [[(o-C6F4Hg)3](B12H12)]2- (4), and [[(o-C6F4Hg)3]2(B12H12)]2- (5). According to IR data, the bonding of the [B10H10]2- and [B12H12]2- ions to the macrocycle in these complexes is accomplished through the formation of B-H-Hg bridges. Complexes 2, 3, and 5 have been isolated in analytically pure form and have been characterized by spectroscopic means. X-ray diffraction studies of 3 and 5 have revealed that these compounds have unusual sandwich structures, in which the polyhedral di-anion is located between the planes of two molecules of 1 and is bonded to each of them through two types of B-H-Hg bridges. One type is the simultaneous coordination of a B-H group to all three Hg atoms of the macrocycle. The other type is the coordination of a B-H group to a single Hg atom of the cycle. According to X-ray diffraction data, complex 2 has an analogous but half-sandwich structure. The obtained complexes 2-5 are quite stable; their stability constants in THF/acetone (1:1) at 20 degrees C have been determined as 1.0 x 10(2)Lmol(-1), 2.6 x 10(3)L(2)mol(2), 0.7 x 10(2)Lmol(-1), and 0.98 x 10(3)L(2)mol(-2), respectively.

Fluorescent chromophore, alkylamino-(tetra-hydronaphthalenylidene)- benzothiazolium derivatives (HBTN dyes), are proposed as covalent labels for proteins via aliphatic amino groups. Spectral-luminescent properties of 3-methyl-2-{(E)-[7-(methylamino)-4,4a,5,6-tetra-hydronaphthalen-2(3H)-ylidene]methyl}-1,3-benzothiazol-3-ium chloride (HBTN, R=Me) and its predecessor, 2-[(E)-(7-methoxy-4,4a,5,6-tetrahydronaphthalen-2(3H)-ylidene)methyl]-3-methyl-1,3-benzothiazol-3-ium chloride (ABTN), are studied for free dyes and in the presence of DNA and BSA. Considerable spectral-luminescent changes accompany the transformation of ABTN into HBTN that allows monitoring conjugation reaction. In presence of DNA and BSA the HBTN increases its emission in 15 and 4 times respectively and becomes strongly fluorescent. The conditions for labeling are developed and a model conjugate of HBTN dye with BSA is synthesized. It was shown that using of HBTN dye as a fluorescent label allows detection by eye of about 3 mug/band of BSA on polyacrylamide gel upon UV-irradiation.

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RuCl2(PPh3)3 (1), when heated with an equimolar amount of nido-5,6-C2B8H12 (2) in toluene for a few hours, effected rather unexpected polyhedral contraction of 2 to give the new half-sandwich small ruthenacarborane closo-C2B4H6Ru(PPh3)2HCl (3) in moderate yield along with minor amounts of the two isomeric 11-vertex ruthenacarboranes [3-Cl-1-(η6-C6H5Me)-1,2,4-RuC2B8H9] (4) and [6-Cl-1-(η6-C6H5Me)-1,2,4-RuC2B8H9] (5) with open MC2B8 cluster structure. These new complexes were characterized by 1H, 13C, and 11B NMR spectroscopy and, in the case of 3 and 5, also by an X-ray crystal structure analysis.

The vibrational spectrum, geometrical structure and electron-density distribution (EDD) of the formally closo (2n+2)-electron cluster species [B 11 H 11 ] 2-have been studied. The presence of two low-frequency vibrational modes is evidence of cluster nonrigidity. A rationale for this lies in the results of EDD calculations which show that the polyhedron lacks twocentre edge-localized B-B bonds of the 6k-5k type and that its surface exhibits two six-membered rings with low electron