Syntheses and structures of N-phenylmaleimidetriazoles and by-products

The syntheses, properties, and structures of N-phenylmaleimidetriazole derivatives are described. Intermediates and by-products are also discussed. 1b. a = 43.997(7) Å, 5.7610(9) Å, 8.245(1) Å, = 99.339(4), C₂/c; 2a. a = 13.646(4) Å, b = 7.744(2) Å, c = 10.612(3) Å, = 91.979(6), P2₁/c. 3a. a = 22.245(1) Å, b = 22.245(1) Å, 10.010(1) Å, P42/n. 3a. a = 11.727(2) Å, b = 14.075(3) Å, c = 16.080(3) Å, = 105.859(3), = 105.331(3), = 98.187(3), P-1. 3b. a = 8.561(3) Å, b = 14.755(5) Å, c = 22.771(7) Å, = 97.006(5), P2₁/c. 3c. a = 10.500(2) Å, b = 12.189(2) Å, c = 13.040(2) Å, = 109.091(3), = 106.089(3), = 101.022(3), P-1. 8a. a = 16.389(8) Å, b = 5.749(3) Å, c = 19.316(3) Å, = 97.467(9), P2₁/n. 8b. a = 5.822(2) Å, b = 10.114(3) Å, c = 16.705(4) Å, = 84.681(5), = 82.840(5), = 75.769(4), P-1. 9b. a = 11.251(1) Å, 13.335(3) Å, 13.376(3) Å, = 102.456(4), P2₁/n. 9c. a = 15.836(3) Å, b = 8.236(2) Å, c = 5.447(3) Å, = 92.551(3), P2₁/c. 10a. a = 13.177(2) Å, b = 14.597(2) Å, c = 5.5505(8) Å, = 110.979(2), Cc. 11a. a = 14.720(2) Å, b = 13.995(2) Å, c = 38.245(6) Å, = 94.430(3), P2₁/n. 12b. a = 15.067(5) Å, b = 20.378(6) Å, c = 8.669(5) Å, = 99.16(4), = 99.32(3), = 105.23(3), P-1. 13b. a = 8.2824(6) Å, b = 10.5245(7) Å, c = 15.518(1) Å, = 92.305(1), = 100.473(1), = 100.124(1), P-1. 15a. a = 15.357(3) Å, b = 7.778(2) Å, c = 22.957(2) Å, Pbca. 16b. a = 18.0384(4) Å, b = 12.474(3) Å, c = 20.078(5) Å, Pbca.     

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.     

Single-crystal structure determination of a new polymorph (ε-Alq<Subscript>3</Subscript>) of the electroluminescence OLED (organic light-emitting diode) material,tris(8-hydroxyquinoline)aluminum (Alq<Subscript>3</Subscript>)

Tris(8-hydroxyquinoline) aluminum, Alq₃, is the most widely used electroluminescent material in organic light-emitting diode (OLED), chemistry. Single-crystal structure determination of a new polymorph of Alq₃, designated as -Alq₃, is described. There are three molecules of Alq₃ in the asymmetric unit. This octahedrally coordinated complex crystallizes in the triclinic space group P-1, lattice parameters a = 13.5190(5) Å, b = 15.8550(6)~Å, c = 18.7110(8) Å, = 95.4940(19), = 109.774(2), = 114.6270(16), Volume = 3296.8(2) ų, Z = 6, Z = 3.     

Crystal and molecular structure of an ion-pair complex based on [Ni(mnt)<Subscript>2</Subscript>]<Superscript>2−</Superscript> anion and imidazolium derivative cations

A new ion-pair complex, 1-methyl-3-benzylimidazolium bis(maleonitrile-dithiolato) nickelate(II), has been synthesized and characterized by IR spectroscopy, UV-visible spectroscopy and X-ray crystallography. The crystallographic data for the complex: triclinic , a = 8.415(1) Å, b = 9.924(1) Å, c = 11.333(2) Å, = 114.11(1), = 102.46(1), = 100.88(1), V = 801.8(2) ų, Z = 1. The molecular packing pattern showed a completely separated column stacking for cations and anions of the complex along with the b-axis. The anion is not completely planar. The five-membered nickel-containing rings are slightly puckered. The cation, [BzIm]⁺, adopts a conformation where the benzene ring and imidazole ring twisted with the reference plane C10–C11–N3.     

Synthesis and crystal structure of [ReOCl<Subscript>2</Subscript>(L)] (HL = 2-(1-ethanolaminomethyl)-1-methylimidazole)

The title compound was prepared from the reaction of (n-Bu₄N)[ReOCl₄] with the ligand HL in acetonitrile. The chelate L is coordinated as a terdentate uninegative N, N,O^–-donor ligand in a distorted octahedral coordination geometry around the rhenium(V) ion. The structure has a triclinic space group P-1 with a = 6.9796(3), b = 7.1530(3), c = 12.0416(6) Å, = 73.742(2), = 86.458(2), = 73.928(3), V = 554.50(4) ų, and Z = 2.     

Synthesis and structural studies of <Emphasis Type="Italic">tris</Emphasis>-2-chlorobenzylamine and <Emphasis Type="Italic">tris</Emphasis>-2-bromobenzylamine

The tris-2-chloro and 2-bromotribenzylamines are prepared from aqueous ammonia and 2-chlorobenzyl chloride and 2-bromobenzyl bromide, respectively, in ethanol. Recrystallization yielded colorless cubes of each product. The crystal structures are each solved in space group P , and are isostructural. The tris-2-chloro compound, 1, has a = 7.4226(5) Å, b = 9.0825(7) Å, c = 14.529(1) Å, = 78.279(1), = 82.389(1), = 84.661(1), and V = 948.41(12) ų with Z = 2, and d_calc = 1.368 Mg/m³. The tris-2-bromo analog, 2, has a = 7.6569(11) Å, b = 9.0922(13) Å, c = 14.614(2) Å, = 79.286(2), = 81.777(2), = 85.401(2), and V = 987.9(2) ų with Z = 2, and d_calc = 1.762 Mg/m³. Lithium–halogen exchange experiments conducted in tetrahydrofuran at –78C using n-butyl lithium revealed that no exchange occurred for the tris-2-chloro compound, but did occur for the tris-2-bromo analog to yield tribenzylamine upon quench and work-up.     

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).     

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,characterization and crystal structure of oxovanadium(IV) complex with tridentate o-van-gly and bidentate phenanthroline

A novel oxovanadium(IV) complex with tridentate schiff base and bidentate phenanthroline ligands, VO(o-van)(phen) 2H₂O[o-van-gly: o-vanillin-glycine; phen: phenanthroline], was synthesized and characterized by elemental analysis, IR and UV-vis spectra. The crystal structure was determined by X-ray single crystal diffraction analysis. The crystal of title complex (C₂₂H₂₁N₃O₇V, M_w = 490.36) belongs to triclinic, space group P-1 with the following crystallographic parameters: a = 9.247(3) Å, b = 10.125(4) Å, c = 13.100(5) Å, = 106.343(6), = 96.042(7), = 101.726(7), V = 1135.0(7) ų, Z = 2, D_c = 1.435 Mg m^–3, (MoK = 0.485 mm^–1, F(000) = 506, and final R₁ = 0.0779, wR₂ = 0.1598 for observed reflections 1606 (I > 2(I)). V(IV) is six-coordinate with three oxygen atoms and three nitrogen atoms in a distorted octahedral geometry. The complex forms a 3-D network via – stacking and hydrogen bonds.     

Hydrogen-bonded networks formed by substituted 2,6-diarylpyrazines

The X-ray crystal structure of 2,6-bis(4-hydroxyphenyl)pyrazine and 2,6-bis(4carboxyphenyl)pyrazine are reported. The structure of the 2,6-bis(4-carboxyphenyl) pyrazine dimethylsulfoxide complex (C₁₈H₁₂N₂O₄)(C₂H₆OS) is triclinic, P-1, with a = 7.9933(8), b = 10.7165(10), c = 12.1337(12) Å, = 66.385(2), = 84.070(2), = 77.219(2). The structure comprises stacked two-dimensional sheets of the hydrogen bonded complex. The two-dimensional sheets comprise hydrogen-bonded ribbons of the (carboxyphenyl)pyrazine that are connected by bridging hydrogen bonds to the dimethylsulfoxide. The structure of 2,6-bis(4-hydroxyphenyl)pyrazine, C₁₆H₁₂N₂O₂, is monoclinic, P2₁/c, with a = 10.6107(13) Å, b = 14.6743(18) Å, c = 8.3772(10) Å and = 104.982(2). The structure reveals that two-dimensional hydrogen-bonded sheets are formed with pyrazine–phenol and phenol–phenol hydrogen bonds.     

Hydrothermal synthesis and crystal structure of a new europium fumarate compound

The complex {[Eu₂F₃4H₂O]3H₂O}_n (H₂F = fumaric acid) has been synthesized and structurally characterized by single crystal X-ray diffration methods. The complex crystallizes in the monoclinic system with space group P2₁/n, lattice parameters a = 9.475(3) Å, b = 14.700(5) Å, c = 14.810(4) Å, = 90, = 91.250(5), = 90, V = 2062.1(11) ų, Z = 4, D_calc = 2.487 Mg/m³. The Eu(III) center is in distorted tricapped trigonal prism coordination environment that is coordinated by nine oxygen atoms, seven from five F^2– groups, two from two water molecules. Eu(III) ions are connected into three-dimensional coordination network structure by the oxygen atoms of the carboxyl groups and hydrogen bonds.     

Synthesis and structural characterization of the bitopic ferrocene-based tris(pyrazolyl)methane ligand Fe[C5H4CH2OCH2C(pz)3]2 (pz = pyrazolyl ring)

The structure of Fe[C₅H₄CH₂OCH₂C(pz)₃]₂ (pz = pyrazolyl ring) contains 1.5 independent molecules in the asymmetric unit. One molecule has no imposed symmetry with the iron atom located on a general position while in the other the iron atom is located on an inversion center. The two independent molecules are arranged into a three-dimensional supramolecular structure by a series of C—H s N and C—H s O weak hydrogen bonding interactions and C—H s interactions. The crystals are triclinic, space group, P , with a = 8.1202(4) Å, b = 16.7209(9) Å, c = 18.6540(10) Å = 85.8270(10), = 85.4740(10), = 81.5910(10), and Z = 3     

Synthesis and X-ray structural analysis of (2<Emphasis Type="Italic">Z</Emphasis>)-3(4-hydroxyphenyl)-2-pyridin-4-ylacrylonitrile and (2<Emphasis Type="Italic">Z</Emphasis>)-3-(3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxyphenyl)2-pyridin-4-ylacrylonitrile

Synthesis and X-ray structural investigations have been carried out for the two title compounds C₁₄H₁₀N₂O (3a) and C₂₂H₂₆N₂O (3b). Compound 3a crystallizes in the monoclinic space group P2₁/c, with a = 3.843(1) Å, b = 24.618(5) Å, c = 11.318(2) Å, = 92.61(3), V = 1069.7(4) Å,³ and Z = 4. Compound 3b crystallizes in the triclinic space group P-1, with a = 9.004(2) Å, b = 9.447(2) Å, c = 11.713(2) Å, = 76.70(3), = 83.12(3), = 82.16(3), V = 956.5(3) Å,³ and Z = 2. Both stilbazole derivatives have Z-geometry about the ethylene bridge which links the heterocyclic and aromatic rings. The molecular skeleton of 3a is slightly non-planar: the dihedral angles between the acrylonitrile linkage and the pyridine ring, and between this linkage and the p-hydroxyphenyl ring are 7.2(2) and 4.1(2), respectively. The molecular skeleton of 3b is less planar: the values of similar dihedral angles are 17.0(2) and 20.8(2), respectively. In the crystal of 3a, the molecules are packed in stacks along the a axis with head-to-head orientation. Intermolecular hydrogen bonds O=H s N and C=H s N link molecules into sheets parallel to (100) plane. In the crystals of 3b, the molecules have a head-to-tail orientation and intermolecular hydrogen bonds O=H s N link the molecules into infinite chains along [01-1] direction.     

Synthesis and structures of two chiral bis(pyrazolyl)borate complexes, [{H<Subscript>2</Subscript>B(4-Mepz)(3,5-Me<Subscript>2</Subscript>pz)}<Subscript>2</Subscript>M], M = Co,Zn

The title compounds are chiral and have similar molecular geometries. The Co complex crystallizes in space group P2₁/c with a = 8.475(4) Å, b = 7.706(8) Å, c = 35.778(9) Å, = 95.779(18) and Z = 4, while the Zn complex crystallizes in space group P2₁/n with a = 8.353(3) Å, b = 20.768(4) Å, c = 13.818(3) Å, = 100.96(2) and Z = 4. The metal atoms are tetrahedrally coordinated to two bidentate ligands with M–N distances in the ranges 1.985(2)–2.018(2) Å (Co) and 1.985(2)–2.008(2) Å (Zn), and N–M–N angles in the ranges 96.07(7)–128.23(7) (Co) and 98.50(8)–125.63(8) (Zn). No agostic bonds are formed. The molecules display C₁ symmetry; geometric considerations indicate that the formation of the other two possible conformers, with C₂ symmetry, is sterically less favorable.     

Crystal structure of 1,5,8-trihydroxyl-3-methoxy xanthone from Swertia chirayita

In order to study the relationship between biological and pharmacological activities with their structures, a series of tri-, tetra-oxygenated xanthones including 1-hydroxyl-2,3,4,7-tetramethoxy xanthone 1, 1-hydroxyl-2,3,4,5-tetramethoxyl xanthone 2, 1-hydroxyl-3,5-dimethoxy xanthone 3, 1,8-dihydroxyl-3,5-dimethoxyl xanthone 4, 1,5,8-trihydroxyl-3-methoxy xanthone 5 has been isolated from Swertia chirayita. Their structures were established on the basis of spectral and chemical evidence. The crystal structure of 5 was also investigated by single crystal X-ray diffraction analysis. It crystallizes in the triclinic system, space group P , with a = 7.1540(10) Å, b = 7.520(2) Å, c = 10.671(2) Å, V = 562.7(2) ų, = 86.50(3), = 80.06(3), = 85.00(3), Z = 2, D_c = 1.618 g m^–3, R_int = 0.0230, wR(F²) = 0.1028, F(000) = 284. The molecular structure is nearly plane and four substituents are much closer to the plane of the molecule. Compound 5 also shows three intermolecular hydrogen bonds. A recent study shows that phenolic hydroxyls in xanthones are the main active groups capable of scavenging OH and O₂.     

Synthesis and crystal structures of cis- and trans-1-(3′-N, N-dimethylthiocarbamoyl-4′-methoxy)-2-(3″, 4″, 5″trimethoxyphenyl) ethene

The combretastatin A-4 analogue cis-1-(3-N,N-dimethylthiocarbamoyl-4-methoxy)-2-(3,4, 5-trimethoxyphenyl) ethene (1) and its trans stereoisomer (2) were synthesized. The molecular structures of these compounds were obtained by single-crystal X-ray diffraction. Crystallization of 1 occurs in the centrosymmetric monoclinic space group C2/c (No. 15) with a = 21.468(5), b = 7.932(1), c = 23.949(3); and = 100.75(1) and Z = 8. Crystallization of 2 occurs in the centrosymmetric monoclinic space group P2₁/n (No. 14) with a = 11.7825(7), b = 11.562(1), c = 14.911(1) and = 93.294(6); and Z = 4. Details of the synthesis and the structural characterization of the title compounds are presented and discussed.     

Preparation and crystal structure of spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1′-cyclohexane)

Spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1-cyclohexane) (C₁₆H₂₀O₄) was prepared by alkylation of o-lithio 3,5-dimethoxy-N-methyl benzamide with methylene cyclohexane oxide followed by alkaline hydrolysis and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes into monoclinic space group P2₁/c with unit cell parameters: a = 11.914(3) Å, b = 9.861(3) Å, c = 12.508(7) Å, = 91.34(3), Z = 4. The structure has been solved by direct methods and refined to R = 0.039 for 1870 observed reflections. The heterocyclic ring adopts distorted sofa conformation while cyclohexane ring assumes a highly symmetric chair conformation. The dihedral angle between the mean planes of isocoumarin nucleus and cyclohexane ring is 105.51(5). Molecules are held together in the crystal by C=H ... O hydrogen bonds.     

Crystal structure, vibrational spectra and thermal decomposition of a new tetrazinc(II) dipyrophosphate decahydrate, Zn4(P2O7)2 < eqid1 > ?10H2O

A new zinc(II) pyrophosphate, Zn₄(P₂O₇)₂ < eqid1 > 10H₂O, has been synthesized and characterized by single-crystal X-ray diffraction [orthorhombic space group Pnma, with unit cell parameters of a = 9.1508(2) A, b = 25.5271(5) Å, c = 8.3574(2) Å, Z = 4]. All the pyrophosphate anions show nonlinear P–O–P bonds with an average angle of 126.5. The framework of this new pyrophosphate is made up of packed layers of ZnO₆ octahedra connected by double-tetrahedra P₂O₇ groups and a layer of Zn(H₂O)₆ units. The [P₂O₇]^4– anions adopt a bent, near-staggered conformation. The absence of coincidences for the majority of the IR and Raman bands is in accord with the centrosymmetric structure of the material. The vibrational spectra have been interpreted in part on the basis of factor group effects. The structural changes occurring during heating have been investigated by TG-DSC, powder X-ray diffraction, and IR and Raman spectroscopy. When Zn₄(P₂O₇)₂ 10H₂O is gradually heated, it decomposes and -Zn₂P₂O₇ is formed at 481C. On further heating, -Zn₂P₂O₇ is transformed into -Zn₂P₂O₇ at 750C. The conversion between the and -Zn2P2O7 forms is irreversible and, on cooling -Zn2P2O7 to room temperature, it reverts back to -Zn2P2O7. The crystal structure of the new zinc(II) pyrophosphate material is compared with the known structures of the related anhydrous products -, -, and -Zn2P2O7.     

Synthesis and X-ray structure of 3-(4-methyl phenyl)-2-(4-biphenyl)-1,3-thiazolidin-4-one

The title compound (C₂₂H₁₉NOS) was synthesized, characterized and structure was determined by X-ray diffraction method. It crystallizes in the monoclinic space group P2₁/c with cell parameters a = 22.181(2) Å, b = 6.0760(4) Å, c = 13.349(3) Å, = 95.615(3)^, and {Z = 4}. The final residual factor is 0.0625 for 1724 reflections with I > 2(I). 4-thiazolidinone ring moiety shows twisted conformation.     

Crystal structure analysis of (<Emphasis Type="Italic">N</Emphasis>-methyl piperazino) (phenyl) (dicyclohexylamino) phosphiniminocyclotrithiazene

The title compound (NC₄H₈NCH₃)(C₆H₅)[N(C₆H₁₁)₂]P{—N–S₃N₃ crystallizes in the triclinic crystal system with unit cell dimensions: a = 9.7572(2), b = 10.6845(1), c = 16.9381(3) Å, = 71.75(1), = 80.65(2), = 65.93(1), and Z = 2. The tricoordinated sulfur atom (S1) in the cyclotrithiazene deviates from the mean plane of the other five atoms by 0.716(6) Å, which is the highest among the known phosphiniminocyclotrithiazene structures. In the exocyclic P{—N4–S1 moiety, the two bond distances are short: 1.585(6) and 1.527(6) Å; but the bond angle is large 135.3(4). The S1 displacement is highly correlated with the endocyclic angle at the nitrogen atom (diagonally opposite to S1), but the nature of correlation is bimodal (R = 1.0 + or –1.0) for the cyclic and acyclic substituents (R) in the (R)(C₆H₅)[N(C₆H₁₁)₂]P{—N–S₃N₃ series. On the other hand, the S1–N4 bond distances are negatively correlated (R = –0.94) with the P{—N4–S1 bond angle in the above series.