Crystal and Molecular Structures of 2-Amino-4-Nitrobenzoic Acid and Its Cocrystals with 2,2′-Bipyridine (2/1) and Bis(pyridin-2-yl)ketone (1/1)

Abstract  

The eight-membered {···HOC=O}₂ synthon featured in the crystal structure of 2-amino-4-nitrobenzoic acid (1) is replaced by carboxylic acid···N-pyridine hydrogen bonds in its cocrystals with 2,2′-bipyridine (2/1; 2) and bis(pyridin-2-yl)ketone (1/1; 3) indicating the robust nature of the latter synthon. Disruption of the three-dimensional architecture based on O–H···O and N–H···O(nitro) hydrogen bonds in (1) is evident in the cocrystals which form supramolecular tubes (2) and chains (3) based on O–H···N and N–H···O hydrogen bonding. Compound (1) crystallizes in the monoclinic space group P2₁/n with a = 3.6291(1) ?, b = 7.7339(3) ?, c = 26.561(1) ?, β = 91.385(2)°, and Z = 4. Compound (2) crystallizes in the monoclinic space group C2/c with a = 27.562(3) ?, b = 6.8300(6) ?, c = 12.923(1) ?, β = 110.593(5)°, and Z = 4. Compound (3) crystallizes in the monoclinic space group P2₁/c with a = 3.795(3) ?, b = 12.024(8) ?, c = 35.65(2) ?, β = 92.131(6)°, and Z = 4 (determined from synchrotron data).     

Structures of two N-{2-([(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-halophenyl}acetamides

Abstract  

The compounds, N-{2-[(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-chlorophenyl}acetamide (1: X = Cl) and N-{2([(5-amino-1,3,4-thiadiazol-2-yl)difluoromethyl]-4-bromo-phenyl}acetamide (1: X = Br), are isostructural. The molecules are near ‘‘V’’ shaped with the angles between the two aromatic planes ca. 84° in each case. The various intermolecular interactions, namely N–H···O, N–H···N, N–H···F, and C–H···N hydrogen bonds and C–H···π, C–Cl···π and C–O···π interactions, generate 3-D arrays. Compound (1: X = Cl) crystallizes in the monoclinic space group P21/c with a = 16.9032(7) ?, 10.2193(4) ?, c = 7.5227(4) ?, β = 100.179(3)° and Z = 4. Compound (1: X = Br) crystallizes in the monoclinic space group P21/c with a = 17.2119(4) ?, 10.2167(2) ?, c = 7.5677(2) ?, β = 100.326(2)° and Z = 4.     

Tetraallyl Ethers of Thiacalix[4]arenes in the 1,3-Alternate Conformation

Abstract  

The O-alkylation of thiacalix[4]arene and of two derivatives substituted in p-position by NO₂ and p-N=N–C₆H₄–NO₂ with allylbromide leads to tetraallyl ethers in the 1,3-alternate conformation (1–3) as proved by X-ray crystallography. Compound 1 crystallized in the trigonal space group P3₂21 with unit cell parameters a = 10.9608(4) ?, b = 10.9608(4) ?, c = 24.6730(12) ?; α = 90°, β = 90°, γ = 120° and Z = 3. Compound 2 crystallized in the orthorhombic space group Pbca with unit cell parameters a = 12.8608(4) ?, b = 17.5209(5) ?, c = 33.6527(9) ?; α = 90°, β = 90°, γ = 90° and Z = 8. Compound 3 crystallized in the monoclinic space group P2₁/n with unit cell parameters a = 18.7825(19) ?, b = 17.6662(13) ?, c = 19.7828(18) ?; α = 90°, β = 114.152(7)°, γ = 90° and Z = 4. Subtle differences in the molecular shape of the calix[4]arene core were found. The unsubstituted compound 1 forms three alternating layers with parallel tubes of different orientation, while for 3 all molecules are arranged in tubes parallel to the a-axis. Layers of molecules parallel to the a, b-plane are found for compound 2.     

Synthesis and Crystal Structure of Compound 1-Phenyl-2-(1H-1,2,4-triazolo-yl)-3-phenyl-propen-1-one and 1-Diphenyl-3-(1,2,4-triazolo-yl)-1H,4H-1,5-benzothiazepine

Abstract  

The crystal structures of the compounds 1-phenyl-2-(1H-1,2,4-triazolo-yl)-3-phenyl-propen-1-one (2), and 2,4-diphenyl-3-(1,2,4-triazolo-yl)-1H,4H-1,5-benzothiazepine (3) were obtained by single crystal X-ray diffraction. Compound 2 crystallizes in the triclinic system with space group P − 1, a = 8.5553(17) ?, b = 9.6229(19) ?, c = 9.924(2) ?, α = 106.16(3)°, β = 108.03(3)°, γ = 105.14(3)°, V = 690.1(2) ?³, Z = 2. The compound 3 crystallizes in the orthorhombic system with space group Pbca, a = 12.904(3) ?, b = 15.864(3) ?, c = 19.140(4) ?, α = 90°, β = 90°, γ = 90°, V = 3918.3(14) ?³, Z = 8. H-bonds and π–π stacking are the main non-bonding interactions in the molecular structure. Details of the synthesis, structures, and spectroscopic properties of the two compounds are discussed.     

Crystal Structure Studies of Two Regioisomers of Bromo-4-Aryloxymethylcoumarins

Abstract  

The 4-(2-bromo-4-methyl-phenoxymethyl)-6-methylcoumarin (1) have been synthesized from bromination of corresponding 4-aryloxymethyl coumarin, which is a regioisomer of 4-(2-bromo-4-methyl-phenoxymethyl)-7-methylcoumarin (2) (CCDC-695895). The compound 1 crystallizes with triclinic space group P-1, a = 8.0943(3) ?, b = 9.3502(3) ?, c = 10.1476(4) ?, α = 90.234(2)°, β = 94.065(2)°, γ = 95.106(2)°, Z = 2 and compound 2 crystallizes with monoclinic space group P2₁/n, a = 8.465(5) ?, b = 13.649(5) ?, c = 13.304(5) ?, α = 90.000(5)°, β = 90.740(5)°, γ = 90.000(5)°, Z = 4. Both the compounds are planar with variation in their intermolecular hydrogen bonds between C–H···O and C–H···π.     

Interesting Reactivity in the Thermolysis and Photolysis of 2,3-Diphenyl-1-naphthol

Abstract  2,3-Diphenyl-1-naphthol (1) undergoes two unexpected reactions under different conditions. Compound (1) was heated in DMSO-d₆ and underwent a Pummerer type thermal reaction to give two isomeric products, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d₅ which crystallized in the space group with a = 7.1610(9) ?, b = 11.2795(15) ?, c = 12.8905(17) ?, α = 114.049(2)°, β = 96.589(2)°, and γ = 102.945(2)°, and 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d₅ which crystallized in the space group with a = 8.5981(5) ?, b = 10.4374(6) ?, c = 11.1078(6) ?, α = 78.748(2)°, β = 67.709(2)°, and γ = 83.184(2)°. Photolysis (254 nm) of (1) resulted in 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol which crystallized in the space group P2₁/c with a = 26.3616(11) ?, b = 10.1707(4) ?, c = 23.3376(9) ?, and β = 99.034(2)°. Graphical Abstract  When 2,3-diphenyl-1-naphthol was heated in DMSO-d₆ two unexpected isomers, 1-(methylthio)methoxy-2,3-diphenyl naphthol-d₅ and the racemate 2-(methylthio)methyl-2,3-diphenyl 1(2H)-naphthalenone-d₅ were produced. Photolysis in THF at 254 nm led to the unexpected product 2,2′,3,3′-tetraphenyl-1,1′-bi-2-naphthol. All structures were elucidated by X-ray crystallography.      

Crystal and Molecular Structures of Two Triazole Derivatives: 4-Cyclopropyl-4,5-dihydro-1H-1,2,3-triazole and Methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate

Abstract  

The molecule in 4-cyclopropyl-4,5-dihydro-1H-1,2,3-triazole (I) is disposed about a mirror plane with the triazole ring lying in the plane and being orthogonal to the cyclopropyl ring. Considerable delocalization of π-electron density within the triazole ring is indicated by the pattern of bond distances in (I). The molecule of methyl 1-benzyl-1H-1,2,3-triazole-4-carboxylate (II) adopts a curved shape with the dihedral angle formed between the triazole and benzene rings being 63.23(8)°. By contrast to (I), localization of π-electron density within the triazole ring in (II) is indicated. Both (I), via N–H···N hydrogen bonding, and (II), via C–H···O and C–H···N interactions, associate in the solid state to form supramolecular chains. In (I), the chain is a zigzag with a flat topology, whereas in (II) the linear chain has a curved topology. Compound (I) crystallizes in the orthorhombic space group Pnma with a = 5.6470(2) ?, b = 7.3359(4) ?, c = 13.4404(7) ?, and Z = 4. Compound (II) crystallizes in the monoclinic space group P2₁/c with a = 12.1314(5) ?, b = 5.5951(2) ?, c = 16.4339(7) ?, β = 111.269(2)°, and Z = 4.     

Synthesis,Crystal Structure and Thermal Properties of <Emphasis Type="Italic">N</Emphasis>-Acetyl-3-(2-furyl)-5-ferrocenyl-2-pyrazoline and <Emphasis Type="Italic">N</Emphasis>-Acetyl-3-(2-thienyl)-5-ferrocenyl-2-pyrazoline

Abstract  

Two novel ferrocenyl substituted N-acetyl-2-pyrazolines, N-acetyl-3-(2-furyl)-5-ferrocenyl-2-pyrazoline (3) and N-acetyl-3-(2-thienyl)-5-ferrocenyl-2-pyrazoline (4), have been synthesized and characterized by FTIR, ¹H-NMR, ¹³C-NMR techniques, elemental analysis and X-ray structure analysis. Thermal properties of these compounds have been determined by TGA, DTA and DSC analysis. Compound 3 (C₁₉H₁₈N₂O₂Fe) crystallizes in the monoclinic space group P21/c and Z = 4, with a = 8.6970(4) ?, b = 18.4725(9) ?, c = 11.0041(5) ?, β = 110.942(3)°. Compound 4 (C₁₉H₁₈N₂OSFe) crystallizes in the orthorhombic space group Fdd2 and Z = 16, with a = 84.242(2) ?, b = 13.5416(5) ?, c = 5.9405(2) ?, β = 90°. In terms of crystal packing, each compound shows different molecular arrangement, which are stabilized by C–H···O intermolecular weak hydrogen bonds, and/or C–H···π interactions.     

Study of Hydrogen Bonding in <Emphasis Type="Italic">N</Emphasis>′-(4,6-disubstituted-pyrimidin-2-yl)-<Emphasis Type="Italic">N</Emphasis>-[2-(2,4-dichlorophenoxypropionyl)]thiourea

Abstract  

Two of N′-N′-(4,6-disubstituted-pyrimidin-2-yl)-N-[2-(2,4-dichlorophenoxypropionyl)]thiourea (4a-4b) had been synthesized and their crystal structures had been determined by X-ray diffraction method. 4a crystallizes in the triclinic space group P-1, with a = 8.053(12) ?, α = 102.84(2)°, b = 10.541(16) ?, β = 106.99(2)°, c = 12.461(19) ?, γ = 94.615(19)°, and D _c  = 1.470 mg/m³ for Z = 2. 4b crystallizes in the triclinic space group P-1, with a = 7.939(5) ?, α = 105.302(10)°, b = 10.183(7) ?, β = 105.729(9)°, c = 12.764(9) ?, γ = 90.698(11)°, and D _c  = 1.517 mg/m³ for Z = 2.     

Hydrogen Bonding in the Crystal Structures of New Imidazolium Triflimide Protic Ionic Liquids

Abstract  The synthesis and crystal structures of 1,3-diamino-2-methylimidazolium bis(trifluoromethylsulfonyl)imide (1), 1,3-dihydroxy-2-methylimidazolium bis(trifluoromethylsulfonyl)imide (2) and 1-(2-(diethylammonio)ethyl)-3-methylimidazolium bis(bis(trifluoromethylsulfonyl)imide) (4) are reported. The salts 1, 2 and 4 have melting points below 100 °C, the intermediate 1-(2-(diethylamino)ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (3) is liquid at room temperature. Compound 1 is monoclinic, space group P2₁/n with a = 8.4979(4) ?, b = 12.2803(6) ?, c = 13.9400(7) ?, β = 93.086(4)°, and Z = 4. Compound 2 is monoclinic, space group P2₁/c with a = 7.6165(2) ?, b = 20.5323(8) ?, c = 9.7654(3) ?, β = 111.046(2)°, and Z = 4. Compound 4 is triclinic, space group with a = 8.5313(4) ?, b = 9.2157(4) ?, c = 20.5812(8) ?, α = 84.668(2)°, β = 83.738(2)°, γ = 63.096(2)°, and Z = 2. The ions in 1 build a network of N–H···O hydrogen bonds, in 2 they are linked to chains by O–H···N and bifurcated O–H···O hydrogen bonds, whereas in 4 they form pairs by N–H···O contacts. The triflimide anions adopt transoid conformations. Index Abstract  Short interionic contacts, conformational flexibility, and disorder phenomena were identified in the crystal structures of three new, low-melting, protic imidazolium triflimides.      

Syntheses,Characterization and Crystal Structures of <Emphasis Type="Italic">N′</Emphasis>-(5-Chloro-2-Hydroxybenzylidene)-4-Dimethylaminobenzohydrazide and <Emphasis Type="Italic">N′</Emphasis>-(2,4-Dichlorobenzylidene)-4-Dimethylaminobenzohydrazide

Abstract  

The hydrazone compounds, N′-(5-chloro-2-hydroxybenzylidene)-4-dimethylaminobenzohydrazide (1) and N′-(2,4-dichlorobenzylidene)-4-dimethylaminobenzohydrazide (2), have been synthesized by the condensation reaction of equimolar quantities of 4-dimethylaminobenzohydrazide with 5-chlorosalicylaldehyde and 2,4-dichlorobenzaldehyde, respectively, in methanol. The compounds were characterized by elemental analysis, IR, ¹HNMR spectra, and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 35.014(3) ?, b = 10.407(2) ?, c = 18.505(2) ?, β = 112.046(2)°, V = 6250.0(15) Ǻ³, Z = 16, R ₁ = 0.0624, and wR ₂ = 0.1187. Compound 2 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.625(2) ?, b = 12.688(3) ?, c = 13.005(2) ?, α = 101.271(2)°, β = 112.945(1)°, γ = 104.966(2)°, V = 1747.6(6) Ǻ³, Z = 2, R ₁ = 0.0523, and wR ₂ = 0.1138. In the asymmetric unit of each compound, there exists two hydrazone molecules linking together by an N–H⋯O hydrogen bond. Furthermore, compound (2) contains one methanol molecule and one water molecule of crystallization.     

Stereochemical Assignment of Substituted 2-Aminobicyclo[3.1.0]hexane and 2-Aminobicyclo[5.1.0]octane Derivatives via Single Crystal X-ray Diffraction

Abstract  

Crystals of benzyl (RS,RS,RS)-7-phenylbicyclo[5.1.0]octan-2-ylcarbamate 9 and (RS,RS,RS)-N-[3′-(4″-methylpiperazin-1″-yl)propyl]-N-{5-(4′′′-cyanophenyl)bicyclo[3.1.0]hexan-2-yl}amine dihydrochloride 10·2HCl were synthesised and single crystal X-ray diffraction was used to establish unambiguously the relative configurations within these structures. Compound 9 crystallizes in the orthorhombic space group P2 ₁ 2 ₁ 2 ₁ with cell parameters of a = 6.85340(10) ?, b = 9.8732(2) ?, c = 27.5407(6) ?, V = 1863.54(6) ?³ and Z = 4. In the crystal structure adjacent molecules are linked by N–H···O=C hydrogen bonds. Compound 10·2HCl crystallizes as the corresponding monohydrate in the monoclinic space group P2 ₁/n with cell parameters of a = 7.1540(17) ?, b = 39.763(12) ?, c = 8.163(3) ?, β = 91.062(7)°, V = 2321.7(11) ?³ and Z = 4. In the crystal structure adjacent molecules are linked by a series of hydrogen bonds between the ammonium groups, chloride ions and adventitious water molecules.     

Synthesis and crystal structures of the bis-Schiff bases of 2-(methylthio)aniline with isophthaldehyde, terephthaldehyde, and para-diacetylbenzene

The crystal structures of the new compounds 1,3-bis(((2-methylthio)phenylimino)methyl)benzene (1), 1,4-bis(((2-methylthio)phenylimino)methyl)benzene (2), and 1,4-bis(1-((2-methylthio)phenylimino)ethyl)benzene (3) were obtained by single crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pna2₁ with a=16.8250(13) ?, b=18.1068(13) ?, c=6.3086(5) ?; and Z=4. Compound 2 crystallizes in the triclinic space group with a=6.7532(7) ?, b=9.4433(9) ?, c=15.2473(15) ?; and α=86.339(2)°, β=80.609(2)°, γ=80.962(2)°; and Z=2. Compound 3 crystallizes in the triclinic space group with a=6.787(3) ?, b=7.517(3) ?, c=10.653(4) ?; and α=89.998(7)°, β=72.341(7)°, γ=75.998(7)°; and Z=1. Details of the synthesis, structures, and spectroscopic results are discussed.     

Structures of Eight Thio(semi)carbazones Derived from 2-Acetylpyrazine, 2-Acetythiazole and Acetophenone

Abstract  The structures of eight related thio(semi)carbazones are described. These are syn,1E-2-acetylpyrazine-3-thiosemicarbazone (1), syn,1E,4Z-2-acetylpyrazine-4-ethyl-3-thiosemicarbazone, (2) and syn,1Z-2-acetylpyrazine-4,4-dimethyl-3-thiosemicarbazone (3), syn,1E,4Z-2-acetylthiazole-4-phenyl-3-thiosemicarbazone (4), syn,1Z-phenyl-4,4-dimethyl-3-thiosemicarbazone (5), syn,1E,4Z-phenyl-4-methyl-3-thiosemicarbazone (6), syn,1E,4Z-phenyl-4-ethyl-3-thiosemicarbazone (7), syn,1E,4Z-2-acetophenone-5-(N-aminothionyl)-3-thiocarbazone (8). Crystal data: for 1: triclinic, P-1, a = 5.4053(10) ?, b = 7.435(3) ?, c = 11.772(4) ?, α = 81.70(3)°, β = 82.59(2)°, γ = 77.38(2)°, and Z = 2: for 2: triclinic, P-1, a = 7.322(3) ?, b = 7.8239(16) ?, c = 9.783(4) ?, α = 87.73(2)°, β = 79.46(3)°, γ = 80.41(2)°, and Z = 2; for 3: orthorhombic, Pnma, a = 13.5210(15) ?, b = 6.6914(5) ?, c = 11.7214(10) ?, and Z = 4; for 4: triclinic, P-1, a = 5.7058(7) ?, b = 9.8776(15) ?, c = 11.869(2) ?, α = 76.389(12)°, β = 86.364(13)°, γ = 88.322(12)°, and Z = 2; for 5: triclinic, P-1, a = 7.5362(3) ?, b = 8.6331(4) ?, c = 9.8753(4) ?, α = 91.401(4)°, β = 102.532(4)°, γ = 110.540(4)°, and Z = 2; for 6: monoclinic, P2(1)/c, a = 10.7178(4) ?, b = 5.5866(2) ?, c = 18.7647(9) ?, β = 104.392(5)°, and Z = 4; for 7: monoclinic, P2(1)/c, a = 8.9557(3) ?, b = 9.7418(4) ?, c = 13.6864(5) ?, β = 94.044(4)°, and Z = 4; for 8: triclinic, P-1, a = 9.8091(5) ?, b = 10.6173(4) ?, c = 16.4691(7) ?, α = 75.540(4)°, β = 80.305(4)°, γ = 65.192(4)°, and Z = 4. Structures 1, 2, 4, 5, 7, and 8 form intramolecular N4–H···N1 hydrogen-bonds. Structures 3 and 5 exist in the tautomeric form in which N1 is protonated. Graphical Abstract  Structures of thio(semi)carbazones were found to fall into two categories: those with intramolecular N4-H…N1 hydrogen-bonds, and those which show a tautomeric form in which N1 is protonated.      

Crystal Structures of N-(4-butyryl-3-hydroxyphenyl)acetamide Monohydrate and 4-(4-Chlorophenyl)-2-methyl-4-oxobutanoic Acid: Possibilities of Yang Photocyclization

Abstract  

N-(4-butyryl-3-hydroxyphenyl)acetamide monohydrate, (I), and 4-(4-chlorophenyl)-2-methyl-4-oxobutanoic acid, (II), are photochemically inert, which is a result of their conformation. The geometrical parameters describing the molecular conformation and possibilities of the Yang photocyclization in crystals have been calculated and discussed. Compound (I) forms double ribbons along the a axis, stabilized by hydrogen bonds and π⋯π interactions. Compound (II) forms dimers. (I): triclinic, space group \textP[`1] {\text{P}}\bar{1} , a = 6.9291(12) ?, b = 7.5736(16) ?, c = 13.0528(18) ?, α = 79.643(17)°, β = 85.818(15)°, γ = 63.97(2)°, Z = 2. (II): monoclinic, space group P2₁/c, a = 11.904(2) ?, b = 9.6508(12) ?, c = 10.666(2) ?, β = 110.64(2)°, Z = 4.     

Synthesis,Crystal Structure and Thermodynamic Calculations of 1,3-Diethyl-5-(diethylaminium)methylene-2-thiobarbituric Acid Adduct

Abstract  

5-[(Diethylammonio)methyl]-1,3-diethyl-6-oxo-2-thioxo-1,2,3,6-tetrahydro-4-pyrimidinolate (3) was obtained in good yield from the reaction of 1,3-diethyl-6-oxo-5-(1-pyridiniumylmethyl)-2-thioxo-1,2,3,6-tetrahydro-4-pyrimidinolate (2) and diethylamine. The crystal structure of 3 and thermodynamic calculations pertaining to that structure are discussed. The obtained product was characterized using different techniques including single crystal X-ray diffraction, NMR spectroscopy and uni (bi)-molecular systems in gaseous phase. Compound 3 crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 13.3701(11) ?, b = 10.9983(7) ?, c = 20.8855(15) ?, β = 105.448(6)°, V = 2960.2(15) ?, Z = 8.     

Crystal Structures of a Series of 1,1-Spiro-bis(1,2,3,4-tetrahydronaphthalene)-Based Derivatives

Abstract  

The structures of four spirobisnaphthalenes based monomers 1, 2, 3a and 3b are reported. Each compound represents a methoxylated precursor which after deprotection led to the formation of a monomer successfully used for the synthesis of Polymers of intrinsic microporosity. The spiro-centre represents the site of contortion that, since its rigidity, leads to inefficient packing in the solid state inducing microporosity in the final polymer. Compound 1 crystallized in the monoclinic P2/c space group with unit cell parameters a = 8.1659(19) ?, b = 7.5298(18) ?, c = 19.130(5) ?, β = 97.935(4)°, V = 1165.0(5) ?³, Z = 2, D = 1.210 Mg m⁻³. Compound 2 crystallized in the monoclinic P2₁/n space group with unit cell parameters a = 12.6940(9) ?, b = 7.7267(6) ?, c = 19.9754(15) ?, β = 97.220(1)°, V = 1943.7(3) ?³, Z = 4, D = 1.355 Mg m⁻³. Compound 3a crystallized in the monoclinic P2₁/c space group with unit cell parameters a = 16.8137(14) ?, b = 10.5577(9) ?, c = 31.344(3) ?, β = 103.618(1)°, V = 5407.5(8) ?³, Z = 8, D = 1.308 Mg m⁻³. Compound 3b crystallized in the monoclinic Pc space group with unit cell parameters a = 15.594 ?, b = 12.564 ?, c = 18.339 ?, β = 90.224(1)°, V = 3593.0 ?³, Z = 4, D = 1.236 Mg m⁻³.     

Synthesis and Structure of bis(β-Diketiminate) Chromium(II) Complexes

Abstract  

The new ligand 2,4-N,N′-bis(napthylamino)-pent-2-ene (L^napth) (1) has been synthesized and crystallizes in space group P2₁2₁2₁ with crystal cell parameters a = 8.196(3) ?, b = 9.119(3) ?, c = 25.746(10) ?, V = 1924.3(12) ?³ and Z = 4. The complexes bis[2,4-pentane-N,N′-bis(napthyl)ketiminato] chromium(II) (2), bis[2,4-pentane-N,N′-bis(isopropylphenyl)ketiminato] chromium(II) (3), and bis[2,4-pentane-N,N′-bis(tertbutylphenyl)ketiminato] chromium(II) (4) were synthesized and structurally characterized. Complex 2, the first complex reported with a bis(napthyl) β-diketiminate ligand, crystallizes in space group P − 1 with crystal cell parameters a = 12.0824(15) ?, b = 12.2462(16) ?, c = 14.8975(19) ?, α = 87.035(2)°, β = 80.615(2)°, γ = 62.756(2)°, V = 1932.9(4) ?³ and Z = 2. Complex 3 crystallizes in space group P2₁/n with crystal cell parameters a = 13.088(3) ?, b = 22.222(5) ?, c = 14.206(3) ?, β = 102.310(4)°, V = 4036.6(17) ?³ and Z = 4. Complex 4 crystallizes in space group P2₁/n with crystal cell parameters a = 20.831(6) ?, b = 11.575(4) ?, c = 21.373(7) ?, β = 107.241(5)°, V = 4922(3) ?³ and Z = 4. The degree of twist between the ligand planes is dependent on the steric bulk of the ligand.     

Syntheses, Crystal Structures and Antibacterial Activities of Two Antipyrine Derivatives

Abstract  

Two new antipyrine derivatives, 4-{[1-(5-bromo-2-methoxyphenyl)methylidene]amino}-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (C₁₉H₁₈BrN₃O₂, 1) and 4-{[1-(2-hydroxy-3-ethoxyphenyl)methylidene]amino}-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (C₂₀H₂₁N₃O₃, 2), were synthesized and structurally characterized by elemental analysis, IR and single crystal X-ray diffractions. Compound 1 crystallizes in the monoclinic space group P2₁/n with unit cell dimensions a = 6.987(1) ?, b = 27.930(2) ?, c = 9.483(1) ?, β = 109.36(2)°, V = 1745.9(4) ?³, Z = 4, R ₁ = 0.0430, and wR ₂ = 0.0870. Compound 2 crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 19.523(2) ?, b = 7.466(1) ?, c = 12.954(2) ?, β = 108.797(1)°, V = 1787.5(4) ?³, Z = 4, R ₁ = 0.0421, and wR ₂ = 0.1032. X-ray structure determinations revealed that the molecules of both compounds display trans configurations about the C=N double bonds. In the crystal structures, molecules are linked together by intermolecular C–H···O hydrogen bonds. Both compounds show strong antibacterial activities.     

Characterization of Molecular Complexes of 1,4-Naphthoquinone Derivatives

Abstract  

The structures of sulphur atom tethered quinone containing flexible carboxylic acid (3-methyl-1,4-dioxo-1,4-dihydronaphthalen-2-ylsulfanyl)acetic acid (1) and its molecular complex with 4,4′-bipyridine (3) are determined. The compound 1 crystallizes in P-1 (triclinic, a = 7.5378(6) ?, b = 7.6413(7) ?, c = 10.3101(9) ?; α = 89.779 (7)°, β = 81.042 (5)°, γ = 89.101(7)°) and the molecular complex 3 crystallises in P2(1)/n (monoclinic, a = 9.3383(7) ?, b = 3.970(3) ?, c = 42.130(3) ?, β = 91.056(5)°) space groups, respectively. The R₂²(8) type hydrogen bonding between dicarboxylic acid groups present in the parent compound 1 is lost on interaction with 4, 4′-bipyridine; in the molecular complex 3 R₂²(7) type of O···H–C and O–H···N interactions are present between the pyridine rings and carboxylic acid groups. The molecular complex (4) derived from 3-carboxymethylsulfanyl-1,4-dihydroxynaphthalen-2-yl-sulfanyl) acetic acid (2) with triphenylphosphine oxide in 1:2 ratio, crystallises in C2/c space group have monoclinic, a = 26.0494(13) ?, b = 10.5402(5) ?, c = 17.1023(8) ?, β = 108.719 (5)°). The triphenylphosphine oxide molecules are preferentially held by O–H···O interactions between carboxylic acid and P=O bond.