Structure and molecular chirality of the 2∶1 salt of quinine with biphenyl 2,2′-dicarboxylic acid (diphenic acid)

The molecule of the salt consists of two quinine cations and a biphenyl 2,2-dicarboxylic dianion. Both of the quinine cations are protonated at the nitrogen atoms of the quinuclidine fragments. Each carboxylic group of the diphenic dianion acts as a proton donor with respect to the quinuclidine N(1) atom of one of the quinine cations, and as a proton acceptor with respect to the carbinol O(12)-H(12) group of the other. Thus, the interlocking hydrogen-bond system forms a rigid structure. The molecular conformation around the C(8)-C(9) bond is synclinal. The conformational parameters of the diphenic dianion are considerably different from those of diphenic acid in solid state. The absolute configuration of the biphenyl 2,2-dicarboxylic dianion (S) is defined by the positive torsion angle around the line which connects the centers of both phenyl rings. The molecular chirality of the salt arises from the coupling between the quinoline and the biphenyl chromophores, as well as from the coupling of the quinoline-quinoline long-axis polarized-band transition moments.     

Crystal and molecular structure of the inclusion compound between 1,1′-binaphthyl-2,2′-dicarboxylic acid and acetylacetone (1∶1)

The lattice type crystalline inclusion compound of 1,1-binaphthyl-2,2-dicarboxylic acid (BNDA) with acetylacetone (AcAc) 11 has been investigated by single crystal X-ray diffraction. AcAc is present as the enolic tautomer, stabilized by a notably short intramolecular hydrogen bond. This H-bond closes a six-membered ring with delocalization of the system of conjugated double bonds. In the crystal the AcAc molecules are incorporated into channels, delimited by bulky binaphyl moieties, in a hydrogen-bonded framework of BNDA, and they do not show any disorder. The strictly stoichiometric host:guest ratio seems to be enforced by packing forces only.     

Crystal structures of two substituted biphenyl derivatives: 5,5′-di t-butyl-2-2′-biphenyldiol and 5,5′-dimethyl-2,2′-biphenyldiol

5,5-Di t-butyl-2,2-biphenyldiol (I), C₂₀H₂₆O₂, crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 18.243(2), b = 9.947(2), c = 9.685(3) Å, and Z = 4; 5,5-dimethyl-2,2-biphenyldiol (II), C₁₄H₁₄O₂, crystallizes in the monoclinic space group P2₁/c with a = 9.959(2), b = 7.932(3), c = 15.392(2) Å, = 105.43(2)°, and Z = 4. The aromatic rings are tilted by 52.7(1) and 43.8(1)° to each other in compounds (I) and (II), respectively. Strong intra- and inter-molecular H-bonds connect the molecules in the crystals.     

Crystal and molecular structures of three 2,2′-thio- and 2,2′-sulfonyl-bis(1,3-diarylprop-2-en-1-ones)

The X-ray crystal structures of 2,2-thio- and 2,2-sulfonylbis(1,3-diarylprop-2-en-1-ones) are determined [1: 2,2-thiobis(3-(p-chlorophenyl)-1-phenylprop-2-en-1-one), C₃₀H₂₀Cl₂O₂S, space group C2/c, a = 14.275(3), b = 6.280(1), c = 26.533(5) Å, = 94.55(3)°, Z = 1/2; 2: 2,2-sulfonylbis(1,3-diphenylprop-2-en-1-one), C₃₀H₂₂O₄S, space group P , a = 9.652(1), b = 12.044(1), c = 12.182(1) Å, = 61.985(6), = 77.511(5), = 74.340(6)°, Z = 1; 3: 2,2-sulfonylbis(3-(p-chlorophenyl)-1-phenylprop-2-en-1-one), C₃₀H₂₀Cl₂O₄S, space group P , a = 8.294(1), b = 13.175(2), c = 13.470(1) Å, = 62.870(9), = 83.796(7), = 85.282(8)°, Z = 1]. The C=C double bonds are all clearly defined. The sulfide 1 crystallizes on a crystallographic twofold axis, leading to a symmetric molecular conformation. The sulfones 2 and 3 crystallize on general positions, with different and irregular conformations.     

Crystal and Molecular Structure of 6,6′-Dimethoxy-gossypol:Acetic acid (1:1)

Abstract By crystallization from dilute solutions of acetic acid (2–4%) in diethyl ether, acetone, or methyl ethyl ketone, 6,6′-dimethoxy-gossypol forms a solvate with acetic acid in a one-to-one molar ratio. The compound crystallizes in the triclinic P space group and has unit cell dimensions of a = 7.5793(10) ?, b = 14.7211(19) ? and c = 14.740(2) ?, α = 106.260(3)°, β = 102.310(3)°, γ = 95.975(3)°, Z = 2. The structure was solved by direct methods and refined to an R1 value of 0.0394 on 4252 observed reflections. Enantiomeric pairs of dimethoxy-gossypol molecules form centrosymmetic dimers that are characterized by a pair of intermolecular hydrogen bonds and by hydrophobic stacking between pairs of naphthalene rings. The acetic acid molecule accepts a hydrogen bond from a gossypol hydroxyl group and donates to a hydrogen bond with one of the aldehyde groups of an adjacent gossypol molecule. Although there is less hydrogen bonding in this structure than in the gossypol:acetic acid (1:1) structure, the molecular packing of the two compounds is similar. Graphical abstract Crystal and molecular structure of 6,6′-dimethoxy-gossypol:acetic acid (1:1) Michael K. Dowd and Edwin D. Stevens The molecular structure of the acetic acid solvate of 6,6′-dimethoxy-gossypol is presented.      

Crystal and molecular structure of the photocatalyst tris(2,2′-bipyrazine)ruthenium(II) hexafluorophosphate

The X-ray structure determination of the complex tris(2,2-bipyrazine)ruthenium(II) hexafluorophosphate, [Ru(C₈N₄H₆)₃](PF₆)₂, has shown that the compound crystallizes in the monoclinic space group P2₁/c witha=13.459(5),b=23.486(8),c=17.913(10) Å,=139.85(1)°, andZ=4. Each asymmetric unit also contains one dimethylformamide and one water molecule. Least-squares refinement led to an R factor of 0.074 based on 3463 reflections for which I>2(I). The [Ru(C₈N₄H₆)₃]²⁺ cation has no crystallographic symmetry, but the requirements for point symmetry 32 are nearly met. The six Ru-N bond lengths agree within experimental error and have an average length of 2.05(1) Å.     

Structure of the adduct of bis(2,2′biimidazole)copper(II) perchlorate with 4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-7-one

The crystal structure of the compound [Cu(biim)₂](ClO₄)₂(7HtpO)₂ (where 7HtpO is 4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine-7-one and biim is 2,2'biimidazole) has been determined at room temperature. The dark green crystals are monoclinic, space group C2/c with unit dimensions a = 19.666(2) Å, b = 11.7586(8) Å, c = 13.4808(9) Å, = 103.690(8)°, Z = 4, and Dx = 1.761 Mg-m^–3. The structure was refined by a full-matrix least-squares procedure on F ² to final R = 0.0806 using 4407 reflections. The cation is slightly distorted square planar and 7HtpO is not directly linked to the metal, the interaction between the cation and the triazolopyrimidine moiety taking place via stacking.     

Structure of 2,2′-bis(4-cyanatophenyl)isopropylidene

The title compound is monoclinic:a=13.345(3),b=11.393(2),c=10.046(5)Å,=108.48(2)°,Z=4,P2₁/c. The structure was determined by direct methods, using MoK diffractometer data, and refined by full-matrix least squares toR=0.045 for 1463 reflections. The structure shows a central tetrahedral carbon atom surrounded by two methyl and two phenylcyanate groups. The geometry of the cyanate group compares well with that in 4-chloro-3,5-dimethyl-phenyl cyanate, the only example of an organic cyanate in the Cambridge Crystallographic database (V.3). The intermolecular nitrile, C-N, distances were examined for evidence of a possible dimerization interaction; no significant distances were found.     

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.      

X-ray crystal structure of the 1∶2 triethyleneglycol dimethyl ether (triglyme): Dichloropicric acid adduct

The anhydrous 12 triglyme:Dichloropicric acid adduct is triclinic, space group ; at 24°Ca=8.703(5),b=10.381(4), c=10.404(3) Å, =114.42(3), =99.69(5), =106.40(6)°,D _x=1.656 g cm^–3, V = 776(2)ų,Z=1. Bond lengths and angles are normal except that one C–C–O–C torsion angle in the triglyme is approximately 90° rather than the expected 60 or 180°. Each phenolic OH group hydrogen bonds with a terminal OCH₃ of the polyether. The O...O distance, 2.557(3) Å, is in fair agreement with the 2.52 Å estimated from the single observed IRv (OH) stretch at 1714 cm^–1.     

The condensation of p-nitrothiophenol with formaldehyde and trichloroacetaldehyde. Structure of 2,2-bis(4′-nitro-1′-mercaptophenyl)-1,1,1-trichloroethane

The condensation ofp-nitrothiophenol with formaldehyde and with trichloroacetaldehyde is described. 2,2-Bis(4-nitro-1-mercaptophenyl)-1,1,1-trichloroethane is monoclinic,P2₁/c,a=7.717(2),b=34.666(5),c=7.258(1) (Å),=116.32 (1) (deg.),V=1740.35 (ų),Z=4. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by full-matrix least squares to a finalR value of 0.052 using 1722 reflections. The torsion angles S-C-S-C_Ar are 159.7(3) and –90.5(4) (deg). The mean planes of the aromatic rings are at 46.8(2) (deg.) to one another. Evidence of intramolecular crowding is given by the inequality of several pairs of angles which would otherwise have been expected to be equal. The bond lengths are normal.     

Structure of (2,2′-bipyridine)lead(II) saccharinate monohydrate

The structure of (2,2-bipyridine)lead(II) saccharinate monohydrate has been investigated by X-ray diffraction. The compound crystallizes in the monoclinic space group P2 ₁/n with a = 22.903(7), b = 12.608(3), c = 8.682(2) Å, = 96.76(3)°, and Z = 4. The structure consists of Pb²⁺ cations, 2,2-bipyridine ligands, saccharinato anions and water molecules. The Pb²⁺ cation is surrounded by two O atoms and four N atoms. The two saccharinato ions are nonequivalent. The water molecule forms hydrogen bonds of O_W···O_CO [2.810(16) Å] and O_W···O_SO2 [2.893(16) Å] type.     

Crystal and molecular structure of aquabis(2,2′-bipyridine)nitratomanganese(II) nitrate monohydrate

A new monomeric manganese(II) nitrate complex with 2,2-bipyridine (bpy), [Mn(bpy)₂(NO₃)(H₂O)](NO₃)·H₂O, has been prepared and characterized by X-ray crystallography. The complex crystallizes in the triclinic space group witha=9.721(3),b=14.691(5),c=8.578(3) Å, =106.79(3), =96.05(3), =82.55(3)°,V=1159.9 ų andZ=2. The structure comprises discrete cation [Mn(bpy)₂(NO₃)(H₂O)]⁺ in which the metal atom is coordinated by a pair of bidentate bpy ligands [Mn–N=2.261(4)–2.299(4) Å], a unidentate nitrato [Mn–O=2.284(4) Å] and aqua [Mn–O=2.160(3) Å] ligands in a highly distorted octahedral arrangement.     

Structure of the adduct of bis(O,O′-diisopropyldithiophosphato) metal with pyridine: Ni[(iPrO)2PS2]2(py)2 and Cd[(iPrO)2PS2]2 (py)2(py = pyridine)

The crystal and molecular structures of the complex of [Ni{(iPrO)₂dtp}₂(py)₂] and [Cd{(iPrO)₂dtp}₂(py)₂] (dtp = dithiophosphate, py = pyridine) have been determined by X-ray crystallography. They are isomorphous. The crystal structures are very similar and consist of discrete molecules of [Ni{(iPrO)₂dtp}₂(py)₂] and [Cd{(iPrO)₂dtp}₂(py)₂], respectively. They both crystallize in the monoclinic system, space group P2₁/c, the former with lattice parameters a = 6.489(1) Å, b = 14.830(3) Å, c = 16.386(3) Å, = 99.74(3), and Z = 2; the latter with a = 6.461(3) Å, b = 14.583(4) Å, c = 17.433(4) Å, = 99.55(3)°, and Z = 2. They all display distorted octahedral geometry around the central metal atom. In the complexes, two O,O-diisopropyl dithiophosphate ions act as bidentate ligands with their S atoms coordinated to metal. Each forms a four-membered chelate ring in the equatorial plane. The N atoms from two pyridine ligands are axially coordinated to the metal atom. The Ni–S bond distances are 2.5137(10) and 2.5386(9) Å, and the Ni–N bond distances are 2.127(3) Å. The Cd–S(1) and Cd–S(2) bond distance are 2.694(1) and 2.704(1) Å, respectively, and the Cd–N bond distances are 2.399(3) Å. The IR spectra data is in agreement with the structural data.     

Synthesis and Characterization of Two Pb(II) Complexes of 2,2′-dihydroxy,Dimethoxy-1,1′-binaphthyl-3,3′-dicarboxylic Acid

Two new complexes {[Pb(L¹)(DMSO)₂(H₂O)]·DMF}_n (1, L¹ = 2,2′-dihydroxy-l,l′-dinaphthyl-3,3′-dicarboxylate) and {[Pb(L²)(DMS O)·DMSO}_n (2, L² = 2,2′-dimethoxy-l,l′-dinaphthyl-3,3′-dicarboxylate) have been synthesized under mild conditions and structurally characterized. Crystal structural analysis reveals that complex 1 adopts a 1D infinite chain structure which forms 2D sheet by hydrogen bonds interactions. Complex 2 possesses a 2D sheet structure, which was further assembled into a 3D supramolecular network through the π-π weak interactions. IR spectra indicates the carboxyl group coordinates with the Pb²⁺ ion. TGA shows that complex 2 is highly thermally stable up to 120°C.     

Structure of 2,2′-anhydro-3′-O-acetyl-2′thio-1-β-D-arabinofuranosylcytosine hydrochloride1

2,2-Anhydro-3-O-acetyl-2-thio-1--D-arabinofuranosylcytosine hydrochloride crystallizes in space group P2₁2₁2₁ witha=10.373(1),b=14.517(2),c=9.496(1) Å. Reflections were measured on a diffractometer and the structure was solved by direct methods. Least-squares refinement converged atR=0.056 andR _w =0.063. The study of this crystal structure showed that the alterations in the geometry of 2,2-anhydro-1--D-arabinofuranosylcytosine when the bridge oxygen is replaced by sulfur are localized in the region of the fused ring. The angle at the bridge atom decreases to nearly 90°, with concomitant enlargements of about 5°–7° in the angles opposite to the bridge atom. Angle C(1)-N(1)-C(6) decreases by 4°. Also, the amount of double bond character in the bond formed by C(2) and the bridge atom decreases. A survey of the conformational features of S,2-cyclonucleosides and comparison with O,2-cyclonucleosidcs showed that their preferred conformations are the same. However, S,2-cyclonucleosides exhibit a wider range of P and values. This correlates with a greater ease of the sulfur containing five-membered ring to pucker as compared to the oxygen-cyclo ring.This paper is part of the authors' dissertation (Vitali, 1986).     

The crystal structure of the molecular complex of 2′,6′-dimethoxyflavone with picric acid: Alternating π-stacking and hydrogen-bonding interactions

The title complex is monoclinic with a = 15.100(5), b = 7.624(3), c = 39.997(15) Å, = 99.49(4)°, Z = 8, and space group P2₁/c. There are two geometrically independent, hydrogen-bonded pairs of molecules in the asymmetric part of the structure. Picric acid and 2,6-dimethoxyflavone are held together by hydrogen bonding between the hydrogen of the phenol group and the oxygen of the carbonyl. Additionnally, this hydrogen forms an intramolecular hydrogen bond with the O atom of an ortho-nitro group. Moreover, a stacking interaction is observed between the -benzopyrone portion of the flavone and picric acid.     

Crystal and molecular structure of the (−)-N-hydroxyimide of (10-pinene-2-yl) succinimic acid

Two independent molecules in the unit cell are the same enantiomer of the title compound but possess slightly different conformations. Both conformers are joined by H-bonds to one water molecule. The configuration at C11 was established asR.Crystal data: C₁₄H₁₉O₃N×1/2H₂O; trigonal,P3₂;a=17.486(2),b=17.486(2),c=8.024(1)Å;V=2124.72(6)ų;Z=6; (CuK)=1.54178 Å;F(000)=834; finalR=0.0495 for 2376 reflections (of 2747 unique data).     

Mechanochromic Photoluminescent Liquid Crystals Containing 5,5′-Bis(2-phenylethynyl)-2,2′-bithiophene

5,5′-Bis(2-phenylethynyl)-2,2′-bithiophene derivative 1 containing dendritic moieties linked through amide groups was synthesized. Compound 1 exhibits a rectangular columnar phase on slow cooling from the isotropic liquid. In contrast, a cubic phase is formed as a metastable liquid-crystalline phase by rapid cooling of the isotropic melt. Mechanical shearing induces a cubic–columnar phase transition, accompanied by the change of a photoluminescent color from yellow-green to green. The infrared spectra of 1 suggest that the mechanical stimuli can induce the partial dissociation of the hydrogen bond. This may lead to more disordering of the π-stacks of chromophores.     

Crystal and molecular structure of the H-bonded complex between 1-chloro-2-hydroxynaphthalene-3-carboxylic acid and dimethylformamide (1∶1)

Crystal structure determination of the title complex reveals that the dimethylformamide solvent is bound to the carboxylic function of the hydroxy acid, in the form of a 7-membered hydrogen-bonded loop involving both the expected O-HO and an apparently weak C-HO interaction between host and guest. There is a strong intramolecular hydrogen bond between the phenolic OH and the carbonyl oxygen. Close packing of the complex units is afforded by a herringbone type alignment of host molecules.