Yurii T. Struchkov

Electrochemical transformation of cyanoacetic ester and aldehydes into 3-substituted 1,2-dicyanocyclopropane-1,2-dicarboxylates

Abstract Electrolysis of cyanoacetic ester in the presence of aldehydes and NaBr in alcohols in an undivided cell results in formation of 3-substituted 1,2-dicyanocyclopropane-1,2-dicarboxylates.

Macrobicyclic d-metal tris-dioximates obtained by cross-linking with p-block elements Part IV. Crystalline and molecular structure of an iron(II) complex with macrobicyclic fluoroborate-containing tris-diphenylglyoximate ligand and its Mössbauer (57Fe) parameters

Abstract Hexagonal FeBd 3 (BF) 2 ·5CHCl 3 single crystals (space group P 6 3 , a =14.975(2), c =16.301(3) A, V =3166(1) A 3 , Z =2) have been obtained by recrystallizing a preliminarily synthesized clathrochelate diphenyl- glyoximate complex. The iron atom is encapsulated by the macrobicyclic ligand and surrounded by a distorted trigonal prismatic coordination consisting of six nitrogen atoms. The distortion angle value found experimentally ( c. 29.3°) is close to that estimated earlier from Mossbauer parameters (27–30°). The FeN bond length (1.91(2) A) is characteristic of clathrochelate boron-containing iron(II) dioximates and is determined by the superposition of the contributions of metal eletron configuration and ligand geometry.

Polynuclear molybdenum(VI)–molybdenum(V) complex: a precursor of the catalyst for dinitrogen reduction

Crystal structure was determined of the complex {[Mg2Mo8O22(MeO)6(MeOH)4]2–[Mg(MeOH)6]2+}· 6MeOH (1), isolated from methanolic solution containing MoV, MoVI, and MgII compounds; when reduced to the MoIII state the complex forms an active catalyst for N2 reduction in methanol at ambient temperature and pressure.

MACROBICYCLIC D-METAL TRIS-DIOXIMATES OBTAINED BY CROSS-LINKING WITH P-BLOCK ELEMENTS. PART VI. PREPARATION, MOLECULAR STRUCTURE AND MÖSSBAUER (57FE, 119SN) PARAMETERS OF AN IRON(II) COMPLEX WITH A MACROBICYCLIC TIN-CONTAINING TRIS-NIOXIMATE LIGAND

Abstract The tin-containing clathrochelate complex of Fe(II) with cyclohexanedione-1,2-dioxime (nioxime, H2Nx), [FeNx3(SnCl3)2]2- · (Et2NH+ 2)2 · Et2NH2 + · Cl− · 2Pri OH was prepared by slowly adding diethylamine to a solution containing the macrobicyclic [FeNx3(SnCl3)2]2- anion. The structure of the complex has been determined by X-ray methods. Crystal data: monoclinic, space group P21/c, a = 10.565(2), b = 25.413(5), c = 20.198(4)A, β=95.40(3)°, Z = 4. The iron atoms is encapsulated by the clathrochelate ligand and surrounded by a distorted trigonal antiprismatic coordination sphere comprising by six nitrogen atoms of three dioxime residues. The experimental value of the distortion angle (ca 37.5°) is close to that predicted by the Mossbauer (57Fe) parameters (ca 40°). The average Fe-N bond length of 1.923A is somewhat greater than that in boron-containing analogues. The Sn atoms have a slightly distorted octahedral coordination, which also correspond to Mossbauer (119Sn) spectroscopic data. The six-me...

2-benzopyrylium salts. XXXVII. Oxygen analogs of reissert compounds : molecular structure and reactions with sodium hydroxide

Abstract The weak intensity of the CN stretching band in IR spectra for 1-cyanoiso chromenes is obviously determined by the steric position of the CN group in the molecule, as it was established by X-ray structural analysis for the cyanide addition product 2d of 1-isopropyl-3-methyl-2-benzopyrylium salts. Depending on the other substituent in position 1, 1-cyanoisochromenes in aqueous solutions of sodium hydroxide eliminate hydrogen cyanide 2a , b , e , undergo inter- 3a , b or intra-mlecular 2c , d recyclisation, or hydrolysis of the cyano group in 2f ; reaction products include α-naphthols 7c , e , β-naphthol 7d , acylchrysenes 5a , b , or the iso chromene-amide 11f , a stable 1-alkylideneisochromene 3e was obtained, and the intermediacy of 3-hydroxy-1-alkylideneiso chromenes was proved by their isolation in the cases of 10c , d

MACROBICYCLIC d-METAL TRIS-DIOXIMATES OBTAINED BY CROSS-LINKING WITH p-BLOCK ELEMENTS. XV. CRYSTAL AND MOLECULAR STRUCTURES OF TWO MACROBICYCLIC TIN-CONTAINING COBALT(III) TRIS-DIOXIMATES

Abstract The structure of the tin-containing clathrochelates cyclohexadione-1,2-dioximate (NBu4)[CoNx3 (SnCl3)2] (A) and dimethylglioximate (NBu4)[CoDm3(SnBr3)2]·H2O (B) have been determined by X-ray methods. Crystal data: (A) is orthorhombic, space group P212121 a = 16.566(4), b = 16.551(4), c = 16.560(4)A, Z = 4; (B) is orthorhombic, space group Pca21, a = 16.271(3), b = 15.337(3), c = 18.572(4)A, Z = 4. The cobalt(III) atoms are encapsulated by the clathrochelate ligands and surrounded by a distorted octahedral coordination polyhedron.

An unusual ring closure reaction with formation of pyrrolidin-2,5-dione derivatives

Mild oxidation of amidine (1) bearing two sterically crowded phenol moieties leads to the formation of the dispirocyclohexadienone derivative (6) of pyrrolidin-2,5-dione N-arylamine through an intramolecular ring closure recombination of the intermediate biradical (4).