X-ray Crystal Structure Of Bis Research Articles

Bis(Nitroxymethylisoxazolyl) Furoxan: A Promising Standalone Melt-Castable Explosive.

The synthesis and crystal structure of the heterocyclic explosive bis(nitroxymethylisoxazolyl) furoxan, C10 H6 N6 O10 , are described. In addition, we report its physical properties and theoretical performance. This material was found to exhibit standalone melt-castable explosive properties, with a melting point of 89.8 °C and an onset decomposition temperature of 193.8 °C. Bis(nitroxymethylisoxazolyl) furoxan features an insensitive behavior to impact, friction, and electrostatic discharge, with a calculated detonation pressure about 25 % higher than the state-of-the-art melt-castable explosive TNT.

Aromaticity of metal acetylacetonates and a Möbius chelate of a cadmium(II) complex of an N4 helical ligand

Interaction of a benzene C–H tip with a metallacycle of various metal acetylacetonates are studied by means of DFT calculations at M062X/LanL2DZ and M062X/6-311++G(2d,p) levels. It is concluded that an angular interaction with a tilt angle θ of the C–H tip is diagnostic of aromaticity of a chelate ring in a metal acetylacetonate. Larger the θ value, the more aromatic is the probed molecule. This finding is supported by the known X-ray crystal structure of bis(acetylacetonato)platinum(II)-benzene. Acetylacetonate anion has 6 π electrons fulfilling Hückel’s 4n+2 rule for aromaticity. A thirteen membered 12 π electron chelate ring in a cadmium(II) complex of a helical N4 ligand is shown to be aromatic by establishing it as a Möbius object.

Synthesis and characterization of new 2-pyrimidyl chalcogen (S, Se, Te) compounds: X-ray crystal structure of bis(4,6-dimethyl-2-pyrimidyl)diselenide and 4,6-dimethyl-2-(phenylselanyl)pyrimidine

New and synthetically important symmetrical bis(4,6-dimethyl-2-pyrimidyl)dichalcogenides have been synthesized by reacting 4,6-dimethyl-2-chloropyrimidine with the corresponding dichalcogenide (E22− where E = S, Se, Te) ion. The unsymmetrical 4,6-dimethyl-2-(arylchalcogenyl)pyrimidines have also been prepared by reacting 4,6-dimethyl-2-chloropyrimidine with the arylselenide ion, ArSe− (Ar = phenyl, naphthyl, p-tolyl, 4-chloro-2-pyrimidyl). All the newly synthesized compounds have been thoroughly characterized with the help of various spectroscopic techniques viz., NMR (1H, 13C, 77Se), FT-IR and mass spectrometry (in representative cases). The crystal structures of bis(4,6-dimethyl-2-pyrimidyl)diselenide and 4,6-dimethyl-2-(phenylselanyl)pyrimidine have been determined by X-ray crystallography.

Synthesis and X-ray Crystal Structure of Bis(<i>O</i>-propylxanthato)-bis(3-chloropyridine)nickel(II)

Synthesis and X-ray Crystal Structure of Bis(<i>O</i>-propylxanthato)-bis(3-chloropyridine)nickel(II)

Synthesis and spectral studies of Ni(II) heterocyclic dithiocarbamates with S2PN chromophore: X-ray crystal structures of bis(1,2,3,4-tetrahydroquinolinecarbodithioato- S,S′)nickel(II) and 1,2,3,4-tetrahydroquinolinecarbodithioato-S,S′)(thiocyanato-N)(triphenylphosphine)nickel(II)

Synthesis and spectral studies of Ni(II) heterocyclic dithiocarbamates with S2PN chromophore: X-ray crystal structures of bis(1,2,3,4-tetrahydroquinolinecarbodithioato- S,S′)nickel(II) and 1,2,3,4-tetrahydroquinolinecarbodithioato-S,S′)(thiocyanato-N)(triphenylphosphine)nickel(II)

Synthesis and electrical conductivity of perchlorate-doped TTF–diamide nanofibers with double and triple helix structures

We synthesized 4,5-bis(octadecylthio)-4′,5′-bis(ethylcarbamoyl)tetrathiafulvalene and measured the electrical conductivity of its perchlorate (ClO4−)-doped nanofibers, which have double and triple helix structures. The nanostructure of the bis(octadecylthio)-TTF–diamide and its ClO4−-doped fibers in a 3 : 1 ratio was deduced in relation to the X-ray crystal structure of bis(methylthio)-TTF–diamide. The doubly coiled nanofibers form when initially formed spiral ribbons of lamellarly arranged TTF–diamide perchlorate split in the middle, and a further split of the double helix produces the triplex structure. Temperature-dependent conductance and current–voltage (I–V) characteristics of the coiled fibers were measured in the temperature (T) range of 70–300 K. The conductance decreased with a decrease in T, and the I–V characteristics were nonlinear over the entire T range. The results were analyzed by using a modified fluctuation-induced tunneling conduction model, where the barrier height and width were linearly dependent on the electric field.

A one-flask synthesis and characterization of novel symmetrical pyridyl monoselenides and X-ray crystal structure of bis(5-bromo-2-pyridyl) selenide and bis(2-bromo-5-pyridyl) selenide

Abstract The present work reports an efficient one-pot synthesis of symmetrical pyridyl monoselenides by the reaction of bromo-/iodopyridines with the isopropylmagnesium chloride, iPrMgCl followed by quenching with selenyl chloride, SeCl2. The current methodology constitutes a convenient synthesis of bis(5-bromo-2-pyridyl) selenide (I), bis(2-bromo-5-pyridyl) selenide (II) and bis(2,5-dibromo-3-pyridyl) selenide (III) under cryogenic conditions requiring shorter time duration to give satisfactory yields. The hitherto unknown compounds have been characterized by elemental analysis and various spectroscopic techniques i.e., 1H NMR, 13C NMR, FT-IR, mass spectrometry and X-ray crystallography.

Preparation and characterization of bis[4-dimethylamino-2-pyrimidyl] dichalcogenides (S, Se, Te): X-ray crystal structure of bis[4-dimethylamino-2-pyrimidyl] diselenide and its physicochemical behavior in microemulsion media

Novel and synthetically important bis[4-dimethylamino-2-pyrimidyl] dichalcogenides (S, Se, Te) have been prepared and characterized with the help of elemental analysis and various spectroscopic techniques. The methodology employs hydrazine hydrate in dimethylformamide to reduce elemental chalcogen to generate the dichalcogenide anions, E 2 2− (E=S, Se, Te), followed by reaction with 2,4-dichloropyrimidine to afford bis[4-dimethylamino-2-pyrimidyl] dichalcogenides in good yield. It further exploits the additional compositional degree of freedom available in mixed surfactant solution to allow solubilization and stabilization of bis[4-dimethylamino-2-pyrimidyl] diselenide in microemulsion media.

Synthesis and characterization of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) complexes of benzyl N-[1-(thiophen-2-yl)ethylidene] hydrazine carbodithioate and benzyl N-[1-(thiophen-3-yl)ethylidene] hydrazine carbodithioate and the X-ray crystal structure of bis{benzyl N-[1-(thiophen-2-yl)ethylidene] hydrazine carbodithioate}nickel(II)

Two bidentate Schiff bases have been synthesized by reaction of S-benzyldithiocarbazate with 2-acetylthiophene and 3-acetylthiophene to give benzyl N-[1-(thiophen-2-yl)ethylidene] hydrazine carbodithioate (SB2ATP) and benzyl N-[1-(thiophen-3-yl)ethylidene] hydrazine carbodithioate (SB3ATP). The SB2ATP and SB3ATP were then reacted with five metal ions, cobalt(II), nickel(II), copper(II), zinc(II) and cadmium (II) to form 10 metal complexes, all of general formula ML 2. The compounds synthesized were assayed for their bioactivities against selected pathogens and cancer cells. X-ray crystal structure analysis of Ni(SB2ATP) 2 showed it to be a distorted square planar complex. All the compounds are non-electrolytes in DMSO. Cu(SB2ATP) 2 showed strong activity towards Candida lypolytica. SB2ATP, SB3ATP, Co(SB2ATP) 2, Cd(SB2ATP) 2 and Cu(SB3ATP) 2 showed weak activity against several microbes and fungi while the others showed no activity toward these targets. SB2ATP and Cd(SB3ATP) 2 showed significant bioactivity towards human myeloid leukemia (HL-60) while Co(SB3ATP) 2 showed slight cytotoxic activity towards this cell line. SB2ATP, SB3ATP, Co(SB2ATP) 2, Cu(SB2ATP) 2, Cu(SB3ATP) 2, Zn(SB2ATP) 2 and Cd(SB2ATP) 2 showed significant chemotherapeutic activity against human breast carcinoma with positive estrogen receptor (MCF-7) while the remainder of the compounds showed significant bioactivity. The Schiff bases displayed higher cytotoxic activity compared to their metal complexes except for Cu(SB3ATP) 2. None of the compounds showed any cytotoxic activity towards human cervical cancer (HeLa) or towards human breast carcinoma with negative estrogen receptors (MDA-MB-231).

Synthesis and magnetic characteristic of new tetrabromo- and tetrachloroferrates(III) with 2-methylquinolinium cation: X-ray crystal structure of bis(2-methylquinolinium) bromide tetrabromoferrate(III)

The crystal and molecular structure of a new 2-methylquinolinium [2-Me(QH)] salt of stoichiometry (2-Me(QH)) 2FeBr 5 was determined. The iron cation is four coordinated by bromine anions, and it adopts a slightly distorted tetrahedral coordination with two angles smaller than tetrahedral, two equal to tetrahedral and two larger than tetrahedral. In the structure two intermolecular N–H⋯Br hydrogen bonds link the 2-MeQH + cations to dimers via a Br − bridge. The compound is isostructural with its chloride analog, (2-Me(QH)) 2FeCl 5. Magnetic measurements of the powdered samples gave negative values of Weiss constants equal −3.1 K for (2-Me(QH)) 2FeCl 5 and −10.2 K for (2-Me(QH)) 2FeBr 5 that suggest antiferromagnetic coupling. The susceptibility curves for (2-Me(QH)) 2FeBr 5 exhibit a maximum at 6 K indicating the presence of antiferromagnetic interactions transmitted in the crystal lattice.

Highly Selective Copper‐Catalyzed Monoarylation of Aniline

AbstractA series of mono‐, bi‐ and tridendate ligands was investigated in the copper‐catalyzed monoarylation of aniline with p‐chloronitrobenzene. Excellent selectivities at high conversions were observed when bridged bisimidazolidenes as well as biphenyl‐bisalkylphosphines were employed. The X‐ray crystal structure of bis(tert‐butyl)biphenylphosphine‐copper complex indicates a significant binding of the metal center to the aryl moiety and, thus, an almost bidendate coordination mode. Chelating bisphosphines, glycol, phenanthroline or other mono‐ to tridendate ligands led to less selective or productive catalysts.

Self-immobilized titanium and zirconium catalysts with phenoxy-imine ligands for ethylene polymerization. X-ray crystal structure of bis( N-(3- tert-butylsalicylidene)-4′-allyloxyanilinato) zirconium (IV) dichloride

Four self-immobilized FI catalysts with allyl substituted phenoxy-imine ligands [{4-(CH 2CHCH 2O)C 6H 5NCHC 6H 3(3- tert-C 4H 9)O} 2MCl 2] ( 1: M=Ti; 2: M=Zr), [{3-(CH 2CHCH 2O)C 6H 5NCHC 6H 3(3- tert-C 4H 9)O} 2MCl 2] ( 3: M=Zr), [{4-(CH 2CHCH 2-2,6-(iso-C 3H 7) 2)C 6H 5NCHC 6H 3(3,5-(NO 2) 2)O} 2MCl 2] ( 4: M=Zr) have been synthesized and characterized. The molecular structure of 2 has been determined by X-ray crystallographic analysis. The results of ethylene polymerization showed that the self-immobilized titanium (IV) and zirconium (IV) catalysts 1– 3 kept high activity for ethylene polymerization and 4 showed no activity. SEM showed the immobilization effect could greatly improve the morphology of polymer particles to afford micron-granula polyolefin as supported catalysts.

Synthesis of adducts from mercury(II) with N and S donor ligands as models of adsorbent materials for the retention of heavy metals: X-ray crystal structure of bis(3,5-dimethylpyrazol-1-yl)methane(dichloro)mercury(II)

A series of adducts of the type (LL′)HgCl 2 have been obtained by the reaction of the corresponding ligand and the mercury salt. (LL′)=bis(3,5-dimethylpyrazol-1-yl)methane ( 3), 2-(methylthio)pyrazine ( 4), 2-(methylthio)benzothiazole ( 5) and four new trialkoxysilane ligands ( 1a and 1b) and ( 2a and 2b) with attached 2-mercaptopyridine and 2-mercaptobenzothiazole units. The mercury adducts ( 6– 10), which are models of modified heavy metal adsorbing silicas, have been characterized by analytical and spectroscopic data. [(3,5-Dimethylpyrazol-1-yl)methane]HgCl 2 ( 8) has been characterized by X-ray diffraction.

Complex Salts Derived from the Reactions of Organotin(IV) with 6-Methylpyridine-2-Carboxaldehyde Phenylhydrazone: X-Ray Crystal Structure of BIS[6-Methylpyridine- 2-Carboxaldehydehydrazodium]- Tetrachlorodimethylstannate(IV)

Reactions of organotin(IV) chloride (Me 2 SnCl 2 , PhSnCl 3 and n -BuSnCl 3 ) with the Schiff base 6-methylpyridine-2-carboxaldehyde phenylhydrazone ( L ) result in the formation of organotin(IV) anionic complexes. Me 2 SnCl 2 reacts with L in dichloromethane to form [ L H + ] 2 [Me 2 SnCl 4 ] 2 m . X-ray structural analysis has been carried out on the complex salt bis[6-methylpyridine-2-carboxaldehydehydrazodium]tetra-chlorodimethylstannate(IV), [ L H + ] 2 [Me 2 SnCl 4 ] 2 m wherein the tin moieties exist as monomers. Reactions of PhSnC1 3 and n -BuSnCl 3 with L form the complexes [ L H + ] 2 [PhSnCl 5 ] 2 m and [ L H + ] 2 [ n- BuSnCl 5 ] 2 m . Compounds were also characterized by FTIR, 1 H and 13 C NMR spectroscopy.

Coordination chemistry and bioactivity of Ni 2+, Cu 2+, Cd 2+ and Zn 2+ complexes containing bidentate Schiff bases derived from S-benzyldithiocarbazate and the X-ray crystal structure of bis[ S-benzyl-β- N-(5-methyl-2-furylmethylene)dithiocarbazato]cadmium(II)

New bidentate isomeric NS and NS′ Schiff bases were derived from the condensation of S-benzyldithiocarbazate (SBDTC) with 5-methyl-2-furyldehyde and 2-furyl-methylketone. Reaction of NS ligand with Ni(II), Cu(II), Cd(II) and Zn(II) salts gave solid complexes. Only the Ni(II) complex of the NS′ ligand was isolated. All complexes were characterized by a variety of physico-chemical techniques, viz. elemental analyses, molar conductivity, i.r. and electronic spectral studies. The Schiff bases behaved as uninegatively charged bidentate ligands. Square-planar structures have been proposed for the Cu(II) complex containing the NS Schiff base ligand and the Ni(II) complexes of the bidentate NS and NS′ Schiff base ligands. Single crystal X-ray diffraction study of [Cd(NS) 2] showed that the complex was bis chelated with a distorted tetrahedral structure. The antimicrobial properties of the Schiff bases and their metal complexes indicate that the organic compounds are stronger antifungal agents than their complexes with the metals studied. However, the zinc complex of the Schiff base, S-benzyl-β- N-(5-methyl-2-furyl)methylenedithiocarbazate, (NS), was found to be highly active against CEM-SS (Human cell T-lymphoblastic leukemia) with a CD 50 value of 2.0 μg cm −3, while [Cd(NS) 2] was moderately active with a CD 50 value of 4.95 μg cm −3. None of the compounds were found to be active against HT-29 (Human colon adenocarcinoma cells). The bioactivity of a previously reported tridentate NNS Schiff base (SBD1) and its metal complexes with nickel(II) and copper(II) are also discussed.

Synthesis and X-ray Crystal Structures of Bis(oxazolinyl)phenyl-Derived Chiral Palladium(II) and Platinum(II) and -(IV) Complexes and Their Use in the Catalytic Asymmetric Aldol-Type Condensation of Isocyanides and Aldehydes

The transmetalation of (Phebox)SnMe3 (3; Phebox = 2,6-bis(oxazolinyl)phenyl) with PdCl2(PhCN)2 or K[PtCl3(C2H4)](H2O) gave (Phebox)MIICl complexes (4, M = Pd; 5, M = Pt) in modest to good yields. The (Phebox)PtIVCl3 complexes 8 were also synthesized by the reaction of 5 with CuCl2(H2O)2 as an oxidant. These chloride complexes, 4, 5, and 8, were in turn converted to the cationic complexes by treatment with the corresponding silver salts (AgX: X = BF4, OTf, OCOCF3). X-ray structure studies revealed that the octahedral structure of (Phebox)PtIVCl2 fragment G is isosteric with the (Phebox)RhIIICl2 fragment D, and the (Phebox)MII fragment H (M = Pd, Pt) is almost the same configuration with a square-planar structure. In these complexes, the cationic BF4 aqua complexes (9, M = PdII; 10, M = PtII; 11, M = PtIV) were found to act as chiral catalysts for the aldol-type condensation of isocyanides and aldehydes in the presence of i-Pr2NEt. Excellent trans diastereoselectivities and modest to good enantioselectivities were obtained in the reaction of tosylmethyl isocyanide (TosMIC, 1) by the use of [(i-Pr-Phebox)PtII(H2O)](BF4) (i-Pr-10).

Synthesis and X-ray crystal structures of bis (3-hydroxy-4-methyl-2(3 H )-thiazolethiolato- S 2 , O ) bis (dimethylsulfoxide- O )M, M = cobalt(II) and nickel(II)

Crystallisation of the divalent nickel and cobalt complexes of 3-hydroxy-4-methyl-2(3H)-thiazolethione (HMTT) from DMSO yields isostructural chelate complexes M(MTT)2(dmso)2, M = CoII/NiII. The metal atom adopts distorted octahedral coordination via two bidentate MTT ligands arranged in a trans-conformation and two DMSO molecules coordinated through oxygen. Powder X-ray diffraction (PXRD) and energy-dispersive X-ray (EDX) analysis show that the materials form a continuous solid solution CoxNi1−x(MTT)2(dmso)2 over the entire composition range 0 ≤ x ≤ 1.

An effective synthesis of alkyl β-cyano-α,γ-diketones using chlorosulfonylisocyanate and a representative Cu(II) complex

Chlorosulfonylisocyanate, a source of electrophilic cyanide equivalent, was used for the synthesis of three β-cyano-α,γ-diketones. The reactions proceeded in a straightforward fashion and the desired organic compounds were isolated in high-yield and excellent purity. The ligands then yielded homoleptic Cu(II) coordination complexes stabilized by intermolecular contacts. This is illustrated in the X-ray crystal structure of bis(4-cyano-2,2,6,6-tetramethyl-3,5-heptanedionato)copper(II).

Syn−anti Conversion in Octahedral Bis(β-diketonato)diorganotin(IV) Derivatives Containing Fluorinated 4-Acyl-5-pyrazolonato Donors

Six-coordinate organotin derivatives L2SnR2 [L = 3-methyl-1-(4-trifluoromethylphenyl)-4-R3-C=O-5-pyrazolonato (R3 = CH3, L = L1; R3 = C6H5, L = L2; R3 = CF3, L = L3; R = CH3, n-C4H9, C6H5)] have been synthesized and characterized by analytical and spectroscopic (1H, 13C, 119Sn, and 19F NMR, IR) techniques. Partial dissociation of one ligand in chloro-hydrocarbon solvents gives rise to cationic five-coordinate L-(solvent)-diorganotin(IV) complexes. The X-ray crystal structure of bis[4-benzoyl-3-methyl-1-(4-trifluoromethylphenyl)pyrazolon-5-ato]diphenyltin (6) shows the metal in a distorted octahedron (skewed trapezoidal bipyramidal) with the two β-diketonato donors in syn positions, a C−Sn−C bond angle of 165.2(2)° and two sets of tin−oxygen bonds [2.141(5) and 2.139(3) A for Sn−O(pyrazolonato) and 2.250(4) and 2.272(5) A for Sn−O(acyl)]. Surprisingly, the recently reported dimethyltin derivative has the anti configuration, in contrast to expectations based on all previous experience. Large scale Hartree−Fock (HF) and Density Functional Theory (DFT) calculated structures for the anti configuration of bis[4-benzoyl3-methyl-1-(4-trifluoromethylphenyl)pyrazolon-5-ato]dimethyltin show good agreement with the experimental structure obtained from X-ray methods. The hypothetical syn configuration of bis[4-benzoyl-3-methyl-1-(4-trifluoromethylphenyl)pyrazolon-5-ato]dimethyltin was also studied theoretically and both methods also predict characteristic structural features, such as: (from HF) a C−Sn−C bond angle of 150.0°, Sn−O(pyrazolonato) bond lengths of 2.088 and 2.084 A and Sn−O(acyl) bond lengths of 2.385 and 2.401 A. Results from the syn calculated structures suggest that intramolecular repulsive F···F interactions contribute to the syn−anti conversion.

Synthesis, Solution Dynamics, and X-ray Crystal Structure of Bis(2,4,6-tris(trifluoromethyl)- phenyl)(1,2-dimethoxyethane)nickel

Reaction of dichloro(1,2-dimethoxyethane)nickel with 2 equiv of (tris(2,4,6-trifluoromethyl)phenyl)lithium, generated in situ, produced bis(2,4,6-tris(trifluoromethyl)phenyl)(1,2-dimethoxyethane)nickel. Significant nickel−fluorine interactions are revealed both in the solid state (X-ray crystal structure data) and in solution (variable-temperature 19F NMR spectral data).