Crystal Structures of (2-oxo-2H-Quinaxalin-1-yl)-acetic Acid and its Cobalt and Nickel Complexes and Their Comparison with (1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-acetic Acid

Abstract The crystal structures of (2-oxo-2H-quinaxalin-1-yl)-acetic acid and its cobalt and nickel complexes are determined. The (2-oxo-2H-quinaxalin-1-yl)-acetic acid (1) crystallizes in orthorhombic, Pbca, a = 12.8571(11) ?, b = 9.4267(8) ?, c = 15.0095(13) ?, the cobalt complex of (2-oxo-2H-quinaxalin-1-yl)-acetic acid (2) crystallizes as dihydrate in triclinic, P-1 space group with a = 4.81150(10) ?, b = 11.8631(2) ?, c = 12.4867(3) ?, α = 71.7800(10)°, β = 79.2490(10)°, γ = 84.9020(10)° whereas the nickel complex of (2-oxo-2H-quinaxalin-1-yl)-acetic acid (3) crystallizes in monoclinic, P2₁/c space group with a = 14.9210(5) ?, b = 4.81730(10) ?, c = 15.7672(5) ?. and β = 99.823(2)°. The crystal structure of the ligand and the complexes are compared with structures of (1,3-dioxo-1,3-dihydro-isoindol-2-yl)-acetic acid and its cobalt and nickel complexes. Index Abstract The crystal structures of (2-oxo-2H-quinaxalin-1-yl)-acetic acid and its nickel and cobalt complexes are compared with (1,3-dioxo-1,3-dihydro-isoindol-2-yl)-acetic acid and its corresponding complexes with nickel(II) and cobalt(II).      

X-ray Structures of Pharmacologically Active 2-(3,5-Dimethyl-pyrazol-1-yl)-methylacetanilides

Abstract X-ray structures of three pharmacologically active lidocaine analogs, containing a common, substituted pyrazole moiety as the basic residue and variously substituted phenyl rings as the hydrophobic residue, have been determined. This isomeric series comprises 2-(3,5-dimethyl-pyrazol-1-yl)-2′-methylacetanilide (1), 2-(3,5-dimethyl-pyrazol-1-yl)-3′-methylacetanilide monohydrate (2), and 2-(3,5-dimethyl-pyrazol-1-yl)-4′-methylacetanilide (3). Crystal data are 1: space group P2 ₁ /c with a = 4.7617(2), b = 11.5638(4), c = 23.603(1) ?, β = 90.736(2)°, Z = 4; 2: P2 ₁ /c with a = 4.7260(1), b = 13.7001(4), c = 21.7006(6) ?, β = 93.425(1)°, Z = 4; 3: P2 ₁ /n with a = 6.4103(3), b = 24.584(1), c = 8.4449(4) ?, β = 100.273(3)°, Z = 4. In 1–3, the amide bond is trans-planar but the basic and hydrophobic residues adopt different orientations relative to this plane. Hydrogen bonding in 1 and 3 is based on C(4) linear arrays whereas in the monohydrate 2, the presence of water gives rise to R ₄ ⁴ (16) ring motifs. A summary of the local anesthetic and anti-arrhythmic properties of 1–3 is provided. Graphical abstract X-ray Structures of Pharmacologically Active 2-(3,5-Dimethyl-pyrazol-1-yl)-methylacetanilides Christina Zalaru, Mino R. Caira, Mircea Iovu, and Elena Cristea The title compounds are lidocaine analogs that display local anesthetic and anti-arrhythmic activities. X-ray analyses revealed a range of solid-state conformations among these isomeric compounds as well as variation in hydrogen bonding schemes, namely C(4) (R = o-, p-CH3) and R44(16) (R = m-CH3, monohydrate crystal). 1,1-Os3(CO)9(μ-CO)(phen)     

Synthesis and Crystal Structure of 4,6-dihydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]-benzene-1,3-dicarbaldehyde

Abstract The title compound, 3, 6-dihydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]- benzene-1,3-dicarbaldehyde was synthesized by Vilslmeier reaction from resveratrol (trans-3,4′,5-trihydroxystilbene). Its structure was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2₁/n with crystallographic parameters: a = 7.2950(15) ?, b = 14.781(3) ?, c = 12.202(2) ?, β = 96.57(3)°, μ = 0.108 mm⁻¹, V = 1307.1(5) ?, Z = 4, Dx = 1.445 g/cm³, F(000) = 592, T = 293(2) K, 2.17°≤ θ ≤ 26.00°. The X-ray results demonstrated that the Vilslmeier reaction of resveratrol with DMF, POCl₃ and CH₃CN yielded 4,6-dhydroxy-2-[2-(4-hydroxy-phenyl)-vinyl]-benzene-1,3-dicarbaldehyde. Graphical Abstract In this article, a resveratrol derivative was prepared and structurally characterized by single crystal X-ray diffraction.      

Synthesis and Crystal Structure of Compound 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine

Abstract The crystal structure of title compound has been determined. The compound crystallizes in the triclinic system with space group P-1, lattice parameters; a = 9.2938 (5) ?, b = 11.9992 (7) ?, c = 25.5918 (13) ?, α = 91.343 (2)°, β = 95.8360 (10)°, γ = 101.005 (2)°, V = 2784.3 (3) ?³, Z = 4, X-Ray analysis reveals that the molecular backbone consists of tricyclic system with the central seven-membered ring in twisted chair-like conformation. Graphical abstract The crystal structure of 1,5-bis(4-methoxyphenyl)-3a-(2-phenyl-2H-1,2,3-triazol-4-yl)-4,5-dihydro-3aH-benzo[b][1,2,4]oxadiazolo[4,5-d][1,4]thiazepine was first determined by single-crystal X-ray diffraction which reveals that the molecular backbone consists of a tricyclic system with the central seven-membered ring in twisted chair-like conformation .     

Synthesis of <Emphasis Type="Italic">E</Emphasis> Isomer and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile

Abstract Details of the synthesis of the E isomer of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile, and the X-ray crystal structures of both the E and Z isomers of this compound are presented. The E isomer crystallizes in the P2₁/c space group with cell parameters, a = 8.5659(17) ?, b = 16.399(3) ?, c = 11.224(2) ?, α = 90°, β = 95.27(3)°, γ = 90°and Z = 4. The Z isomer crystallizes in the Pca2₁ space group with cell parameters, a = 4.1223(8) ?, b = 19.113(4) ?, c = 19.453(4) ?, α = 90°, β = 90°, γ = 90° and Z = 4. Index Abstract Synthesis of E isomer and X-ray crystal structure determination of both E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile are presented.      

Crystal and Molecular Structure of <Emphasis Type="Italic">trans</Emphasis>-1,2-bis(2-benzothiazolyl)ethene

Abstract The crystal and molecular structure of trans-1,2-bis(2-benzothiazolyl)ethene is reported. Crystal data for 1: monoclinic, space group C 2/c, a = 24.926(3) ?, b = 4.843(1) ?, c = 11.164(1) ?, β = 105.274(5) °, V = 1300.0(3) ?³, and D _c = 1.50 g/cm³ for Z = 4 and R = 0.028. The molecule crystallizes in the form of a colorless plate and forms one-dimensional slipped π-stacks. Graphical Abstract The title compound crystallizes to form 1D slipped π-stacks in the solid state. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Structures of Bis(1-ethylbenzimidazol-2-yl)alkyl Copper(II) Dichlorides: An Unusual Cocrystallization

Abstract  Two structures containing pseudo-tetrahedral Cu(II)N₂Cl₂ coordination complexes are reported. The first molecular structure (A) of the compound, 1,1′bis(1-ethylbenzimidazol-2-yl)propane copper(II) dichloride (triEtBBIM)Cu(II)Cl₂, 1, is reported. The complex crystallized in the triclinic space group P-1 with a = 8.616(3) ?, b = 9.302(3) ?, c = 14.314(4) ?, α = 85.613(6)°, β = 85.170(6)°, γ = 66.117(6)° and V = 1044.1(5) ?³ with Z = 2. The second structure (B) contains 1 and (3,3′bis(1-ethylbenzimidazol-2-yl)pentane) copper(II) dichloride (tetEtBBIM)Cu(II)Cl₂, 2, both of which, cocrystallize in an equal molar ratio with a nitromethane solvate molecule. The complex crystallized in the monoclinic space group P2₁/c with a = 18.876(4) ?, b = 14.975(3) ?, c = 18.344(4) ?, β = 116.75(3)°, and V = 4630.3(16) ?³ with Z = 4. The cocrystallization of such discrete complexes has been coined a chemical Janus. Graphical Abstract  The title complexes contain pseudo-tetrahedral Cu(II)N₂Cl₂ coordination. One of the structures is the result of an unusual cocrystallization, in which two different discrete Cu(II) molecules cocrystallize in an equimolar ratio with a nitromethane solvate molecule.      

Synthesis and Crystal Structure of 3-[(Naphthalen-2-yl)methyl]Isocoumarin

Abstract 3-[(Naphthalen-2-yl) methyl]isocoumarin was synthesized by the reaction of homophthalic acid with 2-(naphthalen-2-yl)acetyl chloride at elevated temperature and its crystal structure has been determined (C₂₀H₁₄O₂), Mr = 286.31, a = 13.704(3), b = 7.356(4), c = 7.042(7) ?, β = 99.21(3)°, space group Pc, Z = 2, and V = 700.7(8) ?³. The isocoumarin and the naphthalene ring systems are individually planar and the dihedral angle between the mean planes of these two ring systems is 70.05(8)°. Graphical Abstract Synthesis and crystal structure of 3-[(Naphthalen-2-yl)methyl]isocoumarin Aamer Saeed, Junmei Liang, Masood Parvez The synthesis and crystal structure of a novel isocoumarin, 3-[(naphthalen-2-yl)methyl]isocoumarin has been presented.      

Synthesis,Separation and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid

Abstract Synthesis, separation and X-ray crystal structures of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid are reported. Separation of E and Z isomers from a 1:1 mixture has been carried out by selective acidification of their sodium salts carefully controlling the pH of the solution. The structures of E and Z isomers were confirmed by determining crystal structures of these isomers using single crystal X-ray diffraction. The E isomer crystallizes in the P2₁/c space group with a = 11.493(2) ?, b = 5.5456(11) ?, c = 24.900(5) ?, α = 90°, β = 92.36(3)°, γ = 90°, Z = 4. The Z isomer crystallizes in the P2₁/c space group with a = 10.192(2) ?, b = 12.893(3) ?, c = 13.948(3) ?, α = 90°, β = 92.18(3)°, γ = 90°, Z = 4. Details of the synthesis and structural characterization and X-ray crystal structure determination of the title compounds are presented. Index Abstract Synthesis, Separation and Crystal Structures of E and Z Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid Balachandra Chenna, Bidhan A. Shinkre, Shweta Patel, Samuel B. Owens Jr., Gary M. Gray, Sadanandan E. Velu* Separation of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid from a 1:1 mixture has been carried out by selective acidification of their sodium salts and the structures of the individual isomers have been determined by X-ray single crystal diffraction.      

Synthesis,Characterization and Crystal Structure of 1-Phenyl-3-methyl-4-(salicylidene hydrazide)-phenylethylene-pyrazolone-5

Abstract A new compound 1-phenyl-3-methyl-4-(salicylidene hydrazide)-phenylethylene-pyrazolone-5 (PMPeP-SHZ) has been synthesized and characterized by elemental analysis, IR spectrum, MS and single crystal X-ray diffraction. The compound crystallizes in a monoclinic, space group P2(1)/c with cell parameters: a = 10.8275(19) ?, b = 24.689(4) ?, c = 9.7167(16) ? and β = 95.127(4)°, Z = 4, S = 1.097. In the crystal structure, the compound presents in the diketo form. The structure exhibits both intra- and intermolecular hydrogen bonding and the molecules are interlinked through hydrogen bonds forming an infinite 2D network. The fluorescent result shows blue emission at room temperature in solid state. Graphical Abstract Synthesis, Characterization and Crystal Structure of 1-Phenyl-3- methyl-4-(salicylidene hydrazide)-phenylethylene-pyrazolone-5 Li Zhang, Guan-Cheng Xu, Lang Liu, Guang-Fei Liu, and Dian-Zeng Jia* Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal and Molecular Structure of Perphenazine {2-Chloro-10-(3-[4-(2-hydroxyethyl)-piperazin-1-yl) propyl phenothiazine}: Conformational Variabilities of the Phenothiazine Ring

Abstract Crystals of Perphenazine (P), obtained from water/propanol, are triclinic, space group P1, with a = 8.149 (2), b = 11.879 (2), c = 12.093 (2) ?, α = 60.49(1), β = 89.54(2), γ = 89.98(2)°, V = 1018.9 ?³, Z = 2, D _obs = 1.32 g/cm³, D _calc = 1.317 g/cm³. The crystal structure was solved with CAD-4 data (4287 reflections, 2267 ≥ 3σ) using the SHELX-86 programs and refined to a final R value of 0.059. There are two independent molecules in the asymmetric unit, each with slightly different conformations. The dihedral angle between the planes of the butterfly tricyclic ring system is 142° and 138° in the two molecules respectively whereas it is 141° in the published monoclinic form of Perphenazine. The C–S–C angle in the tricyclic groups are 97° and 100° and the C–S distances are 1.707 and 1.738 ?. The piperazine has the chair conformation. An analysis of the conformation of the phenothiazine ring system in the different structures solved to date shows a conformational variability in the dihedral angle between the tricyclic ring systems (134–155°). Index Abstract Crystals of Perphenazine, obtained from water/propanol, are triclinic and their structure was determined using single crystal diffractometric data. There are two independent molecules in the asymmetric unit, each with slightly different conformations. An analysis of the conformation of the phenothiazine ring system in the different structures solved to date shows a conformational variability in the dihedral angle between the tricyclic ring systems (134–155˚). Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

An X-ray Crystallographic Study of the Related Triazenes, 1,4-Di[(<Emphasis Type="Italic">E</Emphasis>)-2-(2-nitrophenyl)-1-diazenyl]piperazine and Methyl 4-{(E)-2-(4-methylpiperazino)-1-diazenyl}benzoate

Abstract The crystal structures of methyl 4-{(E)-2-(4-methylpiperazino)-1-diazenyl}benzoate (2a) and 1,4-di[(E)-2-(2-nitrophenyl)-1-diazenyl]piperazine (3a) have been determined by single crystal X-ray diffraction analysis. The bis-triazene (3a) adopts an unusual pseudo-boat conformation in the piperazine ring, with a dihedral angle of 52.20(0.06)° between the two planes defined within the piperazine ring. The crystal structures of 2a and 3a are compared with the structure of the triazene (4) and the closely related bis-triazene (5). The piperazine ring of 2a adopts a typical chair conformation, whereas the piperazine ring of 3a adopts an unusual boat conformation. Crystal data: 2a C₁₃H₁₈N₄O₂, monoclinic, space group P2₁ /n, a = 13.849(3) ?, b = 6.577(1) ?, c = 14.904(3) ?, α = 90°, β = 96.098(3)°, γ = 90° and V = 1,349.8(4) ?³, for Z = 4. 3a C₁₆H₁₆N₈O₄, triclinic, space group P-1, a = 7.6066(6) ?, b = 8.3741(7) ?, c = 14.507(1) ?, α = 78.673(1)°, β = 81.877(1)°, γ = 73.445(1)° and V = 865.0(1) ?³, for Z = 2. Index abstract The crystal structures of methyl 4-{(E)-2-(4-methylpiperazino)-1-diazenyl}benzoate (2a) and 1,4-di[(E)-2-(2-nitrophenyl)-1-diazenyl]piperazine (3a) have been determined by single crystal X-ray diffraction analysis.     

Supramolecular Cobalt(II), Copper(II) and Cadmium(II) Complexes Obtained from a Proton Transfer Compound including Pyridine-2,6-dicarboxylate and Propane-1,3-diaminium Ions; Synthesis,Characterization and Crystal Structure

Abstract The three complexes (pnH₂)[Co(pydc)₂]·4H₂O 1, (pnH₂)[Cu(pydc)₂]·4H₂O 2, and (pnH₂)[Cd(pydc)₂]·3.5H₂O 3 (pn: propane-1,3-diamine, pydc: pyridine-2,6-dicarboxylate) were prepared using a proton transfer compound (pnH₂)(pydc)·(pydcH₂)·2.5H₂O, LH ₂ and corresponding metallic salts. The characterization was carried out using elemental analysis, IR and NMR spectroscopy, and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in space group P , but complex 3 crystallizes in space group P2/c. Cell parameters of the complexes are a = 8.449(1) ?, b = 11.668(1) ?, c = 12.801(1) ?, α = 115.748(2)°, β = 93.038(2)°, γ = 97.867(2)° for 1; a = 7.973(2) ?, b = 16.632(2) ?, c = 25.280(5) ?, α = 94.178(6)°, β = 95.186(6)°, γ = 91.603(5)° for 2 and a = 20.055(1) ?, b = 13.8161(9) ?, c = 8.2418(5) ?, β = 100.086(1)° for 3. The three crystal structures illustrate that the metal ion is six-coordinated by two pydc’s. In structures of 2 and 3, it can be seen that propane-1,3-diaminium fragments have different conformations. The complexes have ion-pairing interactions, O–H···O, N–H···O and C–H···O hydrogen bonds, π–π stacking as well as van der Waals forces as the main factors in formation of their supramolecular structures. Index Abstract Supramolecular Cobalt(II), Copper(II) and Cadmium(II) Complexes Obtained from a Proton Transfer Compound including Pyridine-2,6-dicarboxylate and Propane-1,3-diaminium Ions; Synthesis, Characterization and Crystal Structure Hossein Aghabozorg, Mohammad Ghadermazi,Bahar Nakhjavan, Faranak Manteghi The synthesis, characterization, crystal structure and non-covalent interactions of three supramolecular complexes of Co(II), Cu(II) and Cd(II) obtained by the reaction of a proton transfer compound i.e. (pnH₂)(pydc)·(pydcH₂)·2.5H₂O with the corresponding metallic salts are reported. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal structures of 3-[1-Benzenesulfonyl-3-phenylsulfanyl-1H-indol-2-yl]-1-[4-(methyl (I)/methoxy (II) phenyl)]-2-phenyl-propane-1-one

The compounds 3-(1-Benzenesulfonyl-3-phenylsulfanyl-1H-indol-2-yl)-1-[4-methyl (I)/methoxy (II)phenyl)]-2-phenyl-propane-1-one crystallize in triclinic space group P . The details are: compound I a = 11.941(6) ?, b = 12.154(7) ?, c = 13.006(7) ?, α = 63.124(8)°, β = 84.464(9)°, γ = 64.810(8)°, V = 1519.7(14) ?³, Z = 2, D _cal = 1.284 Mg m⁻³, and R = 0.0382 (wR = 0.0978); compound II a = 11.897(6) ?, b = 12.268(6) ?, c = 13.001(7) ?, α = 61.919(8)°, β = 83.480(8)°, γ = 64.676(7)°, V = 1504.0(14) ?³, Z = 2, D _cal = 1.333 Mg m⁻³, and R = 0.0422 (wR = 0.1049). The indole ring system in both the molecules I and II are not strictly planar and the dihedral angles formed by the pyrrole and benzo planes are 4.0(7)° and 3.5(8)°, respectively. The C–HO, C–Hπ and ππ types of interactions stabilize the molecules in the unit cell in addition to van der Waal's forces in I and II.     

F-type or T-type Aromatic–Aromatic Interaction in Two Isoflavone Derivatives

Abstract Two isoflavone derivatives, 5,6,7,4′-tetramethoxyisoflavone (I) and 6,4′-dimethoxy- 7-ethoxy-5-hydroxylisoflavone (II), have been synthesized and their crystal structures were determined by ¹H NMR and single crystal X-ray diffraction studies. I is triclinic, space group P-1 with a = 7.828(1) ?, b = 10.285(2) ?, c = 11.608(2) ?, α = 104.90(2)°, β = 110.546(9)°, γ = 99.54(1)° and Z = 2. II is orthorhombic, space group Pna2 ₁ with a = 7.0244(6) ?, b = 15.0104(15) ?, c = 15.7538(15) ?, and Z = 4. Molecules of I are linked into two-dimensional structure by a combination of C–H···O hydrogen bond and F-type aromatic–aromatic interactions. II shows some discrepancies with I and the molecules are linked into columns by T-type aromatic-aromatic interaction. Graphical Abstract F-type or T-type Aromatic–Aromatic Interaction in Two Isoflavone Derivatives Zun-Ting Zhang,* Xue-Ling Zhang Molecules of 5,6,7,4′-tetramethoxyisoflavone are linked into two-dimensional structure by a combination of C–H···O hydrogen bond and F-type aromatic–aromatic interactions; 6,4′-dimethoxy-7-ethoxy-5-hydroxylisoflavone shows some discrepancies with 5,6,7,4′-tetramethoxyisoflavone and the molecules are linked into columns by T-type aromatic–aromatic interaction.      

X-ray Crystal Structure of Trans -UO2(N(SiMe3)2)2(THF)2: One in a Series of Uranyl(VI) Complexes Supported by Bis(trimethylsilyl)amido Ligands

Abstract The title compound trans-UO₂(N(SiMe₃)₂)₂(THF)₂ (1) was synthesized and characterized by X-ray crystallography. The complex crystallizes in the monoclinic space group C2/c (#15) with lattice parameters a = 16.0771(5) ?, b = 13.1196(4) ?, c = 16.9391(6) ?, β = 116.853(1)°, V = 3187.61(18) ?³, Z = 4, D _calc = 1.532 g cm^-3. The six-coordinate uranium(VI) center adopts an all-trans octahedral geometry consisting of mutually trans oxo groups, silylamido ligands, and neutral THF donors. Structural comparisons of this uranyl(VI) bis(amido) complex with a related tris(amido) derivative within the series are made based on symmetry, charge, and coordination number. Graphical Abstract The X-ray crystal structure of the title complex is reported, providing comparisons based on symmetry, charge, and coordination number with a related uranyl(VI) amido derivative within this series.      

Dimer Formation in 4-Benzyl-5-Methoxymethyl-3-Methyl-1<Emphasis Type="Italic">H</Emphasis>-Pyrrole-2-Carboxylic Acid Benzyl Ester

Abstract A new substituted pyrrole, a precursor of meso-free-porphyrins, has been synthesised and characterised by single-crystal X-ray diffraction: monoclinic, P2₁/c with a = 14.607(9) ?, b = 5.136(2) ?, c = 25.832(17) ?, β = 108.14(5)°, Mr = 349.41, V = 1841.6(18) ?³, Z = 4. The molecules are assembled in centrosymmetric dimers via strong N–H...O hydrogen bonds. The dimers are gathered into chains via C–H...π intermolecular interactions. Graphical abstract The molecules in 4-benzyl-5-methoxymethyl-3-methyl-1H-pyrrole-2-carboxylic acid benzyl ester are joined in dimmers by strong hydrogen bonds. The dimmers are aggregated in chains running along the b axis through C-H...?€ intermoleculear interactions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and Crystal Structure of One-Dimensional Carboxylate-Bridged Copper(II) Complex with 2-Pyridylmethylamino-3-butyric acid

Abstract The tridentate Schiff base carboxylate-containing ligand 2-pyridylmethylamino-3-butyric acid (Hpaba) reacts with copper(II) perchlorate to give the one-dimensional chain complex {[Cu(μ-paba)](ClO₄)·H₂O} _n (1). The coordination geometry of each copper(II) ion is best described as a square-plane with two nitrogen atoms and one carboxylate oxygen atom of the ligand, and one carboxylate oxygen atom belong to another ligand. It crystallizes in the monoclinic system P2₁/c with a = 12.717(2), b = 7.9163(15), c = 14.981(2) ?, β = 111.14(1)°, V = 1406.8(4) ?³, Z = 4. Cyclic voltammogram of 1 undergoes the reversible one-electron oxidation to the Cu(III) and the reversible one-electron reduction to the Cu(I) state. Graphical Abstract Crystal structure of 1 reveals a syn-anti carboxylate-bridged one dimensional chain complex in which the coordination environment around each copper(II) ion exhibits a distorted square plane.      

Imino-Diels-Alder Adducts. Part XIII. Polymorphism in Pyrano [3,2-c] Quinolines

Abstract Crystallization by slow evaporation of methanol solution of 5-(4-nitrophenyl)-3,4,4a5,6,10b-hexahydro-2H-pyrano[3,2-c] quinoline, yields two polymorphs. Rectangle plate-like crystals have a triclinic (P ) structure, with one molecule in the asymmetric unit, a = 8.2299(5) ?, b = 9.7774(6) ?, c = 11.0047(7) ?, α = 65.718(1)°, β = 75.699(1)° and γ = 71.617(1)°, while, long needle-like crystals exhibit a monoclinic (C2/c) crystal structure in which two independent molecules comprise the asymmetric unit, a = 32.285(3) ?, b = 9.4045(7) ?, c = 22.804(2) ? and β = 114.965(1)°. The crystal structures reveal the molecule in both the polymorphs as an endo-Imino-Diels-Alder cycloadduct isomer. The stereochemistry of the pyran ring in both the polymorphs is exo to the quinoline ring formed in the cycloaddition step. The molecules are linked by N–H···O hydrogen bonds into centrosymmetric dimers forming R₂ ²(18) rings in the triclinic form, while they are arranged to form a helical chain in the monoclinic form. Index abstract Crystallization by slow evaporation of methanol solution of 5-(4-nitrophenyl)-3,4,4a5,6,10b-hexahydro-2H-pyrano[3,2-c] quinoline, yields two polymorphs. The crystal structures reveal the molecule in both the polymorphs as an endo-Imino-Diels-Alder cycloadduct isomer. The stereochemistry of the pyran ring in both the polymorphs is exo to the quinoline ring formed in the cycloaddition step. The molecules are linked by N–H···O hydrogen bonds into centrosymmetric dimers forming R₂ ²(18) rings in the triclinic form, while they are arranged to form a helical chain in the monoclinic form. In the present study, we have determined the crystal structures of two polymorphs of pyranoquinoline, I and II.     

The Synthesis, Crystal, and Molecular Structure of Two Mononuclear Arylimido Tungsten Tetrachloride Complexes, [WCl4(NC6H4I-p)(CH3CN)] and [WCl4(NC6H3-2,6-i-Pr 2)(CH3CN)]

Abstract We report two new crystal and molecular structures of the following monomeric arylimido tungsten tetrachloride complexes, [WCl₄(NC₆H₄I-p)(CH₃CN)] (1) and [WCl₄(NC₆H₃-2,6-i-Pr ₂)(CH₃CN)] (2), containing weakly coordinating acetonitrile ligands. Complex 1 crystallizes in the triclinic space group P-1 with lattice parameters a = 6.292(1) ?, b = 8.251(1) ?, c = 15.126(2) ?, α = 78.42(1)°, β = 82.33(2)°, γ = 77.89(1)°, V = 748.7(3) ?³, Z = 2. Complex 2 crystallizes in the monoclinic space group P2 ₁ /c with lattice parameters a = 9.629(1) ?, b = 16.790(2) ?, c = 24.155(2) ?, β = 95.42(1)°, V = 3888.7(6) ?³, Z = 8. Despite the different electronic/steric characteristics of the arylimido ligands, the structures show no significant differences in bond lengths or bond angles in the core {N–W(Cl)₄–N} fragment and are similar to those reported for other arylimido tungsten tetrachloride complexes. Index Abstract The Synthesis, Crystal, and Molecular Structure of Two Mononuclear Arylimido Tungsten Tetrachloride Complexes, [WCl ₄ (NC ₆ H ₄ I -p ) (CH ₃ CN)] and [WCl ₄ (NC ₆ H ₃ - 2,6- i-Pr ₂ )(CH ₃ CN)] Jeffrey C. Duhacek, Tasneem A. Siddiquee, Dennis W. Bennett, and Dean C. Duncan* The crystal and molecular structures of two new arylimido tungsten tetrachloride complexes are reported herein. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.