A. F. Smol’yakov

Complexation of trimeric copper(i) and silver(i) 3,5-bis(trifluoromethyl)pyrazolates with amine-borane

A complexation of trimeric copper(i) and silver(i) 3,5-bis(trifluoromethyl)pyrazolates ((ML)3) with BH3NEt3 was studied by IR spectroscopy in hexane and dichloromethane solutions. In hexane, two complexes [(ML)3][BH3NEt3]2 (1) and [(ML)3][BH3NEt3] (2) were formed depending on the ratio of reagents. In dichloromethane, only one complex [(ML)3][BH3NEt3] (2) was found. The thermodynamic parameters (ΔH○, ΔS○) of complex 1 in hexane and complex 2 in dichloromethane were obtained. The complex [(AgL)3][BH3NEt3] was isolated in the solid state, its structure was established by X-ray diffraction. The complex is formed due to two bridges B-H-Ag, one BH group is not involved in the complexation. In crystal, molecules 2 form supramolecular dimers due to the intermolecular interactions between metals of two macrocycles.

Synthesis and molecular structures of dibenzo(perhydrotriazino)aza-14-crown-4 ethers

By triple condensation of thiourea or guanidine with 1,ω-bis(2-formylphenoxy)-3-oxapentane and ammonium acetate first representatives of the new class of ethers bis(benzo)aza-14-crown-4 were obtained in 28–73% yield that included as a subunit a symm-perhydrotriazine ring. This reaction also proceeds readily with N-monomethyl- and N-monopropenyl-substituted thioureas affording the corresponding derivatives of triazinoazacrown ether. At the same time urea in the similar condensation does not form the expected perhydrotriazinoazacrown ether. The molecular structure of one perhydroazacrown ether as a complex with a chloroform molecule was established by XRD analysis.

Formation of “three-bridge” cobalt-copper commo-cluster with the (B-H)3...Cu bond in the reaction of [Cs][commo-3,3′-Co(1,2-C2B9H11)2] with copper(i) and copper(ii) compounds

Zwitterionic 4,8,8′-exo-{Ph3PCu}-4,8,8′-(μ-H)3-commo-3,3′-Co(1,2-C2B9H9)-(1′,2′-C2B9H10) and ionic [(PPh3)3Cu][commo-3,3′-Co(1,2-C2B9H11)2 complexes were synthesized in moderate yields by the reaction of anionic commo-complex [Cs][commo-3,3′-Co-(1,2-C2B9H11)2]) in a CH2Cl2 solution with anhydrous CuCl2 or CuCl in the presence of PPh3. The complexes were also synthesized by alternative methods and characterized by NMR and X-ray diffraction methods.

Orientation in the metalation of amide, carbamate, ureido, and allylic derivatives of cymantrene

The orientation in the metalation of monosubstituted carbamate-, amide-, ureido-, and allyl-containing derivatives of cymantrene was determined for the first time. The data obtained open up a synthetic route to polyfunctional 1,2- and 1,3-disubstituted cymantrenes. They can serve as the starting materials for the preparation of chelate complexes of (dicarbonyl)-(cyclopentadienyl)manganese, which hold promise as novel organometallic photochromes. A method for the synthesis of earlier unknown chiral derivatives of cymantrene with a quaternary carbon atom in position 1 of the side chain was proposed.

Efficient methods for the preparation of bromine-containing exo-nido- and closo-ruthenacarborane clusters

An efficient method for the synthesis of bromine-containing exo-nido-clusters of a general formula exo-5,6,10-[Br(Ph3P)2Ru]-5,6,10-(μ-H)3-10-H-7,8-R2-nido-7,8-C2B9H6 (R = H, Me) was developed using the reactions of RuBr2(PPh3)3 with [K][7,8-R2-7,8-nido-C2B9H10]. Replacement of the phosphine ligands in the starting exo-nido-cluster (R = H) with the diphosphine ones afforded a series of diamagnetic (18-electron) closo-bromoruthenacarboranes, 3-Br-3,3-[κ2-Ph2P(CH2)nPPh2]-3-H-closo-3,1,2-RuC2B9H11 (n = 3−5). A mild thermal method of the halide ligands exchange (Cl → Br) upon heating of diamagnetic chlorine-containing complexes 3,3-[κ2-Ph2P(CH2)nPPh2]-3-H-3-Cl-closo-3,1,2-RuC2B9H11 (n = 3−5) with excess of CBr4 in benzene (70–80 °C) was suggested for the synthesis of paramagnetic (17-electron) bromine-containing ruthenacarboranes, 3-Br-3,3-[κ2-Ph2P(CH2)nPPh2]-closo-3,1,2-RuC2B9H11 (n = 3, 4) or 3-Br-3,3,8-[κ2-Ph2(CH2)5PPh]-μ-. Paramagnetic chlorine-containing clusters 3-Cl-3,3-[κ2-Ph2P(CH2)nPPh2]-closo-3,1,2-RuC2B9H11 (n = 2−4) were alternatively used as the starting compounds in the exchange reaction. Complexes with dppp and dppb (dppp is 1,3-bis(diphenylphosphino)propane, dppb is 1,4-bis(diphenylphosphino)butane) were used as examples to study the thermal reactions (toluene, 110 °C) leading in the presence of CBr4 to paramagnetic mono(P-o-phenylene)- and bis(P,P-o-phenylene)cycloboronated clusters, 3-Br-3,3,8-[κ2-Ph2(CH2)nPPh]-μ- and 3-Br-3,3,4,8-[κ2-Ph2(CH2)nP]-μ- (n = 3, 4). The compounds obtained were characterized by NMR spectroscopy (in the case of diamagnetic complexes), ESR spectroscopy and mass spectrometry (in the case of paramagnetic compounds). X-ray diffraction experiments were carried out for two cycloboronated paramagnetic complexes.

Synthesis and Optoelectronic Properties of Conjugated Phosphorescent Copolyfluorenes Containing Iridium Complexes in Main Chains and Light-Emitting Diodes Formed on Their Basis

New copolyfluorenes containing covalently bound iridium β-diketonate complexes (featuring high values of phosphorescence efficiency) in the backbone are synthesized through the targeted selection of molar ratios of monomers containing functional groups responsible for various irradiation regions under conditions of the Yamamoto reaction. All copolymers show solubility in organic solvents, such as DMF, DMAA, DMSO, toluene, THF, and chloroform, and feature reversible redox electrochemical properties. The electroluminescence spectra of the copolymers show broad intense bands in the visible region with maxima at 482–538 nm and a maximum brightness of 320 cd/m2 at a current density of 2900 A/m2. The iridium-containing copolyfluorenes are of interest as effective electroluminescent materials for light-emitting diodes.

Synthesis of 12-vertex mixed ligand closo-cobaltacarborane complexes and molecular structure of [3,3-(Ph2P(CH2)2PPh2)-3-Cl-closo-3,1,2-CoC2B9H11]

A reaction of complexes CoCl2(dppe) (dppe is the 1,2-bis(diphenylphosphino)ethane) or CoCl2(dppp) (dppp is the 1,3-bis(diphenylphosphino)propane) with [K][7,8-nido-C2B9H12] upon reflux in benzene led to the mixed ligand closo-cobaltacarboranes [3,3-(Ph2P(CH2)nPPh2)-3-Cl-closo-3,1,2-CoIIIC2B9H11] (n = 2 and 3, respectively) in moderate yields (34 and 16%). The structure of the 18-electron complexes in solution and the solid state was studied by NMR and IR spectroscopy, the structure in the case of the closo-complex with dppe-ligand was confirmed by X-ray crystallography.

Conformational preference of 2,5-disubstituted phosphacymantrenes evidenced by the data of quantum chemical calculations and topology analysis of electron density

Quantum chemical calculations and topological analysis of the electron density distribution r(r) were performed in the framework of the “Atoms in molecules” theory for a series of 22,5-substituted phosphacymantrene derivatives. The electronic structure of the cyclic π-ligand caused by the donor-acceptor properties of the substituents determines the preferential orientation of the Mn(CO)3 fragment relative to the heterocycle. The change in the number of bond paths between the Mn atom and heterocycle affects “fine” changes in the character of the M-π-interaction, depending on the nature of the substituents and orientation of the carbonyl groups.

Synthesis and properties of quinazoline derivatives containing cymantrenyl group

The synthesis of new quinazoline derivatives with 2,3- and 4-positioned cymantrenyl fragment is described. Alkylation of 2-substituted quinazolin-4-ones with cymantrenylalkyl bromides on using K2CO3, potassium tert-butoxide, and sodium hydride as bases has been studied. It is established for the first time that condensation of 2-methylquinazolin-4-ones with aldehydes can cause elimination of the substituent at the nitrogen atom in position 3. The new cymantrene derivatives possess fluorescence properties.

Oxidative transformatons of 2-aryl-1,2,3,4,7,8-hexahydroacenaphtho[5,6-bc]azepin-4-ones

Reactions of partial (elimination of H2 from the bimethylene unit) and exhaustive (elimination of 2H2 from the bimethylene unit and the seven-membered heterocycle) dehydrogenation of 2-aryl-1,2,3,4,7,8-hexahydroacenaphtho[5,6-bc]azepin-4-ones were performed. The effect of the electronic structure of initial and dehydrogenated compounds on their spectral characteristics was discussed. New peri-fused heterocyclic systems were obtained.