Molecular and crystal structure of two nickel(II) 1,2-dithiooxalato-S,S′ complexes using 1-(Rbenzyl)pyridinium cation (R = 4′-bromo-2′-fluoro or 4′-bromo)

[BrFPy]₂[Ni(dto)₂] (1) and [BrPy]₂[Ni(dto)₂] (2) complexes have been prepared by reaction of Na₂[Ni(S₂C₂O₂)₂] and the corresponding 1-(Rbenzyl)pyridinium bromide salt (R₁ = 4-bromo-2-fluoro, R₂ = 4-bromo). The crystallographic data for 1: monoclinic P2₁/c, a = 14.2192(1) Å, b = 14.2533(4) Å, c = 15.6535(3) Å, = 96.463(1)°, V = 3152.34(11) ų, Z = 4. Two cations, [Br₁F₁Py]⁺ and [Br₂F₂Py]⁺, both adopt a conformation where both the aromatic rings are twisted to the corresponding N(1)–C(10)–C(11) or N(2)–C(22)–C(23) reference plane. Data for 2: triclinic , a = 9.4042(3) Å, b = 9.6814(4) Å, c = 10.3357(4) Å, = 80.155(1)°, = 65.245(1)°, = 64.259(1)°, V = 769.68(5) ų, Z = 1. The [Ni(dto)₂]^2– anion exhibits a quasi-planar structure in both complexes. An extensive hydrogen bond network of C–H O is clearly observed in 1 and 2, and two complexes show similar crystal packing.     

Synthesis and crystal structure of bis(2,2′-bipyridyl)mononitritozinc(II) perchlorate. An example of a six-coordinate cis-octahedral ZnN4O2 chromophore

The crystal structure of bis(2,2-bipyridyl)mononitritozinc(II) perchlorate, [Zn(bipy)₂ (ONO)][ClO₄] (1) has been determined. The complex is monoclinic, with a = 10.9195(4) Å, b = 12.2320(5) Å, c = 16.5477(8) Å, = 105.6150(10), P2₁/n space group, with final R1 = 0.0657 and wR2 = 0.1630. The complex involves a [Zn(bipy)₂ (ONO)]⁺ cation and a [ClO₄]^– anion. The ZnN₄O₂ chromophore is six-coordinate, with a cis-distortion of the two oxygens of the nitrite, O(1) and O(2), at distances 2.216(5) and 2.197(5) Å from the zinc (Zn– O _mean = 2.206(5) Å, O = 0.019(5) Å) and two out of plane Zn–N bonds, Zn–N(2) and Zn–N(3), at 2.129(4) and 2.135(4) Å (Zn–n _mean/out = 2.132(4) Å, n _2,3 = 0.006(4) Å). The two inplane nitrogens, N(1) and N(4), at distances Zn–N(1) = 2.090(4) and Zn–N(4) = 2.085(4) Å (Zn–n _mean/in = 2.087(4) Å, n _1,4 = 0.005(4) Å) are greater than 2.0 Å, but slightly shorter than the axial bonds. The inplane angles ₁, ₂, and ₃ in 1 have values 150.33(18), 108.98(17), and 99.73(18) respectively. The stereochemistry is cis-distorted octahedral, with an ₃ = 99.37(18), which is lower than ₃ = 103.4(1) observed in [Zn(bipy)₂(ONO)][NO₃] (5). Comparison with the corresponding [Cu(bipy)₂(ONO)][Y] complexes suggested that the cis-distortion of the CuN₄O₂ chromophore in the copper(II) series does not originate in the Jahn–Teller or pseudo-Jahn–Teller effect.     

Crystal structures of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes

The crystal and molecular structure of a series of 3,8-di[-2-aryl-1-azenyl]-1,3,6,8-tetraazabicyclo[4.4.1]undecanes (1–5) have been determined by single crystal X-ray diffraction analysis. In all five compounds, the tetraazabicycloundecane portion of the molecule assumes a cage-like, folded structure with the aryltriazene moieties aligned approximately parallel; the structure is held in the folded configuration by either intramolecular or intermolecular – stacking forces. Crystal data: 1 C₁₉H₂₂N₁₀O₄, monoclinic space group P2₁/c, a = 10.1846(7), b = 9.9556(7), c = 20.819(2) Å, = 98.725(1)°, V = 2086.5 (3) ų, Z = 4; 2 C₂₃H₂₈N₈O₄, triclinic, space group P, a = 6.7064(7), b = 12.9662(14), c = 14.054(2) Å, = 94.796(2), = 91.621(2), = 104.836(2)°, V = 1175.7(2) ų, Z = 2; 3 C₁₉H₂₂N₁₀O₄, monoclinic, space group P2₁/c, a = 14.237(2), b = 13.520(2), c = 11.5805(12) Å, = 113.514(2)°, V = 2044.0(4) ų, Z = 4; 4 C₂₁H₂₂N₁₀, monoclinic, space group C2/c, a = 54.247(3), b = 11.5531(7), c = 12.9670(7) Å, = 95.710(1)°, V = 8086.4(8) ų, Z = 16; 5 C₂₅H₃₂N₈ 0₄, monoclinic, space group P2₁/c, a = 10.2908(7), b = 16.5687(12), c = 15.1662(10) Å, = 94,188(1)°, V = 2579.0(3) ų, Z = 4.     

Synthesis and structural characterization of five new coordination polymer chain structures using a new,Z-shaped ligand, 2,2′-bis-(4-pyridylethynyl)tolane

Using the new ligand, 2,2-bis-(4-pyridylethynyl)tolane we have synthesized five new coordination polymers: HgBr₂[2,2-bis-(4-pyridylethynyl)tolane] (1), HgI₂[2,2-bis-(4-pyridylethynyl)tolane] (2), Ni(acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane] (3), Zn(acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane] (4), and Cu(hexafluoro acetylacetonate)₂[2,2-bis-(4-pyridylethynyl)tolane]CHCl₃ (5). 2,2-Bis-(4-pyridyl ethynyl)tolane is a rigid ligand with a Z-shape that promotes the formation of zig-zag chains. Compounds 1– 5 were characterized by single crystal X-ray diffraction; and compounds 1– 3 were additionally characterized by IR, elemental analysis, and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic space group C2/c with a = 29.761(3) Å, b = 5.0531(5) Å, c = 16.7823(15) Å, = 104.090(2), V = 2447.9(4) ų, Z = 4. Each mercury is bound to two tolane ligands and two bromine anions, resulting in a tetrahedral coordination environment. Compound 2 crystallizes in the monoclinic space group P2/c, with a = 20.3061(17) Å, b = 5.6303(5) Å, c = 24.5459(19) Å, = 110.338(2), V = 2631.4(4) ų, Z = 4. Here also, each mercury is bound to two tolane ligands and two iodine anions in a tetrahedral coordination environment. The ligand orientation differs in compounds 1 and 2 being trans oriented in 1 and cis oriented in 2. Compound 3 crystallizes in the monoclinic space group P2₁/c with a = 14.5947(14) Å, b = 6.3082(6) Å, c = 18.3939(18) Å, = 112.112(2), V = 1568.9(3) ų, Z = 2. Each nickel is bound to two tolane ligands and two bidentate AcAc anions, resulting in an octahedral coordination environment. Compound 4, which is isostructural with 3, also crystallizes in the monoclinic space group P2₁/c with a = 14.6990(9) Å, b = 6.2724(4) Å, c = 18.6433(11) Å, = 112.8610(10), V = 1583.86(17) ų, Z = 2. Compound 5 crystallizes in the triclinic space group P-1 with a = 6.5487(4) Å, b = 11.6471(7) Å, c = 14.3225(9) Å, = 70.1360(10), = 89.3990(10), = 88.7680(10), V = 1027.18(11) ų, Z = 1. Each copper in 5 is bound to two tolane ligands and two bidentate hfAcAc anions, resulting in an octahedral coordination environment identical to that found in 3 and 4.     

Synthesis and crystal structure of 7-ethoxyl-4′-hydroxyisoflavone

7-Ethoxyl-4-hydroxyisoflavone was prepared and its crystal structure was examined by X-ray diffraction. Crystallization of the title compound occurs in the monoclinic, space group P2(1)/c with a = 11.144(2) Å, b = 10.209(1) Å, c = 13.191(2) Å, = 113.43(1) and Z = 4. The molecular structure of title compound consists of a benzopyranone moiety, a phenyl moiety, a hydroxyl and an ethoxyl group. The benzopyranone ring is not coplanar with the phenyl ring, the dihedral angle being 46.75. The ethoxyl group is nearly coplanar with its corresponding ring with the torsion angle 175.23(2). Three kinds of hydrogen bond and two kinds of aromatic stacking interaction link the title compounds into a three-dimensional networking structure.     

Synthesis,thermal reactivity and structure of 1,2-bis(4-hydroxy-3-methoxyphenylethynyl)benzene

The crystal structure of the new enediyne 3 was determined by X-ray diffraction. 3 crystallizes in the orthorhombic space group Pbca (No. 61) with a = 12.7148(9) Å, b = 7.4872(8) Å, c = 38.890(4) Å, = = = 90 and Z = 8. The three-dimensional structure is characterized by an 8-membered cyclic array linking four molecules of 3 by hydrogen bonding between phenolic and methoxy groups. Furthermore, stabilization by –-stacking and CH s interactions is present. The important cd distance (between the two terminal acetylene carbons of the enediyne) which is relevant for the Bergman cyclization, was determined to 401 pm, being in good agreement with the high cyclization barrier ( G = 147.9 kJ mol^–1 at 220C) that was determined by differential scanning calorimetry (DSC).     

Unique assemblies of alternating positively and negatively charged layers, directed by hydrogen bonds, ionic interactions, and π-stacking in the crystal structures of complexes between mellitic acid (benzenehexacarboxylic acid) and five planar aromatic bases

Benzenehexacarboxylic acid, mellitic acid (MA), has been used as a core motif to study possible radial self-assembly using complementary aromatic bases. By mixing water solutions of the components, crystals of the salts of MA with 4-aminopyridine (AP), 4-dimethylamino-pyridine (DM), 2,2-bipyridine (DP), o-phenanthroline (PL), and melamine (ML) have been obtained. The MA^–n ions have assembled in either extended sheets for MA^–2 or extended ribbons for MA^–4 by direct hydrogen bonding between MA and MA and additionally through mediation of hydrogen bonds to water molecules that distribute the negative charges throughout the MA sheet or ribbon. Most of the O atoms in carboxyl groups in the MA ions in the five complexes have been rotated significantly out of the plane of the central benzene ring. There are multiple base molecules, two or four, for each mellitic acid ion in the five complexes. Most of the NH⁺ moieties in all five bases make direct NH⁺ O–C hydrogen bonds with MA^–n . The planar base ions are generally arranged in stacks in which the components range from being parallel, with interplanar separations of 3.5 Å, to having a considerable tilt with respect to each other with nearest interplanar separation of atoms greater than 3.9 Å. These geometric characteristics are reflected in the color of the crystals. The three-dimensional networking makes some of the crystals very hard. Cell dimensions: 1, C₃₂H₃₀N₈O₁₂ 2H₂O, C2/c, a =13.764(2) Å, b =18.053(3) Å, c =14.876(4) Å, =105.99(2)° 2, C₂₆H₂₆N₄O₁₂ 3H₂O, P2₁/n, a =15.891(1) Å, b =10.444(1) Å, c =18.242(1) Å, =97.00(1); 3, C₆₄H₄₄N₈O₂₄ 7H2O, P2₁/c, a =23.016(4) Å, b =15.241(2) Å, c =19.124(2) Å, =100.60(1)° 4, C₃₆H₂₂N₄O₁₂, P2₁/n, a =14.581(1) Å, b =10.472(1) Å, c =20.607(2) Å, =106.43(1); 5, C₁₈H₁₈N₁₂O₁₂ 2H₂O, , a =8.257(2) Å, b =8.986(2) Å, c =9.383(1) Å, =98.60(1)°, =96.38(2)°, =117.07(1)°.     

A structural study on gallium and indium β-diketonates

In an attempt to prepare pentacoordinate chlorobis(-diketonato) gallium(III) and indium(III) complexes only the corresponding tris-products, Ga(PhCOCHCOPh)₃ (1), Ga(^tBuCOCHCO^tBu)₃ (1a), and In(PhCOCHCOPh)₃ (2), could be isolated. The crystal and molecular structures of 1 and 2 were determined. Both the complexes were found to have triclinc crystal system, with P1 space group. Cell parameters: 1 – a = 9.913(3) Å, b = 10.534(6) Å, c = 18.05(2) Å, = 93.86(5)°, = 94.40(4)°, = 106.58(4)°, V = 1805(2) ų, z = 2; 2 – a = 10.507(3) Å, b = 11.448(3) Å, c = 16.322(4) Å, = 107.38(2)°, = 97.38(2)°, = 102.23(2)°, V = 1792(1) ų, z = 2.     

Structure of bis[α-(1,2,4-triazole-1-yl)-acetophenone] dichorozinc(II) complex [ZnCl2(C2H2N3CH2COPh)2]

The crystal and molecular structure of [ZnCl₂(N⁴-trzCH₂COPh)₂] (trz = 1,2,4-triazole) has been determined by X-ray crystallography. It crystallizes in the monoclinic system, space group C2/c, with lattice parameters a = 26.7892(4) Å, b = 4.9392(2) Å, c = 20.7872(1) Å, = 127.517 (1), and z = 4. The complex has C ₂ symmetry. The coordination geometry of each Zn atom is distorted tetrahedral formed by two Cl atoms and two tertiary N atoms of the -(1,2,4-triazole-1-yl)-acetophenone ligands. The two equivalent Zn–Cl and Zn–N bonds form bond angles around the Zn(II) atom in the range 101.4(1)–120.8(1). C–H O intermolecular interactions link the molecules in infinite chains in the [101] direction.     

Molecular structure of N-(2-phenylethyl)amide of α-(1,1-ethylenedioxy)-ethyl γ-hydroxybutyric acid (I) and1H NMR spectra of (I) and N-(p-methoxybenzyl)derivative (III)

The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The¹H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C₁₆H₂₃O₄N, crustallizes in the monoclinic space groupP2 ₁/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C₂(O3)=2.4° and ||_av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, X_N =7°, X_c =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds.     

X-ray structures of new substituted 2-(pyrazol-1-yl)-2′-nitroacetanilides with pharmacological activity

The X-ray structures of four pharmacologically active lidocaine analogs, containing substituted pyrazole moieties as the basic residue and an o-nitrophenyl moiety as the hydrophobic residue, have been determined. They are 2-(pyrazol-1-yl)-2-nitroacetanilide (1), 2-(3,5-dimethyl-pyrazol-1-yl)-2-nitroacetanilide (2), 2-(3,5-dimethyl-4-iodo-pyrazol-1-yl)-2-nitroacetanilide (3), and 2-(3,5-dimethyl-4-nitro-pyrazol-1-yl)-2-nitroacetanilide (4). Crystal data are 1: space group Pn with a = 4.6944(1), b = 22.3890(3), c = 15.7481(2) Å, = 96.810(1)°, Z = 6; 2: P with a = 4.7277(2), b = 11.6878(5), c = 12.0355(6) Å, = 87.689(2), = 85.048(2), = 85.975(2)°, Z = 2; 3: I2/a with a = 24.108(5), b = 4.7321(9), c = 25.337(5) Å, = 96.09(3)°, Z = 8; 4: P2₁ with a = 5.7788(2), b = 8.9844(3), c = 14.0304(5) Å, = 101.611(1)°, Z = 2. Molecules of compound 1 adopt a unique, folded conformation stabilized by intramolecular hydrogen bonds and the crystal structure lacks significant intermolecular interactions. In contrast, molecules of 2–4 adopt common, extended conformations and their crystal structures are based on linear arrays of hydrogen bonded (N—H...O=C) molecules. Compound 3 displayed the highest local anesthetic activity while 2 was the most active in tests for anti-arrhythmic effects.     

Complexes of 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane (4,13-diaza-18-crown-6) with 2,5-pyridinedicarboxylic and 2,2′-dithiosalicylic acids

A 1:2:2 complex of 1,4,10,13-tetraoxa-7,16-diazacyclooctadecane with 2,5-pyridinedicarboxylic acid and water (1) and its 1:1:1.75 complex with 2,2-dithiosalicylic acid and water (2) have been obtained and characterized by x-ray diffraction. C₂₆H₄₀N₄O₁₄ (1), triclinic, , a = 9.574(1) Å, b = 9.632(1) Å, c = 9.723(1) Å, = 112.70(1)°, = 91.07(1)°, = 115.45(1)°, V = 728.35(13) ų, Z = 1. C₂₆H_39.5N₂O_9.75S₂ (2), M = 600.22, triclinic, , a = 10.492(1) Å, b = 10.945(1) Å, c = 14.535(2) Å, = 102.74(1)°, = 109.08(1)°, = 90.68(1)°, V = 1532.2(3) ų, Z = 2. In complex 1, both N-atoms of the macrocyclic ring are protonated. The following types of H-bonding have been found: (1) between protonated aza groups of the macrocycle and ionized carboxylic groups; (2) between the protonated aza groups and N-atoms of the pyridine nuclei (D–A distance slightly exceeds 3 Å); (3) between water molecules and C=O groups of the non-ionized carboxylic groups; and (4) between the nonionized and ionized groups of the carboxylic acid. The above interactions give rise to the formation of a developed supramolecular network in the crystals of 1. In complex 2, despite the presence of several types of hydrogen bonds involving the aza crown, 2,2-dithiosalicylic acid and water, the aromatic anions are H-bound only to the two other components, and not to each other. The H-bonds found in complex 2 are between (1) one of the protonated aza groups and water, (2) protonated aza groups and O-atoms of the ionized carboxylic groups, (3) water molecule and carboxylic O-atom, (4) water molecule and sulfur atom, and (5) water molecule and O-atom of diaza-18-crown-6.     

Synthesis and crystal structure of N-<Emphasis Type="Italic">tert-</Emphasis>butyl-N′-thio [O-(1-methylthioethylimino)-N″-methylcarbamic acid]-N,N′-dibenzoylhydrazine

The novel compound N-tert-butyl-N-thio[O-(1-methylthioethylimino)-N-methyl carbamic acid]- N,N-dibenzoylhydrazine has been synthesized by the reaction of N-tert-butyl-N,N-dibenzoylhydrazine with N-sulfenyl chloride of O-(1-methylthio ethylimino) -N-methylcarbamic acid. Its structure was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2₍₁₎/n with the following crystallographic parameters: a = 7.569(3) Å, b = 20.585(7) Å, c = 16.347(5) Å, = 90, = 92.606(6), = 90, V = 2544.4(14) ų, z = 4, Dx = 1.276 mg/m³, F(000) = 1032, T = 293(2) K, 2.34 25.01, the final R factor: R₁ = 0.0475, wR₂ = 0.0907. The N–N bond adopts a gauche conformation with a dihedral angle() of 98.8 for C(17)=N(1)=N(2)=C(7), whereas its parent compound N-tert-butyl-N,N-dibenzoyl hydrazine has the dihedral angle of –71.8.     

Preparation and crystal structures of the Ce(IV) β-diketonates, [Ce(tmhd)4] and [Ce(pmhd)4] (tmhd =2,2,6,6-tetramethylheptane-3,5-dionate and pmhd = 1-phenyl-5-methylhexane-1,3-dionate)

The cerium(IV) -diketonate compounds [Ce(-diket)₄] [where -diket = tmhd (2,2,6,6-tetramethylheptane-3,5-dionate) 1, pmhd (1-phenyl-5-methylhexane-1,3-dionate) 2] were prepared by reacting cerium(IV) ammonium nitrate [CAN; Ce(NH₄)₂(NO₃)₆] with the respective Na(-diket) compound in ethanol, and structurally characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group with a = 12.472(4), b = 19.972(5), c = 21.436(3) Å, = 97.05(7), = 90.16(2), = 106.55(3)°, V = 5076(2) ų, Z = 4, T = 150(2) K. Compound 2 crystallizes in the monoclinic space group P2₁/n. with a = 14.817(6), b = 17.123(6), c = 19.146(3) Å, = 105.46(4)°, V = 4682(3) ų, Z = 4, T = 150(2) K. Crystals of 1 contain two independent [Ce(tmhd)₄] molecules, with four chelating tmhd ligands bonded to each metal in a distorted dodecahedral arrangement; the cerium atom in 2 is also bonded to four chelating pmhd ligands but in this case the coordination geometry is closer to square antiprism. Both complexes are air and moisture stable. Sublimation studies reveal that 1 sublimes almost quantitatively, while 2 is comparatively involatile.     

Crystal structure of (3,3′,4,4′-tetramethyl-1,1′-diphosphaferrocen-2-yl) carboxylic acid and its bis-[W(CO)5] complex·0.5C5H12: Conformation of 1,1′-diphosphaferrocenes

The structures of (3,3,4,4-tetramethyl-1,1-diphosphaferrocen-2-yl)carboxylic acid (1) and its bis-[W(CO)₅] pentane solvate complex (2) have been determined by X-ray analysis. The compound 1 crystallizes in the monoclinic P2₁ /n space group with Z = 4; a = 7.8404(9), b = 14.9441(16), c = 11.7730(14) Å, = 92.773(10)°, V = 1377.8(3) ų, and D_calc = 1.553 g cm^–3. The compound 2 crystallizes in the triclinic space group with two complex molecules and one pentane molecule in the unit cell. Cell parameters: a = 10.7070(2), b = 12.577(2), c = 13.239(3) Å, = 84.00(2), = 77.58(1), = 66.06(1)°, V = 1591.0(5) ų, and D_calc = 2.100 g cm^–3 .The fully eclipsed conformation of the phospholyl rings with P···P secondary bonding of 3.353(1) Å is observed in 1 and a partially eclipsed conformation is found in 2. The 10 possible conformations of 1,1-diphosphaferrocenes were described as the function of conformational parameter and observed geometry of the phospholyl rings.⁷ We suppose that the earlier conclusions concerning the destabilizing nature of 1,1-diphosphaferrocene conformations with < 100° cannot be considered as general. The mode of W – P coordination, the structural changes of 1 by W(CO)₅ coordination, the structural effect of phospholyl rings substitution by the –COOH group, and hydrogen bonds are analyzed.     

Bis[aqua(2,5-bis(4-pyridyl)-1,3,4-oxadiazole)thiocyanate] cadmium(II): A three-dimensional framework built from hydrogen bonds and π-π stacking interactions

A three-dimensional (3D) network complex [Cd(L)₂(NCS)₂(H₂O)₂], L being 2,5-bis(4-pyridyl)-1,3,4-oxadiazole, has been synthesized and structurally determined by X-ray diffraction analysis: triclinic, space group P-1 with a = 7.8863(9) Å, b = 8.6287(10) Å, c = 11.4696(12) Å, = 94.346(2)°, = 109.331(2)°, = 94.354(2)°, Mr = 713.04, V = 730.13(14) ų, Z = 1. The crystal structure of the title complex reveals that it is a neutral molecule and the Cd(II) ion is at the center of symmetry. Each Cd(II) is six-coordinated and the CdN₄O₂ coordination sphere can be considered as an octahedron. The most striking feature of this complex resides in the formation of a 3D network through hydrogen bonds and - stacking interactions.     

C(4) helices,Br⋅<Emphasis Type="Italic">s</Emphasis>Br interaction and <Emphasis Type="Italic">R</Emphasis><Stack><Subscript>4</Subscript><Superscript>2</Superscript></Stack> (10) ring in bromoipriflavone

The title compound, 8-bromo-7-isopropoxyisoflavone (bromoipriflavone), C₁₈H₁₅O₃Br, crystallizes in tetragonal crystal system, space group I4₁/a with cell constants a = 21.396(2) Å, c = 13.588(2) Å, V = 6220.2(14) ų and Z = 16. Bromoipriflavone is composed of a benzopyranone moiety, a phenyl moiety, an isopropoxy group and a bromine atom. The benzopyranone ring is not coplanar with the phenyl ring with a dihedral angle of 55.1. The molecules are stacked into a C(4) helices down [001] via – stacking and hydrogen bonds, the C(4) helices are assembled into three-dimensional network via strong BrsBr interactions and synthons R₄²(10) formed by two tri-centered C–HsO hydrogen bonds, resulting in a distinctive high-symmetry supramolecule. The title compound was also characterized by IR and ¹H NMR.     

Crystal and molecular structure of a nickel(II) complex with a macrocyclic [14]N4 ligand

The crystal and molecular structure of a macrocyclic oxamido Schiff base Ni(II) complex [NiL] has been determined by X-ray crystallography. L is the dianion of diethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo[1,4,8,11]tetraazacyclotetradecine-13,18-dicarboxylate. Ni(II) is located in the coordination cavity formed by the four nitrogen donors of the deprotonated macrocyclic oxamido ligand with a distorted square-planar geometry. C–H O hydrogen bonds have been observed in the crystal. The macrocyclic complex crystallizes in the triclinic space group P – 1, with lattice parameters a = 7.977(3) Å, b = 12.581(4) Å, c = 12.679(4) Å, = 112.669(6)°, = 96.849(7)°, = 106.204(7)°, V = 1089.9(6) ų, Z = 2.     

Chemical preparation and crystal structure of 6′-butoxy-2,6-diamino-3,3′azo-dipyridine monohydrate

Chemical preparation, X-ray single crystal, and calorimetric studies of C₁₄H₁₈N₆O·H₂O are described. The compound crystallizes in the triclinic space group, P with unit cell dimensions: a = 6.2640(3), b = 10.9840(4), c = 12.2220(3) Å, = 105.03(2), = 96.96(2), = 101.6(2)°, V = 712.10(5) ų, and Z = 2. The 6-butoxy-2,6-diamino-3,3-azo-dipyridine monohydrate structure is built up from organic layers parallel to the (120) plane linked via O—H···N bond.     

The preparation and crystal structures of a covalent tetrafluoroborato complex, (CO)<Subscript>3</Subscript>(dppfe)MnFBF<Subscript>3</Subscript>, and of a related ionic complex, [(CO)<Subscript>4</Subscript>(dppfe)Mn]BF<Subscript>4</Subscript> [(dppfe) = bis-(1,1′-diphenylphosphino)ferrocene]

The titled covalent tetrafluoroborato dppfe complex was prepared by treating the precursor hydride, (CO)₃(dppfe)MnH, with tetrafluoroboric acid. Similar treatment of analogous hydrido complexes with other chelating phosphines always gave ionic tetrafluoroborates, presumably via similar intermediate FBF₃ covalent complexes, which however could not be isolated. Crystal structures for the covalent complex (CO)₃(dppfe)MnFBF₃.3/2CH₂Cl₂, 3, and the ionic complex [(CO)₄(dppfe)Mn]BF₄.CH₂Cl₂, 4, were determined. Crystal data for 3, monoclinic crystal system, space group = P2₁/n, a = 11.458(2) Å, b = 19.348(3) Å, c = 17.810(3) Å, = 104.410(4), V = 3823.9(12) ų, Z = 4; for 4, monoclinic crystal system, space group = P2₁/n, a = 15.6521(2) Å, b = 14.3107(4) Å, c = 17.0933(5) Å, = 95.075(1), V = 3813.8(2) ų, Z = 4.