Structures of anti,Z-4,4-dimethyl-3-thiosemicarbazide, syn,E,Z-2,4-dimethyl-3-thiosemicarbazide and syn,E-1-cyclopentano-3-thiosemicarbazone

The structures of three alkyl derivatives of thiosemicarbazide are described: anti,Z-4,4-dimethyl-3-thiosemicarbazide (1), syn,E,Z-2,4-dimethyl-3-thiosemicarbazide (2), and syn,E-1-cyclopentano-3-thiosemicarbazone (3). Crystal data: for 1: triclinic, P-1 (#2), a = 5.802(1)Å, b = 6.935(1)Å, c = 8.104(2)Å, = 78.35(1)°, = 82.13(1)°, = 70.71(1)°, and Z = 2; for 2: orthorhombic, Pbca (#61), a = 9.417(3)Å, b = 8.624(2)Å, c = 15.169(3)Å, and Z = 8; for 3: triclinic, P-1 (#2), a = 6.068(3)Å, b = 8.145(4)Å, c = 8.666(5)Å, = 83.75(4)°, = 86.16(5)°, = 74.07(4)°, and Z = 2. In general, molecules are linked by N–H···S hydrogen bonds with sulfurs accepting two or three hydrogen bonds. Structures 2 and 3, which adopt the syn conformation, form N–H···N intramolecular hydrogen bonds. The solid-state structures are consistent with their infrared and proton nuclear magnetic resonance spectra.     

Crystal structure of 1-phenylamino-2-phenyl-4-p-chlorophenylimidazole, C21H16N3Cl

The condensation of amidrazones with -bromoketones through ring closure affords two isomeric products. The minor product was subjected to X-ray diffractometric analysis and turned-out to be a substituted imidazole. The title compound crystallizes in space group P2₁/c, with a = 11.838(2), b = 13.249(1), c = 11.226(2) Å, = 91.01(1)°. The packing of molecules is determined by a hydrogen bond N–HN (2.908(5)).     

4- and 5-nitro-2-benzoylbenzoic acid

The structures of two isomeric nitro 2-benzoylbenzoic acids have been determined. 4-Nitro-2-benzoylbenzoic acid, C₁₄H₉NO₅, monoclinic, P2₁/c, a = 9.455(5), b = 6.632(2), c = 21.333(7)Å, = 107.96(3)°, Z = 4, V = 1270.6(9)ų, 5-nitro-2-benzoylbenzoic acid, C₁₄H₉NO₅, monoclinic, P2₁/c, a = 10.201(6), b = 8.515(4), c = 14.573(7)Å, = 101.35(4)°, Z = 4, V = 1241.1(11)ų. Both carboxylic acids form the usual H-bonded dimers across crystallographic centers of inversion. The nitro groups are essentially in the ring planes, and the interplanar angle between the mean planes described by the atoms of the benzoyl substituents and those of the benzoic acid aryl rings are 69(1)° and 84(1)°, respectively. The lower cell volume, higher density, and lower solubility in ethyl ethanoate correlates with the greater packing efficiency in 5-nitro-2-benzoylbenzoic acid.     

4- and 5-nitroindane

Mononitration of indane produces a mixture of 4- and 5- nitroindanes. Crystallization from mixtures occurs after distillation improves composition of a major component to above 80%. 4-Nitroindane: triclinic, space group (#2),a=7.332(4) Å,b=8.304(4) Å,c=8.358(4) Å, =61.43(4)°, =67.60(4)°, =70.15(4)°,V=405.4(4) ų,Z=2. Non-H-atoms are nearly planar, aliphatic H's are eclipsed. 5-Nitroindane: monoclinic, space groupP2₁/c (#14),a=10.946(8) Å,b=15.643(10) Å,c=9.415(6) Å, =92.34(5)°,V=1611(2) ų,Z=8. Non-H-atoms in the two molecules differ in torsion of the nitro group with respect to indane and fold of the nonbenzylic methylene group. Semiempirical calculations (PM3) suggest that distorsion from planarity may be associated with the two lowest energy vibrational modes. Uv, ir, ms, proton, and¹³C-nmr spectra are correlated with the solid state structures.     

The crystal structure of 1-phenyl-3-methyl-4(salicylaldehyde hydrazone)-propenylidene-5-pyrazolone

The crystal structure of 1-phenyl-3-methyl-4-(salicylaldehyde hydrazone)-propenylidene-5-pyrazolone (PMPP-SH) was characterized by the single-crystal X-ray diffraction method. The cell parameters of PMPP-SH in the monoclinic P2₁/c space group are a = 10.851(1) Å, b = 11.679 (1) Å, c = 14.043 (2) Å and β = 91.89 (1)^∘. Analyzing the molecular structure suggest that, in the solid state, the title compound exists mainly in enaminopyrazolone form, which is stabilized by intramolecular hydrogen bonding, rather than NH-form.     

Synthesis and crystal structure of 1-phenyl-3-methylthio-4-imino-5-allyl-pyrazolo[3,4-d]pyrimidine

The title compound 1-phenyl-3-methylthio-4-imino-5-allyl-pyrazolo[3,4-d]pyrimidine, C₁₅H₁₅N₅S, has been synthesized and characterized by x-ray diffraction: orthorhombic, space group Pbca, with a = 17.3480(9), b = 8.5022(5), c = 19.8132(11) Å. Z = 8, V = 2922.4(3) ų. The compound shows a fully delocalized pyrazolo[3,4-d]pyrimidine system with a sp² hybridization of the N(4) atom.     

Synthesis,characterization, single crystal X-ray diffraction and DFT studies of ethyl 5-methyl-1-phenyl-1H-pyrazole-4-carboxylate

The present study describes the synthesis, spectroscopic, and single crystal X-ray structural analysis of ethyl 5-methyl-1-phenyl-1H-pyrazole-4-carboxylate. The pyrazole ester of formula [C₁₃H₁₄N₂O₂] was prepared from the three-component one-pot condensation reaction of ethyl acetoacetate, N,N-dimethyldimethoxymethanamine, and phenyl hydrazine. The product was crystallized by using ethanol as solvent. The structure of the compound was confirmed by elemental analysis, Fourier transforms infrared (IR), thermogravimetric analysis, UV-visible (UV-Vis), ¹H NMR, and single-crystal X-ray diffraction studies. The gas-phase molecular geometry and the electronic structure-property of the molecule were calculated at the density functional theory. The frontier molecular orbitals, theoretical UV-Vis, and IR stretching vibrations were also reported. The compound crystallizes in the monoclinic system with the space group P2₁/c and Z = 4. The unit cell parameters are a = 12.141(3) Å, b = 13.934(4) Å, c = 7.2777(18) Å, and β = 97.816(14)⁰. The structure is stabilized by an intermolecular interaction of type C-H···O and the structure also involves C-H···π interactions.     

Tetra-n-butylammonium bromide-thiourea (1/2), a layer-type inclusion compound

The inclusion compound built of tetra-n-butylammonium bromide-thiourea (1/2), [(n-C₄H₉)₄N⁺Br^– 2(NH₂)₂CS], has been prepared and characterized by X-ray crystallography. The compound crystalline in orthorhombic space group Pbca, with a = 16.872(6) Å, b = 17.214(6) Å, c = 18.561(6) Å, V = 5390(3) ų, Z = 8. The compound features a sandwich-like crystal structure built up from planar layers. In the crystal structure, zigzag hydrogen-bonded thiourea ribbons are linked by bromide anions to generate puckered layers matching the (100) planes, and the (n-C₄H₉)₄N⁺ cations occupy the intervening space.     

Molecular structure of isopropyl 1-phenyl-4-phenylhydrazono-5-oxo-3-pyrazolecarboxylate

The new azopyrazolone dye has been synthesized and its crystal structure has been investigated. Crystals of C₁₉H₁₈N₄O₃ are triclinic: ,a=7.484(1),b=10.646 (1),c=11.897(1) Å, =82.28(1), =72.86(1), =86.83(1)°,Z=2. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.050 for 2622 unique reflections. The tautomeric form of the molecules has been determined as a hydrazo form. Delocalization of the C5=O3 and C4=N3 -electrons and delocalization of the lone-pair electrons of N1, N3, and N4 atoms has been observed. The intramolecular N–H...O hydrogen bond forms the six-membered ring C₂N₂H...O condensed with the pyrazolone ring. The molecules are connected by intramolecular C–H...O hydrogen bonds.     

Crystal and molecular structure of 3-tert-butyl-1-ethyl-1-[(4-chlorobenzene) sulfonyl] urea

The crystal structure of the title compound, C₁₃H₁₉SN₂O₃Cl, has been solved by direct methods with X-ray diffraction data collected using Cu K radiation. The crystals are monoclinic, witha=9.415(2),b=9.836(3),c=16.928(3)Å,=95.77(3)° and space groupP2₁/c. The structure was refined with 1806 observed [I>2(I)] unique reflections measured on Siemens AED single Crystal diffractometer equipped with a IBM PS2/30 personal computer, to a finalR value of 0.076. The molecule has similar geometrical and conformational features to those observed in 3-tert-butyl-1-methyl-1-[(4-chlorobenzene) sulfonyl] urea (Ghoshet al., 1992) and most of the sulfonamide structures.     

Structure of 1,4-dihydro-1-ethyl-4-iminecinnoline-3-carboxylic acids, classical isosters of quinolone antibacterials: Crystal structures of hydrochlorides of 7-chloro and 7-methyl derivatives

Crystal structures of hydrochlorides of 7-chloro- and 7-methyl-4-iminecinnoline analogs of antibacterial quinolones have been determined by X-ray diffraction methods. The cell parameters for the 7-chloro (1) analog in the space group P2₁/c are a = 9.061(1), b = 19.062(1), c = 7.310(1)Å, = 104.92(1)°, Z = 4, and D _calc = 1.569 g/cm³ and for the 7-methyl (2) analog in the space group P are a = 7.277(5), b = 9.080(5), c = 10.058(5) Å, = 106.10(1), = 102.38(1), = 90.18(1)°, Z = 2, and D _calc = 1.429 g/cm³. Despite geometrical equivalency of methyl and chlorine and some resemblance of their packings, the crystal structures are not isostructural. Each compound forms a strong intramolecular hydrogen bond between protonated 4-imine (a donor) and 3-carboxylic (an acceptor) groups. Compounds with a similar bond, but with reversed functionality and orientation of the 3-carboxylic group, form common quinolones, being mostly 4-oxoquinoline-3-carboxylic acids. The difference should exclude chemical affinity of 4-imine analogs to the guanine base of a bacterial DNA in DNA-gyrase complex, as proposed by Shen et al. ² for 4-oxoquinoline-3-carboxylic acids showing antibacterial activity. Also the free acidic function of a carboxyl group may significantly lower permeability of 4-imine-3-carboxylic analogs of quinolones. Surprisingly, they have demonstrated antibacterial activity comparable with that of nalidixic acid.     

Synthesis, characterization, peripheral studies, and structural analysis of E-4-(N-methylanilino)-3-pentene-2-one, C12H15NO

Crystallographic structural refinement of E-4-(N-methylanilino)-3-pentene-2-one (I) has been carried out by means of three-dimensional single-crystal X-ray diffractometry. The title compound crystallizes in space group C2 (No. 5,Z = 4). The lattice constants are a = 21.543(4), b = 6.433(1), c = 8.019(2) Å, and = 97.82(3)°. Characterizations include physical property determinations and spectrometric identifications employing IR, ¹H and ¹³C NMR, and X-ray powder analyses. The molecules in the crystal lattice are held together by van der Waals forces. Selected bond distances and angles are presented and discussed as well as synthesis and peripheral studies.     

Synthesis and X-ray crystal structure studies of 1-ethyl-3-(2-chlorophenyl)-1,2,3-triazolium perchlorate

The isolation of stable carbenes of the Arduengo (1a) and Wanzlick (2a) type has prompted us to look for stable nitrenium ions of the related structural type 1-ethyl-3-(2-chloropenyl)-1,2,3-triazolium perchlorate (6⁺ClO₄ ^–). The title compound was synthesized and the structure was investigated by X-ray crystallography. It crystallizes in the monoclinic space group P2 ₁/n with cell parameters a = 7.066(4) Å, b = 27.680(6) Å, c = 7.486(2) Å, = 111.22(3)°, and Z = 4. The structure exhibits arrangement of the molecules with intermolecular hydrogen bonds within the layers.     

Construction of Three Novel Coordination Complexes by 3-Nitrophthalic Acid Plus N-Donor Ligands: Synthesis,Structure, and Properties

In order to explore new coordination frameworks with novel designed 3-nitrophthalic acid and N–donor ancillary ligands, three novel coordination complexes, namely, [Co₂(3-NPA)₂(2,2′-bipy)₂(H₂O)₂]?2H₂O (1), [Mn₂(3-NPA)₂(4,4′-bipy)₃(H₂O)₆]?(4,4′-bipy) (2), and [Pb₂O(3-NPA)]_n (3) (where 3-NPAH₂ = 3-nitrophthalic acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been hydrothermally synthesized. X-ray structure analysis reveals that 1 and 2 are dinuclear structures, while 3 is a two-dimensional (2D) network polymer. And the hydrogen bonds and π–π stacking also play important roles in affecting the final structure where complexes 1-2 have 3D and 2D supramolecular architectures, respectively. These complexes have been characterized by powder X-ray diffractions (PXRD) and thermal gravimetric analyses (TGA). In addition, their photochemical properties have also been investigated.     

Crystal and molecular structure of 1-methyl-3-ethyl-2,6-diphenyl-4-piperidone and a study of the geometry of the 4-piperidone ring

The title compound crystallizes in the monoclinic system, space groupC2/c, witha=21.526(2),b=6.096(2),c=25.958(1),=97.29(2) andZ=8. The structure was solved by direct methods and refined by full-matrix least-squares, givingR=0.054 for 2309 unique observed reflections. The 4-piperidone ring has a slightly distorted chair conformation with a mean torsion angle of 55.3(2)°; the puckering is enhanced around N1 and decreased around C4. A comparative study of the geometry of 4-piperidone rings in 13 compounds is also reported. The 4-piperidone ring exists in a distorted chair form in seven compounds while in the remaining six it is in the distorted sofa form.Contribution No. 788.     

Unexpected crystallization and X-ray crystal structure of racemic 1-phenyl-2-(4-pyridyl)ethanol intermediate

We have isolated, by crystallization, the intermediate, 1-phenyl-2-(4-pyridyl)ethanol, from the condensation reaction of 4-methylpyridine with benzaldehyde in which the aim was to obtain the model compound 4-styrylpyridine in absence of a condensing agent. Single crystal X-ray analysis shows the formation of an intermolecular hydrogen bond O–H···N between the nitrogen atom of a pyridine group and the oxygen atom of the OH of the neighboring molecule, which helps to stabilize the crystal structure. Crystal structure determination clearly revealed that the solid is chiral and racemic, as expected. The title compound crystallizes in an orthorhombic system with a space group Pna2₁ with two pairs of R and S enantiomers in each crystal cell (a = 15.591(1) Å, b = 12.691(1) Å, and c = 5.589(1) Å). Spectroscopic NMR data gave evidence that the isolated compound is actually the alcohol just before the dehydration process that yields the double bond of the 4-styrylpyridine.     

Crystallographic and conformational analysis of 2-methyl-3-(2-nitro-phenyl)-4-phenyl-[1,2,4]oxadiazolidin-5-one

Molecular and crystal structure of 2-methyl-3-(2-nitro-phenyl)-4-phenyl-[1,2,4]oxadiazolidin-5-one, C₁₅H₁₃N₃O₄, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 10.0313(8) Å, b = 9.0372(5) Å, c = 15.5964(14) Å, β = 96.926(7)^∘, Z = 4, D_x = 1.42 g/cm³, μ (Mo-K_α) = 0.105 mm⁻¹, and space group is P 2₁/c. The structure was solved by direct methods and refined to a final R = 0.036 for 1894 reflections with I > 4σ (I). The crystal structure is stabilized by C–H⋅sO type inter-molecular, C–H⋅sN and C–H⋅sO type intra-molecular, π–π stacking and edge to face (C–H⋅s π-ring) interactions. To enlighten conformational flexibility of the title molecule, selected two torsion angles are varied from −180^∘ to +180^∘ in every 10^∘ separetely and then molecular energy profile is calculated and construed.     

Molecular structure,DFT studies,Hirshfeld surface analysis,energy frameworks,and molecular docking studies of novel (E)-1-(4-chlorophenyl)-5-methyl-N′-((3-methyl-5-phenoxy-1-phenyl-1H-pyrazol-4-yl) methylene)-1H-1, 2, 3-triazole-4-carbohydrazide

Abstract

The synthesis of the compound and its crystal structure having a monoclinic crystal system has been reported earlier. Optimized bond lengths and angles are showing good agreements with experimental data using DFT/B3LYP method. Energy of highest occupied molecular orbital and lowest unoccupied molecular orbital has been predicted to analyze the stabilities of compound. Crystal explorer 17.5 helps to visualize intermolecular interactions and its contributions to each interaction within molecule. The preeminence of dispersion energy component over the other components was established by interaction energy calculations and lattice energy framework analysis using same software. The molecular docking study was performed for molecule using AutoDock software.     

Synthesis, crystal structure, and molecular modeling (AM1) of Methyl 6-chloro-4-(2-chlorophenyl)-5-formyl-2-methyl-1, 4-dihydropyridine-3-carboxylate

The synthesis and structural characterization of Methyl 6-chloro-4-(2-chlorophenyl)-5-formyl-2-methyl-1,4-dihydropyridine-3-carboxylate is described. The structure was refined to R₁ = 0.0470 for 2665 reflections (with I > 2(I)). Crystal data: C₁₅H₁₃C₁₂NO₃, monoclinic,space group P2₁/c, a = 11.163(9), b = 14.484(8), c = 9.422(7) Å, V = 1512.9(19) ų, Z = 4. The results of crystallographic and molecular modeling (AM1) were compared. The Cl atom attached to the phenyl group has two possible orientations, having 75% (sp) and 25% (ap) occupancy, respectively. The molecules in the crystal are held together by means of intermolecular hydrogen bonds of the type N=H...O and by C=H...O interactions.