E. Yu. Matveev

Nickel(II) complexes with nitrogen-containing derivatives of the closo-decaborate anion

The reactions of the salt (Bu4N)[2-B10H9O2C4H8] (1) with ammonia and ethylenediamine in ethanol were studied. These reactions afford substituted closo-decaborates with nitrogencontaining groups linked to the cluster through a diethylene glycol spacer. Using this method, we synthesized derivatives of the closo-decaborate anion with the pendant groups -NH3+ and -NHCH2CH2NH2; the complexes [Ni(H2O)(en)(L)] (7) and [Ni(en)(L)]·0.5H2O (8), where L = [2-B10H9O(CH2)2O(CH2)2NH(CH2)2NH2]2−, were synthesized. The X-ray diffraction study showed that the coordination sphere of the Ni2+ ions in complexes 7 and 8 have the same composition (4 N + 2 O). However, the coordination environment differs in the nature of the oxygen atom. Thus the oxygen atom directly bonded to the boron cluster is involved in the coordination of the metal ion in compound 8, whereas a water molecule is involved in the coordination in compound 7.

Cleavage of the cyclic substituent in the [B10H9O2C4H8]−, [B10H9OC4H8]−, and [B10H9OC5H10]− anions upon the interaction with negatively charged N-nucleophiles

The interaction of the [B10H9O2C4H8]−, [B10H9OC4H8]−, and [B10H9OC5H10]− anions with negatively charged N-nucleophiles has been studied. It has been shown that such reactions yield doubly charged substituted closo-decaborates with a nitrogen-containing group attached to the cluster through an alkoxyl spacer. Compounds with pendant NO2−, N3−, N(CO)2C6H4−, and NHC6H5 groups have been synthesized.

Reactions of the [B10H10]2− anion with nucleophiles in the presence of halides of group IIIA and IVB elements

The study deals with reactions of the closo-decaborate anion [B10H10]2− with a number of nucleophiles (cyclic ethers and thioethers, N,N-substituted amides, and nitriles) in the presence of Lewis acids, halides of Group IIIA and IVB elements (BF3 · Et2O, AlCl3, TiBr4, TiI4, ZrCl4, ZrI4, and HfCl4), which act as electrophilic inductors of the nucleophilic substitution. This group of reactions allows the preparation of closo-decaborate derivatives with one or two exopolyhedral substituents. The method is distinguished by high yields (more than 80%) and high regioselectivity of substitution and can also be used to prepare disubstituted closo-decaborate derivatives.

New method for preparation of sulfanyl derivative of closo-decaborate anion [B10H9SH]2−

Reactions of undecahydrodecaborate anion [B10H11]− and closo-decaborate anion [B10H10]2− with N,N′-disubstituted thioureas were studied. A new simple method for preparing sulfanyl derivative of closo-decaborate anion [B10H9SH]2− in a good yield was proposed on the basis of these reactions. The prepared substituted [B10H9SH]2− and [2-B10H9SC(NH(C6H5))2] were characterized by IR and NMR (1H, 11B, 13C) spectroscopy and ESI/MS spectrometry. X-ray diffraction study was performed for (n-Bu4N)2[2-B10H9SH].

Polydentate ligands based on closo-decaborate anion for the synthesis of gadolinium(iii) complexes

A reaction of the closo-decaborate anion 1,4-dioxane derivative with polyatomic alcohols (ethyleneglycol, glycerol, triethanolamine) was studied. These reactions include the ring opening of the cyclic substituent and the addition of the alcohol molecule to boron cluster through the alkoxy spacer chain. The products obtained form coordination compounds upon the reaction with gadolinium(iii) salts, playing the role of polydentate ligands. The compounds obtained were studied by IR spectroscopy, NMR spectroscopy, ESI mass spectrometry, elemental and thermographic analysis.

Reaction of the [B 10 H 9 O 2 C 4 H 8 ] – anion with C-nucleophiles

The reactions of 1,4-dioxane-substituted closo-decaborate anion ([B10H9O2C4H8]–) with metal acetylenides, diethyl malonate, ethyl acetoacetate, triethyl orthoformate, acetylacetone, and malonodinitrile were studied. The reactions were shown to be accompanied with substituent ring opening and attachment of the corresponding pendant functional group. The obtained compounds were characterized by various physicochemical methods (IR and polynuclear NMR spectroscopy, ESI mass spectrometry).

Interaction of [В10H10]2– and [В12H12]2– with nitro compounds

The interaction of the [B10H10]2– and [B12H12]2– anions with aliphatic and aromatic nitro compounds (RNO2, where R = Et, n-Pr, i-Pr, tert-Bu, Ph) has been studied under irradiation with visible and UV light. It has been shown that, depending on the reaction conditions, both mono- and disubstituted nitro-closo-decaborates can be selectively obtained in yields up to 50%.