scholarly journals Crystal structure of 5-amino-4H-1,2,4-triazol-1-ium pyrazine-2-carboxylate: an unexpected salt arising from the decarboxylation of both precursors

2015 ◽  
Vol 71 (7) ◽  
pp. 840-843 ◽  
Author(s):  
José A. Fernandes ◽  
Bing Liu ◽  
João P. C. Tomé ◽  
Luís Cunha-Silva ◽  
Filipe A. Almeida Paz
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Dicarboxylic Acid ◽  
Dihedral Angle ◽  
Carboxylate Anion ◽  
Stacking Interactions ◽  
Carboxylate Group ◽  
Decarboxylation Reaction ◽  
Graph Set

Both the 3-amino-2H,4H-1,2,4-triazolium cation and the pyrazine-2-carboxylate anion in the title salt, C2H5N4+·C5H3N2O2−, were formed by an unexpected decarboxylation reaction, from 5-amino-1H-1,2,4-triazole-3-carboxylic acid and pyrazine-2,3-dicarboxylic acid, respectively. The dihedral angle between the pyrazine ring (r.m.s. deviation = 0.008 Å) and the carboxylate group in the anion is 3.7 (3)°. The extended structure of the salt contains a supramolecular zigzag tape in which cations and anions are engaged in strong and highly directional N—H...N,O hydrogen bonds, formingR22(8) andR22(9) graph-set motifs. The packing between the tapes is mediated by π–π stacking interactions between the triazole and pyrazine rings.

scholarly journals Crystal structure of 2-amino-4,6-dimethoxypyrimidinium thiophene-2-carboxylate

2015 ◽  
Vol 71 (7) ◽  
pp. o479-o480 ◽  
Author(s):  
Ammaiyappan Rajam ◽  
P.T. Muthiah ◽  
Ray J. Butcher ◽  
Jerry P. Jasinski
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Carboxylate Anion ◽  
Stacking Interactions ◽  
Carboxylate Group ◽  
Ring Plane ◽  
Π Stacking ◽  
Methoxy Groups ◽  
Ring Motif

In the title salt, C6H10N3O2+·C5H3O2S−, the 2-amino-4,6-dimethoxypyrimidinium cation interacts with the carboxylate group of the thiophene-2-carboxylate anion through a pair of N—H...O hydrogen bonds, forming anR22(8) ring motif. These motifs are centrosymmetrically pairedviaN—H...O hydrogen bonds, forming a complementaryDDAAarray. The separateDDAAarrays are linked by π–π stacking interactions between the pyrimidine rings, as well as by a number of weak C—H...O and N—H...O interactions. In the anion, the dihedral angle between the ring plane and the CO2group is 11.60 (3)°. In the cation, the C atoms of methoxy groups deviate from the ring plane by 0.433 (10) Å.

Supramolecular hydrogen-bonding patterns in two cocrystals of the N(7)–H tautomeric form ofN6-benzoyladenine:N6-benzoyladenine–3-hydroxypyridinium-2-carboxylate (1/1) andN6-benzoyladenine–DL-tartaric acid (1/1)

2015 ◽  
Vol 71 (11) ◽  
pp. 985-990 ◽  
Author(s):  
Ammasai Karthikeyan ◽  
Robert Swinton Darious ◽  
Packianathan Thomas Muthiah ◽  
Franc Perdih
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Tartaric Acid ◽  
Dihedral Angle ◽  
Tautomeric Form ◽  
Stacking Interactions ◽  
Graph Set ◽  
Purine Ring ◽  
Ring Motif

Two novel cocrystals of the N(7)—H tautomeric form ofN6-benzoyladenine (BA), namelyN6-benzoyladenine–3-hydroxypyridinium-2-carboxylate (3HPA) (1/1), C12H9N5O·C6H5NO3, (I), andN6-benzoyladenine–DL-tartaric acid (TA) (1/1), C12H9N5O·C4H6O6, (II), are reported. In both cocrystals, theN6-benzoyladenine molecule exists as the N(7)—H tautomer, and this tautomeric form is stabilized by intramolecular N—H...O hydrogen bonding between the benzoyl C=O group and the N(7)—H hydrogen on the Hoogsteen site of the purine ring, forming anS(7) motif. The dihedral angle between the adenine and phenyl planes is 0.94 (8)° in (I) and 9.77 (8)° in (II). In (I), the Watson–Crick face of BA (N6—H and N1; purine numbering) interacts with the carboxylate and phenol groups of 3HPA through N—H...O and O—H...N hydrogen bonds, generating a ring-motif heterosynthon [graph setR22(6)]. However, in (II), the Hoogsteen face of BA (benzoyl O atom and N7; purine numbering) interacts with TA (hydroxy and carbonyl O atoms) through N—H...O and O—H...O hydrogen bonds, generating a different heterosynthon [graph setR22(4)]. Both crystal structures are further stabilized by π–π stacking interactions.

scholarly journals Bis(tetraethylammonium) oxalate dihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o2382-o2383 ◽  
Author(s):  
Timothy J. McNeese ◽  
Robert D. Pike
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Molar Ratio ◽  
Water Molecules ◽  
Oxalate Dihydrate ◽  
Carboxylate Groups ◽  
Graph Set ◽  
Oxalate Ion

The title compound, 2C8H20N+·C2O42−·2H2O, synthesized by neutralizing H2C2O4·2H2O with (C2H5)4NOH in a 1:2 molar ratio, is a deliquescent solid. The oxalate ion is nonplanar, with a dihedral angle between carboxylate groups of 64.37 (2)°. O—H...O hydrogen bonds of moderate strength link the O atoms of the water molecules and the oxalate ions into rings parallel to thecaxis. The rings exhibit the graph-set motifR44(12). In addition, there are weak C—H...O interactions in the crystal structure.

scholarly journals 4-Bromobenzoic acid–6-(4-bromophenyl)-3-methyl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole (1/1)

2012 ◽  
Vol 68 (4) ◽  
pp. o1185-o1186
Author(s):  
Kamini Kapoor ◽  
Vivek K. Gupta ◽  
Satya Paul ◽  
Seema Sahi ◽  
Rajni Kant
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Maximum Deviation ◽  
Carboxyl Group ◽  
Stacking Interactions ◽  
Acid Molecule ◽  
Ring Plane ◽  
Title 1 ◽  
Benzene Ring Plane

In the title 1:1 co-crystal, C10H7BrN4S·C7H5BrO2, the triazolothiadiazole system is approximately planar [with a maximum deviation of 0.030 (4) Å] and forms a dihedral angle of 8.6 (1)° with the bromophenyl ring. In the carboxylic acid molecule, the carboxyl group is rotated by 6.4 (3)° out of the benzene ring plane. The crystal structure features O—H...N and C—H...O hydrogen bonds, π–π stacking interactions [centroid–centroid distances = 3.713 (2), 3.670 (2) and 3.859 (3) Å] and short S...N [2.883 (4) Å] contacts.

scholarly journals The crystal structure of 3-chloro-2-(4-methylphenyl)-2H-pyrazolo[3,4-b]quinoline

2015 ◽  
Vol 71 (5) ◽  
pp. 567-570 ◽  
Author(s):  
Haliwana B. V. Sowmya ◽  
Tholappanavara H. Suresha Kumara ◽  
Jerry P. Jasinski ◽  
Sean P. Millikan ◽  
Hemmige S. Yathirajan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Phenyl Ring ◽  
Pyrazole Ring ◽  
Stacking Interactions ◽  
Π Stacking ◽  
Ring Centroid

In the molecule of 3-chloro-2-(4-methylphenyl)-2H-pyrazolo[3,4-b]quinoline, C17H12ClN3, (I), the dihedral angle between the planes of the pyrazole ring and the methylated phenyl ring is 54.25 (9)°. The bond distances in the fused tricyclic system provide evidence for 10-π delocalization in the pyrazolopyridine portion of the molecule, with diene character in the fused carbocyclic ring. In the crystal, molecules of (I) are linked by two independent C—H...N hydrogen bonds, forming sheets containing centrosymmetricR22(16) andR64(28) rings, and these sheets are all linked together by π–π stacking interactions with a ring-centroid separation of 3.5891 (9) Å.

Succinimidyl 7-(diethylamino)-2-oxo-2H-chromene-3-carboxylate chloroform solvate

2006 ◽  
Vol 62 (7) ◽  
pp. o3079-o3081
Author(s):  
Ghasem Rezanejade Bardajee ◽  
Mitchell A. Winnik ◽  
Alan J. Lough
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Stacking Interactions ◽  
Two Dimensional ◽  
Π Stacking

In the title molecular structure, C18H18N2O6·CHCl3, the dihedral angle between the two fused, essentially planar, six-membered rings is 5.4 (2)°. In the crystal structure, weak intermolecular C—H...O hydrogen bonds and π–π stacking interactions connect molecules into two-dimensional layers.

scholarly journals Crystal structure of 4-[(E)-(4-chlorobenzylidene)amino]-3-(2-methylbenzyl)-1H-1,2,4-triazole-5(4H)-thione

2014 ◽  
Vol 70 (9) ◽  
pp. o1015-o1016
Author(s):  
Kamni ◽  
B. K. Sarojini ◽  
P. S. Manjula ◽  
B. Narayana ◽  
Sumati Anthal ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Triazole Ring ◽  
Dihedral Angles ◽  
Benzene Rings ◽  
Graph Set ◽  
Title Molecule

In the title molecule, C17H15ClN4S, the benzene rings form dihedral angles of 16.6 (1) and 77.2 (1)° with the triazole ring. The dihedral angle between the benzene rings is 86.6 (1)°. In the crystal, pairs of N—H...S hydrogen bonds form inversion dimers with graph-set notationR22(8). Weak C—H...S hydrogen bonds link these dimers into layers parallel to (100). Weak intramolecular C—H...S and C—H...N contacts are observed.

scholarly journals Crystal structure of Dehydrodieugenol B methyl ether, a neolignan from Nectandra leucantha Nees and Mart (Lauraceae)

2018 ◽  
Vol 74 (4) ◽  
pp. 518-521
Author(s):  
Simone S. Grecco ◽  
Gerold Jerz ◽  
Joao Henrique G. Lago ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Methyl Ether ◽  
Title Compound ◽  
Side Chains ◽  
Stacking Interactions ◽  
Aromatic Rings ◽  
Torsion Angles ◽  
Compound C

In the title compound, C21H24O4 (systematic name: 4,5′-diallyl-2,2′,3′-trimethoxydiphenyl ether), the aromatic rings lie almost perpendicular to each other [dihedral angle = 85.96 (2)°]. The allyl side chains show similar configurations, with Car—C—C=C (ar = aromatic) torsion angles of −123.62 (12) and −115.54 (12)°. A possible weak intramolecular C—H...O interaction is observed. In the crystal, molecules are connected by two C—H...O hydrogen bonds, forming undulating layers lying parallel to the bc plane. Weak C—H...π and π–π stacking interactions also occur.

scholarly journals 2-(3,4-Dimethyl-5,5-dioxo-2H,4H-pyrazolo[4,3-c][1,2]benzothiazin-2-yl)acetic acid

2012 ◽  
Vol 68 (6) ◽  
pp. o1970-o1971 ◽  
Author(s):  
Sana Aslam ◽  
Hamid Latif Siddiqui ◽  
Matloob Ahmad ◽  
Muhammad Zia-ur-Rehman ◽  
Masood Parvez
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Pyrazole Ring ◽  
Chair Conformation ◽  
Thiazine Ring ◽  
The Mean ◽  
Graph Set ◽  
Title Molecule

In the title molecule, C13H13N3O4S, the heterocyclic thiazine ring adopts a half-chair conformation in which the S and an adjacent C atom are displaced by 0.919 (3) and 0.300 (4) Å, respectively, on the same side of the mean plane formed by the remaining ring atoms. The mean planes of the benzene and pyrazole rings are inclined at a dihedral angle of 18.32 (12)° with respect to each other. The acetate group is oriented at 80.75 (8)° with respect to the pyrazole ring. The crystal structure is stabilized by O—H...N and C—H...O hydrogen bonds, resulting in fused eight- and seven-membered rings with R 2 2(8) and R 2 2(7) graph-set motifs, respectively.

scholarly journals Crystal structures of the two epimers from the unusual thermal C6-epimerization of 5-oxo-1,2,3,5,5a,6,7,9b-octahydro-7,9a-epoxypyrrolo[2,1-a]isoindole-6-carboxylic acid, 5a(RS),6(SR),7(RS),9a(SR),9b(SR) and 5a(RS),6(RS),7(RS),9a(SR),9b(SR)

2016 ◽  
Vol 72 (10) ◽  
pp. 1429-1433
Author(s):  
Dmitry S. Poplevin ◽  
Fedor I. Zubkov ◽  
Pavel V. Dorovatovskii ◽  
Yan V. Zubavichus ◽  
Victor N. Khrustalev
Keyword(s):  
Carboxylic Acid ◽  
Nitrogen Atom ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Dihedral Angle ◽  
Bond Angle ◽  
Tetracyclic System ◽  
Graph Set ◽  
Hydrogen Bonded

The isomeric title compounds, C12H13NO4(Ia) and C12H13NO4(IIa), the products of an usual thermal C6-epimerization of 5-oxo-1,2,3,5,5a,6,7,9b-octahydro-7,9a-epoxypyrrolo[2,1-a]isoindole-6-carboxylic acid, represent the two different diastereomers and have very similar molecular geometries. The molecules of both compounds comprise a fused tetracyclic system containing four five-membered rings (pyrrolidine, pyrrolidinone, dihydrofuran and tetrahydrofuran), all of which adopt the usual envelope conformations. The dihedral angle between the basal planes of the pyrrolidine and pyrrolidinone rings are 14.3 (2) and 16.50 (11)°, respectively, for (Ia) and (IIa). The nitrogen atom has a slightly pyramidalized geometry [bond-angle sum = 355.9 and 355.3°, for (Ia) and (IIa)], respectively. In the crystal of (Ia), molecules form zigzag-like hydrogen-bonded chains along [010] through strong O—H...O hydrogen bonds and are further linked by weak C—H...O hydrogen bonds into complex two-tier layers parallel to (100). Unlike (Ia), the crystal of (IIa) contains centrosymmetric cyclic hydrogen-bonded dimers [graph setR22(14)], formed through strong O—H...O hydrogen bonds and are further linked by weak C—H...O hydrogen bonds into ribbons extending across [101].

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