5-Pyridine 4-yl-3H-(1,3,4) Oxadiazole-2 Thione Hydrochloride Monohydrate, (I), and 4 [5-Ethylsulfanyl)-(1,3,4) Thiadiazole-2-yl]-Pyridinium Perchlorate, (II)

Abstract  

The title compounds C₇H₈ClN₃O₂S, (I), and C₉H₁₀ClN₃O₄S_2, (II), both crystallize in monoclinic space group P2₁ /c with unit cell parameters (I) a = 7.9402(7), b = 10.6312(9), c = 11.7626(10), ?, β = 99.271(5)°, Z = 4 and (II) a = 5.1439(2), b = 9.0636(4), c = 27.1814 (7), ?, β = 95.116(2)°, Z = 4. In (I) the molecule consists of a 5-pyridine-4-yl group bonded to the carbon atom at the 5 position of (1, 3, 4) oxadiazole-2 thione hydrochloride monohydrate. The angle between the mean planes of the oxadiazole and pyridine rings is 9.6(6)°. Crystal packing in (I) is stabilized by strong N–H···O hydrogen bonds in concert with a solvent water molecule and weak O–H···Cl, O–H···S, N–H···Cl intermolecular interactions. The crystal structure of compound (II) consists of 4 [5-ethylsulfanyl)-(1, 3, 4) thiadiazole-2-yl]-pyridinium perchlorate, (C₉H₁₀N₃S₂)⁺(ClO₄)⁻, cation–anion pairs, containing strong intermolecular N–H···O hydrogen bonds and weak C–H···O and N–H···O intermolecular interactions operating between the ionic species that form a cooperative hydrogen-bonded, infinite chain O–H···O–H···O–H network which generates a sheet motif structure in the unit cell. It is also supported by weak intermolecular Cg···Cg π–π and Cl–O···Cg π-ring interactions which gives additional support to molecular packing stability in the unit cell. Geometry optimized MOPAC AM1 computational calculations on each compound provides support to the structural features in their respective crystal structures.     

The Synthesis and Structure of 2-Amino-4,6-dimethylpyrimidine 2-Hydroxybenzoate

Abstract  

The title compound, 2-amino-4,6-dimethylpyrimidine 2-hydroxybenzoate was studied by X-ray diffraction methods. This compound crystallized in a monoclinic system; space group P2(1)/n with the unit cell parameters a = 7.5380(14) ?, b = 20.246(4) ?, c = 9.2029(17) ?, β = 108.594(3), V = 1331.2(4), Z = 4. The hydroxybenzoic acid group has been protonated by the aminopyrimidine moiety. The neighbouring two pyrimidine are bridged by N3–H3A···N2 hydrogen bonds, and the constituting dimers are linked together to form a discrete unit, these units, in turn, are linked together by C–H···O interactions. The protonated N1 atom is attached to the carboxyl group (O2) of the neighbouring phenyl by a hydrogen bond, together with the N3–H3B···O3 hydrogen bond to form a eight-membered ring with graph-set notation R₂¹(8). The C5 and O1 through hydrogen bond forms a supramolecular chain along the b-axis, which is further strengthened by O1–H1···O3 hydrogen bond, bridging the hydroxide radical and carboxyl via hydrogen bonded rings, R₁¹(6).     

Syntheses and Crystal Structures of Two Ferrocenyl Dicarboximides

Abstract  

Reactions of 1,1′-ferrocenedicarboxylic chloride with 2-aminopyrimidine and 2-aminopyrazine produce organometallic dicarboximides I and II, respectively. They crystallize in space groups F dd2 and P2₁/c, respectively. The molecules of I lying on twofold rotation axes are linked into a B-faced sheet by a C–H···O=C hydrogen bond [H····O = 2.46, C···O = 3.163(7) ? and C–H···O = 132°]. The sheets are linked into a layered structure by two types of weak C–H···O=C hydrogen bonds [H···O = 2.71, C···O = 3.340(8) ? and C–H···O = 126°; H···O = 2.69, C···O = 3.303(10) ? and C–H···O = 124°]. The molecules of II are linked into a centrosymmetric R ₂²(12) dimer by a C–H···O hydrogen bond [H···O = 2.40, C···O = 3.321(10) ? and C–H···O = 172°]. The dimers are further packed along the a axis by a C–H···O hydrogen bond [H···O = 2.69, C···O = 3.416(9) ? and C–H···O = 135°] to give an [100] double-chain. The double-chain is packed in the [010] direction by a C–H···O=C hydrogen bond [H···O = 2.69, C···O = 3.532(9) ? and C–H···O = 150°]. Further the intermolecular C–H···N hydrogen bond involving the cyclopentadienyl group as a hydrogen-bond donor and pyrazine N atom as an acceptor [H···O = 2.71, C···N = 3.536(10) ? and C–H···N = 148°] leads to a three-dimensional framework structure.     

Synthesis, Spectroscopic Characterization and Crystal Structure of a New Acetyl phosphorylamidate P(O)[NHC(O)C6H4(4-NO2)][N(CH(CH3)2)(CH2C6H5)]2

Abstract  

A new acetyl phosphorylamidate P(O)[NHC(O)C₆H₄(4-NO₂)][N(CH(CH₃)₂)(CH₂C₆H₅)]₂ has been synthesized and characterized by elemental analysis, ¹H, ¹³C and ³¹P NMR, IR and single crystal X-ray diffraction. Single crystal X-ray analysis shows that it belongs to triclinic system, space group P[`1] P\bar{1} , with a = 10.5868(16) Å, b = 11.8058(18) Å, c = 12.4364(19) Å, α = 65.410(3)°, β = 67.492(4)°, γ = 85.879(3)°, V = 1,298.6(3) Å³, and Z = 2. The intermolecular PO···HN hydrogen bond makes H-bonded dimer of molecule with Ci symmetry. In the crystal network, the dimers are aggregated in the chain arrays through π-stacking between p-NO₂–C₆H₄–C(O)–NH– moieties. Moreover, weak C–H···O and C–H···π interactions exist in the crystal network.     

Crystal Structure of a Second Polymorph of Gabapentin Hydrochloride Hemihydrate with a Three-Center Bifurcated Hydrogen Bond

Abstract  

Gabapentin hydrochloride hemihydrate, a derivative of Gabapentin [or 1-(aminomethyl) cyclohexaneacetic acid; Gpn, C₆H₁₇NO₂], is a salt of C₉H₁₈NO₂ ⁺ Cl⁻ 0.5 H₂O, which crystallizes in the monoclinic space group I 2/a with unit cell parameters a = 13.2467(3), b = 6.5552(2), c = 26.0094(8) ?, β = 96.561(3)°, Z = 8. The crystal structure and bonding network is compared to its isostructural and previously reported polymorphic derivative, Gpn hydrochloride hemihydrate [C₉H₁₇NO₂ HCl ? H₂O]. Both of these derivatives exhibit extensive inter and intra molecular hydrogen bonding networks between the NH₃ ⁺ group and neighboring Cl⁻, water and carboxyl oxygen atoms as well as similar interactions between the chloride anion and nearby water and carboxyl oxygen atoms. A unique and relatively rare three-center hydrogen bond configuration (with a bifurcated chlorine Cl⁻···H–(N,O) and Cl⁻···H–O acceptor hydrogen bonds) as well as N–H···O donor hydrogen bonds can be seen linking the molecules into chains along the [1 0 1] plane of the unit cell.     

Synthesis,Crystal Structure and Hydrogen-Bonding Patterns in (RS)-1-Carbamoyl Pyrrolidine-2-Carboxylic Acid

Abstract  

The title compound, N-carbamoyl-dl-proline, C₆H₁₀N₂O₃, crystallizes in the triclinic P-1 space group with unit cell parameters a = 7.610 (4) Å, b = 9.259 (5) Å, c = 11.749 (7) Å, α = 110.294 (11)°, β = 101.304 (13)°, γ = 91.391 (16)°, with two crystallographically independent molecules in the asymmetric unit. The ureido and carboxyl groups are equatorial and axial to the pyrrolidine rings, respectively. The pyrrolidine rings adopt envelope and twisted conformations in the residue A and B, respectively. The molecules are joined by N–H···O and O–H···O hydrogen bonds into cyclic structures with graph set R ₂²(8), forming infinite chains parallel to the cb plane with graph set C ₂²(14), that are further connected via N–H···O hydrogen bonds into a three-dimensional network.     

Hydrogen Bonding Patterns in Trimethoprimium Cinnamate 1.52 Hydrate

Abstract  

In the title compound, [C₁₄H₁₉N₄O₃ ⁺, C₉H₅ O₂ ⁻, H₂O, O0.52] the asymmetric unit contains a protonated trimethoprim cation and a cinnamate anion and two water molecules. The crystal structure was determined by single crystal X-ray diffraction. This compound crystallized in the triclinic system; space group P−1 with the unit cell parameters a = 10.010(2) ?, b = 10.339(3) ?, c = 13.486(8) ?, α = 105.32(3)°, β = 109.88(3)°, γ = 100.89(3)°, V = 1204.6(10) ?³, Z = 2. The cinnamate group is disordered. The trimethoprim (TMP) molecule is protonated at one of the pyrimidine nitrogen atoms. The carboxylate group of the cinnamate anion interacts with the protonated pyrimidine atom N1 and the 2-amino group via a pair of N–H···O hydrogen bonds, generating the R₂²(8) ring motif. The inversion related TMP cations are paired via N–H···N hydrogen bonds. In addition to the base pairing, the O1W atom bridges the 2-amino and 4-amino groups on either side of the paired bases, resulting in a self complementary DADA array. Two inversion related TMP cations and water molecules (O1W) are linked via N–H···O and O–H···O hydrogen bonds, forming a 22 membered ring with graph-set R₄⁴(22).     

Hydrogen Bonded 3D Supramolecular Architectures of Two Organic Salts Assembled from 2-Aminoheterocyclic Compounds and Phosphoric Acid

Abstract  

Two phosphate salts (2-aminopyrimidine): (phosphoric acid): H₂O [HL1⁺ (H₂PO₄) ⁻ ]·H₂O (1), and (4-phenylthiazol-2-amine): (phosphoric acid) [HL2⁺·(H₂PO₄)⁻] (2) based on 2-aminoheterocyclic compounds, 2-aminopyrimidine (L1), and 4-phenylthiazol-2-amine (L2) were prepared and structurally characterized by X-ray crystallography. Compound 1 crystallizes in the triclinic, space group P-1, with a = 6.2201(7) Å, b = 8.6139(9) Å, c = 9.4800(10) Å, α = 109.685(2)°, β = 106.3340(10)°, γ = 95.4450(10)°, V = 448.72(8) Å³, Z = 2. For 1, the cations were linked to each other via intermolecular C–H···N hydrogen bonds to form a 1-D chain structure running along the a-axis direction. The anions and the water molecules were connected alternatively along the a-axis direction through O–H···O hydrogen bonds to form a 1-D chain also. The cationic chains and the anionic chains were alternatively connected along the c-axis direction through N–H···O and C–H···O hydrogen bonds to form a 2D corrugated sheet. Adjacent sheets were combined together through π–π interaction to form double sheet. These double sheets were further joined together by O–H···O and N–H···O hydrogen bonds to produce a 3D network structure. Compound 2 crystallizes in the Orthorhombic, space group Pbca, with a = 10.1929(10) Å, b = 8.4406(9) Å, c = 27.589(2) Å, α = 90°, β = 90°, γ = 90°, V = 2373.6(4) Å³, Z = 8. In 2, the phosphates formed 1D chain along the b-axis through two P–O–H···O = P hydrogen bonds. The cations formed 1D zigzag chain along the b-axis direction under the CH–π interaction. The anionic chains were intercalated between two adjacent cationic chains through N–H···O, O–H···O, C–H···O, and O–S contacts. Such stacking repeated along the c-axis direction to form a 3D network structure.     

Crystal Structure of 2′,3′-Di-<Emphasis Type="Italic">O</Emphasis>-Acetyl-5′-Deoxy-5-Fluorocytidine with N–H···(O,F) Proton Donor Bifurcated and (C,N)–H···O Bifurcated Acceptor Dual Three-Center Hydrogen Bond Configurations

Abstract  The title compound, C₁₃H₁₆O₆N₃F, features a central furan ring containing four carbon atom chiral centers with a 4-amino-5-fluoro-2-oxopyrimidine group, two acetyl groups and a methyl group bonded at the 2,3,4,5 positions, each in an absolute R configuration (2R,3R,4R,5R). It crystallizes in the monoclinic space group C2 with unit cell parameters a = 14.5341(3), b = 7.26230(10), c = 16.2197(3) ?, β = 116.607(2)°, Z = 4. An extensive array of intra and intermolecular hydrogen bond interactions dominate crystal packing in the unit cell highlighted by a relatively rare three-center proton-bifurcated donor N–H···(O,F) hydrogen bond interaction in cooperation with a second, (C,N)–H···O bifurcated acceptor three-center hydrogen bond in a supportive fashion. Additional weak Cg π-ring intermolecular interactions between a fluorine atom and the 4-amino-5-fluoro-2-oxopyrimidine ring in concert with multiple donor and acceptor hydrogen bonds significantly influence the bond distances, bond angles and torsion angles of the deoxy-5-fluorocytidine group. Comparison to a MOPAC computational calculation provides support to these observations. Index Abstract  Crystal structure of (2R,3R,4R,5R)-2-(4-amino-5-fluoro-2-oxopyrimidin-1(2H)-yl)-5-methyl-tetrahydrofuran-3,4-diyl diacetate with dual N–H···(O,F) proton donor bifurcated and (C,N)–H···O bifurcated acceptor three-center hydrogen bond configurations is reported and its geometric and packing parameters described and compared to a MOPAC computational calculation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Crystal Structure and Energy Optimization of Dichlorobis(ethylanthranilatonicotinamide)Zinc(II)

Abstract  

The title compound, C₃₀H₂₈Cl₂N₄O₆Zn, dichlorobis(ethylanthranilatonicotinamide)zinc(II) crystallized in a triclinic space group, P − 1, with cell parameters a = 7.787(3), b = 13.468(1), c = 15.735(1), α = 110.25(1), β = 95.11(1), γ = 99.32(1) and Z = 2, with the whole molecule being the asymmetric unit. In this compound, zinc is bound to two ethylanthranilatonicotinamide (EAN) ligands and two chloride ligands in a distorted tetrahedral configuration. The nitrogen of the nicotinamide ring participates in bonding with zinc through its lone pair while the anthranilate nitrogen remains free. In one of the two EAN ligands, the anthranilate and nicotinamide groups are nearly co-planar while in the other, the angle between the two is ~35.5°. The complex shows three hydrogen bonds, two being C–H···O bonds and the other being C–H···Cl bond. The amidic N–H groups do not participate in hydrogen bond formation as they are buried in the core structure and are not accessible for other groups for association. Both the C–H···O bonds occur from C–H bonds present on the twisted EAN moiety.     

Molecular Association of Almotriptan with Oxalate and Terephthalate Anions

Abstract  

Crystal structures of anti-migraine drug almotriptan were crystallized with oxalic acid (I) and with terephthalic acid (II) and their crystal structures and molecular associations were determined using X-ray diffraction methods. Crystals of both (I) and (II) are monoclinic, space group P2₁/c, with a = 5.6270(4) ?, b = 27.6419(19) ?, c = 13.6228(9) ?, β = 93.057(1)°, V = 2115.9(3) ?³, Z = 4 (I) and a = 13.3756(15) ?, b = 15.6065(17) ?, c = 10.7238(12) ?, β = 98.017(2)°, V = 2216.7(4) ?³, Z = 4 (II). In almotriptan oxalate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium semioxalate}, C₁₇H₂₆N₃O₂S⁺, C₂HO₄ ⁻, (I) and in almotriptan hemi terephthalate hydrate {systematic name: N,N-dimethyl-2-[5-(pyrrolidin-1-ylsulfonyl-methyl)-1H-indol-3-yl]-ethanaminium hemi terephthalate monohydrate}, C₁₇H₂₆N₃O₂S⁺, 0.5(C₈H₄O₄ ²⁻), H₂O, (II), both the almotriptan cations form a trimer with the corresponding anions via N–H···O hydrogen bonds. In (I), the oxalate salt is monoprotonated and in (II), the terephthalic acid is located across the inversion centre and exists as doubly protonated anion. In (I), the cation and anion are interlinked by the N–H···O and O–H···O hydrogen bonds into continuous two-dimensional layers generate an R₆⁶(34) hydrogen-bonded motif tetramers running parallel to the (0 0 1) plane. In (II), the cation and water form a centrosymmetric tetramer of R₄⁴(22) hydrogen-bonded motif via N–H···O and O–H···O hydrogen bonds and further cross-linked by centrosymmetric anions to form an infinite three-dimensional supramolecular hydrogen-bonded networks.     

Structure of a New Bioactive Agent Containing Combined Antibacterial and Antifungal Pharmacophore Sites: 4-{[(<Emphasis Type="Italic">E</Emphasis>)-(5-Bromo-2-hydroxyphenyl)methylidene]amino}-<Emphasis Type="Italic">N</Emphasis>-(5-methyl-1,2-oxazol-3-yl)benzenesulfonamide

Abstract  

The title compound (3), C₁₇H₁₄BrN₃O₄S, is a Schiff base compound of 5-bromosalicylaldehyde (1) and sulfamethoxazole (2). The structure of (3) was determined by spectral (IR, ¹H and ¹³C NMR), elemental analyses and X-ray diffraction data. Compound (3) crystallizes in the monoclinic space group C2/c, with a = 31.936(3), b = 6.2571(5), c = 16.903(1) ?, β = 94.867(8), V = 3365.5(5) ?³, Z = 8. In the molecule of compound (3), the molecule is bent at the S atom with a C–SO₂–NH–C torsion angle of −86.3(3)°. Pairs of molecules, related by inversion centres, form intermolecular N–H···N hydrogen bonds to produce a dimer. An intramolecular phenolic O–H···N hydrogen bond is also formed. Intermolecular hydrogen bonding and π–π stacking hold the molecules together. The average distance between stacked benzene ring planes is 3.625(2) ?.     

Near Supramolecular Isomorphism Involving Homologous Solvents: Pyrimethaminium Terephthalate Methanol Solvate and Pyrimethaminium Terephthalate Ethanol Solvate

Abstract  

Two nearly isostructural pseudopolymorphic forms of pyrimethaminium terephthalate have been synthesized and their supramolecular architectures analyzed. In both the crystals, the protonated pyrimethamine (PMN) cation interacts with the carboxylate anion via N–H···O hydrogen bonds to form the robust R₂²(8) motif. The centrosymmetrically (N–H···N) paired PMN cations are bridged on either sides by interaction of the solvent molecules with the amino groups (N–H···O) of PMN cations. The combination of two R₂²(8) motifs formed between the PMN cations and PMN cation solvent, leads to the formation of the complementary DADA (D = hydrogen bonded donor, A = hydrogen bonded acceptor) array of quadruple hydrogen bonds. The solvent molecule further interacts with the corresponding anion via O–H···O hydrogen bonds. Moreover, both the solvates exhibit several edge to face stacking interactions. They have in common, two C–H···π interactions; one between the symmetry related cations and other between the cation and anion. The molecular packing of the ethanol solvate is further strengthened by C–H···O and C–H···π interaction between the solvent and the ions.     

Crystal and Molecular Structure Studies of 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo-[3.2.1]octane-3,4′-imidazolodine]-2′,5′-dione

Abstract  

The title compound, C₂₃H₂₃FN₃O₂ has been synthesized and the structure was investigated by X-ray diffraction studies. The compound crystallizes in the triclinic crystal class in the space group P[`1]P\overline{1} with cell parameters a = 9.345(2) ?, b = 10.940(3) ?, c = 11.986(4) ?, α = 72.349(6)°, β = 68.106(18)°, γ = 66.867(5)°, Z = 2 and V = 1027.8(5) ?³. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O, C–H···O and C–H···N. One of the oxygen atoms attached to the hydantoin ring simultaneously accepts two hydrogen bonds to form a three centered hydrogen bonding pattern.     

Synthesis,Characterization and Crystal Structure of a Mononuclear Zinc(II) Complex Derived from 2-[(2-Propylaminoethylimino)methyl]phenol

Abstract  

A new zinc(II) complex, [Zn(C₁₂H₁₈N₂O)Cl₂]·CH₃CN, derived from the Schiff base ligand 2-[(2-propylaminoethylimino)methyl]phenol, has been synthesized and characterized by elemental analysis, IR spectra, and X-ray crystallography. The complex crystallizes in the orthorhombic space group Pbcn with unit cell dimensions a = 26.387(9) ?, b = 7.389(2) ?, c = 18.731(6) ?, V = 3,652(2) ?³, Z = 8, R ₁ = 0.0455 and wR ₂ = 0.1143. The asymmetric unit of the compound contains a mononuclear [Zn(C₁₂H₁₈N₂O)Cl₂] complex and an acetonitrile molecule linked together by an intermolecular N–H···N hydrogen bond. Crystal packing is stabilized by intermolecular N–H···O hydrogen bonds linking the molecules into chains along the b axis of the unit cell.     

The Crystal Structure of 1-[2-(furan-2-yl)-6-methyl-1,2,3,4-tetrahydroquinolin-4-yl]Pyrrolidin-2-one

Abstract  

The title compound, C₁₈H₂₀N₂O₂, a potential pharmaceutical agent, crystallizes in the monoclinic P2₁/n space group with unit cell parameters a = 11.157 (7) ?, b = 8.776 (6) ?, c = 16.460 (11) ?, β = 103.08 (3)°. The tetrahydroquinoline ring system formed by the fusion of the benzene ring and the piperidine ring via two carbon atoms is coplanar, with the later adopting a sofa conformation. The pyrrolidine group in position 4 adopts an envelope conformation. Dimers related by inversion centers and linked by hydrogen bonds of the type N–H···O form cycles described by the graph set R₂²(16). Additionally, the dimers connect through weak hydrogen bonds of the type C–H···O with graph set C(10) to form chains extending along [001].     

<Emphasis Type="Italic">Mangifera indica</Emphasis>: Crystal Structures of Two Cycloartane Type Triterpenoids Present in the Bark

Abstract  

Cycloart-23-ene-3-oxo-26-oic acid or Mangiferolic acid (C₃₀H₄₈O₃), compound 1 and Cycloart-23-ene-3β,25-diol (C₃₀H₅₀O₂) compound 2, were isolated from the bark of Mangifera indica. The structures of both compounds 1 and 2 were established by spectral and X-ray diffraction studies. Compound 1 crystallizes in the monoclinic space group P2₁ with unit cell parameters a = 8.416(1), b = 20.638(2), c = 17.203(2) Å, β = 91.779(2)°, Z = 2. Compound 2 crystallizes in the monoclinic space group C 2 with unit cell parameters a = 33.824(9), b = 7.413(2), c = 11.136(3) Å, β = 98.347(4)°, Z = 4. Both structures (1 and 2) were solved by direct methods and refined to R = 0.0511 and 0.0588, respectively. For compound 1, there are two independent molecules (1A and 1B) per asymmetric unit and one disordered trichloride methane molecule. For compound 2, there is positional disorder of the side chain at C17 beginning from C23 up to C27. All the rings of both steroid skeletons are trans connected. For structures 1A, 1B and 2, the six-membered rings A, B and C have a deformed chair, deformed chair and sofa conformations. The five-membered rings D adopt a half-chair conformation. In structure 1, there are two types of hydrogen bonds, the first type, the molecules 1A and 1B are linked by pairs of O(3A)–H···O(1B) and O3B H3B···O1A hydrogen bonds. In addition, both O(1A)–H and O(1B)–H hydroxyl groups participate in a second type of hydrogen bond involving the atoms O(2A) and O(2B) of adjacent molecules, respectively. In structure 2, there is a characteristic pattern observed in packing diagram is that both hydroxyl groups (O1–H and O2–H) participate as hydrogen bond donors and acceptors. In both structures 1 and 2, the hydrophobic part of the steroid nucleus is stabilized by C–H···O interactions and van der Waals forces.     

Hydrogen Bonded Supramolecular Assembly in N6-Benzyladeninium Nitrate and N6-Benzyladeninium 3-Hydroxy Picolinate: A Synthetic Cytokinin

Abstract  

N ⁶-benzyladeninium nitrate, (1), C₁₂H₁₂N₅ ⁺ NO₃ ⁻ crystallizes in P2 ₁/c, with a = 15.0035(13), b = 5.3788(5), c = 16.8954(13) ?, β = 107.331(6)°, Z = 4 and N ⁶-benzyladeninium 3-hydroxy picolinate, (2), C₁₂H₁₂N₅ ⁺ C₆H₄NO₃ ⁻, crystallizes in P1, with a = 8.3017(4), b = 14.6170(7), c = 14.7909 (8) ?, α = 78.801 (4), β = 81.979 (4),γ = 88.849 (4)°, Z = 4. In both the salts, the cation exists as N(7)H tautomer with protonation at the N₃ atom. The dihedral angle of 76.64 (16)° for (1), 67.91(12)° for (cation A) and 68.27 (13)° for (cation B) in (2), between the adenine plane and phenyl ring plane, the distal orientation of the N6 substituent with respect to the imidazole ring and the free N1 position, make these benzyladeninium cations meet all the requirements necessary for cytokinin activity. The crystal structures are stabilized by N–H···N, N–H···O, C–H···O hydrogen bonds and C–H···π stacking interaction between symmetry related benzyladenine molecule.     

Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide

Abstract  Bis(2-amino-5-fluoro-3-methylphenyl)disulfide was obtained by oxidation of 2-amino-5-fluoro-3-methylbenzenethiol and was characterized by elemental analysis, IR and ¹H-NMR spectroscopy. The X-ray structure was determined. Crystal data: C₁₄H₁₄N₂F₂S₂: Monoclinic, P2₁ /n, a = 11.8268(3), b = 9.5770(3), c = 12.3977(3) ?, β = 98.079(2)°, V = 1390.29(7) ?, Z = 4. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds. Index Abstract  Inter- and Intra-Molecular Hydrogen Bonding in Bis(2-amino-5-fluoro-3-methylphenyl)disulfide J. E. Drake¹, M. B. Hursthouse², M. E. Light², R. Maheshwari³, K.G. Ojha³, R. Ratnani^3* Bis(2-amino-5-fluoro-3-methylphenyl)disulfide is linked into a three-dimensional frame work by a combination of intermolecular N–H···F and N–H···N and intramolecular N–H···S hydrogen bonds. The supramolecular structure arises because the NH₂ groups form three center S···H···F hydrogen bonds and two center N–H···F and N–H···S hydrogen bonds.      

Synthesis and Crystal Structures of Methyl 3-(Benzoylamino)-6-methyl-2-oxo-2<Emphasis Type="Italic">H</Emphasis>-pyran-5-carboxylate and <Emphasis Type="Italic">N</Emphasis>-[5-(3,4-Dimethoxyphenyl)-6-methyl-2-oxo-2<Emphasis Type="Italic">H</Emphasis>-pyran-3-yl]benzamide

Abstract  

The compounds methyl 3-(benzoylamino)-6-methyl-2-oxo-2H-pyran-5-carboxylate (1), C₁₅H₁₃NO₅, and N-[5-(3,4-dimethoxyphenyl)-6-methyl-2-oxo-2H-pyran-3-yl]benzamide (2), C₂₁H₁₉NO₅, crystallize as a centrosymmetric hydrogen-bonded dimer facilitated by N–H···O interactions involving the amide and carbonyl moiety of the lactone group of adjacent molecules. Supramolecular aggregation in 1 is controlled by a combination of π–π interactions [centroid–centroid distance = 4.0745(11) ?] and weak C–H···O hydrogen bonding between the phenyl ring of the benzoylamino group and the carbonyl atom of the methoxycarbonyl group and in 2 by a combination of π–π interactions [centroid–centroid distance = 4.0699(8) and 4.1556(10) ?], weak C–H···O interactions between the methoxy substituents of the adjacent dimethoxyphenyl group and weak C–H··· π interactions.