Reaction of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne with Co(II) generates coordination monomers not polymers: Crystal structure of 4-(2,6-dicarboxypyridin-4-yl)ethynylpyridine-2,6-dicarboxylatotriaqua cobalt(II) monohydrate

Reaction and crystallization of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne with Co(II) produces crystals containing monomers of 4-(2,6-dicarboxypyridin-4-yl)ethynylpyridine-2,6-dicarboxylatotriaqua cobalt(II) monohydrate complex (1), [Co(C₁₆H₆N₂O₈)(H₂O)₃]·H₂O, instead of a rigid 1-D metal–organic framework consisting of a linear coordination polymer. This complex crystallizes in the monoclinic space group C2/c with a=6.8028(9) ?, b=36.781(5) ?, c=7.5135(9) 2.474(2)° and Z=4. The complex sits on a symmetry axis such that the two halves of the molecule are related by two-fold rotation symmetry. The molecules form layers in which the molecules are joined by intermolecular O–H⋯O interactions involving hydrogen bonds between CO₂H⋯CO₂ ⁻, H₂O⋯CO₂ ⁻, H₂O⋯CO₂H and H₂O⋯H₂O groups.Supplementary material CCDC-289569 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data request/cif, by e-mailing data request@ccdc.cam.ac.uk or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 IEZ, UK; fax: +44(0)1223-336033.     

Synthesis and Crystal Structure of Nickel(II) Complex with 2,2′-Biimidazole and 4-Aminobenzoic Acid

Abstract  The Ni(II) complex, [Ni(H₂biim)₂(PABA)₂]Cl₂·2H₂O, H₂biim being 2,2′-biimidazole, PABA being 4-aminobenzoic acid has been synthesized and the crystal structure determined using X-ray crystallography. The complex crystallizes in triclinic system, space group P − 1 with unit cell parameters a = 8.3920(9) ?, b = 9.8436(11) ?, c = 9.8874(11) ?, α = 94.862(2)°, β = 109.142(2)°, γ = 90.992(2)°, V = 767.95(15) ?³ and Z = 1. The molecules of the complex in the crystal assemble by way of N–H⋯Cl, O–H⋯Cl, O–H⋯O hydrogen bonds as well as π–π stacking interactions to provide a two-dimensional supramolecular structure. Index Abstract  Synthesis and Crystal Structure of Nickel(II) Complex with 2,2′-Biimidazole and 4-Aminobenzoic Acid Yanping Li and Pin Yang* The molecules of the title complex [Ni(H₂biim)₂(PABA)₂]Cl₂·2H₂O in the crystal assemble by way of N–H⋯Cl, O–H⋯Cl, O–H⋯O hydrogen bonds as well as π–π stacking interactions to provide a two-dimensional supramolecular structure.      

Synthesis,Crystal Structure and Characterizations of New 3,4,7,8-Tetrachloro-1,10-Phenanthroline Zn(II) Complex

Abstract  

A novel 3,4,7,8-tetrachloro-1,10-phenanthroline (Cl₄phen) Zn(II) complex has been synthesized. The complex, [Zn(Cl₄phen)₂(H₂O)₂](NO₃)₂·CH₃CH₂OH (1), has been identified and characterized by single crystal X-ray diffraction, elemental analysis, FT-IR, thermogravimetric analysis and photoluminescence studies. Single crystal X-ray diffraction analysis reveals that complex (1) belongs to the monoclinic system, space group P2(1)/c, a = 10.061(2) Å, b = 18.924(4) Å, c = 18.189(4) Å, β = 100.94(3)°, and Z = 4. Complex (1) consists of cationic species [Zn(Cl₄phen)₂(H₂O)₂]²⁺, NO₃ ⁻ and CH₃CH₂OH. The zinc atom displays a distorted cis-N₄O₂ octahedral geometry. Via extended Zn–O–H···O–N–O···H–O–Zn bridge, every mononuclear unit is linked with other ones to form one-dimensional (1D) infinite chain of hydrogen bond system. Three-dimensional (3D) polymeric network arrangement was built via weak C–H···O and π-stacking interactions between Cl₄phen moieties. A solvent-dependency effect of complex (1) was observed in spectroscopic properties.     

Hydrogen Bonded 3D Supramolecular Architectures of Three Saccharinate Salts

Abstract  

Three saccharinate salts (2-aminopyrimidine): (saccharin) (1), (4-phenylthiazol-2-amine): (saccharin) (2), and (2-methylquinoline): (saccharin) (3) were prepared and structurally characterized by X-ray crystallography. Salt 1 crystallizes in the monoclinic, space group P2(1)/c, with a = 7.1782(9) ?, b = 13.5105(16) ?, c = 12.2251(12) ?, β = 93.3410(10)°, V = 1183.6(2) ?³, Z = 4. Compound 2 crystallizes in the triclinic, space group P-1, with a = 7.4584(7) ?, b = 8.6930(9) ?, c = 12.9179(14) ?, α = 108.952(2)°, β = 91.7510(10)°, γ = 97.2280(10)°, V = 783.57(14) ?³, Z = 2. Compound 3 crystallizes in the monoclinic, space group P2(1)/c, with a = 7.781(8) ?, b = 19.4209(19) ?, c = 10.9719(12) ?, β = 107.7390(10)°, V = 1579.2(16) ?³, Z = 4. The different hydrogen bonding interaction modes of the saccharinate anions and the cations lead to 3D network structure, 3D staircase structure, and 3D ABAB layer structure for 1, 2, and 3 respectively. Despite variations in the cation shape on the aromatic N–heterocyclic compounds, there all existed strong intermolecular N–H⋯O(carbonyl) hydrogen bonds. In compounds 1, and 3 the N⁺–H⋯O interaction between the N⁺–H group of the cation and the C=O group of the saccharinate anion is the most important interaction in this family of salts. However, in 2, there was a N–H⋯O interaction between the amino proton and the C=O group of the saccharinate anion. At the next level, the aromatic C–H proton interacts with the sulfonyl O atom. There are also π–π interactions in compounds 1–2, there is CH₃–π interaction in 3. Under these interactions the three compounds exhibit synthons I–III respectively. These interactions are responsible for the high-yielding supramolecular assembly of N-containing aromatic bases and the saccharinate into salts.     

Reaction of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne and imidazole with Cu(II) generates a discrete complex not a coordination polymer: crystal structure of [μ-4,4′-(1,2-ethynediyl)-bis(pyridine-2,6-dicarboxylato)-N,O, O′-μ-N′, O′′, O′′′]-diaqua-bis(imidazole)-dicopper(II)

Reaction of 1,2-bis(2,6-dicarboxypyridin-4-yl)ethyne and imidazole with Cu(II) produces crystals containing a discrete complex of [μ-4,4′-(1,2-ethynediyl)-bis(pyridine-2,6-dicarboxylato)-N, O, O′-μ-N′, O′′, O′′′]-diaqua-bis(imidazole)-dicopper(II) complex (1), [(C₁₆H₄N₂O₈)(C₃H₄N₂)₂(H₂O)₂Cu₂] instead of a linear coordination polymer. The complex crystallizes in the monoclinic space group P2₁/n with a = 5.3763(8) ?, b = 18.522(3) ?, c = 11.4827(7) ?, β = 93.705(3) ° and Z = 2. The complex sits on a center of symmetry such that the two halves of the molecule are related by inversion symmetry. The molecules pack in layers in which the molecules are joined by intermolecular N–H⋯O hydrogen bonds between imidazole and carboxylate groups and O–H⋯O hydrogen bonds between carboxylate groups and water.     

Unclassical Hydrogen Bonds of C–H⋯N and C–H⋯Cl in the Crystal Structures of 2-((<Emphasis Type="Italic">E</Emphasis>)-1,3-diarylallylidene)malononitriles

Abstract  

The 2-((E)-3-(2-nitrophenyl)-1-(4-methoxyphenyl)allylidene)malononitrile and 2-((E)-3-(2-chlorophenyl)-1-(4-bromophenyl)allylidene)malononitrile were synthesized and characterized by IR, ¹H NMR, and elemental analysis. The molecular structures were further confirmed by X-ray diffraction analysis. The former 1, C₁₉H₁₃N₃O₃, is triclinic, space group P−1, a = 7.3834(13), b = 10.901(3), c = 11.227(2) ?, α = 88.64(2), β = 71.596(14), γ = 78.186(18), Z = 2, V = 838.5(3) ?³. The unclassical hydrogen bond of C–H⋯N links the molecules forming polymers. The latter 2, C₃₆H₂₀Br₂Cl₂N₄, is orthorhombic, space group Pnma, a = 20.900 (4), b = 7.0710 (11), c = 10.9170 (18) ?, Z = 2, V = 1613.4(5) ?³. The same hydrogen bond of C–H⋯N and another type of C–H⋯Cl hydrogen bond link the adjacent molecules forming polymers along a axis.     

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.     

Molecular Association of Almotriptan with Oxalate and Terephthalate Anions

Abstract  

Crystal structures of anti-migraine drug almotriptan were crystallized with oxalic acid (I) and with terephthalic acid (II) and their crystal structures and molecular associations were determined using X-ray diffraction methods. Crystals of both (I) and (II) are monoclinic, space group P2₁/c, with a = 5.6270(4) ?, b = 27.6419(19) ?, c = 13.6228(9) ?, β = 93.057(1)°, V = 2115.9(3) ?³, Z = 4 (I) and a = 13.3756(15) ?, b = 15.6065(17) ?, c = 10.7238(12) ?, β = 98.017(2)°, V = 2216.7(4) ?³, Z = 4 (II). In almotriptan oxalate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium semioxalate}, C₁₇H₂₆N₃O₂S⁺, C₂HO₄ ⁻, (I) and in almotriptan hemi terephthalate hydrate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium hemi terephthalate monohydrate}, C₁₇H₂₆N₃O₂S⁺, 0.5(C₈H₄O₄ ²⁻), H₂O, (II), both the almotriptan cations form a trimer with the corresponding anions via N–H···O hydrogen bonds. In (I), the oxalate salt is monoprotonated and in (II), the terephthalic acid is located across the inversion centre and exists as doubly protonated anion. In (I), the cation and anion are interlinked by the N–H···O and O–H···O hydrogen bonds into continuous two-dimensional layers generate an R₆⁶(34) hydrogen-bonded motif tetramers running parallel to the (0 0 1) plane. In (II), the cation and water form a centrosymmetric tetramer of R₄⁴(22) hydrogen-bonded motif via N–H···O and O–H···O hydrogen bonds and further cross-linked by centrosymmetric anions to form an infinite three-dimensional supramolecular hydrogen-bonded networks.     

Crystal Structure and Conformational Analysis of 4-[(<Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethylamino)Benzylidene]-2-Phenyloxazole-5-One

Abstract  

Molecular and crystal structure of 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazol-5-one, C₁₈H₁₆N₂O₂, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 12.1704(23) ?, b = 3.9810(5) ?, c = 30.9603(56) ?, β = 101.176(15)°, Z = 4, D _x = 1.32 g/cm³, μ(Mo Kα) = 0.087 mm⁻¹, and space group is P12₁/c1. The structure was solved by direct methods and refined to a final R = 0.047 for 3166 reflections with I > 2σ(I). The crystal structure is stabilized by C–H⋯O and C–H⋯N type intra-molecular, C–H⋯O type inter-molecular interactions. To enlighten the flexibility and the geometric isomerism (E or Z) of the title compound, the selected torsion angle is varied from −180 to 180° in every 10° separately and molecular energy profile is calculated and analyzed.     

Synthesis and Crystal Structure of <Emphasis Type="Italic">Tris</Emphasis>-(<Emphasis Type="Italic">N</Emphasis>–<Emphasis Type="Italic">N</Emphasis> dimethyl benzylammonium)-hexachlorobismuthate(III)

Abstract  The salt tris-(N–N dimethyl benzylammonium)-hexachlorobismuthate(III) crystallizes in the triclinic system P1 with unit cell parameters: a = 9.0300(12), b = 9.9220(3), c = 19.575(2) ?, α = 79.955(5), β = 89.952(2), γ = 88.108(6)°, V = 1726.0(3) ?³, Z = 2. The examination of the structure shows an alternate stacking of inorganic layers of hexachlorobismuthate(III) anions and organic layers of [C₆H₅CH₂NH(CH₃)₂]⁺ cations parallel to the a-axis. The cohesion forces of the packing of N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Index Abstract  The examination of the structure shows a layer arrangement parallel to the a-axis: planes of octahedral anions [BiCl₆]³⁻ alternate with planes of [C₆H₅CH₂NH(CH₃)₂]⁺ cations (Fig. 3). The cohesion forces of the packing of the N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The Crystal and Molecular Structure of the Dinuclear Mo(VI) Species: [(cis-MoO2L)(μ-O)(cis-MoOL(OH2)]?·?CHCl3 where L?=?(S-benzyl 3-(2-Hydroxyphenyl)Methylenedithiocarbazate)

Abstract  The title dinuclear complex, [(cis-MoO₂L)(μ-O)(cis-MoOL(OH₂)], was characterized as a chloroform solvate. In this structure, one Mo atom features a cis-[MoO₂]²⁺ core to which is also bonded a dinegative, tridentate S-benzyl 3-(2-hydroxyphenyl)methylenedithiocarbazate ligand (= L), via sulfur-, oxygen-, and nitrogen-donors, and a water molecule completes the distorted octahedral coordination geometry. A similar NO₄S donor set is found for the other Mo atom but in this case, the water molecule is substituted by a bridging oxo atom derived from the first Mo species. Two dimers associate via cooperative O–H⋯O hydrogen bonds to form a supramolecular dimer which, in turn, are linked into supramolecular chains via O–H⋯N hydrogen bonding. The complex crystallizes in the triclinic space group P-1 with a = 10.4714(12) ?, b = 10.7627(14) ?, c = 16.708(2) ?, α = 87.916(7)°, β = 76.249(6)°, γ = 83.610(7)°, and Z = 2. Index Abstract  Dinuclear [(cis-MoO₂L)(μ-O)(cis-MoOL(OH₂)], characterized as a chloroform solvate, with octahedral Mo centers, are connected into supramolecular dimers via O–H⋯O hydrogen bonding which are connected via O–H⋯N hydrogen bonds into chains.      

Synthesis and Crystal Structures of 4-(3-Nitropyridin-2-ylamino)phenol and 4-(3-Aminopyridin-2-ylamino)phenol

Abstract  

The title compounds, 4-(3-nitropyridin-2-ylamino)phenol (I) and 4-(3-aminopyridin-2-ylamino)phenol (II), are two intermediates for the synthesis of a potential antitumor agent ABT-751. The reaction of 4-aminophenol with 2-chloro-3-nitropyridine yielded I which was converted into II by reduction. Instead of the Pd/C catalytic hydrogenation described in many literature, reduction with cheap sodium sulfide in aqueous media was utilized for shorting the reaction time and simplifying the operation. The crystal structures of the resultant compounds were determined by single-crystal X-ray diffraction. The compound I is crystallized in P2₁/c space group of monoclinic system, with a = 11.5236(19) ?, b = 8.7389(17) ?, c = 10.684(3) ? and α = 90.00°, β = 107.76(3)°, γ = 90.00°. The compound II is crystallized in Cc space group of monoclinic system, with a = 10.688(2) ?, b = 14.2181(18) ?, c = 7.9836(15) ? and α = 90.00°, β = 125.801(7)°, γ = 90.00°. In both crystal structures, the intermolecular N–H–O and O–H–N hydrogen bonds link the molecules, which effectively stabilize the structures.     

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.     

X-ray diffraction, DFT, and spectroscopic study of N , N ′-difluoroboryl-5-(2-thienyl)dipyrrin and fluorescence studies of related dipyrromethanes, dipyrrins and BF2-dipyrrins and DFT conformational study of 5-(2-thienyl)dipyrrin

To explore the characteristics of potential fluorescent probes that could be used to screen prospective HDS catalysts, new 5-thienyl dipyrromethene derivatives have been prepared. 5-(2-thienyl)- (1a), 5-(3-thienyl)- (1b), and 5-(3-(2,5-dibromothienyl))-dipyrromethane (1c), were oxidized with DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) separately to give the corresponding dipyrrins 2a–2c. These were subsequently treated with F₃B·OEt₂ to afford the respective N,N′-difluoroboryl-5-(thienyl)dipyrrin compounds, 3a–3c; the latter two may serve as polymer precursors. Significant fluorescence signal enhancement is achieved with 3a–3c over 2a–2c. Orange fluorescence is observed for 3a whereas its isomer 3b gives green fluorescence (365 nm). An X-ray diffraction study of 3a was performed (orthorhombic, P2₁2₁2₁, a=10.684(10) ?, b=15.208(13) ?, c=7.256(6) ?, V=1179.0(17) ?³, Z=4, R ₁=0.0428, wR ₂=0.0686) and its geometry was studied by way of DFT (Gaussian 03; B3LYP/6-31G^*) to give a HOMO/LUMO energy level difference of 414 nm, and a 2-thienyl group rotational barrier of ∼6 kcal/mol, compared to that of ∼12 kcal/mol for the phenyl derivative. Theoretical modeling of 2a demonstrated that the [N–H⋯N] interaction is favored by ca. 10 kcal/mol, whereas [N–H⋯S] bonding is sterically unattainable.     

5-Pyridine 4-yl-3H-(1,3,4) Oxadiazole-2 Thione Hydrochloride Monohydrate, (I), and 4 [5-Ethylsulfanyl)-(1,3,4) Thiadiazole-2-yl]-Pyridinium Perchlorate, (II)

Abstract  

The title compounds C₇H₈ClN₃O₂S, (I), and C₉H₁₀ClN₃O₄S_2, (II), both crystallize in monoclinic space group P2₁ /c with unit cell parameters (I) a = 7.9402(7), b = 10.6312(9), c = 11.7626(10), ?, β = 99.271(5)°, Z = 4 and (II) a = 5.1439(2), b = 9.0636(4), c = 27.1814 (7), ?, β = 95.116(2)°, Z = 4. In (I) the molecule consists of a 5-pyridine-4-yl group bonded to the carbon atom at the 5 position of (1, 3, 4) oxadiazole-2 thione hydrochloride monohydrate. The angle between the mean planes of the oxadiazole and pyridine rings is 9.6(6)°. Crystal packing in (I) is stabilized by strong N–H···O hydrogen bonds in concert with a solvent water molecule and weak O–H···Cl, O–H···S, N–H···Cl intermolecular interactions. The crystal structure of compound (II) consists of 4 [5-ethylsulfanyl)-(1, 3, 4) thiadiazole-2-yl]-pyridinium perchlorate, (C₉H₁₀N₃S₂)⁺(ClO₄)⁻, cation–anion pairs, containing strong intermolecular N–H···O hydrogen bonds and weak C–H···O and N–H···O intermolecular interactions operating between the ionic species that form a cooperative hydrogen-bonded, infinite chain O–H···O–H···O–H network which generates a sheet motif structure in the unit cell. It is also supported by weak intermolecular Cg···Cg π–π and Cl–O···Cg π-ring interactions which gives additional support to molecular packing stability in the unit cell. Geometry optimized MOPAC AM1 computational calculations on each compound provides support to the structural features in their respective crystal structures.     

Synthetic and structural studies of the trans bis(2-N-H-pyrrolylcarbaldimine) complexes of nickel(II) and palladium(II)

The molecular bis(2-N-H-pyrrolylcarbaldimine)nickel(II) and palladium(II) complexes are isolated in moderate yield (30–35%) from in situ assembly of the Schiff base with metal(II) salt, base, and pyrrole-2-carbaldehyde in aqueous ammonia solution. The nickel(II) complex, 1, is monoclinic, space group P2₁/c, with a=11.289(6) ?, b=5.611(3) ?, c=8.287(5) ?, β=111.620(6)°, and V=488.0(5) ?³ with Z=2, for d _calc=1.667 Mg/m³. The palladium analog, 2, is isomorphous, space group P2₁/c, with a=11.481(3) ?, b=5.5738(10) ?, c=8.276(2) ?, β=110.923(12)°, and V=494.7(2) ?³ with Z=2, for d _calc=1.965 Mg/m³. In both crystal structures, the metal resides on an inversion center. In the IR spectra, ν(C=N) appears at 1561 cm⁻¹ in 1, and 1557 cm⁻¹ in 2, while ν(N–H) shows at 3345 cm⁻¹ and 3335 cm⁻¹, respectively. The ¹H-nmr spectra reveal the C–H and N–H protons of the imine group as sharp and broad doublets, respectively, at 7.62 and 8.38 δ in 1 and at 7.92 and 9.73 δ in 2.     

NH?O and NH?N Hydrogen Bonded Networks in Imidazole-Based Phosphane Oxides: Structures of Tris(2-Isopropylimidazol-4(5)-yl)Phosphane Oxide, Bis(2-Isopropylimidazol-4(5)-yl)Phosphane Oxide and Diphenyl-2-Isopropylimidazol-4(5)-yl Phosphane Oxide

Abstract  

The three title compounds show extensive hydrogen bonding networks in the solid state. The structure of diphenyl-2-isopropylimidazol-4(5)yl phosphane oxide (3) is dominated by N–H⋯OP hydrogen bonds, whereas in bis(2-isopropylimidazol-4(5)-yl)phenyl- (2) and tris(2-isopropylimidazol-4(5)yl)phosphane oxide (1) both, N–H⋯N and N–H⋯OP hydrogen bonds determine the solid-state structures. Compound 1 crystallises in the monoclinic space group Cc with cell parameters a = 19.5447(6) ?, b = 10.45764(16) ?, c = 10.8549(3) ? and β = 121.418(4)°; 2 in the orthorhombic space group Pna2₁, with a = 11.5997(3) ?, b = 9.5836(2) ?, c = 16.1860(4) ? and 3 in the orthorhombic space group Pca2₁, with a = 10.8430(2) ?, b = 10.9277(2) ? and c = 27.7088(6) ?.     

Crystal Structure of Tetrakis Imidazole Copper(II) Diadipate Complex

Abstract  The title compound, [Cu(C₃H₄N₂)₄(COO–(CH₂)₄–COOH)₂] is a neutral complex and exist as a monomeric unit. The Cu atom occupies at the center of symmetry (0, 0.5, 0) with a distorted octahedral geometry. Imidazole nitrogens N1 and N6 (Cu1–N1 = 1.993(3) ?; Cu1–N6 = 2.008(3) ?) from two different imidazole group which are symmetrically disposed provides the square base and the long carboxylate oxygens (Cu1–O2 = 2.582(3) ?) from the protonated end of symmetrically oriented dibasic acid at the trans axial position. The adipate monoanion is in weak coordination with the metal center via monodentate fashion. The strong carboxylate-carboxylic acid intermolecular O–H…O interaction between the adjacent molecules is present in this structure as observed in the crystal structure of hexanedioic acid is noteworthy. In addition to the O–H…O H-bonding other molecular interactions such as N–H…O and C–H…O in packing generates a 3-D hydrogen bond network. Graphical Abstract  The title compound tetrakis imidazole Cu(II) diadipate is a neutral complex and exist as a monomeric unit with the metal atom occupies at the center of symmetry. Strong inter and intramolecular H-bonding interactions such as O–H…O, N–H…O and C–H…O in packing generates a 3-D hydrogen bond network.     

Synthesis and Crystal Structure of 2-Amino-4,6,6-trimethyl-cyclohex-2-en-1,1,3,4(S)-tetracarbonitrile

Abstract  

Crystal structure analysis of the novel 2-amino-4,6,6-trimethyl-cyclohex-2-en-1,1,3,4(S)-tetracarbonitrile, obtained in 70% yield, by the Bi(OTf)₃ catalyzed reaction of acetone and malononitrile, at room temperature, is described. For the first time Bi(OTf)₃–Et₃N has been used in this inverse electron demand Diels–Alder cycloaddition reaction involving the participation of carbonitrile π-bond. The structure of the molecule was established by spectral analysis and X-ray diffraction studies. The compound crystallizes in the monoclinic space group P2₁/n with unit cell parameters: a = 8.0580 (17), b = 13.038 (3), c = 12.641 (3) ?, β = 101.883 (4)°, Z = 4. The crystal structure was solved by direct methods and refined to R = 0.0506 for 2,456 observed reflections. The cyclohexene ring of the molecule adopts a distorted sofa conformation. The molecules in the unit cell are arranged in layers. The crystal structure in stabilized by C–H⋯N and N–H⋯N interactions.     

The preparation and crystal structures of [Ru(bpy) (η2-tpy)(CO)CH2OAc]PF6 and [Ru(η3-tpy)(CO)CH2OAc] PF6 (bpy = 2,2′-bipyridine; tpy = 2,2′:6′,2″ terpyridine)

The first titled compound, 1, was obtained by treating [Ru(bpy)(η²-tpy)(CO)CH₂OH]PF₆ with acetic anhydride. Heating 1 in acetonitrile afforded 2, [Ru((η³-tpy)(MeCN)(CO) CH₂OAc]PF₆. Allowing 2 to stand in CH₂Cl₂ followed by concentration and precipitation afforded the second titled compound, 3 ([Ru((η³-tpy)(CO)–CH₂OAc]PF₆), in which the acetoxymethyl group had become bidentate. Crystal data for 1, monoclinic crystal system, space group C2/c, a=26.001(4) ?, b=13.0395(18) ?, c=20.718(3) ?, β=107.700(2)°, V=6691.7(16) ?³, Z=8; for 3, monoclinic crystal system, space group P2₁/n, a=10.864(2) ?, b=16.922(4) ?, c=11.127(2) ?, β=90.907(3)°, V=2045.4(8) ?³, Z=4.