The trans–iso isomerization of the dimeric borohydride cluster anion [B 20 H 18 ] 2– in the course of the silver(I) complexation reaction with triphenylphosphine has been described for the first time. The isomeric complexes [Ag 2 (Ph 3 P) 6 [ trans -B 20 H 18 ]] and [Ag 2 (Ph 3 P) 6 [ iso -B 20 H 18 ]] have been isolated and characterized by physicochemical methods. The structures of the compounds have been determined by X-ray crystallography.

The reactions of the salt (Bu 4 N)[2-B 10 H 9 O 2 C 4 H 8 ] ( 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 -NH 3 + and -NHCH 2 CH 2 NH 2 ; the complexes [Ni(H 2 O)(en)(L)] ( 7 ) and [Ni(en)(L)]·0.5H 2 O ( 8 ), where L = [2-B 10 H 9 O(CH 2 ) 2 O(CH 2 ) 2 NH(CH 2 ) 2 NH 2 ] 2− , were synthesized. The X-ray diffraction study showed that the coordination sphere of the Ni 2+ 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 .

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

A new method of synthesis of polyhedral metallaboranes [ MB9 H9 ] ( M = Ni , Pd ) with an apical metal atom was suggested . The method consists in a reaction between ((C6H5)4P)2[B9H9] and different metal complexes of Ni(I), Ni(II) and Pd(II) both in organic solutions and in solid state with mechanical activation. The obtained metallaboranes were described with IR, NMR spectral data and elemental analysis.

A new method for the synthesis of oxonium derivatives of the closo-decaborate anion in high yields was described. Reactions of the anion B10H10 2− with cyclic ethers (tetrahydrofuran (THF) and tetrahydropyran) in the presence of dry HCl are stepwise processes. Depending on the reaction temperature and time, either mono- or disubstituted products were obtained. Their structures were determined using 11B, 13C, and 1H NMR and IR spectroscopy, ESI mass spectrometry, and elemental analysis for boron.

The reaction of the [B 10 H 9 O 2 C 4 H 8 ] − , [B 10 H 9 OC 4 H 8 ] − , and [B 10 H 9 OC 5 H 10 ] − anions with negatively charged S-nucleophiles, such as SH − , SCN − , and S 2 O 3 2− , resulted in the ring opening of the cyclic substituent and the formation of derivatives with the terminal thiol, thiocyanate, and thiosulfate groups. The structures of the products were confirmed by the IR, mass, and 1 H, 11 B, and 13 C NMR spectra.

The low-temperature heat capacity of Zn 0.98 Co 0.02 O oxide was measured by adiabatic calorimetry. The formation of a solid solution was shown to be accompanied by a change in the entropy by 0.4 J/(K mol). No anomalies in the heat capacity or the thermal behavior confirming the phase transformations found earlier by other methods were observed. A heat capacity anomaly was revealed below 15 K and tentatively attributed to a change in the magnetic properties of the substance.

A method for the synthesis of complexes of sodium and lithium borohydrides with crown ethers is proposed. The complexes of sodium borohydride with benzo-15-crown-5, 4′-aminobenzo-15-crown-5, dibenzo-18-crown-6, and diaza-18-crown-6 and the complexes of lithium borohydride with benzo-15-crown-5 and dibenzo-18-crown-6 are synthesized. These complexes can be used for the preparation of hydrogen in their reactions with methanol. The complex formation does not affect the purity of hydrogen formed.

Copper(I) complexes with a closo -dodecaborate anion were synthesized: Cat[CuB 12 H 12 ], where Cat = Cs + , Ph 4 P + , Ph 4 As + , or R x NH 4− x + (R = Me, Et, Pr, or Bu; x = 3 or 4). The complexes were synthesized from the copper(II)- closo -dodecaborate-sulfur dioxide (sodium sulfite) system. The structure of [Cu 2 (NCCH 3 ) 4 B 12 H 12 ] was determined using X-ray crystallography.

The interaction of closo-decaborate (B10H102-) and undecahydrodecaborate (B10H10-) anions with cyclic ethers was studied. It was shown that nucleophilic substitutions in anion B10H102- occur only in the presence of trifluoroacetic acid through the protonation of the closo-borate cage. Anions 2-B(10)H(9)Nu(-) with >B-E+< (E = S, O) bonds are the major products of exo-polyhedral substitution.

Reactions of an amino derivative of the closo -decaborate anion [1-B 10 H 9 NH 3 ] − with aromatic aldehydes afforded Schiff bases [1-B 10 H 9 NH=CHAr] − (Ar=Ph, C 6 H 4 -2-OMe, or C 6 H 4 -4-NHCOMe). The reduction of the latter with sodium borohydride gave the corresponding benzylamino derivatives [1-B 10 H 9 NH 2 CH 2 Ar] − .

The interaction between the undecahydrodecaborate anion B10H11- and acetonitrile has been studied. A probable mechanism is proposed for the substitution of acetonitrile for exo-polyhedral hydrogen atoms the B10H102- anion in an acidic medium, which results in the [2-B10H9NCCH3](-) anion. The reaction is one more piece of experimental evidence of the participation of the B10H11- anion in nucleophilic acid-catalyzed exo-polyhedral substitution.

Nitrosation of dodecahydro- closo -dodecaborate anions with nitrous acid in an aqueous solution and with isoamyl nitrite and nitrosyl chloride in nonaqueous solutions was studied. The main reaction product is the mononitrosoundecahydro- closo -dodecaborate anion. Conditions were selected for the preparation of the nitroso-substituted anion in the highest yield as alkylammonium, tetraphenylphosphonium, and alkali-metal salts. The salts were studied using IR, UV, and 11 B NMR spectroscopy.

Conditions for the synthesis of salts of the B10H11–anion with different cations in the Cat2B10H10+ RCOOH (R = H, CF3; Cat = Me4N+, Et4N+, Bu4N+, Ph4P+, Ph4As+) systems were studied depending on the acid strength (pKa) and size of the cation. It was established that reactions with trifluoroacetic acid give compounds of this anion with any one of the quaternary ammonium, phosphonium, or arsonium cations, while formic acid can only give salts with the largest of these cations.

Protonation ability of the highest representative of polyhedral boron hydrides-the B(12)H(12)(2-) anion-is studied. The solutions of salts in organic solvents acidified with trifluoroacetic acid are investigated by the (11)B and (11)B{(1)H} NMR spectroscopic methods. It is found that, instead of the protonated form of the initial anion, as was earlier observed for B(6)H(6)(2-) and B(10)H(10)(2-,) the B(24)H(23)(3-) dimer is formed in the acidic non-aqueous solutions of the salts of B(12)H(12)(2-) anion.

The methods of (19)F and (11)B NMR spectroscopy and X-ray diffraction analysis are used to characterize the synthesized and isolated B(12)H(3)F(9)(2-), B(12)H(9)F(3)(2-), and B(12)H(11)F(2-) anions, which are missing from the fluorination scheme B(12)H(12)(2-) + xHF(-) -> B(12)H(12).(x)F(x) + xH(2). The B(12)H(11)F(2-) anion is synthesized by reacting B(12)H(12)(2-) with KHF(2) in melt. The (11)B and (19)F NMR spectral data are presented for all of the B(x)H(12-x)F(x)(2-) anions isolated. The structures of all fluorinated compounds are determined, and the results are used to construct a complete scheme of the stereoselective fluorination of B(12)H(12)(2-), illustrating the spatial-aromatic character of the latter. It is shown that, at all fluorination steps, the previously introduced fluorine atoms behave as strong meta orienting agents with respect to the newly introduced atoms.

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