Hydrogen Bonding Patterns in 2,6-diamino-4-oxopyrimidinium Sulfosalicylate Monohydrate

The title compound, [C₄H₇N₄O⁺, C₇H₅O₆S^? . H₂O] contains one 2, 6-diamino-4-oxopyrimidinium cation, one sulfosalicylate anion and a water molecule. The crystal structure was determined by single crystal X-ray diffraction. This compound crystallized in the orthorhombic system; space group Pna2₁ with the unit cell parameters a = 13.402(3) Å, b = 16. 221(3) Å, c = 6.714(2) Å, V = 1459.6(6), Z = 4. The sulfonic acid group has protonated the aminopyrimidine moiety. The protonated N1 atom and N4 amino group are hydrogen bonded to the keto group (O1) of the neighbouring pyrimidine forming a six-membered ring with graph-set notation R₂ ¹(6) and a supramolecular chain along the c-axis. This supramolecular chain is further strengthened by one of the sulfonate oxygen atoms (O3), bridging the pyrimidines via hydrogen bonded rings, R₃ ²(10) involving N(3)–H(3)···O(3) and N(2)–H(2B)···O(3) hydrogen bonds. The other two oxygen atoms of the sulfonate groups are bridged by water molecules via O-H···O hydrogen bonds constituting a supramolecular chain. The water molecule also acts as hydrogen bond acceptor with respect to the carboxyl group.     

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.      

Dihydrogen Phosphate and Hydrogen Sulphate of 1,4-Dimethyl-1,4-diazabicyclo[2.2.2]octane-1,4-diium: Crystal Structures, Hydrogen Bonding and Infrared Spectra

Abstract  

The crystal structures of the title compounds consist of 1,4-dimethyl-1,4-diazabicyclo[2.2.2]octane-1,4-diium cation [C₈H₁₈N₂]²⁺ and [H₂PO₄]⁻ or [HSO₄]⁻ anions. Both crystal structures are monoclinic, the structure of the dihydrogen phosphate (I) is non-centrosymmetric (P2₁) with a = 6.4090(2) ?, b = 13.6920(5) ?, c = 7.6140(3) ?, β = 94.620(2)°, V = 665.97(4) ?³, Z = 2; whereas the unit cell of the hydrogen sulphate (II) is centrosymmetric (P2₁/c) with a = 13.8460(2) ?, b = 12.6610(2) ?, c = 8.0360(2) ?, β = 99.5800(12)°, V = 1389.10(5) ?³, Z = 4. Both the structures are formed by the different bonding patterns of the anions interlinked by strong and moderate O–H···O hydrogen bonds. While the structure of (I) consists of a two-dimensional network of the hydrogen bonded dihydrogen phosphates, the infinite chains of the hydrogen bonded hydrogen sulphates are the basic building unit of the structure (II). In addition to the dominant electrostatic interaction the divalent cations stabilize themselves in the structures by forming several C–H···O hydrogen bonds to the oxygen atoms of the anions. The IR spectra of both the compounds are strongly affected by the hydrogen bonds whose influence on OH stretching vibrations is analysed by means of the DFT calculations in the solid state.     

Isomerism in some 1-oxa-3,5-dithians and the X-ray structure determination of 2,6-bis(trichloromethyl)-4-dichloromethylene-1-oxa-3,5-dithian

2,6-bis (trichloromethyl)-4-dichloromethylene-1-oxa-3,5-dithian is triclinic,P¯1,a=10.125(3),b=10.294(3),c=14.631(10) Å,=92.84(5),=96.51(5), =96.18(2)°,V=1503 ų,Z=4. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by least squares to a finalR value of 0.035 using 3961 reflections. The conformation of the molecules is twist-boat, one molecule being almost symmetrically twisted about the O-C(Cl₂) direction. The range of endocyclic O-C-S angles is 111.8(3) to 115.1(3)° and data are given which support the possibility of there being a correlation between the endocyclic O-C(X)-S angle, the C-O-C(X)-C(Cl₃) torsion angle, and the C-S-C(X)-C(Cl₃) torsion angle. The -CCl₃ groups are in pseudoequatorial positions. Average bond lengths (Å) for the two molecules are C-O 1.405, C(sp ³)-S 1.822, C(sp ²)-S 1.759, C-C_eq 1.529 and average endocyclic angles (°) are O 117.3, C (sp ³) 113.5, S 97.4, C(sp ²) 119.3, the esds on the individual bond lengths and angles being in the ranges of 0.003–0.004 Å and 0.2–0.4° respectively.     

Hydrogen Bonding Patterns of the Co-Crystal Containing the Pharmaceutically Active Ingredient Isoniazid and Terephthalic Acid

Abstract  

The title co-crystal (terephthalic acid)·(isonicotinic acid hydrazide)₂ was prepared by solution methods and solvent-assisted grinding. The crystal belongs to the monoclinic space group P2₁/c with a = 6.2395(4), b = 3.7705(3), c = 41.220(3) ? and β = 94.494(6)°. X-ray single crystal structure analysis reveals that the carboxylic acid···pyridine heterosynthon is utilized to co-crystallize the anti-tubercolosis drug isoniazid with the co-crystal former terephthalic acid. The co-crystal crystallizes out as needles, and the homosynthons associated with the isoniazid and the π stacking of the terephthalic acid produce fastest crystal growth in the direction of the needle axis, corresponding to the short (~3.7 ?) b crystallographic axis.     

Crystal and Molecular Structures of Six Differently with Halogen Substituted Bis (benzylimido) perylene

The structures of bis (3,5‐dichlorobenzylimido) perylene, bis (3‐chlorobenzylimido) perylene, bis (3‐fluorobenzylimido) perylene, bis (3,5‐difluorobenzylimido) perylene, bis (4‐chlorobenzylimido) perylene, and bis (2,6‐difluorobenzylimido) perylene were solved by single crystal analysis. The compounds crystallize in four different space groups, that is, in sequence of the compounds listed P‐1, P‐1, P2₁/a, C2/c, Pbcn, P2₁/n, respectively, although their chemical constitutions are very similar. The packing in different arrangements causes the twist of the benzene ring to differ with respect to the perylene ring and amounts to 111.4°, 112.3°, 98.6°, 105.1°, 80.3°, 72.0° for the sequence of compounds listed, respectively. The first two compounds crystallizing in space group P‐1 are isomorphous in structure and exhibit the same dark blue color. The C‐F bond distances lie between 1.36 and 1.38 Å, the C‐Cl bond distances between 1.73 and 1.75 Å. For all six structures investigated the planes of two adjacent perylene skeleton planes are 3.43 to 3.50 Å apart and the tilt angles versus the shortest unit cell dimension lie between 20° and 45°.     

4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(methoxycarbonyl), 4-(2,4-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(methoxycarbonyl), and 4-(2,3,5-trichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(methoxycarbonyl): conformational observations in the crystalline state

Hydrogen bonding interactions displayed by three crystalline chloro-substituted 4-phenyl-1,4-dihydropyridine molecules 4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(methoxycarbonyl), 4-(2,4-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis (methoxycarbonyl) and 4-(2,3,5-trichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis (methoxycarbonyl), suggests that, in contrast to previous observation, sp orientation of the 3 or 5 substituted carbonyl group accomodates hydrogen bonding to the carbonyl oxygen atom when polar orthosubstituents exist on the phenyl ring.     

Interplay of Hydrogen and Halogen Bonds in Supramolecular Framework of Oxy-Acid Based 3-Chloroanilinium Hydrogen Sulfate,Bis(2,5-dichloroanilinium) Sulfate and 2,5-Dichloroanilinium Perchlorate Hydrate Salts

Crystallography Reports - In title compound bis(2,5-dichloroanilinium) sulfate, the equally disordered sulfate anion occupies 2-fold rotation axis with equivalent component generated through the...     

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.      

Crystal and molecular structure of 2,6-di (o-chloro)phenyl-3,5-dimethyl-N-nitrosopiperidin-4-one(NOCDMPO)

The title compound (C₁₉H₁₈O₂N₂Cl₂) crystallized in the monoclinic space groupP2₁/n witha=13.062(2),b=10.931(2),c=13.120(2)Å, and=104.57(1)°. The structure was solved by direct methods and refined toR=0.047 for 2776 reflections. The piperidine ring assumes a distorted boat conformation. The angle between phenyl rings is 78.98(7)°. The nitroso group is oriented by 138.22(7)° to the best plane of the piperidine ring. The interaction between the molecules are van der Waals in nature.DCB Contribution No. 814.     

Hydrogen Bonding in Proton-Transfer Compounds of 5-Sulfosalicylic Acid with a Series of Aliphatic Nitrogen Lewis Bases

Abstract  

The crystal structures of the proton-transfer compounds of 5-sulfosalicylic acid (3-carboxy-4-hydroxybenzenesulfonic acid) with the aliphatic nitrogen Lewis bases, hydroxylamine, triethylamine, pyrrolidine, morpholine, N-methylmorpholine and piperazine, viz. hydroxyammonium 3-carboxy-4-hydroxybenzenesulfonate (1), triethylaminium 3-carboxy-4-hydroxybenzenesulfonate (2), pyrrolidinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (3), morpholinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (4), N-methylmorpholinium 3-carboxy-4-hydroxybenzenesulfonate monohydrate (5) and piperazine-1,4-diium bis(3-carboxy-4-hydroxybenzenesulfonate) hexahydrate (6) have been determined and their comparative structural features and hydrogen-bonding patterns described. Crystals of 4 are triclinic, space group P-1 while the remainder are monoclinic with space group either P2₁/c (1–3) or P2₁/n (5, 6). Unit cell dimensions and contents are: for 1, a = 5.0156(3), b = 10.5738(6), c = 18.4785(9) ?, β = 96.412(5)^o, Z = 4; for 2, a = 8.4998(4), b = 12.3832(6), c = 15.4875(9) ?, β = 102.411(5)^o, Z = 4; for 3, a = 6.8755(2), b = 15.5217(4), c = 12.8335(3) ?, β = 92.074(2)^o, Z = 4; for 4, a = 6.8397(2), b = 12.9756(5), c = 15.8216(6) ?, α = 90.833(3), β = 95.949(3), γ = 92.505(3)^o, Z = 4; for 5, a = 7.0529(3), b = 13.8487(7), c = 15.6448(6) ?, β = 90.190(6)^o, Z = 4; for 6, a = 7.0561(2), b = 15.9311(4), c = 12.2102(3) ?, β = 100.858(3)^o, Z = 2. The hydrogen bonding generates structures which are either two-dimensional (2 and 5) or three-dimensional (1, 3 , 4 and 6). Compound 6 represents the third reported structure of a salt of 5-sulfosalicylic acid having a dicationic piperazine species.     

Polymorphic transformation in TlSe and the electrical properties of phases

Alloys in the TlSe-Se system on the side of the TlSe compound in the phase diagram have been investigated using differential thermal, X-ray powder diffraction, and microstructural analyses. The phase diagram of the system has been constructed, and the temperature dependences of the electrical conductivity of the phases obtained have been examined. An analysis of the thermograms of alloys in the (TlSe)_0.96-Se_0.04 system has revealed a structural phase transition at a temperature of 470 ± 1 K. Investigations into the temperature dependences of the electrical conductivity in the range 120–450 K have demonstrated that the temperature dependence of the electrical conductivity for the (TlSe)_0.96-Se_0.04 alloy exhibits metallic behavior.     

Structural characterization of 2,6-di(2-thioenyl)-3,5-dimethyl piperidin-4-one (DTMP) in solution and solid state

The structure of the title compound, DTMP (C₁₅H₁₇NS₂O), has been investigated in solution and in the solid state by IR, NMR and X-ray methods. The crystal structure was solved by direct methods and refined by least-squares procedures to anR-factor of 0.073. The piperidine ring adopts achair conformation. The methyl and thioenyl rings are in theequatorial position. The angle between the best plane of the piperidine ring and the thioenyl rings A and B are 88.1(1)° and 89.5(1)°, respectively.DCB contribution No. 846     

Crystal structure of 2,6-bis-hydrazinopyridine dihydrate,its tosylate salt and 2,6-bis(3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butylpyrazolyl)pyridine

The crystal structures of the new compounds 2,6-bis-hydrazinopyridine dihydrate (2), its tosylate salt (3) and 2,6-bis-(3,5-di-tert-butylpyrazolyl)pyridine (4) were obtained by single-crystal X-ray diffraction. Crystallization of 2 occurs in the centrosymmetric monoclinic space group P2₁/c (No. 14) with a = 9.6218(18), b = 6.7331(12), c = 13.489(3); and β = 109.292(8)^∘ and Z = 4. Crystallization of 3 occurs in the centrosymmetric monoclinic space group P2₁/c (No. 14) with a = 26.530(3), b = 16.6456(18), c = 9.9458(10) and β = 96.828(5) and Z = 8, while 4 crystallizes in P2₁/n (No. 14) with a = 15.0555(10), b = 10.4496(7), c = 16.9599(12) and β = 101.480(4) and Z = 4. These are the only structures for any bis-hydrazinopyridines reported to date. Details of the synthesis, structures and spectroscopic results are presented and discussed.