Crystal structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(4-phenyliminopentan-2-onate)

trans-Bis-(4-phenyliminopentan-2-onato)Cu(II) (5), which is a phenyl-substituted ketoimine, was synthesized, and an X-ray study was performed for this compound. Crystal data for CuN₂O₂C₂₂H₂₄: a = 11.4557(3) Å, b = 26.6845(9) Å, c = 14.2976(5) Å, β = 113.2270(10)°; space group P2₁/n, Z = 8, d _calc = 1.363 g/cm³, R = 0.033. The structure is molecular and built of isolated trans complexes. The central copper atom is surrounded by four atoms (2O+2N) with the average distances Cu-O 1.904(3) Å and Cu-N 1.962(3) Å. The polyhedron around the copper atom is a distorted tetrahedron; the average values of the O-Cu-O and N-Cu-N trans bond angles are 147(2)° and 150(2)°, respectively. The average value of the O-Cu-N angles is 94(1)°.     

Crystal and molecular structure of <Emphasis Type="Italic">tris</Emphasis>-(1,1,1-trifluoro-5,5-dimethylhexan-2,4-dionato)iron(III)

Synthesis and results of the single crystal X-ray diffraction study of iron(III) pivaloyltrifluoroacetonate are reported. Crystal data for C₂₄H₃₀FeF₉O₆: a = 9.2205(6) Å, b = 9.6584(10) Å, c = 17.3799(17) Å, α = 75.902(2)°, β = 80.517(3)°, γ = 82.746(3)°, space group P-1, V = 1474.6(2) ų, Z = 2. The structure is molecular with the octahedral environment of Fe atom, Fe-O_av 1.991 Å, ∠O-Fe-O_av 86.48°. The van der Waals energy of intermolecular interactions is calculated and compared to thermodynamic data.     

Crystal structure of <Emphasis Type="Italic">trans</Emphasis>-bis(trifluoro-acetylacetonato)copper(II)

Triclinic modification of trans-bis(trifluoroacetylacetonato)copper(II) is studied by single crystal X-ray diffraction (diffractometer X8 APEX BRUKER, MoK _α radiation, T = 173(2) K). The structure is molecular. Square environment of the Cu atom (Cu-O_av 1.916 Å, ∠O-Cu-O_av 93.4°) is completed to a bipyramid by two atoms of neighboring molecules, Cu...C_γ 3.18 Å and 3.23 Å.     

Crystal and molecular structure of <Emphasis Type="Italic">tris</Emphasis>(<Emphasis Type="Italic">m</Emphasis>-chlorophenyl)phosphine selenide

The crystal and molecular structure of tris(m-chlorophenyl)phosphine selenide, C₁₈H₁₂Cl₃PSe (I), was investigated by X-ray diffraction (XRD) analysis. The trigonal rhombohedral structure of I (space group \(R\overline 3 c\), a = 14.110(2) Å, c = 32.360(4) Å, Z = 12) was solved by direct methods and refined by least squares in an anisotropic approximation (R = 0.029) for 1319 averaged measured reflections (CAD-4 automatic diffractometer, λCuK_α).     

Crystal and molecular structure of copper(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(2-(methylimino)-4-pentanonate)

Synthesis and X-ray diffraction study of trans-bis-(2-(methylimino)-4-pentanonato)Cu(II), which is methyl-substituted ketoiminate, is reported. Crystal data for CuN₂O₂C₁₂H₂₀: a = 7.374(1) , b = 9.171(1) , c = 10.823(2) ; = 96.51(1)°, = 106.12(1)°, = 96.81(1)°, space group P , Z = 2, d _calc = 1.38 g/cm³, d _exp = 1.37 g/cm³, R = 0.037. The structure is molecular and consists of isolated trans-complexes. The coordination polyhedron of the copper atom is intermediate between the square and tetrahedron; the average distances are Cu-O 1.91 and Cu-N 1.95 , the O-Cu-O and N-Cu-N trans bond angles are 145.5° and 150.3°, respectively. The O-Cu-N chelate angle is 94.6°. The calculated energies of van der Waals intermolecular interactions are compared with the thermogravimetric characteristics of the complex with ketoiminate and copper(II) ethylenediamine-bis-acetylacetonate.Original Russian Text Copyright © 2004 by I. A. Baidina, P. A Stabnikov, A. D. Vasiliev, S. A. Gromilov, and I. K. IgumenovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 706–712, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Crystal structure of 1-(2-pyridiniomethyl)-2,4-<Emphasis Type="Italic">bis</Emphasis>(phenylsulfonyl)benzene bromide

The crystal structure of 1-(2-pyridiniomethyl)-2,4-bis(phenylsulfonyl)benzene bromide, (C₂₄H₂₀NO₄S₂)⁺. Br^– (I) has been investigated by X-ray diffraction (XRD)analysis. The triclinic structure of I (space group P1, a = 7.863 , b = 8.350 , c = 9.043 , = 94.00°, = 97.81°, = 104.62°, Z = 1) was solved by direct methods and refined by full-matrix least-squares analysis in an anisotropic approximation to R = 0.048 for all 4570 reflections collected (CAD-4 automatic diffractometer, CuK ). The geometrical parameters of the organic cation were determined with a sufficient degree of accuracy. The crystal structure of I involves a very strong interionic hydrogen bond N⁺-HBr^–.Original Russian Text Copyright © 2004 by A. N. ChekhlovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 759–763, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Synthesis of (<Emphasis Type="Italic">E</Emphasis>)-<Emphasis Type="Italic">N</Emphasis>-(3-alkoxy-4-acyloxyphenylmethylene)-<Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">e</Emphasis>-cyclohexyl)amines

Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine.     

Crystal and molecular structure of new tetrahydrobenzo[<Emphasis Type="Italic">e</Emphasis>]pyrano[4,3-<Emphasis Type="Italic">b</Emphasis>]pyridines

Three tetrahydrobenzo[e]pyrano[4,3-b]pyridines formed in a diethyl 2,4,6-trioxoheptanedicarboxylic ether-substituted salicylic aldehyde-ammonium acetate system were studied by single crystal X-ray diffraction. After the introduction of a methoxy group in the tricyclic system, the tetrahydropyridine and pyrane rings adopted the half-chair conformation, while in the unsubstituted compound, the tetrahydropyridine ring has a distorted boat conformation, and the pyrane ring has a C-envelope conformation. In the compounds, the N-H?O and O-H?O intermolecular hydrogen bonds give rise to the development of chain structures. In two of the three compounds examined, the hydrogen atoms at the chiral centers are in the trans-position, as in the structure of natural tetrahydrocannabinols.     

Vapor pressure and crystal structure of platinum(II) <Emphasis Type="Italic">trans</Emphasis>-bis-(trifluoroketoiminate)

The temperature dependence of the saturated vapor pressure of the trans-Pt(ktf)₂ complex obtained from fluorinated β-ketoimine (CF₃-CO-CH₂-C(NH)-CH₃) was studied by the flow method. The standard thermodynamic parameters ΔH ₀ ^T and ΔS ₀ ^T of sublimation have been determined. Full crystal-chemical study has been performed for the complex. Crystal data for C₁₀H₁₀F₆N₂O₂Pt: a = 5.9790(8) Å, b = 7.373(2) Å, c = 8.5767(2) Å,α = 84.05(2)°, β = 72.43(1)°, γ = 67.14(1)°, V = 332.1(1) ų, Z = 1, d_calc = 2.496 g/cm³, triclinic, space group \(P\bar 1\). The structure is molecular and consists of isolated trans-Pt(ktf)₂ complexes. The Pt atom lies at the symmetry center and has a square planar environment of two oxygen and two nitrogen atoms; the distances Pt-O (1.984 Å) and Pt-N (1.969 Å) are similar within the limits of 2σ; the OPtN bond angle is 93.9°. Molecular packing in crystal is considered based on structural data; van der Waals energy of the crystal lattice of trans-Pt(ktf)₂ was calculated by the atom-atom potential method.     

A density functional study on magnetic exchange interaction between Mn(II) ion and nitronyl nitroxide radical in <Emphasis Type="Italic">trans</Emphasis>-and <Emphasis Type="Italic">cis</Emphasis>-metal-radical complexes

The magneto-structural correlation between a Mn(ll) ion, coordinated in an octahedral environment, and two nitronyl nitroxide radical ligands in trans- and cis-metal-radical complexes is investigated by the broken symmetry (BS) approach within density functional theory (DFT). The dependences of coupling constants J on three structural parameters: (i) bond angle θ (Mn-O-N (nitroxide)); (ii) rotating angle ψ, defined by the nitronyl nitroxide radical plane rotating around the axial Mn-O (nitroxide); (iii) bond distance R (Mn-O (nitroxide)) are directly calculated. Our calculations showed that both trans- and cis-Mn(ll)-radical complexes behave a stronger antiferromagnetic interaction, consistent with experiments. In view of molecular orbital theory, the direct exchanges, including σ-type and π-type exchanges, are responsible for the magnetic exchange pathways. There is a preferable linear correlation between the calculated coupling constants J and the overlap integral squares S b between the local magnetic orbitals at the various rotating angle ψ at the fixed bond angle θ and bond distance R, in both trans- and cis-Mn(ll)-radical complexes.     

Synthesis,structure, and physicochemical properties of the Cr(<Emphasis Type="Italic">iso</Emphasis>-Bu<Subscript>2</Subscript>PS<Subscript>2</Subscript>)<Subscript>3</Subscript> chelate compound

A paramagnetic (μ_ef = 3.86 BM) complex Cr(i-Bu₂PS₂)₃ (I) has been synthesized. Single crystals I were grown, and the crystal structure of the compound was determined from X-ray diffraction data (X8 APEX diffractometer, MoK _α radiation, 4516 F _hkl , R = 0.0604). Monoclinic crystals, space group P2₁/n, unit cell parameters a = 14.2665(5) Å, b = 11.4400(4) Å, c = 23.1299(8) Å, β = 90.245(1)°, V = 3775.0(2) ų, Z = 4, d _calc = 1.196 g/cm³. The structure is based on discrete mononuclear molecules. The coordination polyhedron of the Cr atom is a distorted S₆ octahedron formed from the S atoms of three cyclic bidentate ligands — i-Bu₂PS ₂ ⁻ ions. Electron spectroscopy data correspond to the octahedral structure of the CrS₆ chromophore. Original Russian Text Copyright ? 2007 by E. A. Sankova, L. A. Glinskaya, T. E. Kokina, R. F. Klevstova, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 2, pp. 374–378, March–April, 2007.     

Synthesis of <Emphasis Type="Italic">N</Emphasis>-(2-chloroethyl)glycine and -<Emphasis Type="SmallCaps">DL</Emphasis>-alanine esters

Two methods for the synthesis of N-(2-chloroethyl)glycine and-DL-alanine esters are proposed: 1) reductive amination of the C=O group of glyoxilic or pyruvic acids upon treatment with 2-chloroethylamine and sodium cyanoborohydride in methanol and 2) alkylation of 2-chloroethylamine with α-haloalkanoic acid esters in K₂CO₃-MeCN two-phase system. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2372–2374, December, 2007.     

An efficient <Emphasis Type="Italic">Mannich</Emphasis>-type synthesis of <Emphasis Type="Italic">bis</Emphasis>(pyrido[2,1-<Emphasis Type="Italic">b</Emphasis>][1,3,5]thiadiazin-7-yl)-methanes

Morpholinium 3-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-thiolate upon treatment with primary amines and a formaldehyde excess under mild conditions produces bis(pyrido[2,1-b][1,3,5]thiadiazin-7-yl)methane derivatives in good yields (67–87%). Correspondence: Victor V. Dotsenko, State Enterprise “Luganskstandartmetrology”, 91021 Lugansk, Ukraine.     

Crystal structures of <Emphasis Type="Italic">trans</Emphasis>-dichlorobis(ethylendiamine) rhodium(III) with univalent anions

The crystal structures of the compounds trans-[Rh(en)₂Cl₂]Cl₂ · H₅O₂ (I), trans-[Rh(en)₂Cl₂]ClO₄ (II), and trans-[Rh(en)₂Cl₂]ReO₄ (III) are determined. The crystal data are: I, a = 10.860(3) Å, b = 7.795(2) Å, c = 9.023(3) Å; β = 111.56(10)°, P2₁/c space group, Z = 4, d _x = 1.875 g/cm³; II, a = 6.593(2) Å, b = 8.309(3) Å, c = 11.922(4) Å, α = 83.55(10)°, β = 79.80(10)°, γ = 75.38(10)°, P \(\bar 1\) space group, Z = 2, d _x = 2.106 g/cm³; III, a = 6.533(2) Å, b = 16.391(4) Å, c = 12.411(3) Å; β = 98.30(10)°, P2₁/c space group, Z = 4, d _x = 2.749 g/cm³. The compounds are examined by IR spectroscopy and powder XRD. The solubility of the isolated crystalline phases in water decreases in the following order: trans-[Rh(en)₂Cl₂]Cl₂·H₅O₂ > trans-[Rh(en)₂Cl₂]ClO₄ > trans-[Rh(en)₂Cl₂]ReO₄.     

Synthesis of <Emphasis Type="Italic">o</Emphasis>(<Emphasis Type="Italic">m</Emphasis>)-carborane-containing azomethines

A method of preparative synthesis of o(m)-carborane-containing azomethines via the condensation of o(m)-carboranyl-C-methylene-4-formylbenzoates with aliphatic, cycloaliphatic, and aromatic amines was developed.     

Crystal and molecular structure of 2-(<Emphasis Type="Italic">o</Emphasis>-hydroxyphenyl)-4,6-diphenylpyridine

Crystal and molecular structure of 2-(o-hydroxyphenyl)-4,6-diphenylpyridine C₂₃H₁₇NO (I) has been studied by single crystal XRD. The structure (monoclinic, space group P2₁/c, a = 8.757(2) Å, b = 20.682(4) Å, c = 9.743(2) Å, β = 108.14(2)°, Z = 4) was solved by the direct method and refined anisotropically in the full-matrix approximation to R = 0.076 using all 2660 measured independent reflections (automated diffractometer CAD-4, CuK_α). OH group of the molecule of I is disordered in the crystal over three positions with occupation factors 70%, 15% and 15%. The structure contains a very strong intramolecular hydrogen bond O-H?N disordered over three directions.     

Conformations and properties of <Emphasis Type="Italic">O</Emphasis>-Alkyl-<Emphasis Type="Italic">S</Emphasis>-(2-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dialkylamino)-ethylmethylthiophosphonates

Conformers of the biologically active compounds CH₃P(O)(OR)(SCH₂CH₂NR ₂ ^′ ), where (I) R = i-C₄H₉, R′ = C₂H₅ and (II) R = C₂H₅, R′ = i-C₃H₇, are calculated within the AM1 level of theory. The elongated and twisted forms with maximum and minimum distances between a nitrogen atom and those of a phosphorus tetrahedron, respectively, and bearing a syn and anti oriented alkoxy group relative to a phosphoryl oxygen, are studied. It is found that the differences between the energy, electronic, and geometric parameters of these forms are apparent in differences between their properties, e.g., the ability to participate in complexation and protonation, reactions that to some extent simulate the interaction between a substance and a biological object.     

Synthesis of (<Emphasis Type="Italic">E</Emphasis>)- and (<Emphasis Type="Italic">Z</Emphasis>)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles

Abstract  An efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations is discussed and the stereochemistries of all products were established by NMR experiments. Graphical abstract        

Asymmetric synthesis and stereochemistry of chiral <Emphasis Type="Italic">cis</Emphasis>- and <Emphasis Type="Italic">trans</Emphasis>-3-alkyl-4-aminopiperidines

Chiral nonracemic 3-substituted cis- and trans-4-aminopiperidines, which are precursors of anilidopiperidine analgesics, were obtained by diastereoselective synthesis from 1-methyl- and 1-benzyl-4-[(S)-1-phenylethyl]iminopiperidines, using the following reaction sequence: metalation with lithium diethylamide, alkylation with alkyl halides, and hydride reduction or hydrogenation over Raney nickel. The steric direction of the reaction, three-dimensional structure, preferred conformation, and absolute configuration of the resultant aminopiperidines were determined.