Russian Journal of Coordination Chemistry最新文献

The reduction of the heteroleptic cobalt(III) complexes with bipyridine ligands of different structures of the model drug molecule is studied by in situ NMR spectroscopy. The nature of the ligand eliminated during reduction is shown to exert a substantial effect on the reduction rate, which indicates that an optimum amount of cobalt should be chosen for the redox-activated delivery of a certain drug.

The Сd(II) complexes with redox amphoteric 2,6-di-(tert-butyl)-4-((2-hydroxyphenyl)imino)cyclohexa-2,5-dienone ligands L¹ and L² (adducts I, II, and III) are synthesized. The structures of coordinated complexes I, II, and III are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 1838319 (II) and 1838310 (III)) and confirmed by the ¹Н, ¹³С, and ¹¹³Cd NMR spectroscopy (for complexes I and III) and IR spectroscopy data.

New crystalline pseudo-polymer complex [Au{S₂CN(CH₂)₆}₂]₄[Ag₅Cl₉] (I) was obtained by binding gold(III) with silver(I) hexamethylenedithiocarbamate from an AuCl₃/2.5 M NaCl solution. Complex I was isolated in a preparative yield and structurally characterized. The X-ray diffraction (XRD) data (CIF file CCDC no. 2205197) show that the isomeric cations of [Au{S₂CN(CH₂)₆}₂]⁺ (A : 2B : C) and complicated pentanuclear anion [Ag₅Cl₉]^4– are the main structural units of the compound. The supramolecular self-organization of the ionic structural units in complex I occurs due to multiple secondary interactions Cl···S and Ag···S, hydrogen bonds C–H···Cl, and anagostic interactions C–H···Ag, resulting in the formation of the 3D pseudo-polymer framework. The thermal behavior of complex I is studied by simultaneous thermal analysis to find that the thermolysis of the double Au(III)–Ag(I) compound is accompanied by the quantitative regeneration of the bound metals under comparatively mild conditions.

Complexes [PdL₂Cl₂] (I) and [PdL₂Вr₂] (II) (L is 5-acetyl-6-methyl-4-(3-nitrophenyl)-1,2,3,4-tetrahydropyrimidine-2-thione) are synthesized and characterized by spectral methods (¹Н, ¹³С NMR and IR spectroscopy). The crystal structure of complex I is determined (CIF file ССDС no. 2233053) in which the palladium atom is coordinated by two halide ions and two sulfur atoms of two ligands L in a distorted square planar geometry. The catalytic activity of the synthesized palladium(II) complexes in the model epoxidation of allyl alcohol is estimated in comparison with the catalytic activity of the corresponding palladium halides and titanium-containing zeolite TS-1.

A new redox-active cobalt(III) complex containing the 2-oxo-2Н-chromene-6,7-diolate dianion and 4,4'-dimethoxy-2,2'-bipyridine as ligands is synthesized. The reduction of the synthesized complex with ascorbic acid in an inert atmosphere is studied in situ by NMR spectroscopy. The reduction is shown to result in the release of 6,7-dihydrocycoumarin acting as a model drug. This process has the first order with respect to the initial complex.

The reaction of aluminum bis-formate acenaphthene-1,2-diimine complex [(Ar^BIG-bian)Al(μ-OC(H)O)₂Li(Thf)₂] (I) (Ar^BIG-bian = 1,2-bis[(2,6-dibenzhydryl-4-methylphenyl)imino]acenaphthene), prepared by binding carbon dioxide by aluminum diimine hydride [(Ar^BIG-bian)Al(H)₂]^–[Li(Thf)₄]⁺, with borane dimethyl sulfide and ammonia was studied. The reaction of I with BH₃∙SMe₂ (1 : 1) in toluene affords the product of hydroboration of one formate group [(Ar^BIG-bian)Al(μ-OC(H)O)(OB(H)OCH₃)Li(Thf)]₂ (II), while the reaction of I with BH₃∙SMe₂ (1 : 2) is accompanied by reduction of both formate groups and gives complex [(Ar^BIG-bian)Al(OBOCH₃)₂OLi₂(Thf)₂BH₄]₂ (III), methoxyboroxine (CH₃OBO)₃ and, presumably, compound [(Ar^BIG-bian)AlOCH₃]. The reaction of I with one equivalent of ammonia in THF gives adduct [(Ar^BIG-bian)Al(NH₃)(μ-OC(H)O)₂Li(Thf)₂] (IV), in which ammonia is coordinated to the aluminum atom, while the key bonds in I have not undergone ammonolysis. Compounds II–IV were characterized by IR and NMR spectroscopy, elemental analysis, and X-ray diffraction (CCDC no. 2255017 (II), 2255018 (III), 2255019 (IV)).