Structure of 2-[(Phenyl)-(3,5-Dimethyl-Pyrazol-1-yl)-Methyl]-Malonic Acid Diethyl Ester

Abstract  

The titled new functionalized ligand of type 2-[(phenyl)-(3,5-dimethyl-pyrazol-1-yl)-methyl]-malonic acid diethyl ester (4) is prepared in good yield through condensation of 3,5-dimethyl-pyrazole, with 2-arylidene-malonic acid diethyl esters 3. The structure of 4 was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. The title compound (4) crystallizes in the monoclinic space group P2₁/a, with a = 7.9253 (2), b = 17.1299 (5), c = 13.4522 (4) ?, β = 90.220 (2)°, V = 1,826.25 (9) ?³, Z = 4 and with R _int = 0.021. The molecular conformation shows two possible pockets ready to coordinate two metal atoms. The crystal structure of (4) is stabilized by inter-molecular C–H⋯O and C–H⋯N hydrogen bonding.     

Synthesis, Structural Characterization and Spectroscopic Properties of 1,2-Bis[4-(3,5-dimethyl-1H-pyrazol-1-yl)-2-oxobutyl]benzene

Abstract  

The crystal structure of the title compound C₂₂H₃₀N₄O₂·H₂O (L), has been determined using X-ray diffraction at 293 K. The crystal of 1,2-bis[4-(3,5-dimethyl-1H-pyrazol-1-yl)-2-oxobutyl]benzene is in triclinic crystal system with space group P(−1) (Z = 2), lattice parameters a = 8.225(6) ?, b = 10.967(6) ?, c = 12.903(6) ?, V = 1119.1(11) ?³. Analyses of single crystals of L, crystallized from dichloromethane/diethyl ether (1:1), revealed that the molecules are arranged in couples, which adopt a pseudo chair conformation, by means of intermolecular O–H···N hydrogen bonding interactions. Moreover, the extended structure revealed a 1D chain caused by several C–H···N intermolecular interactions.     

The R 22 (8) Hydrogen-Bonded Supramolecular Synthon in Two Novel Glycoluril Derivatives

Abstract  

Two new glycoluril derivatives, namely 6-phenyl-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (1), and diethyl 6-(2,4-dichorophenyl)-1,4-dioxo-2,2a,3,4,6,7-hexahydro-1H,5H-2,3,4a,6,7a-pentaazacyclopenta[cd]indene-2a,7b-dicarboxylate (2) have been synthesized and structurally determined by X-ray diffraction analysis. Compound 1 is, monoclinic, space group C2/c, with a = 20.0784(7), b = 9.0316(3), c = 23.0980(8) ?, β = 98.3930(10), V = 4143.7(2) ?³, with Z = 8 for d _calc = 1.338 Mg/m³. The analog 2 is, Triclinic, space group P-1, with a = 8.9353(18), b = 10.466(2), c = 14.679(3) ?, β = 73.60(3), V = 1268.1(4) ?³, with Z = 2 for d _calc = 1.533 Mg/m³. X-ray analysis reveals that both glycoluril derivatives bearing two free syn-urea NH groups and two ureidyl C=O, assemble the same one-dimensional chains in the solid-state running parallel to the [110], [1–10] and [010] directions via N–H···O hydrogen bonds.     

Two-Dimensional Hydrogen-Bonded Polymer from Nickel(II) Tetraaza Macrocyclic Complex and Succinate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12] docosane) with succinic acid (C₄H₆O₄) yields a 2D hydrogen-bonded polymer with formula [Ni(L)(C₄H₅O₄)₂] (1). This polymer complex has been characterized by X-ray crystallography, spectroscopy and cyclic voltammetry. The complex has a center of symmetry. The crystal structure of 1 exhibits a distorted octahedral geometry about Ni atom with four nitrogen atoms of the macrocycle and two oxygen atoms of the succinate ligand at the trans position. Compound 1 crystallizes in the monoclinic system C2/c with a = 14.8203(11), b = 12.3070(8), c = 17.4164(12) ?, β = 107.356(6)°, V = 3032.1(4) ?³, Z = 4. Electronic spectrum of 1 reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Structure Determination of 8-Benzyl-5-phenyl-3-oxa-4,8-diaza-tricyclo[5.2.1.02,6]dec-4-ene and 1-(9-Ethoxy-5-phenyl-3-oxa-4,8-diaza-tricyclo[5.2.1.02,6]dec-4-en-8-yl)-ethanone: Their Synthesis, Chemical Relationship and Comparison with Similar Compounds

Abstract  

The molecular and crystal structures of 8-benzyl-5-phenyl-3-oxa-4,8-diaza-tricyclo[5.2.1.0^2,6]dec-4-ene 11a and 1-(9-ethoxy-5-phenyl-3-oxa-4,8-diaza-tricyclo[5.2.1.0^2,6]dec-4-en-8-yl)-ethanone 13a have been XRD determined. The compounds crystallize in the monoclinic system with space groups P2₁/n and P2₁/c, respectively. The synthesis and chemical relationship between the two compounds are reported and their structures are compared with others of the aza-norbornene and isoxazoline families.     

Synthesis and Characterization of Nickel(II) Complex of 3,14-Dimethyl-2,6,13,17-Tetraazatricyclo[14,4,01.18,07.12]Docosane Containing Pyrazine-2-Carboxylate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with pyrazine-2-carboxylic acid (H-pyc) yields mononuclear nickel(II) complex, [Ni(L)(pyc)₂]·2H₂O (1). This complex has been characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two pyrazine-2-carboxylate ligands. It crystallizes in the triclinic system P-1 with a = 9.6643(17), b = 10.116(3), c = 16.99(4) ?, V = 1633(3) ?³, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Synthesis and Crystal Structure Analysis of Substituted Diethyl Malonate

Abstract  

As intermediates of light stabilizer malonate, diethyl 3,5-di-t-butyl-4-hydroxybenzyl phenyl malonates (F.W. 454.58) was synthesized, characterized by ¹H NMR, element analysis and confirmed by X-ray crystal structure analysis. This compound crystallizes in monoclinic class under the space group P21/c with cell parameters, a = 9.8218(4) ?, b = 13.5571(5) ?, c = 19.7233(8) ?; β = 102.3530(10)°, and Z = 4. The structure exhibits inter-molecular hydrogen bonds of the type O–H–O, leading to the formation of one dimensional chains.     

N–H···π Interactions in Two Isomers of an Amino Group Containing <Emphasis Type="Italic">bis</Emphasis>-Phenol

Abstract  

Crystal structures of two bis-phenols namely bis-(3,5-dimethyl-2-hydroxyphenyl)(3-amino phenyl)methane 1 and bis-(3,5-dimethyl-4-hydroxyphenyl)(3-aminophenyl) methane 2 are determined. The compound 1 crystallises in monoclinic P2₁/c with a = 12.2579(16) ?, b = 16.0906(19) ?, c = 10.6664(13) ?, β = 115.417(7)°, V = 1900.2(4) ?³ whereas 2 crystallizes in monoclinic C2/c, a = 9.2538(2) ?, b = 18.6579(4) ?, c = 23.2725(5) ?, β = 98.796(2)°, V = 3970.89(15) ?³. The crystal lattice of both the compounds shows presence of N–H···π interactions but no O–H···π interactions.     

Crystal Structures and Properties of Bis(2-Aminopyrimidine-N-)-Bis(Thiocyanato-N)Zinc(II) and Catena-[2-Aminopyrimidine-N- (μ-Thiocynanto-S,N)(Thiocyanato-S)Cadmium(II)]

Abstract  

Complexes [Zn(NCS)₂(2-AMP)₂] (2-AMP = 2-aminopyrimidine) 1 and [Cd(SCN)₂(2-AMP)₂]_n 2 are prepared and characterized by X-ray crystallographic methods. 1 crystallizes in the monoclinic, space group C2/c, with a = 13.5761(14), b = 8.3330(10), c = 13.5962(15) ?, β = 99.5450(10)°, V = 1516.8(3) ?³, Z = 4. In 1, the zinc atom is coordinated by four N atoms from two AMP and two NCS⁻. 2 crystallizes in the monoclinic, space group C2/c, with a = 9.7259(11), b = 19.332(2), c = 8.2149(9) ?, β = 99.817(2)°, V = 1522.0(3) ?³, Z = 4. Complex 2 is made up of 1D chains along a-axis. Each Cd is attached to four NCS⁻ bridges and two pendant 2-AMP ligands.     

Two New Salts Based on Bis(1,2,5-thiadiazole-3,4-dithiolate)nickelate Anion with Substituted Benzyl 4-ethylpyridinium: Syntheses,Crystal Structures and Properties

Abstract  

Two new salts based on [Ni(tdas)₂]²⁻ (tdas²⁻ = 1,2,5-thiadiazole-3,4-dithiolate) anion, [Bz4EtPy]₂[Ni(tdas)₂] (1) and [4ClBz4EtPy]₂[Ni(tdas)₂] (2), have been prepared by reaction of Na₂tdas, NiCl₂·6H₂O, and [Bz4EtPy]Br ([Bz4EtPy]⁺ = 1-benzyl-4-ethylpyridinium) or [4ClBz4EtPy]Br ([4ClBz4EtPy]⁺ = 1-(4′-chlorobenzyl)-4-ethylpyridinium), and characterized by elemental analyses, UV, IR, MS spectrum, molar conductivity and single crystal X-ray diffraction. Single-crystal X-ray diffraction analyses indicate that the two salts crystallize in a triclinic system with space group P−1. The unit cell contains two [Bz4EtPy]⁺/[4ClBz4EtPy]⁺ and one [Ni(tdas)₂]²⁻ anion in which the anion exhibits a quasi-planar structure. The crystals of 1 and 2 are stabilized through C–H···S and C–H···Ni hydrogen bonds, π···π stacking interactions and S···Cl short interactions.     

2D d<Superscript>10</Superscript> Metal Assembly Frameworks: Construction of Metal–organic Architecture with Metal Thiocyanate and Dipyridyl Spacer

Abstract  

A new coordination polymer based on Group IB metal thiocyanates, [Ag₂^I (NCS)₂(dpds)₂]_n (1) (dpds = 2,2′-dipyridyldisulfide), has been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, the Ag^I center adopts tetrahedral coordination geometry and the 2-D undulated layers of (4, 4) topology network is formed by dpds ligand with zigzag NCS⁻Ag chains.     

Synthesis and Crystal Structures of Two Binuclear Lanthanide [Ln = Pr,Dy] Complexes with 4-Quinolineacarboxylate

Abstract  

The reaction of the organic ligand, 4-quinolineacarboxylate (L) with Pr(ClO₄)₃·6H₂O and Dy(ClO₄)₃·6H₂O, leads to the formation of two novel complexes [Pr₂(L)₆(H₂O)₄]2H₂O 1 and [Dy₂(L)₆(H₂O)₄]2H₂O 2, which have been characterized by elemental analysis, IR and single-crystal X-ray diffraction analysis (monoclinic system, space group P2(1)/n, with a = 11.805(2), b = 16.645(3), c = 15.367(3) ?, β = 106.78(3)°, V = 2891.1(10) ?³, Z = 4 for 1, monoclinic system, space group P2(1)/n, with a = 11.629(2), b = 16.478(3), c = 5.336(3) ?, β = 105.83°, V = 2827.4(10) ?³, Z = 4). The two isostructure complexes are binuclear and possess an inversion center which is at the midpoint of the linkage of two symmetrical La(III) centers. In two complexes, each metal center adopts nine-coordinated mode coordinated by nine O atoms from two H₂O molecules and three carboxyls of three ligands, and L displays three different coordination modes. Hydrogen bonds join the binuclear complexes into 3D networks.     

Preparation and Characterization of Two Brønsted Acid Ionic Liquids

Abstract  

Two Br?nsted acid task specific ionic liquids based on the benizimidazolium cation (1-ethylbenzimidazolium tetrafluoroborate {[H-eBim]BF₄ (1)} and 1-propylbenzimidazolium tetrafluoroborate {[H-pBim]BF₄ (2)}) were synthesized and characterized. The crystal of 1 is in orthorhombic system with space group Pnma, and the unit cell parameters as follows: a = 9.9308(16), b = 6.8813(11), c = 15.345(3) ?, V = 1048.6(3) ?³, Z = 4, D_c = 1.482 g/cm³. Structure 2 crystallizes in the monoclinic space group P2₁/c, with unit cell a = 4.9688(14), b = 13.684(4), c = 17.295(5) ?, β = 92.090(6)°, V = 1175.2(6) ?³, Z = 4, D_c = 1.402 g/cm³. These molecules are stabilized in solid state by various intra and intermolecular hydrogen bonding interactions to give polymeric structures.     

Synthesis,Crystal Structure Properties of {μ-Nitrato-[<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-ethylene-bis(3-methoxysalicylideneimin) diaqua nitrato Cu(II)La(III)]nitrat}

Abstract  

The [μ-NO₃-LCuLa(NO₃)·(H₂O)₂]NO₃ (I) complex has been prepared and characterized by single crystal X-ray diffraction properties. The title compound crystallizes in the monoclinic system, space group P 2₁/c, with a = 9.1699(4), b = 21.6796(8), c = 13.7068(6) ?, α = γ = 90o, β = 111.308(3)°, V = 2538.63 (18) ?³ and Z = 4. The unit cell contains four discrete the title compounds. The central region is occupied by Cu^II and La^III ions which are brigged by two phenolato oxygen atoms of ligand. The intramolecular La–Cu distance is 3.5016 (3) Ǻ. The copper (II) ion is in a distorted square pyramidal geometry with the imino nitrogen atoms N1 and N2, and the phenolic oxygen atoms O2 and O3 forming the square base. The La^III ion is deca coordinated.     

Hydrogen-Bonding in the Structures of the Hydrated Proton-Transfer Compounds of Isonipecotamide with the Isomeric Indole-2- and Indole-3-Carboxylic Acids

Abstract  

The structures of two hydrated proton-transfer compounds of 4-piperidinecarboxamide (isonipecotamide) with the isomeric heteroaromatic carboxylic acids indole-2-carboxylic acid and indole-3-carboxylic acid, namely 4-carbamoylpiperidinium indole-2-carboxylate dihydrate (1) and 4-carbamoylpiperidinium indole-3-carboxylate hemihydrate (2) have been determined at 200 K. Crystals of both 1 and 2 are monoclinic, space groups P2₁/c and P2/c, respectively with Z = 4 in cells having dimensions a = 10.6811(4), b = 12.2017(4), c = 12.5456(5) ?, β = 96.000(4)° (1) and a = 15.5140(4), b = 10.2908(3), c = 9.7047(3) ?, β = 97.060(3)° (2). Hydrogen-bonding in 1 involves a primary cyclic interaction involving complementary cation amide N–H···O(carboxyl) anion and anion hetero N–H···O(amide) cation hydrogen bonds [graph set R₂²(9)]. Secondary associations involving also the water molecules of solvation give a two-dimensional network structure which includes weak water O–H···π interactions. In the three-dimensional hydrogen-bonded structure of 2, there are classic centrosymmetric cyclic head-to-head hydrogen-bonded amide–amide interactions [graph set R₂²(8)] as well as lateral cyclic amide-O linked amide–amide extensions [graph set R₄²(8)]. The anions and the water molecule, which lies on a twofold rotation axis, are involved in secondary extensions.     

Synthesis and Crystal Structure of Phenolato-Bridged Dinuclear Copper(II) Complex with (2-Hydroxybenzyl)(2-pyridylmethyl)amine

Abstract  

The tridentate Schiff base phenol-containing ligand (2-hydroxybenzyl)(2-pyridylmethyl)amine (Hbpa) reacts with copper(II) perchlorate to give the phenolato-bridged dinuclear complex [Cu(bpa)(H₂O)]₂·2ClO₄ (1). Each copper(II) ion exhibits a distorted square-pyramidal environment, being coordinated by two nitrogen atoms and two phenolato oxygen atoms of the two deprotonated bpa ligands, and one oxygen atom of the water molecule. It crystallizes in the triclinic system P-1 with a = 7.8790(6), b = 8.9345(7), c = 12.0207(9) ?, α = 69.158(1), β = 85.307(1), γ = 76.629(1)°, V = 769.39(10) ?³, Z = 1. Cyclic voltammetry of 1 gives two oxidation and two reduced processes.     

Synthesis and Crystal Structure of 5-Chloro-3-Methyl-1-Phenyl-1H-Pyrazole-4-Carbaldehyde

Abstract  

The title compound, 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde 2, was prepared in a series of syntheses to produce new pyrazole derivatives, and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P2₁/c with unit cell parameters a = 6.7637(4) ?, b = 6.8712(3) ?, c = 22.4188(10) ?, β = 93.8458(14)o, V = 1039.56(9) ?³ and Z = 4. X-Ray reveals that the aldehydic fragment is almost coplanar with the adjacent pyrazole ring, but the two ring planes are inclined at 72.8(1)o. The molecule is linked to its neighbor by two directionally specific C–H···O interactions.     

Synthesis,Characterization and X-Ray Crystal Structure of the Tri Aqua (3-Hydroxy-5-Hydroxymethyl-2-Methylpyridine-4-Carboxaldehyde-3-Methylisotiosemicarbazone: k<Superscript>3</Superscript>, O<Superscript>3</Superscript>, N<Superscript>7</Superscript>, N<Superscript>10</Superscript>) Ni(II) Nitrate

Abstract  

The title complex triaqua (3-hydroxy-5-hydroxymethyl-2-methylpyridine-4-carboxaldehyde-3-methylisothiosemicarbazone-k³,O³,N⁷,N¹⁰)Ni(II) nitrate ([Ni(PLITSC)(H₂O)₃](NO₃)₂, 1) represents the second transition metal complex incorporating an isothiosemicarbazide-pyridoxal based Schiff base that has been crystallographically characterized. Complex 1 crystallizes in a P21/n space group, with lattice constants: a = 11.2254(1) ?, b = 12.9941(2) ?, c = 12.8663(2), β = 96,7713(5)°, V = 1863.64(4) ?³, Z = 4, F(000) = 1016, R ₁ = 0.0681, wR ₂ = 0.1201. The central Ni(II) cation is found in a six-coordinate octahedral geometry formed by the tridentate Schiff base ligand PLITSC and three water molecules. The identity of 1 was further confirmed by elemental analysis, IR spectra, and conductometric and magnetochemical measurements.     

Bis[(2,3,4-Trimethoxy-Benzylidenepropylideneamino)Phenyl]Ether: Synthesis,Characterization and Crystal Structure

Abstract  

New Schiff base compound bis[(2,3,4-trimethoxy-benzylidenepropylideneamino)phenyl]-ether (1) was synthesized and characterized by elemental analyses (CHN), FT-IR and ¹H-NMR spectroscopy and single-crystal X-ray diffraction. The title compound 1 crystallizes in triclinic system, space group P-1, with a = 6.8255(4) Å, b = 10.4346(4) Å, c = 19.4166(8) Å, α = 86.588(3)°, β = 85.019(4)°, γ = 89.042(4)°, V = 1375.12(11) Å³ and Z = 2. It displays a trans configuration about the C=N double bonds.     

Pseudosymmetry in Cr(urea)<Subscript>4</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>·3NO<Subscript>3</Subscript>

Abstract  

The low temperature crystal structure of the complex, Cr(urea)₄(H₂O)₂·3NO₃ (1), displays intriguing pseudosymmetry that complicates the structure determination. 1 crystallises in the centrosymmetric monoclinic space group P2₁/c with Z = 8 and Z′ = 2; a = 18.3338(4) ?, b = 16.5472(4) ?, c = 13.9252(3) ? and β = 106.3260(10)°, V = 4054.19(16) ?³. The two symmetry independent [Cr(urea)₄(H₂O)₂]³⁺ ions in the asymmetric unit both feature coordinated urea (O=C(NH₂)₂) and lie on general positions. A further six independent nitrate anions complete the structure. The unit cell is primitive but the two Cr³⁺ ions are related by a pseudo translation of ?, ?, 0. The deviation from a truly C-centred cell is clear from an examination of geometry of the urea ligands and the hydrogen bonds which they form. The identification of the space group in this case is described and methods for quantifying the degree of deviation from a C-centred cell discussed.