Crystal structure and physical characterization of <Emphasis Type="Italic">N</Emphasis>-(3,3-dimethylbutyl)-<Emphasis Type="SmallCaps">l</Emphasis>-α-aspartyl-<Emphasis Type="SmallCaps">l</Emphasis>-phenylalanine,the hydrolysis product of neotame

The hydrolysis product of neotame, N-(3,3-dimethylbutyl)-l--aspartyl-l-phenylalanine (DMBAP), was crystallized from water as an anhydrate with a melting point at 197C with decomposition. Its crystal structure was determined by single crystal X-ray diffractometry. The crystal is orthorhombic with space group P2₁2_₁2₁ with Z=4 and one molecule per asymmetric unit. The cell constants are a=5.520 (2) Å, $b=10.608$ (5) Å and c= 31.92 (2) Å. The ¹³C solid-state nuclear magnetic resonance spectrum of DMBAP is compared with those of neotame monohydrate and neotame methanol solvate.     

Domain structure and properties of triglycine sulfate crystals with profile <Emphasis Type="Italic">D</Emphasis>,<Emphasis Type="Italic">L</Emphasis>-α- and <Emphasis Type="Italic">L</Emphasis>-α-alanine-doped layers

A complex investigation of the domain structure and dielectric properties of triglycine sulfate (TGS) crystals containing profile layers doped with D,L-α-alanine (DLATGS) and L-α-alanine (LATGS) impurities is carried out. The images of the DLATGS and LATGS layers and ferroelectric domains are obtained by piezoelectric force microscopy; the parameters of the domain structure and the degree of unipolarity are determined. It is established that DLATGS layers are multidomain and LATGS stripes are mainly single-domain. The experimental data on the macroscopic dielectric properties of the crystals are compared with the results of a microscopic analysis of the domain structure.     

Crystal Structure,Infrared Spectra and DFT Study of Benzyl 2,3-Anhydro-β-<Emphasis Type="SmallCaps">d</Emphasis>-Ribopyranoside

Abstract  

The crystal structure of benzyl 2,3-anhydro-β-d-ribopyranoside is orthorhombic, P2₁2₁2₁, Z = 4. The pyranose ring adopts the E _O conformation distorted considerably to the ⁵ H _O direction. The molecules of the title compound are linked into infinite chains running along the a-axis by bifurcated O–H···O hydrogen bonds. Interaction energies of these hydrogen bonds are significantly different, ~−5.4 for the bond with the smaller and ~−1.1 kcal/mol for the bond with the larger O···O separation. The hydrogen-bond pattern is completed by the two weaker C–H···O intermolecular hydrogen bonds, aiming at the epoxy oxygen atom. IR vibrational spectrum was interpreted by means of comparison with the full list of vibrational modes predicted using DFT method in the solid state. While till 1495 cm⁻¹ the individual bands can be reconciled with single calculated modes, the region below this limit is populated by heavily overlapped HCH, HCO, HOC, COC and HCC bending modes merged with few ν(CC) and ν(CO) modes. The respective “red” shifts of the positions of the ν(OH) bands correlate well with the size of the O···O separation.     

Crystal Structure of<Emphasis Type="SmallCaps"> D</Emphasis>(−)-amino-(4-hydroxyphenyl)acetate,the Zwitter Ionic Form of Biologically Active<Emphasis Type="SmallCaps"> D</Emphasis>(−)-4-hydroxyphenylglycine

Abstract  Crystals of D(−)-amino-(4-hydroxyphenyl)acetate were analyzed by single crystal X-ray diffraction. The compound crystallizes in the chiral space group, P2₁ (No. 4) with one molecule in the asymmetric unit and a = 5.0994(10) ?, b = 9.3169(19) ?, c = 8.6960(17) ?, β = 91.50(3)°. The intermolecular interactions in the crystal have been visualised by plotting the Hirshfeld surface of the molecule. Graphical Abstract  The extensive hydrogen bonding network in D(−)-amino-(4-hydroxyphenyl)acetate has been described and visualised by plotting its Hirshfeld surface.      

Synthesis and Crystal Structure of Bis (<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′,<Emphasis Type="Italic">N</Emphasis>′-tetramethylethylendiammonium) Octaiodo Pentachloroantimonate (III)

Abstract  

The synthesis and Crystal structure are given for the bis (N,N,N′,N′-tetramethylethylendiammonium) octaiodo pentachloroantimonate (III) salt. An X-ray investigation has shown that the title compound crystallizes in a monoclinic system, space group P2₁/m with the following lattice parameters a = 9.786(2) Ǻ, b = 14.024(5) Ǻ, c = 14.336(3) Ǻ, β = 91.35(2)° and Z = 2. The structure was solved from 3085 independent reflections with R ₁ = 0.0402 and wR ₂ = 0.0952 and refined with 152 parameters. The structure shows a layer arrangement perpendicular to the [(b)\vec] \vec{b} -axis: planes of [SbCl₅]²⁻, I₃ ⁻ and I₅ ⁻ anions alternate with planes of [(CH₂)₂(NH(CH₃)₂)₂]²⁺ cations. The [SbCl₅]²⁻ square pyramids present an active lone electron pair (LEP) on the Sb atoms and they are interconnected by means of N–H···Cl hydrogen bond originating from [(CH₂)₂(NH(CH₃)₂)₂]²⁺ entities. The polyiodides (I₃ ⁻ and I₅ ⁻) anions form a planer zigzag polymeric chains via I···I linking interactions. These chains are linked to the [SbCl₅]²⁻ anions by a long range contact.     

Synthesis and Crystal Structure of <Emphasis Type="Italic">N</Emphasis>′-(6-Chloropyridin-3-formyl)-<Emphasis Type="Italic">N</Emphasis>-<Emphasis Type="Italic">t</Emphasis>-Butyl Urea

Abstract The crystal structure of N′-(6-chloropyridin-3-formyl)-N-t-butyl urea, C₁₁H₁₄ClN₃O₂, has been established, and which belongs to monoclinic crystal system, space group Pn with unit cell dimensions a = 9.335(3) ?, b = 12.715(3) ?, c = 21.813(6) ?, β = 95.417(6)°, V = 2577.6(12) ?³ and Z = 8. An intramolecular N–H···O hydrogen bond forms a six-membered ring in the central part of the molecule. Both two N–H atoms of single unit participate in intermolecular hydrogen bonds and an intramolecular hydrogen bond, respectively. Index Abstract The crystal structure ofN′-(6-chloropyridin-3-formyl)-N-t-butyl urea, C₁₁H₁₄ClN₃O₂, has been established, and which belongs to monoclinic crystal system withZ = 8, space group Pn.      

Synthesis and Crystal Structure of <Emphasis Type="Italic">Tris</Emphasis>-(<Emphasis Type="Italic">N</Emphasis>–<Emphasis Type="Italic">N</Emphasis> dimethyl benzylammonium)-hexachlorobismuthate(III)

Abstract  The salt tris-(N–N dimethyl benzylammonium)-hexachlorobismuthate(III) crystallizes in the triclinic system P1 with unit cell parameters: a = 9.0300(12), b = 9.9220(3), c = 19.575(2) ?, α = 79.955(5), β = 89.952(2), γ = 88.108(6)°, V = 1726.0(3) ?³, Z = 2. The examination of the structure shows an alternate stacking of inorganic layers of hexachlorobismuthate(III) anions and organic layers of [C₆H₅CH₂NH(CH₃)₂]⁺ cations parallel to the a-axis. The cohesion forces of the packing of N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Index Abstract  The examination of the structure shows a layer arrangement parallel to the a-axis: planes of octahedral anions [BiCl₆]³⁻ alternate with planes of [C₆H₅CH₂NH(CH₃)₂]⁺ cations (Fig. 3). The cohesion forces of the packing of the N–N dimethyl benzylammonium units in the layer and between two adjacent layers are provided by hydrogen bonds (N–H⋯Cl) and van der Waals contacts. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

C–H⋅<Emphasis Type="Italic">s</Emphasis>O hydrogen bond networks in <Emphasis Type="Italic">E</Emphasis>- and Z-unsaturated esters of C-glycosides

Methyl E(Z)-4,7 anhydro-5-benzamido-6,8-di-O-benzoyl-2,3,5-trideoxy-d-allo-oct-2-enoate have been synthesized like intermediates and isolated as single crystals during the synthesis of pyrazole-related C nucleosides as synthetic product with cytotoxic activity.¹ Crystal structures of E(Z) isomers were determined by X-ray analysis. E isomer crystallizes in the triclinic crystal system, space group P1, a = 5.319(1) Å, b = 10.758(2) Å, c = 12.229(2) Å, α = 72.38(2)^∘, β = 89.97(2)^∘, γ = 87.07(2)^∘, D_x = 1.320 Mgm⁻³ and Z isomer in the orthorhombic crystal system, space group P2₁2₁2₁, a = 5.1297(13) Å, b = 19.667(5) Å, c = 25.871(6) Å, D_x = 1.348 Mgm⁻³. The molecular structure was solved by direct method on the basis of 2609 and 2727 unique reflections recorded at the temperature 293 K (E-isomer) and 173 K (Z-isomer) up to the final R-factor 0.0378 and 0.0435, respectively. C–H⋅sO contact networks were analyzed and the correlation established between the existence of the weak C–H⋅sO hydrogen bonds and the melting point of the single crystals.     

Crystal and molecular structure of bis-(1-<Emphasis Type="Italic">tert-</Emphasis>butyl-1,2-dibenzoylhydrazine)-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-sulfide

The structure of the title compound bis-(1-tert-butyl-1,2-dibenzoylhydrazine)-N,N- sulfide was determined by X-ray single crystal diffraction. The crystal belongs to monoclinic, space group P2(1)/c with the following crystallographic parameters: a = 14.681(7) Å, b = 14.501(7) Å, c = 16.535(8) Å, = 90°, = 109.173(9)°, = 90°, V = 3325(3) Å ³, z = 4, Dx = 1.244 mg/m³, F(000) = 1320, T = 293(2) K, 1.47° 25.00°, the final R factor: R₁ = 0.0584, wR₂ = 0.1111. The bond distances and angles in the tert-butyl groups are different, that can interpret its ¹H NMR spectra, which are very unusual for the absorption of –CMe₃ being multiple.     

Synthesis and Structure Determination of <Emphasis Type="Italic">S</Emphasis>,<Emphasis Type="Italic">S</Emphasis>′-(Naphthalen-2-ylmethyl sulfanyl (1-<Emphasis Type="Italic">p</Emphasis>-tolyl-ethylidene) Hydrazine

Abstract  

S,S′-(Naphthalen-2-ylmethyl sulfanyl (1-p-tolyl-ethylidene) hydrazine (SNM4MA) was prepared by the condensation of S-napthalen-2-ylmethyldithiocarbazate (SNMDTC) and 4-methylacetophenone. Yellow needles of SNM4MA were obtained upon slow evaporation of a 50:50 mixture of acetonitrile and DMSO over a period of weeks. The compound crystallizes in the monoclinic system with the space group C 2/c and Z = 4. The unit cell parameters are a = 7.0221(2) ?, b = 22.8428(6) ?, c = 23.5127(6) ? with β = 94.0222(13)°. Single crystal X-ray analysis shows that the molecule has crystallographic two-fold rotational symmetry coincident with the S–S bond. The title compound exists as a trans–cis conformer in which the naphthalene group is trans with respect to the thione sulfur while the benzyl group adopts a cis geometry. ¹³C and ¹H spectra confirm that the dimeric nature is retained in DMSO solution.     

3-[4-Bromo-α(<Emphasis Type="Italic">R</Emphasis>*)-methoxybenzyl]-6-chloro-3(<Emphasis Type="Italic">S</Emphasis>*),4(<Emphasis Type="Italic">S</Emphasis>*)-dihydroxychroman: X-ray and DFT Studies

Sodium borohydride reduction of E-3-benzylidenechromanone epoxides in dry methanol has afforded 3(S*), 4(S*)-dihydroxy-3-[α(R*)-methoxybenzyl]chromans as an interesting class of products, the structures of which have been assigned mainly from spectral data and consideration of the mechanistic aspects. X-ray diffraction study of one of them, 3-[4-bromo-α(R*)-methoxybenzyl]-6-chloro-3(S*),4(S*)- dihydroxychroman, is performed. The title compound crystallizes in the monoclinic sp. gr. P2₁/n, with a = 13.336(6) Å, b = 10.866(5) Å, c = 27.166(11) Å, β = 95.193(6)°, V = 3920(3) ų, and Z = 8. Supramolecular construction of the compound involves O–H···O intermolecular hydrogen bonds as well as three other types of non-covalent interactions which are responsible for crystal packing. Density functional theory was applied for geometry optimization, molecular orbital calculations, and prediction of UV spectral features. The geometric parameters (bond lengths, bond angles, and dihedral angles) for the representative compound obtained from density functional theory with B3LY6-31G basis set were in good agreement with experimental values.     

Crystal Structure of Unsymmetrically <Emphasis Type="Italic">N</Emphasis>-nor-dehydroabietyl-<Emphasis Type="Italic">N</Emphasis>′-isopropyl Urea

Abstract  

The title compound (C₄₆H₇₂N₄O₂, M _r  = 713.08) [systematic name: 1-isopropyl-3-((1R,4aS,10aR)-7-isopropyl-1, 4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthren-1-yl)urea] is a new derivative of dehydroabietic acid. It crystallized in the orthorhombic system, space group P2₁2₁ 2₁ with cell dimensions of a = 9.5950(19) ?, b = 18.740(4) ?, c = 24.654(5) ?, V = 4,433.0(16) ?³, Z = 4, D _c  = 1.068 g/cm³, λ = 0.71073 ?, μ = 0.07 mm⁻¹, F(000) = 1,568, final R = 0.0777 and wR = 0.1731 for 2,048 observed reflections with I > 2σ(I). Two crystallorgraphically independent molecules with different conformations co-exist in the structure. Each molecule exhibit classic tricyclic hydrophenanthrene structure, the two cyclohexane rings form a trans ring junction with chair and half-chair conformations, respectively. The crystal is stabilized by intermolecule hydrogen bonds and the molecules are in a head–tail zigzag arrangement.     

Synthesis,spectroscopic and structural studies of <Emphasis Type="Italic">N</Emphasis>-(1<Emphasis Type="Italic">H</Emphasis>-benzimidazol-2-yl)-<Emphasis Type="Italic">N</Emphasis>′-benzyl propionamidine

N-(1H-Benzimidazol-2-yl) propionimidic acid ethyl ester (1) reacts with benzylamine to yield the corresponding N-(1H-Benzimidazol-2-yl)-N′-benzyl proponamidine (2). The structure and conformation of the amidine 2 were determined by ¹H and ¹³C NMR and X-ray diffraction. The product crystallizes in monoclinic system with space group P2₁/c, a = 10.7913 ?, b = 15.5164 ?, c = 9.1130 ?, β = 108.378° and Z = 4. In the crystal there are two N–HN hydrogen bonds, the first is intramolecular H-Bond links H4 to N1; the second one is intermolecular and it links H2 to N3 of a second molecule leading to inversion-related dimers. The X-ray results were compared with those obtained by semi-empirical and ab-initio calculations.     

X-ray Structure Investigation of 20-<Emphasis Type="Italic">O</Emphasis>-β-<Emphasis Type="SmallCaps">d</Emphasis>-glucopyranosyl-20(<Emphasis Type="Italic">S</Emphasis>)-protopanaxadiol

Abstract  20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol (I) has been isolated as a metabolite of ginseng saponins by Paecilomyces bainier. The crystal structure of (I) was also investigated by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group P2₁, with a = 15.99 2 (3) ?, b = 11.960 (19) ?, c = 20.127 (3) ?, β = 101.85 (4)°, and V = 3767.5 (11) ?³, Z = 4, R _int = 0.1129, ωR(F ²) = 0.1749, F(000) = 1,448. The title compound is a dammarane-type triterpenoid, and the four rings of this compound connect with each other in trans characteristics,with the three-six-membered rings in chair conformation and the five-membered ring adopting envelope one. A β-d-glucopyranosyl group and a 2-methyl-2-pentenyl group connect to C20 of S configuration. The space symmetrical motif is adopted and each packing unit-cell contains two symmetrical compound (I) molecules and four H₂O molecules. The hydrogen-bonding (both intra- and inter-molecular) interactions play a major role in this structural association. Index Abstract  In the present paper, the single-crystal structure of 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol was determined by X-ray analysis      

Unclassical hydrogen bonds of C—H⋅<Emphasis Type="Italic">s</Emphasis>O and C—H⋅<Emphasis Type="Italic">s</Emphasis>N in the crystals of 2-amino-3-cyano-4-(3,4-dichlorophenyl)-5-oxo-1,4,5,6-tetrahydro-4H-pyrano[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

The 2-amino-3-cyano-4-(3,4-dichlorophenyl)-5-oxo-1,4,5,6-tetrahydro-4H-pyrano[2,3-d] pyrimidine (1, C₁₇H₁₅Cl₂N₅O₃) was synthesized and characterized by IR,¹H NMR and elemental analysis. The molecular structure of1 was further studied by using X-ray crystallography. The crystals of compound1 are triclinic, space groupP-1,a = 6.0090(4) Å,b = 10.4056(7) Å,c = 15.6021(11) Å, α = 70.983(4), β = 84.056(6), γ = 84.611(6),Z = 2,V = 915.47(11) ų. Two types of unclassical hydrogen bonds C–H?sO and C–H?sN were presented in the crystals. In addition, there were classical hydrogen bonds in the crystal structure.     

Disaccharide nucleosides: The crystal and molecular structure of 2′-<Emphasis Type="Italic">O</Emphasis>-β-<Emphasis Type="Italic">D</Emphasis>-ribopyranosylcytidine

The crystal structure of a disaccharide nucleoside, 2′-O-β-D-ribopyranosylcytidine, is studied using X-ray diffraction (space group P2₁, a = 6.827(2) Å, b = 12.813(3) Å, c = 9.532(2) Å, β = 92.934(5)°, V = 832.7(4) ų, Z = 2). The stereochemical features of the molecular structure of 2′-O-β-D-ribopyranosylcytidine are analyzed, and the structural data are compared with those obtained for the previously studied disaccharide nucleoside 2′-O-β-D-ribofuranosyluridine.     

Synthesis and Crystal Structure of Di-μ-chlorido-bis{chlorido[4-ethyl-<Emphasis Type="Italic">N</Emphasis>-(pyridin-2-ylmethylidene-κ<Emphasis Type="Italic">N</Emphasis>)aniline-κ<Emphasis Type="Italic">N</Emphasis>]mercury(II)}

The centrosymmetric dinuclear title complex [Hg₂Cl₄(dip)₂] was synthesized using the Schiff base bidentate ligand (E)-4-ethyl-N-(pyridine-2-ylmethylene)benzeneamine (dip) and mercury(II) chloride salts. It has been characterized by elemental analysis, X-ray diffraction, and UV-Visible and infrared spectroscopic techniques. The X-ray analysis shows that the title compound crystallizes in the monoclinic sp. gr. P2₁/n, Z = 2 with a = 7.8233(17) Å, b = 15.178(3) Å, c = 12.559(3) Å, β = 97.021(3)°. The Hg(II) ion has a distorted trigonal–bipyramidal coordination environment formed by the bischelating N-heterocyclic ligands, two bridging Cl atoms and one terminal Cl atom.     

Crystal and Molecular Structure of the 1:2 Adduct Formed Between <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Butylenebis(imidazole) and Carboxylic Acid Derivatives

Abstract  

Two imidazolyl derived complexes [N,N′-butylenebis(imidazole): (fumaric acid)₂ (1), and N,N′-butylenebis(imidazole): (2,4,6-trinitrophenol)₂ (2)] were prepared and structurally characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic, space group P−1, with a = 5.9990(12) ?, b = 8.1772(16) ?, c = 10.419(2) ?, α = 86.88(2)°, β = 84.73(3)°, γ = 77.03(4)°, V = 495.67(17) ?³, Z = 1. For 1, two dimensional network structure is formed through imidazolium moieties forming hydrogen bonds to di-ionic carboxylate groups of fumarate chains. In the same network layers and adjacent layers, C–H···O contact also accompanies the N⁺–H···O⁻ hydrogen bonds, all these lead the extended architecture to show a three-dimensional lamellar structure. Compound 2 crystallizes in the triclinic, space group P − 1, with a = 7.0236(14) ?, b = 8.2831(17) ?, c = 12.053(2) ?, α = 106.05(4)°, β = 99.13(2)°, γ = 98.84(3)°, V = 650.8(2) ?³, Z = 1. In 2, two parallel imidazolium cations and two antiparallel 2,4,6-trinitrophenolate anions formed 32-membered rings through hydrogen bonding interaction, these rings extended along the c axis direction to form one dimensional railway structure. Adjacent parallel railways connect further through C–H···O hydrogen bonds between the 2-CH of the imidazole ring and the NO₂ group O atoms. These weak interactions combined, the complex showed 3D layer structure.     

Synthesis,characterization, and crystal structure of 5,5″-Difluoro-1<Emphasis Type="Italic">H</Emphasis>,1″<Emphasis Type="Italic">H</Emphasis>-[3,3′:3′,3″-terindol]-2′(1′<Emphasis Type="Italic">H</Emphasis>)-one

The new indole derivative, 5,5′′-Difluoro-1H,1′′H-[3,3′:3′,3′′-terindol]-2′(1′H)-one C₂₄H₁₅F₂N₃O, is synthesized in 87% yield, and its crystal structure is determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. P2₁/n, a = 15.4563(7), b = 10.8340(6), c = 16.4718(6) Å, β = 102.403(4)°, Z = 4. Bicyclic indole moieties form dihedral angle of 61.92(5)° with each other; the oxindole ring is twisted with respect to them at angles of 85.70(5)° and 75.62(5)°. The crystal structure is stabilized by N–H···O and C–H···O hydrogen bonds involving both the DMSO solvent molecules. In addition, one C–H···π interaction is observed.     

Synthesis and Crystal Structure of New <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>′-Bis[1-(4-methoxyphenyl)-5-methyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazole-4-carbonyl]hydrazide

Abstract  The N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide 6 was synthesized from aryl triazole acids and its structure is established by MS, IR, and ¹H NMR spectral data. Compound 6, C₂₂H₂₂N₈O₄, Mr = 462.48, crystallizes in the monoclinic space group P2(1)/c with unit cell parameters a = 15.3451(8), b = 8.6486(4), c = 16.8502(9) ?, α = 90.00, β = 95.731(2), γ = 90.00o, V = 2225.1(2) ?³, Z = 4, and Dx = 1.381 mg m⁻³. The final R was 0.0450. The four aromatic rings are close to linear because of N···H–N hydrogen bonds. Index Abstract  Synthesis and crystal structures of N,N′-bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide Heng-Shan Dong, Yan-Fei, Wang, Hong-Ru Dong, Bin, Wang, Bin Quan N,N′-Bis[1-(4-methoxyphenyl)-5-methyl-1H-1,2,3-triazole-4-carbonyl]hydrazide was synthesized.