Solvent mediated reaction of 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-tetrazoline-5-thione with iodine

1-Methyl-1H-tetrazoline-5-thione (1) reacts with iodine in CHCl₃ with formation of 1:1 stable σ-complex (logβ = 3.8 ± 0.1 is found by spectrophotometry). In the ethanol solution irreversible oxidation with formation of disulfide product 5,5′-dithiobis(1-methyl-1H-tetrazole) (2) is observed. The structure of (2) was determined by X-ray diffraction. Strong intermolecular interactions with shortened contacts are observed between sulfur atom of disulfide bridge and heterocyclic nitrogen of the neighboring molecule (S···N 3.0179(15) Å) forming infinite supramolecular chains which are further linked with π–π stacking interaction of tetrazole rings (interplane distance is 3.1685(6) Å).     

A specific intramolecular interaction in a bis(2-thienyl)maleimide derivative

Russian Chemical Bulletin - 3,4-Bis(4-ethoxycarbonyl-3-hydroxy-5-methyl-2-thienyl)-1-phenyl-1H-pyrrole-2,5-dione shows no photochromism in the crystalline state, despite its typical...     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-(2-hydroxyphenyl)-1,8-naphthalimide and its derivatization at the hydroxy group

The reaction of 1,8-naphthalic anhydride with 2-aminophenol afforded N-(2-hydroxyphenyl)-1,8-naphthalimide, which was then derivatized at the hydroxy group.     

Novel hydrazone derivatives of 7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐carbaldehyde

The structures of new oxaindane spiropyrans derived from 7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐carbaldehyde (SP1), namely N‐benzyl‐2‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]hydrazinecarbothioamide, C₂₇H₂₅N₃O₃S, (I), at 120 (2) K, and N′‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]‐4‐methylbenzohydrazide acetone monosolvate, C₂₇H₂₄N₂O₄·C₃H₆O, (II), at 100 (2) K, are reported. The photochromically active C_spiro—O bond length in (I) is close to that in the parent compound (SP1), and in (II) it is shorter. In (I), centrosymmetric pairs of molecules are bound by two equivalent N—H...S hydrogen bonds, forming an eight‐membered ring with two donors and two acceptors.     

Synthesis and Pharmacological Activity of 20-Keto-29-norlupane Derivatives

New 20-oxo- and hydroxyimino-derivatives of betulin that exhibit immunotropic and antiviral activities were synthesized. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 582–584, November–December, 2005.     

Heterometallic (ZrIII)2—Al hydrides [(Cp2Zr)2(μ-H)](μ-H)2AlX2 (X = Cl or Br): preparative synthesis and reactivity. Molecular structure of [(Cp2Zr)2(μ-Cl)](μ-H)2AlCl2

A procedure was developed for the synthesis of trinuclear cyclic (Zr^III)₂—Al hydrides [(Cp₂Zr)₂(μ-H)](μ-H)₂AlX₂ (X = Cl (1a) or Br (1b)). These complexes were prepared in 60–65% yields by the reaction of Cp₂ZrX₂ with LiAlH₄ in the presence of CoBr₂ and tolane. The structures of complexes 1a and 1b and iodide 1c (X = I) were studied by NMR spectroscopy in solvents of different basicities (toluene, THF, and pyridine). Complex 1a is unsolvated and monomeric in all solvents; complex 1b, in toluene and THF; complex 1c, in toluene only. At room temperature, complex 1a does not catalyze hydrogenation of hex-1-ene and does not react with tolane, but reacts with the latter at high temperature to give bis(η⁵-cyclopentadienyl)-2,3,4,5-tetraphenylzirconacyclopentadiene. The reaction of equivalent amounts of complex 1a and HCl produces the [(Cp₂Zr)₂(μ-Cl)](μ-H)₂AlCl₂ complex. The structure of the latter was established by X-ray diffraction. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2418–2423, November, 2005.     

Formation of substituted pyrazolines in the reaction of C,N-diphenylnitrilimine with a zwitterion derived from triisopropylphosphine and ethyl 2-cyanoacrylate

The reaction of C,N-diphenylnitrilimine with a P-zwitterion derived from Prⁱ ₃P and H₂C=C(CN)CO₂Et afforded the first representative of 2-pyrazolines containing the phosphonium group and products of the addition of nitrilimine to Prⁱ ₃P and H₂C=C(CN)CO₂Et. The reaction of the P-zwitterion with C-4-nitrophenyl-N-phenylnitrilimine gave rise to a condensation product of one Prⁱ ₃P molecule and two nitrilimine molecules. The three-dimensional structures of the compounds synthesized were established by X-ray diffraction analysis.     

Magnetic Properties of the Dicationic Iron o-Quinone Complexes with the Pyridinophane Ligands: A Quantum Chemical Study

Russian Journal of Coordination Chemistry - Computer modeling of the dicationic iron o-benzoquinone complexes with the 2,11-diaza[3.3]-(2,6)pyridinophane ligands is performed. The ground states of...