Symmetry-independent Molecules Research Articles

The trimorphic structure of N,N'-bis(5-methylsalicylidene)-4-methyl-1,3-phenylenediamine.

The new Schiff base ligand, N,N'-bis(5-methylsalicylidene)-4-methyl-1,3-phenylenediamine (H2L), has been prepared by condensation of 5-methylsalicylaldehyde with 4-methyl-1,3-phenylenediamine. It was found that this ligand crystallizes in the monoclinic space group P21/c, with Z' = 1. Further studies showed that - as a result of the one-pot metal-promoted reactions - three different polymorphic forms of H2L were obtained, with different numbers (1, 3 or 4) of symmetry-independent molecules depending on the lanthanide metal ion present in the reaction media: La (Z' = 3), Nd (Z' = 4), Sm, Tb, Ho and Yb (all Z' = 1); the last form is identical with that obtained by crystallization of the ligand itself. The geometrical features of all eight independent molecules of H2L are very similar. The relatively strong intramolecular O-H...N hydrogen bonds stabilize almost co-planar conformations of terminal rings and C-C=N-C linkers, at the same time strong hydrogen-bond donors and acceptors involved in these interactions cannot take part in the determination of supramolecular architecture. Therefore, weak intermolecular interactions are important and this can be regarded as one of the reasons for packing conflicts that lead to the presence of polymorphic forms and multiple molecules. The pseudosymmetries are observed in both forms with Z' > 1 and the degree of pseudosymmetry is described by the values of appropriate combinations of the coordinates. In order to elucidate the differences in crystal structures the Hirshfeld surface method was applied. It shows that there are only small differences in the surface shape and in the fingerprint plots; however, the volumes of voids in three structures are significantly different.

Mono- and Binuclear Copper(I) Complexes of Thionucleotide Analogues and Their Catalytic Activity on the Synthesis of Dihydrofurans

The reaction of copper(I) halides with 2-thiouracil (TUC), 6-methyl-2-thiouacil (MTUC), and 4-methyl-2-mercaptopyrimidine (MPMTH) in the presence of triphenylphosphine (tpp) in a 1:1:2 molar ratio results in a mixed-ligand copper(I) complex with the formulas [Cu2(tpp)4(TUC)Cl] (1), [Cu2(tpp)4(MTUC)Cl] (2), [Cu(tpp)2(MPMTH)Cl]·(1)/2CH3OH (3), [Cu(tpp)2(MTUC)Br] (4), and [Cu(tpp)2(MTUC)I]·(1)/2CH3CN (5). The complexes have been characterized by FT-IR, (1)H NMR, and UV-vis spectroscopic techniques and single-crystal X-ray crystallography. Complexes 1 and 2 are binuclear copper(I) complexes. Two phosphorus atoms from tpp ligands are coordinated to the copper(I) ions, forming two units that are linked to each other by a deprotonated TUC or MTUC chelating ligand through a sulfur bridge. A linear Cu-S-Cu moiety is formed. The tetrahedral geometry around the metal centers is completed by the nitrogen-donor atom from the TUC or MTUC ligand for the one unit, while for the other one, it is completed by the chloride anion. Two phosphorus atoms from two tpp ligands, one sulfur atom from MPMTH or MTUC ligand, and one halide anion (Cl, Br, and I) form a tetrahedron around the copper ion in 3-5 and two polymorphic forms of 4 (4a and 4b). In all of the complexes, either mono- or binuclear intramolecular O-H···X hydrogen bonds enhance the stability of the structures. On the other hand, in almost all cases of mononuclear complexes (with the exception of a symmetry-independent molecule in 4a), intermolecular NH···O hydrogen-bonding interactions lead to dimerization. Complexes 1-5 were studied for their catalytic activity for the intermolecular cycloaddition of iodonium ylides toward dihydrofuran formation by HPLC, (1)H NMR, and LC-HRMS spectroscopic techniques. The results show that the geometry and halogen and ligand types have a strong effect on the catalytic properties of the complexes. The highest yield of dihydrofurans was obtained when "linear" complexes 1 and 2 were used as the catalysts. The activity of the metal complexes on the copper(I)-catalyzed and uncatalyzed intramolecular cycloaddition of iodonium ylide is rationalized through electronic structure calculation methods, and the results are compared with the experimental ones.

4-[(5-Bromo-2-hy-droxy-benzyl-idene)amino]-3-ethyl-1H-1,2,4-triazole-5(4H)-thione.

The title compound, C11H11BrN4OS, crystallized as a racemic twin with two symmetry-independent mol­ecules in the asymmetric unit. The dihedral angles between the benzene and triazole rings of the two independent mol­ecules are 56.41 (18) and 54.48 (18)°. An intra­molecular O—H⋯N hydrogen bond occurs in each mol­ecule. In the crystal, pairs of symmetry-independent mol­ecules are linked by pairs of almost linear N—H⋯S hydrogen bonds, forming cyclic dimers characterized by an R 2 2(8) motif. There are weak π–π inter­actions between the benzene rings of symmetry-independent mol­ecules, with a centroid–centroid distance of 3.874 (3) Å.

Synthesis, spectroscopic characterization and crystal structure of 5-bromo-1-(2-cyano-pyridin-4-yl)-1H-indazole-3-carboxylic acid diethylamide

The title compound 5-bromo-1-(2-cyano-pyridin-4-yl)-1H-indazole-3-carboxylic acid diethylamide, C18H16BrN5O, is prepared from 5-bromoindazole-3-carboxylic acid methylester. N1-arylation is carried out with 4-chloro-2-cyanopyridine and the resulting product is converted to diethylamide by reacting with thionyl chloride and diethylamine. The structure is identified from its FT-IR, 1H NMR, 13C NMR spectroscopy, elemental analysis data and unambiguously confirmed by single crystal X-ray diffraction studies. There are two symmetry independent molecules in the asymmetric unit with no significant differences in bond lengths and angles. The title compound crystallizes in the triclinic system, space group \(P\bar 1\), with a = 11.2330(2); b = 11.6130(2); c = 15.4710(3) A, α = 92.515(1)°; β = 109.956(1)°; γ = 107.199(1)°; V = 1788.45(6)A3 and z = 4. An intramolecular C-H…N hydrogen bond forms an S(6) ring motif in one of the unique molecules. In the crystal, two molecules are linked about a center of inversion by C-H…O hydrogen bonded dimers generating an R22(16) ring motif. The crystal packing is stabilized by C-H…N, C-H…O hydrogen bonds and π…π stacking interactions.

Synthesis and Molecular Structure of N-{(1R,5S)-3-Methyl-8-Oxo-1,3,4,5,6,8-Hexahydro-2H-1,5-Methanopyrido[1,2-α] [1,5]Diazocin-9-yl}Acetamide

Compound 2 was isolated by column chromatography over SiO2 in 67% yield and had mp 171–172°C (MeOH) and [ ]D 20 –16.0° (c 0.72, CHCl3). The crystal and molecular structure of 2 were established by an x-ray crystal structure analysis (XSA), for which crystals of 2 were grown by slow crystallization from MeOH. The asymmetric unit of the unit cell of 2 contained two molecules (2a and 2b) that had very similar structures. Figure 1 shows a general view of the symmetry independent molecules 2a and 2b. The compound crystallized in chiral space group P21 and contained two chiral centers (1R,5S). The absolute configuration was the same as that of starting (–)-cytisine. The diazabicyclononane had a chair–half-chair conformation, which is often observed in similar compounds [6–10]. The amide was practically coplanar with the aromatic ring. As we supposed, the trans-orientation of the C9–N1 (C9 –N1 in the second independent molecule) was explained mainly by steric considerations. Thus, the acidic amide proton and the carbonyl O1 atom were oriented on the same side. This favored the formation of the H-bonded dimer. In fact, the two symmetrically independent 2a and 2b were joined in the crystal structure into a dimer through N1–H1...O1 (H...O 2.37 A° , N...O 3.235(2) A° , 1, i.e., when the crystal structure consisted of more than a single independent molecule [11–14]. Apparently, this was due to limitations imposed by the symmetry, which prevented the molecules from adopting the optimum orientation relative to each other. Crystals of C14H19N3O2 (MW 261.32) at 100 K were monoclinic, a = 11.4769(10), b = 9.4595(8), c = 12.9183(11) A ° , = 106.697(2)°, V = 1343.4(2) A° 3, space group P21, Z = 4, dcalc = 1.292 mg/m 3. A data set of 19,378 reflections was collected on a Bruker Smart Apex2 CCD diffractometer ( Mo K -radiation, 2 max = 64°). The starting set of measured intensities was processed using the SAINT and SADABS programs included in the APEX2 program suite [15]. The structure was solved by direct methods and was refined by anisotropic full-matrix least-squares methods over Fhkl for non-hydrogen atoms. The H atoms were placed in geometrically calculated positions with the exception of the amide H, the position of which was located in a difference electron-density synthesis. Then, the N–H distance was normalized to 0.90 A° . The H atoms were refined using a rider model. A total of 4910 independent reflections (Rint = 0.0395) were used in the refinement. The refinement over all independent reflections gave wR2 = 0.1019 [R1 = 0.0422 over 4267 reflections with I > 2 (I)]. All calculations were performed using the SHELXTL programs [16]. Atomic coordinates and thermal factors were deposited in the Cambridge Crystallographic Data Centre (CCDC 981034). Thus, the structure of N-[(1R,5S)-3-methyl-8-oxo-1,3,4,5,6,8-hexahydro-2H-1,5-methanopyrido[1,2-a][1,5]diazocin9-yl]acetamide was characterized for the first time by an XSA. The existence of two symmetrically independent molecules in its crystal structure was explained. 1) Institute of Elementorganic Compounds, Russian Academy of Sciences, 119991, GSP-1, Moscow, B-334, Ul. Vavilova, 28; 2) Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, 450054, Ufa, Prosp. Oktyabrya, 71, e-mail: tsipisheva@anrb.ru.; Translated from Khimiya Prirodnykh Soedinenii, No. 3, May–June, 2014, pp. 501–502, original article submitted January 17, 2014. N N

1-[(Cyclohexylidene)amino]-3-(prop-2-en-1-yl)thiourea

The asymmetric unit of the title compound, C10H17N3S, consists of three symmetry-independent mol­ecules with distinctly different conformations, as indicated for example by the C—N—C—C torsion angles of −155.9 (3), 89.9 (3) and 81.1 (4)° along the bond between thio­urea and allyl units. In the crystal, mol­ecules are connected via N—H⋯N and N—H⋯S hydrogen bonds into chains extending along [110] that are further associated through C—H⋯N inter­actions into layers parallel to (001). The allyl group in one of the independent mol­ecules is disordered over two sets of sites with an occupancy ratio of 0.853 (6):0.147 (6).

Structure-melting relations in isomeric dibromobenzenes.

1,4-Dibromobenzene melts at a considerably higher temperature than the 1,2- and 1,3-isomers. This melting-point difference is consistent with the molecular symmetry, as described by Carnelley's rule, and with the frequency of Br...Br halogen bonds. The lowest melting point of 1,3-dibromobenzene correlates with its two symmetry-independent molecules, indicating their inability to pack closely. Single crystals of 1,2- and 1,3-dibromobenzene have been grown under isochoric conditions in a diamond-anvil cell and at isobaric conditions in a glass capillary. Their structures have been determined in situ by X-ray diffraction. At 295 K 1,2-dibromobenzene crystallizes at 0.2 GPa as orthorhombic, space group Pbca, Z' = 1, and 1,3-dibromobenzene at 0.3 GPa as orthorhombic, space group P212121, Z' = 2. The same crystal phases are formed at ambient pressure by freezing these liquids below 256.15 and 248.45 K, respectively. The third isomer, 1,4-dibromobenzene, is a solid at room temperature and crystallizes as monoclinic, space group P21/a. Striking relations between the structures and melting points of the corresponding dibromobenzene and dichlorobenzene isomers have been discussed.

Supramolecular structures in three thiouracil derivatives: 5,6-trimethylene-2-sulfanylidene-1,2-dihydropyrimidin-4(3H)-one, 2-(4-fluorobenzylsulfanyl)-5,6-trimethylenepyrimidin-4(3H)-one and methyl 2-{[2-(4-fluorobenzylsulfanyl)-5,6-trimethylenepyrimidin-4-yl]oxy}acetate

The molecules of the title compounds, C7H8N2OS, (1), C14H13FN2OS, (2), and C17H17FN2O3S, (3), crystallize in the space groups C2/m, C2/c and Ia, respectively. Compounds (1) and (2), an S-alkylated derivative of (1), consist of only one symmetry-independent molecule, while (3), an O-alkylated derivative of (2), contains two independent molecules in the asymmetric unit. The molecules of (1) sit on crystallographic mirror planes. In the supramolecular structure of (1), a combination of N-H···O and N-H···S hydrogen bonds creates a molecular strap with C(6) and R2(2)(8) motifs, which is further stabilized by an S···S contact. In the packing of (2), a one-dimensional molecular column is made up of two kinds of dimers. One dimer, with an R2(2)(18) motif, is formed by a pair of C-H···O soft hydrogen bonds and the other, with an R2(2)(8) motif, is produced via a pair of N-H···O hard hydrogen bonds. In the packing of (3), molecules A and B form two different types of one-dimensional chain by intermolecular C-H···N hydrogen bonds, and by C···N and O···S contacts, respectively. Two such kinds of chain are connected alternately via interchain C-H···O hydrogen bonds, giving a two-dimensional sheet. Finally, a three-dimensional supramolecular structure is formed through weak intersheet C-H···F hydrogen bonds. The study of the molecular and supramolecular structures of thiouracil derivatives is significant in the development of lipoprotein-associated phospholipase A2 inhibitors.

3-Acetyl-2-fluoro-6H-benzo[c]chromen-6-one.

The title compound, C15H9FO3, was obtained in a one-pot synthesis by Suzuki–Miyaura cross-coupling and nucleophilic substitution reaction of 4′-chloro-2′,5′-di­fluoro­aceto­phenone with o-(meth­oxy­carbon­yl)phenyl­boronic acid. The asymmetric unit contains two crystallographically independent mol­ecules related by a non-crystallographic inversion centre. There are face-to-face stacking inter­actions between the aromatic rings of the benzoate and aceto­phenone units of the symmetry-independent mol­ecules [centroid–centroid distances = 3.870 (3) and 3.986 (3) Å]. In the crystal, mol­ecules are further assembled via stacking inter­actions along the a-axis direction. One of the mol­ecules inter­acts with its inversion equivalent [centroid–centroid distance between the aromatic rings of the benzoate and aceto­phenone units = 3.932 (3) Å], and the other inter­acts with its twofold axis equivalent [centroid–centroid distance between the aromatic rings of aceto­phenone units = 3.634 (3) Å].

The bimolecular structure of aquahexa-μ-chlorido-μ4-oxido-tris(tetrahydrofuran-κO)tetracopper(II)–hexa-μ-chlorido-μ4-oxido-tetrakis(tetrahydrofuran-κO)tetracopper(II)–tetrahydrofuran (2/1/4)

The title bimolecular structure, [Cu4Cl6O(C4H8O)3(H2O)]2[Cu4Cl6O(C4H8O)4] · 4C4H8O, at 100 K has monoclinic (P21/c) symmetry. The structure contains nine symmetry-independent molecules expressed in simplest molecular form as 6[Cu4Cl6O(C4H8O)3(H2O) · 2(C4H8O)]:3Cu4Cl6O(C4H8O)4. The compound exhibits a supercell (smaller than the unit cell based on weak reflections) structure due to pseudotranslational symmetry. The structure displays O-H...O hydrogen bonding between bound water ligands and tetrahydrofuran (THF) solvent molecules. The structure exhibits disorder for 12 of the THF molecules, of which seven are ligated to Cu and five are hydrogen bonded to H2O ligands.

N-(4-Methoxyphenyl)-6-methyl-2-phenyl-5-{[4-(trifluoromethyl)anilino]methyl}pyrimidin-4-amine

The title compound, C26H23F3N4O, crystallizes with two symmetry-independent mol­ecules in the asymmetric unit, denoted A and B, which differ mainly in the rotation of the meth­oxy­phenyl ring. The –CF3 group of mol­ecule B is disordered by rotation, with the F atoms split over two sets of sites; the occupancy factor for the major component is 0.853 (4). The dihedral angles between the pyrimidine ring and the attached phenyl, meth­oxy­phenyl and tri­fluoro­methyl­phenyl rings are 8.1 (2), 37.5 (2) and 70.7 (2)°, respectively, in mol­ecule A, and 9.3 (2), 5.3 (2) and 79.7 (2)° in mol­ecule B. An intra­molecular N—H⋯N hydrogen bond occurs in each mol­ecule. In the crystal, two crystallographically independent mol­ecules associate into a dimer via a pair of N—H⋯N hydrogen bonds, with a resulting R 2 2(12) ring motif and π–π stacking inter­actions [centroid–centroid distance = 3.517 (4) Å] between the pyrimidine rings. For the A mol­ecules, there are inter­molecular C—H⋯O hydrogen bonds between an aryl C atom of meth­oxy­phenyl ring and a meth­oxy O atom of an adjacent mol­ecule. A similar inter­action is lacking in the B mol­ecules.

An X-ray crystallographic and DFT study of the complementary hydrogen bonding of bidentate pyrrolide-imine Schiff base ligands

Three pyrrolide-imine Schiff base compounds: 1-phenyl-N-[(E)-1H-pyrrol-2-ylmethylidene]methanamine (1), 2-phenyl-N-(1H-pyrrol-2-ylmethylidene)ethanamine (2) and 1-(naphthalen-1-yl)-N-[(E)-1H-pyrrol-2-ylmethylidene]methanamine (3) have been synthesized in this work. The compounds were all synthesized via solid-state reactions which proved to be a rapid and high yielding synthetic method. The solid state structures of compounds (1), (2) and (3) were elucidated by single crystal X-ray diffraction. The asymmetric unit of (1) comprises two symmetry independent molecules while the structures of (2) and (3) show a single molecule in the asymmetric unit. In the solid state the Schiff base ligands exist as discrete dimers supported by complementary hydrogen bonds between the pyrrole NH and imine nitrogen atom of an adjacent molecule. The hydrogen bond lengths (D⋯A) for compounds (1), (2) and (3) measure 3.074(1), 2.993(2) and 2.995(1) Å, respectively. In the solid state the dimeric structure of (1) exhibits C1 symmetry while the supramolecular structures of compounds (2) and (3) are inversion dimers (Ci symmetry). The compounds were studied by density functional theory at the B3LYP/6-311G(dp) level of theory, these simulations indicate that the self-recognition through hydrogen bonding is mainly dependant on favorable electrostatic interactions. The simulations show that the lowest energy conformation of (1) is of C2 symmetry, not the C1 symmetry of the solid-state structure. The solid state structure of (2) is of Ci symmetry; however, simulations in vacuo show that this conformation is a saddle point on the potential energy surface. The lowest energy conformation of the dimer is in fact of C2 symmetry and is 3.51kJmol−1 lower in energy than the inversion dimer.

Structural and antivirial studies of dipetalactone and its methyl derivative

Dipetalactone (6,6,10,10-tetramethyl-6H,10H-dipyranocoumarin) and its C4-methyl derivative have been synthesized and structurally studied. The structures of these compounds, explored on the basis of 1D and 2D NMR techniques in solution and the DFT/B3LYP calculations for the single molecule of dipetalactone, are in good agreement with those found in the crystals. In the tetracyclic dipetalactones the central coumarin ring systems are nearly planar and the pyran rings adopt a distorted sofa conformation.Both compounds crystallize with two symmetry independent molecules, A and B. The π-stacking is the main force stabilizing the pairs of centrosymmetric dimers, A⋅A and B⋅B. These dimers interact via the intermolecular CH⋯O and CH⋯π hydrogen bonds forming three-dimensional supramolecular frameworks which are nearly isostructural. The MP2 calculations reveal that the dimers of dipetalactone only slightly distort during the crystal formation as compared with those in the gas phase. The energy increase upon such a distortion was estimated as ca. 4kcalmol−1. In addition, the binding energy for the dimer was found to be ca. 20kcalmol−1.Dipetalactone and its methyl derivative were examined for cytotoxicity as well as anti-HIV activity.

Thiophene-2-carbaldehyde azine

The asymmetric unit of the title compound, C10H8N2S2, is composed of two independent half-mol­ecules, each residing on a center of symmetry. In the crystal, weak C—H⋯π inter­actions join the two symmetry-independent molecules together into interlinked chains parallel to [011]. The crystal structure was refined as a two-component pseudo-merohedral twin using the twin law 001 0-10 100. The refined domain fractions are 0.516 (3) and 0.484 (3).

3β,6β-Diacetoxy-5,9α-dihydroxy-5α-cholest-7-en-11-one acetic acid 0.04-solvate

The title compound, C31H48O7·0.04CH3COOH, is a polyoxy­genated steroid obtained by selective chemical oxidation of 7-de­hydro­cholesteryl acetate. The asymmetric unit comprises three mol­ecules of the steroid (Z′ = 3) and a mol­ecule of acetic acid which has occupancy factor 0.131 (5). The geometric parameters of the independent mol­ecules do not reveal significant differences. In one mol­ecule, the terminal isopropyl group is disordered over two sets of sites with occupancy ratio 0.869 (5):0.131 (5). The three mol­ecules reveal different hydrogen-bonding patterns. Each of them is involved in an intra­molecular S(6) hydrogen-bonding motif, involving hy­droxy groups as donor and acceptor. In the crystal, two independent mol­ecules form dimers through hydrogen bonding between an OH donor and an acetate carbonyl acceptor, giving rise to R 2 2(16) ring patterns. A single hydrogen bond between the OH group and a ketone carbonyl group is observed between two symmetry-independent mol­ecules.

Pressure-Controlled Neutral–Ionic Transition and Disordering of NH···N Hydrogen Bonds in Pyrazole

Pyrazole exhibits exceptional effects of temperature and pressure for H-disorder in hydrogen bonds NH···N. Under normal conditions, α-pyrazole is polar (orthorhombic space group Pna21), but the structure is pseudo-centrosymmetric. Two symmetry-independent molecules differently favor the H-sites at their amine nitrogen atoms. The asymmetric disorder of protons in hydrogen bonds NH···N leads to the disproportionation favoring the cations at one site and anions at the other. High temperature increases distortions of the structure from the centrosymmetric symmetry, activates the disproportionation defects, and stabilizes the averaged ionic disparity of symmetry-independent molecules at the ±0.1 e level. Critical pressure Pc = 0.45 GPa induces a transition to centrosymmetric phase β, space group Pnab. This transition involves the 50:50 H-disordering in NH···N hydrogen bonds and eliminates molecular displacements as well as the favored H-sites. The NH···N bonds are hardly compressed at Pc in pyrazole, and they...

9-[3-(Carbazol-9-yl)-5-methylphenyl]carbazole

The title compound, C31H22N2, crystallizes with two symmetry-independent mol­ecules in the asymmetric unit. The mol­ecules have slightly different conformations, the dihedral angles between the central phenyl ring and the carbazolyl groups being 56.29 (4) and 59.57 (4)° in one mol­ecule and 48.71 (4) and 65.47 (4)° in the other. In the crystal, mol­ecules are linked by weak C—H⋯π and π–π [centroid–centroid distances = 3.7698 (10), 3.8292 (9), 3.9429 (10) and 3.9431 (10) Å].

Pseudosymmetry, polymorphism and weak interactions: 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxylic acid and its derivatives

The crystal structures of three derivatives of 4,4′′-difluoro-5′-hydroxy-1,1′:3′,1′′-terphenyl-4′-carboxylic acid are discussed. The acid itself (1), its ethyl ester (2)and hydrazide (3) have been chosen to study the influence of the hydrogen bonding potential on the crystal packing. In 1 and 2 short intramolecular O–H⋯O hydrogen bonds between the hydroxyl and carbonyl groups engage the strong hydrogen bond donors and acceptors, and both these compounds show the effects of packing conflicts. In 1 almost centrosymmetric, stable hydrogen-bonded dimers form between symmetry independent molecules, but the crystal structure is non-centrosymmetric and contains altogether four symmetry-independent molecules (two independent dimers), which show different pseudo-symmetries. In 2 dimer formation is impossible but two different crystal forms of this compound have been found. Both polymorphs crystallize in the P space group and differ mainly in the orientation of the OEt group. In turn in 3 there are no intramolecular hydrogen bonds and the crystal structure is determined mainly by the open motifs created by classical hydrogen bonds and by the complementarity of the respective hydrophilic and hydrophobic parts of the molecule.

Ethyl (E)-3-(anthracen-9-yl)prop-2-enoate

In the asymmetric unit of the title compound, C19H16O2, there are two symmetry-independent mol­ecules (A and B) that differ in the conformation of the ester eth­oxy group. In the crystal, the mol­ecules form inversion dimers via pairs of C—H⋯O inter­actions. Within the dimers, the anthracenyl units have inter­planar distances of 0.528 (2) and 0.479 (2) Å for dimers of mol­ecules A and B, respectively. Another short C—H⋯O contact between symmetry-independent dimers links them into columns parallel to [10-1]. These columns are arranged into (111) layers and there are π–π stacking inter­actions [centroid–centroid distances = 3.6446 (15) and 3.6531 (15) Å] between the anthracenyl units from the neighbouring columns. In addition, there are C—H⋯π inter­actions between the anthracenyl unit of dimers A and dimers B within the same column.

Synthesis, Characterization, and Crystal Structure of α-Glucosimino-pyranose Anthranilic Acid

The new secondary amine, build of glucose and anthranilic acid—α-glucosiminopyranose anthranilic acid (1)—has been synthesized and characterized by elemental analyses, FT-IR and 1H NMR spectroscopy. Crystal and molecular structure of the hydrate of 1 has been determined by means of X-ray diffraction. 1·H2O crystallizes in monoclinic P21 space group, with a = 15.584(3) A, b = 4.992(1) A, c = 18.928(4) and β = 107.63(3)o. The studies prove that a cyclic secondary amine is formed instead of open chain Schiff base, and only one anomer, α is produced. There are two symmetry-independent molecules of 1·H2O in the asymmetric part of the unit cell, and these independent molecules create complicated hydrogen bonded structures—starting with the homomolecular chains which in turn are joined into three dimensional structure. The differences in the supramolecular structures are correlated with the differences in the bond angles patterns, which result from the different orientations of certain O–H bonds. The antibacterial activities of 1 were also tested but the results were negative.