Structural studies of N-2-(3-picolyl)- and N-2-(4-picolyl)-N′-tolylthioureas

Reactions of 2-aminopicolines with 2- and 4-tolyl isothiocyanates yielded N-2-(4-picolyl)-N-4-tolylthiourea, 1, N-2-(3-picolyl)-N-4-tolylthiourea, 2, and N-2-(4-picolyl)-N-2-tolylthiourea, 3. Compound 1 is monoclinic, of space group P2₁/c with a = 7.456(1) Å, b = 13.135(3) Å, c = 13.959(3) Å, = 104.99(3)°, and V = 1320.5(5) ų with Z = 4, for d _calc = 1.294 g/cm³. Compound 2 is triclinic, of space group with a = 6.877(3) Å, b = 7.590(5) Å, c = 13.213(9) Å, = 78.38(2)°, = 77.96(4)°, = 86.36(4)°, and V = 660.5(7) ų with Z = 2, for d _calc = 1.294 g/cm³. Compound 3 is monoclinic, of space group P2₁/c with a = 12.604(2) Å, b = 15.592(3) Å, c = 6.875(2) Å, = 91.05(2)°, and V = 1350.9(2) ų with Z = 4, for d _calc = 1.265 g/cm³. The three thioureas are found in both solid state and solution in a conformation resulting from intramolecular hydrogen bonding. Compounds 1 and 3 present an intermolecular hydrogen bond involving the thione sulfur and the NH hydrogen, which is not present in 2 owing to the steric hindrance of the methyl group in the phenyl ring. The geometry of the molecule is affected by the position of the methyl groups on the pyridine and aryl rings.     

Synthesis and crystal structure of iodo-1-(2′-aminophenyl)-2,6-diaza-6-methyl-9-amino-1-noneno copper(II) iodide

Reaction of equimolar amounts of 2-aminobenzaldehyde and 3,3-diamino-N-methyldipropyl-amine in methanol affords a novel 11 condensation product, abaMedpt, which has been isolated as the copper(II) complex, [Cu(abaMedpt)I]I. The crystal structure of the complex has been determined from single crystal diffractometer data and refined to a finalR factor of 0.0353 with 2492 unique observations and 206 variables. The complex crystallizes in the monoclinic space group P2₁/c (N° 14) witha=9.263(2),b=18.189(3),c=11.740(3) Å,=92.97(4)°,Z=4,D _c =1.902 g cm^–3. The structure involves a five-coordinate square-pyramid CuN₄I chromophore and an uncoordinated iodide anion. Nitrogen atoms constitute the basal plane, while the bonded iodine occupies the apical position. The structure contrasts with the more usual distorted trigonal-bipyramidal stereochemistries of CuN₄I chromophores reported so far.     

Crystal structures and properties of catena-μ-nitrato (7-amino-5-aza-4-methyl-3-hepten-2-onato) copper(II) and μ3-hydrox-otris(μ-8-amino-5-aza-4-methyl-3-octen-2-onato) tricopper(II) dinitrate

The products of monocondensation of penta-2,4,-dione with 1,2-diaminoethane, HAE, and with 1,3-diaminopropane, HAT, react with copper nitrate hemipentahydrate to give catena--nitrato (7-amino-5-aza-4-methyl-3-hepten-2-onato) copper(II), [Cu(AE)NO₃]_n and a mixture of ₃-hydroxo-tris (-8-amino-5-aza-4-methyl-3-octen-2-onato) tricopper(II) dinitrate [Cu₃(AT)₃OH]-(NO₃)₂ and [Cu(AT)NO₃]_x, respectively. The structure of [Cu(AE)NO₃]_n has been determined from 1601 diffractometer data and refined by least squares methods toR=0.0306. The compound crystallizes in the monoclinic space groupP2₁/a witha=16.856(3)Å,b=8.109(4)Å,c=7.518(3)Å,=90.15(2)°,D _c =1.725 g cm^–3,D _o=1.72 g cm^–3 andZ=4. Copper atoms in [Cu(AE)NO₃]_n are in a 4+1+1^* environment and are linked by the pseudobidentate and bridging nitrato group into infinite chains. The structure of [Cu₃(AT)₃OH](NO₃)₂ has been determined from 3178 diffractometer data and refined toR=0.0544. The compound crystallizes in the triclinic space groupP¯1 witha=11.918(2)Å,b=14.478(2)Å,c=11.501(3)Å,=98.04(2)°,=117.72(2)°, =99.80(1)°,D _c =1.580 g cm^–3,D _o=1.59 g cm^–3 andZ=2. The compound is associated in hexanuclear clusters due to hydrogen bonding interactions. Coordination about Cu is best described as square pyramidal. Magnetic susceptibility data indicate a weak antiferromagnetic exchange within the trinuclear core withJ=–14 cm^–1.     

Structural studies of N-2-(6-picolyl)-N′-tolylthioureas

Reaction of 2-amino-6-picoline with 2-, 3-, and 4-tolyl isothiocyanates produces the three N-2-(6-picolyl)-N-tolylthioureas, 6PicTu2T, 6PicTu3T, and 6PicTu4T. 6PicTu2T is mono-clinic, space group P2₁/n with a = 8.1700(3) Å, b = 25.5840(6) Å, c = 12.6840(5) Å, = 98.8750(16)°, and V = 2619.5(2) ų with Z = 8, for d _calc = 1.305 g/cm³. 6PicTu3T is monoclinic, space group C2/c with a = 23.879(3) Å, b = 6.744(3) Å, c = 17.116(10) Å, = 99.26(4)°, and V = 2720(3) ų with Z = 8, for d _calc = 1.257 g/cm³. 6PicTu4T is triclinic, space group P-1 with a = 8.829(6) Å, b = 8.8950(15) Å, c = 10.495(3) Å, = 68.63(3)°, = 72.19(4)°, = 63.06(4)°, and V = 681.2(5) ų with Z = 2, for d _calc = 1.255 g/cm³. Intermolecular hydrogen bonding involving the thione sulfur and the NH hydrogen and the planarity of the thiourea are affected by the position of substitution on the aryl ring. ¹H NMR studies in CDCl₃ show the NH hydrogen resonance considerably downfield from other signals in the spectrum of each thiourea. The enthalpies of fusion of the present thioureas reflect the extent of intermolecular hydrogen bonding and are compared to other heterocyclic thioureas.     

Synthesis and Structural Characterization of (2,4-Diamino-5-(3′,4′,5′-Trimethoxybenzyl)Pyrimidine Copper (II)) Complex

Abstract  The reaction of Cu(OOCCH₃)₂·H₂O with (2,4-diamino-5-(3′,4′,5′-trimethoxybenzyl) pyrimidine (trimethoprim) in ethanolic solution at 80 °C affords the title complex which has been characterized by elemental, IR, and NMR (¹H and ¹³C).The crystal structure has been determined by single crystal X-ray diffraction. Compound 1 (C₃₆H₄₈Cu₂N₈O₁₄) is triclinic, space group P-1 with a = 7.2676(4) ?, b = 11.6721(7) ?, c = 12.8279(8) ?, α = 95.839(1)°, β = 93.456(1)°, γ = 105.541(1)°, Z = 1. Two copper atoms are coordinated directly to each other as well as are held together by four bridging aceto groups. Each copper atom is also bonded opposite the Cu–Cu vector to a trimethoprim molecule through the N(1) atom of the pyrimidine ring. Trimethoprim acts as a monodentate ligand through the pyrimidine nitrogen N(1) atom. The complex was screened for the activity against several bacteria, showing more activity against bacteria as compared to trimethoprim. Graphical Abstract  To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria was analyzed.      

Crystal and molecular structures of 1,4-dihydro-6-methyl-5-N,N-diethylcarbamoyl-4-phenyl-2(3H)-pyrimidinethione (1) and 1,4-dihydro-6-methyl-5-N-methyl carbamoyl-4-(2′-nitrophenyl)-2(3H)-pyrimidinethione hemihydrate (2)

The crystal structure of 1,4-dihydro-6-methyl-5-N,N-diethylcarbamoyl-4-phenyl-2(3H)-pyrimidinethione, C₁₆ H ₂₁ N ₃OS (1), is monoclinic, space group P2₁/n, a = 6.818(1), b = 13.211(2), c = 18.807(3) Å, = 99.53(1)°, V = 1670.6(4) ų, Z = 4 and d _cal = 1.206 Mg/m³, R = 0.042 (wR = 0.119) for 190 parameters and 2560 observations with I 2(I) and 1,4-dihydro-6-methyl-5-N-methyl carbamoyl-4-(2-nitrophenyl)-2(3H)-pyrimidinethione hemihydrate, C₁₃ H ₁₄N₄O₃S 0.5H₂O, (2), is triclinic, space group P1, a = 7.513(1), b = 14.381(2), c = 15.506(2)Å, = 114.95(2), = 98.11(1), = 93.55(1)°, V = 1490.0(3) ų, Z = 4 and d _cal = 1.406 Mg/m³, R = 0.062 (wR = 0.165) for 388 parameters and 3094 observations with I 2(I).The compound 2 crystallized having two molecules in the asymmetric unit, which can be regarded as monohydrated dimers, and forming a hydrate. The conformation of the central heterocyclic ring (1,4-dihydropyrimidine) in both compounds was found to be close to a half-chair conformation. The 2-nitrophenyl substituent in 2 is in the axial synperiplanar orientation. In both compounds, the conformation of the 3-substituted carbamoyl group appears to be influenced by hydrogen bonding with anticlinal orientation observed for carbonyl groups serving as hydrogen bonding acceptors.     

Synthesis and structure analysis of 2-(2′-propanonylthio)-3-(o-methyl phenyl) quinazol-4(3H)-one

The three-dimensional molecular and crystal structure of 2-(2'-propanonylthio)3-(o-methyl phenyl)quinazol-4(3H)-one has been determined by X-ray crystallographic methods. This compound crystallizes in the orthorhombic space group P_bca with unit cell parameters: a=9.649(5), b=30.102(10), c=11.403(9)Å. It has been solved by direct methods and refined to a residual index of 0.054. The magnitude of torsion along C16— C11— N3— C4 bond is 93.5(4)°. The dihedral angle between the plane comprising all the ring atoms of quinazoline moiety and the atoms of the methyl substituted phenyl ring is 94.12(1)°. The crystal structure is stabilized by one intramolecular C— HsO interaction and three intermolecular C— HsN contacts.     

Crystal structure of 1,3-(N,N′-benzamide)-2-methyl-1-pentene

Crystals of the title compound are monoclinic (C20H22N2O2): space groupP2₁/n,a=11.800(3),b=13.820(2),c=11.004(3) Å,=92.74(3)°. The structure was solved by direct methods and refined by block-matrix least-squares procedure to giveR=0.078 andRw=0.076 for 1960 reflections above 3(I). The two amide groups are not coplanar with respect to their benzene rings. An intramolecular N-HO hydrogen bond was found in the molecules which are joined in chains by other strong N-HO hydrogen bonds.     

Synthesis,Characterization and Structural Conformation Studies of 2-Amino-3-ethoxycarbonyl-4-(4′-methoxy Phenyl)-4H-pyrano-[3,2-c]-chromene-6-methyl-5-one

2-amino-3-ethoxycarbonyl-4-(4′-methoxy Phenyl)-4H-pyrano-[3,2-c]-chromene-6-methyl-5-one was synthesized by the two-component reaction of 6-methyl-4-hydroxy coumarin with 4′-methoxy-2-cyano cinnamate, which was synthesized by Knoevenagel reaction with 88% yield. The compound obtained was characterized by spectroscopic techniques and confirmed by X-ray crystallographic studies. The crystallographic data analysis reveals that the title compound crystallizes in the triclinic space group \(P\overline{1}\) with cell parameters a = 7.7750(8) Å, b = 9.0310(6) Å, c = 15.6120(17) Å, α = 77.249(7)°, β = 115.860(3)°, γ = 70.139(7)°, V = 1,003.0(16) Å³ for Z = 4. The structure has been solved by direct methods and refined to R1 = 0.0552 for 3,164 observed reflections with I > 2 σ(I). The pyran ring is in a flattened boat conformation. The carbonyl group is oriented in a -synperiplanar(cis) conformation.

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Synthesis and Study of New Mesogens II: p-(p′-n-Alkoxycinnamoyloxy)-benzylidene p″ -anisidines (1) and p-(p′-n-Alkoxycinnamoyloxy)- benzylidene anilines (2)

Two new homologous series of liquid crystals viz. p-(p'-n-alkoxycinnamoyloxy) benzylidene p”-anisidines (1) and p-(p'-n-alkoxycinnamoyloxy) benzylidene anilines (2) comprising twenty four mesogens have been synthesized. Both are high melting series of mesomorphs. In the homologous series (1) the nematic mesophase is exhibited from the very first member; however, the first five compounds decompose at high temperatures before passing into isotropic liquid condition. Polymesomorphism is exhibited with the appearance of the smectic mesophase at the octyl derivative and remains up to the last viz. octadecyl homologue. Within polymesomorphic region the nematic mesophase is homeotropic; however, it shows a clear threaded texture where it is the only mesophase shown i. e. in the first seven members of the homologous series (1). The smectic mesophase shows focal conic fan shape texture belonging to smectic-A variety. The nematic-isotropic curve shows descending tendency as the series is ascended-a characteristic of high melting series. The smectic-nematic transition curve rises steeply and shows a levelling off tendency at the octadecyl derivative. In the homologous series (2), no decomposition occurs. The smectic mesophase commences a little early i. e. from hexyl derivative; while polymesomorphism is clearly exhibited up to the dodecyl derivative, the last two homologues are purely smectogens. The usual odd-even effect is observed in case of the nematic-isotropic curve for series (2). The smetic-nematic curve rises gradually and seems to be merging with the falling nematic-isotropic curve at the fifteenth homologue. The mesomorphic ranges in both series are quite wide; however, that of series (1) is wider than one obtained in series (2). Thermal stabilities are good and are in keeping with the molecular characteristics. The textures of the smectic and nematic mesophases are similar to that of the series (1). Both series are comparable with each other and other related series.     

Synthesis and crystal structure of N-(1-phenyl-3-methyl-4-benzal-pyrazolone-5)- N′-salicylidene hydrazine

A novel Schiff base compound, N-(1-phenyl-3-methyl-4-benzal-pyrazolone-5)-salicylidene hydrazine (PMBP-SAH), has been synthesized and characterized by X-ray diffraction: monoclinic, space group C2/c with a = 21.796(5) Å, b = 18.370(3) Å, c = 20.843(3) Å, = 95.440(10)°, V = 8308(3) ų, and Z = 16. The title compound contains two kinds of tautomers: the red compound is the keto form and the other is the enol form. Changes in color are due to the isomerization of the enol and keto forms by the intramolecular proton transfer.     

Synthesis and crystal structure of 1-(1′,3′-dimethyl-5′-chloropyrazol-4′-carbonyl′-3-(2′-chlorophenyl)-5-amino-4-cyanopyrazole

The title compound 1-(1,3-dimethyl-5-chloropyrazol-4-carbonyl)-3-(2-chlorophenyl)-5-amino-4-cyanopyrazole (C₁₆H₁₂Cl₂N₆O) has been synthesized and characterized by X-ray diffraction: Triclinic, space group P1, with a = 8.6712(8) Å, b = 9.5091(10) Å, c = 11.2170(11) Å = 71.531(2)°, = 84.683(2)°, = 74.099(2)° Z = 2; V = 843.7(14) ų. C(10), O(1), C(11), and N(2) atoms are coplanar with the average deviation of 0.0071 Å, which form 11.03° and 43.93° dihedral angles with pyrazole planes (I) and (II), respectively.     

Crystal structure of 1-benzyl-5-bromo-2-oxoindol-3-spiro-2′-(4′-benzoyl-1′-methylpyrrolidin)-3′-spiro-3′′-(1′′-methyl-2′′-oxoindole), C34H28N3O3Br

The title compound crystallizes in space group P-1, with a = 10.574(4) Å, b = 11.262(1) Å, c = 12.536(8) Å, = 90.08(3)°, = 103.63(3)°, = 103.35(2)°. Owing to the centric space group, C3, C3, and C4 chiral centers are either [R, S, S] or [S, R, R].     

Structural characterization and excited-state properties of luminescent <Emphasis Type="Italic">Tris</Emphasis>-(μ -3-methyl-5- trifluoromethylpyrazolato)trigold(I)

Tris-(-(3-methyl-5-trifluoromethylpyrazolato)-N:N)triangulo-trigold(I), (3,5-tfmpz)₃ Au₃, has been synthesized and exhibits a planar nine-member ring containing a central gold triangle with an average intramolecular Au–Au distance of 3.3455(8) Å. The complex crystallizes in the monoclinic space group Cc with a = 12.998(2) Å, b = 22.910 (3) Å, c = 7.217(1) Å, and = 104.781(1). The solid-state structure consists of sheets of (3,5-tfmpz)₃Au₃ units stacked in an offset fashion along the c axis such that one gold atom in each Au₃ unit (Au1) lies approximately over the midpoint of the Au1–Au3 edge of the triangle in the layer below it. The intermolecular Au–Au distances are between 3.880(1) and 4.023(1) Å, which are too long for there to be significant intertrimer bonding interaction suggesting that any supramolecular organization may be due to hydrogen-fluorine and fluorine-fluorine interactions between the molecules. The complex exhibits excitation-dependent emission at room temperature in the solid state. The structured higher energy emission (_em = 468, 517, and 556(sh) nm) is believed to be a ligand-centered ^* transition with a lower energy unstructured emission (_em = 658 nm) assigned to the classical Au–Au excited state transition.     

Crystal and molecular structure of 2-(2′-chloro-5′-nitrostyryl)benzoselenazole

The title compound C₁₅H₉ClN₂O₂Se (nsbse) is orthorhombic, witha=6.823(2),b=7.860(2),c=26.349(5) Å,Z=4,D _x =1.709,(MoK)=28.3 cm^–1,F(000)=720,T=298K in space groupP2₁2₁2₁. The structure was solved by heavy atom and Fourier methods and refined toR=0.045 for 1095 unique observed reflections. The molecule is almost planar, with a dihedral angle of 4.8(2)° between the benzoselenazole and phenyl rings. The C-Se-C angle in the selenazole ring is very small, 84.6(4)°, while the C-N-C angle in that ring is 113.7(7)°.     

Crystal and molecular structure of CI Solvent Yellow 18, 4-(2′,4′-dimethyl phenyl hydrazono)-5-methyl-2-phenyl-3H-pyrazol-3-one

The crystal structure of CI Solvent Yellow 18, C₁₈H₁₈N₄O, has been determined by single crystal X-ray diffraction techniques. It crystallizes in the monoclinic system witha=7.480(2) Å,b=19.184(3) Å,c=11.260(1) Å,=98.00(3)°, space groupP2₁/n andZ=4. The structure has been solved by direct methods, and least-squares refinement has been completed on three-dimensional data (2310 reflections, CuK radiation). The hydrogen atoms have been found, but only their positional parameters refined. Final residual 0.085 (all positive intensity data). The molecule exists as the hydrazone tautomer and intramolecular hydrogen bonding keep the molecule approximately planar. The molecules are packed in layers parallel to the (¯202) plane and in columns parallel tob. Alternate molecules within the columns are in antiparallel. The molecules are linked by van der Waals' forces.     

Crystal structure ofβ-C.I. Solvent Yellow 18, 4(2′,4′-dimethylphenyl hydrazono)-5-methyl-2-phenyl-3H-pyrazol-3-one

The crystal structure of-C.I. Solvent Yellow 18, C₁₈H₁₈N₄O, has been determined by single crystal X-ray diffraction techniques. It crystallizes in the monoclinic system witha=30.948(18)Å,b=4.918(4)Å,c=20.861(9)Å,=91.68(4)°, space groupC2/c,Z=8. The structure has been solved by direct methods and least-squares refinement has been completed on three dimensional data (1237 reflections MoK radiation). The hydrogen atoms have been found but only their positional parameters refined. Final residual 0.092 (all intensity data). The molecule exists as the hydrazone tautomer and intramolecular hydrogen bonding keeps the molecule approximately planar. The molecules are packed in columns parallel to theb axis, while the molecule lies approximately parallel to the (51¯3) plane. The molecules are linked by van der Waals' force.     

Heterocyclic tautomerism. XI. Structures of 5,5′-bitetrazole and 1-methyl-5-(2′-pyridyl)tetrazole at 130 K

The X-ray crystal structures of 5,5-bitetrazole and 1-methyl-5-(2-pyridyl)tetrazole at 130 K are described. 5,5-Bitetrazole exists as the 1 H, 1'H-tautomer and packs in chains held together by pairs of intermolecular hydrogen bonds. It crystallizes in the monoclinic space group P2₁/n witha=4.945(1),b=6.367(1),c=8.491(1) Å and =99.233(7)^o. In 1-methyl-5-(2-pyridyl)tetrazole the two heterocyclic rings are nearly coplanar and the molecular packing is controlled by intermolecular – interactions. It crystallizes in the triclinic space group P1 witha=6.667(1),b=7.135(1),c=9.202(1)Å, =89.59(1), =69.08(1), and =66.62(1)^o.