Synthesis and transformations of metallacycles 42. Cp2ZrCl2-Catalyzed cycloalumination of 3-methylidenespiro[cyclobutane-1,3′-(5′α)-cholestane] with Et3Al

A Cp₂ZrCl₂-catalyzed cycloalumination of 3-methylidenespiro[cyclobutane-1,3′-(5′α)-cholestane] with Et₃Al gives 3-ethyl-3-aluminadispiro[cyclopentane-1,1′-cyclobutane-3′,3″-(5″α)-cholestane] in 84% yield.     

Electrochemical charactreistics of membranes based on Mn(III) tetraphenylporphyrin

Anion-selective electrodes with polymer membranes based on manganese(III) tetraphenylporphyrin (TPP) complexes with various axial ligands (chloride, perchlorate, nitrate, and rhodanide) were studied. The electrodes showed high (compared with other anions) selectivity toward the salicylate anion in a wide range of concentrations at different pH values. The selectivity coefficients of membrane electrodes $K_{Sal^ - /X^{n - } }^{sel} $ were determined by the bi-ionic potential method. A selectivity series was obtained based on $K_{Sal^ - /X^{n - } }^{sel} $ , which differs from Hofmeister series for classical anion exchangers. The possibility of using these electrodes in clinical practice for determining salicylate ions in human blood was shown.     

First cobalt (borole)arene complexes [(η-C4H4BOH)Co(arene)]+

Heating of (η-C₄H₄BCy)Co(CO)₂I (Cy is cyclohexyl) with arene ligands in the presence of AlCl₃ at 80 °C followed by hydrolysis afforded the [(η-C₄H₄BOH)Co(arene)]⁺ complexes (arene = C₆H₆ (2a), C₆H₅Me (2b), and 1,3-C₆H₄Me₂ (2c)). The starting iodide complex was synthesized by the reaction of [(η-C₄H₄BCy)Co(CO)₂]₂ with I₂. The structure of [2a]BPh₄ was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1620–1622, August, 2008.     

Synthesis and spectroscopy of cis-configured mononuclear palladium(II) and platinum(II) complexes of chalcogeno o-carboranes and structures of [Pt(SCboPh)2(dppm)], [Pt(SeCboPh)2(dppm)], [Pt(SCboS)(PMe2Ph)2] and [Pt(SCboS)(PMePh2)2]

The reactions of [MCl₂(P^∩P)] and [MCl₂(PR₃)₂)] with 1-mercapto-2-phenyl-o-carborane/NaSeCb^oPh and 1,2-dimercapto-o-carborane yield mononuclear complexes of composition, [M(SCb^oPh)₂(P^∩P)], [M(SeCb^oPh)₂(P^∩P)] (M = Pd or Pt; P^∩P = dppm (bis(diphenylphosphino)methane), dppe (1,2-bis(diphenylphosphino)ethane) or dppp (1,3-bis(diphenylphosphino)propane)) and [M(SCb^oS)(PR₃)₂] (2PR₃ = dppm, dppe, 2PEt₃, 2PMe₂Ph, 2PMePh₂ or 2PPh₃). These complexes have been characterized by elemental analysis and NMR (¹H, ³¹P, ⁷⁷Se and ¹⁹⁵Pt) spectroscopy. The ¹J(Pt–P) values and ¹⁹⁵Pt NMR chemical shifts are influenced by the nature of phosphine as well as thiolate ligand. Molecular structures of [Pt(SCb^oPh)₂(dppm)], [Pt(SeCb^oPh)₂(dppm)], [Pt(SCb^oS)(PMe₂Ph)₂] and [Pt(SCb^oS)(PMePh₂)₂] have been established by single crystal X-ray structural analyses. The platinum atom in all these complexes acquires a distorted square planar configuration defined by two cis-bound phosphine ligands and two chalcogenolate groups. The carborane rings are mutually anti in [Pt(SCb^oPh)₂(dppm)] and [Pt(SeCb^oPh)₂(dppm)].     

Molecular structure of (4Z)-{[(1<Emphasis Type="Italic">R</Emphasis>,6<Emphasis Type="Italic">S</Emphasis>)-7,7-dimethyl-2-oxo-3-oxabicyclo [4.1.0] hept-4-en-4-yl]methylene}-2-phenyl-l,3-oxazol-5(4H)-one

The (4Z)- {[(1R, 6S)-7,7-dimethyl-2-oxo-3-oxabicyclo[4.1.0]hept-4-en-4-yl]methylene}-2-phenyl-1,3-oxazol-5(4H)-one compound is synthesized and its molecular structure is determined.     

Electrochemical properties and spectrophotometry of membranes based on holmium tetraphenylporphyrinchloride

Protolytic properties of holmium tetraphenylporphyrinchloride were studied by the method of two-phase spectrophotometric titration with potentiometric monitoring of pH of the medium. Apparent constants of the heterophase reaction of the exchange of an anion for the hydroxide ion were determined. It was found that the membranes based on holmium tetraphenylporphyrinchloride with dibutyl phthalate as a solvent-softener are selective to ions of alkaline earth metals (Ca²⁺ and Ba²⁺) in the region of pH > 7 over the concentration range from 1 up to 1×10⁻⁴ M. Selectivity coefficients were determined by two independent methods: the method of biion potentials and the method of mixed solutions. The found selectivity series coincides with traditional Hofmeister series for cations.     

Thiomethylation of heteroaromatic amines

Thiomethylation of heteroaromatic amines with formaldehyde-hydrogen sulfide gave linear and cyclic heteroatom compounds: N,N′-[methylenebis(sulfanediylmethylene)]bishetarenamines and 5-hetaryl-1,3,5-dithiazinanes. N,N′-[Methylenebis(sulfanediylmethylene)]bishetarenamines were found to undergo transformation into 5-hetaryl-1,3,5-dithiazinanes by the action of CH₂O-H₂S. Transamination of 5-methyl-1Hpyrazol-3-amine, 6-nitro-1,3-benzothiazol-2-amine, and 5-bromopyridin-2-amine with 5-methyl-1,3,5-dithiazinane selectively afforded the corresponding 5-hetaryl-1,3,5-dithiazinanes.