The zwitterionic structure of 2-hydroxy-4-[(2-hydroxybenzylidene)amino]benzoic acid

Author(s):  
Anderson A. B. C. Júnior ◽  
Gustavo S. G. De Carvalho ◽  
Lippy F. Marques ◽  
Charlane C. Corrêa ◽  
Adilson D. Da Silva ◽  
...  

The title compound, C14H11NO4, exists in the solid phase in the zwitterionic form, 2-{[(4-carboxy-3-hydroxyphenyl)iminiumyl]methyl}phenolate, with the H atom from the phenol group on the 2-hydroxybenzylidene ring transferred to the imine N atom, resulting in a strong intramolecular N—H...O hydrogen bond between the iminium H atom and the phenolate O atom, forming a six-membered hydrogen-bonded ring. In addition, there is an intramolecular O—H...O hydrogen bond between the carboxylic acid group and the adjacent hydroxy group of the other ring, and an intermolecular C—H...O contact involving the phenol group and the C—H group adjacent to the imine bond, connecting the molecules into a two-dimensional network in the (10\overline{3}) plane. π–π stacking interactions result in a three-dimensional network. This study is important because it provides crystallographic evidence, supported by IR data, for the iminium zwitterionic form of Schiff bases.<!?tpb=12pt>

IUCrData ◽  
2016 ◽  
Vol 1 (9) ◽  
Author(s):  
S. Veeramanikandan ◽  
H. Benita Sherine ◽  
B. Gunasekaran ◽  
G. Chakkaravarthi

The asymmetric unit of the title compound, C18H20N2O5·H2O, consists of a benzohydrazide molecule which exists in anEconformation with respect to the C=N imine bond and a water molecule. The dihedral angle between the aromatic rings is 41.67 (9)°. The methoxy substituent of the 4-methoxyphenyl group is twisted at an angle of 6.8 (3)° out of the plane of the attached benzene ring. In the 2,4,5-trimethoxyphenyl unit, thepara-methoxy group is coplanar with the ring [C—C—O—C = −1.5 (3)°], whereas theortho- andmeta-methoxy groups are twisted out of the plane of the ring [C—C—O—C = 75.4 (2) and −67.1 (2)°, respectively]. Two molecules are connected by two water moleculesviaO—H...O hydrogen bonds, generating anR22(8) ring motif. One of the water H atoms forms an additional hydrogen bond to an N atom. The water molecules act as an acceptor for an N—H...O hydrogen bond. As a result, a three-dimensional network is formed.


2012 ◽  
Vol 68 (6) ◽  
pp. o1614-o1615
Author(s):  
Tong Yu ◽  
Hai-Yan Tian ◽  
Xiao-Feng Yuan ◽  
Shu-Zhi Hu ◽  
Ren-Wang Jiang

The title compound, C24H30O5, is the didehydro product of the steroid hellebrigenin (systematic name: 3β,5,14-trihydroxy-19-oxo-5β-bufa-20,22-dienolide). It consists of three cyclohexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclohexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Å and is β-oriented at the C atom of ring D to which it is attached. There is an O—H...O hydrogen bond in the molecule involving the hydroxy groups. In the crystal, O—H...O hydrogen bonds link the molecules into chains propagating along [010]. The chains are linked by C—H...O contacts into a three-dimensional network.


2007 ◽  
Vol 63 (11) ◽  
pp. o4404-o4404 ◽  
Author(s):  
Shu-Ping Yang ◽  
Li-Jun Han ◽  
Da-Qi Wang ◽  
Hai-Tao Xia

In the title compound, C14H12BrNO2, the molecules are linked by one C—H...Br hydrogen bond, so forming a C(13) chain running parallel to the [010] direction, and these chains are linked by further C—H...π and C—H...Br hydrogen bonds, resulting in a three-dimensional network structure.


2013 ◽  
Vol 69 (12) ◽  
pp. o1781-o1781 ◽  
Author(s):  
M. Umadevi ◽  
V. Saravanan ◽  
R. Yamuna ◽  
A. K. Mohanakrishnan ◽  
G. Chakkaravarthi

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The molecular structure is stabilized by a weak intramolecular C—H...O hydrogen bond. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming a chain along [10-1]. C—H...π interactions are also observed, leading to a three-dimensional network.


2014 ◽  
Vol 70 (10) ◽  
pp. o1106-o1106
Author(s):  
Yong-Le Zhang ◽  
Chuang Zhang ◽  
Wei Guo ◽  
Jing Wang

In the title compound, C9H9N3OS, the plane of the benzene ring forms a dihedral angle of 33.40 (5)° with that of the triazole group. In the crystal, molecules are linked by O—H...N hydrogen bonds involving the phenol –OH group and one of the unsubstituted N atoms of the triazole ring, resulting in chains along [010]. These chains are further extended into a layer parallel to (001) by weak C—H...N hydrogen-bond interactions. Aromatic π–π stacking [centroid–centroid separation = 3.556 (1) Å] between the triazole rings links the layers into a three-dimensional network.


2007 ◽  
Vol 63 (3) ◽  
pp. o1271-o1273 ◽  
Author(s):  
Amel Djedouani ◽  
Abderrahmen Bendaas ◽  
Sihem Boufas ◽  
Magali Allain ◽  
Gilles Bouet ◽  
...  

The title compound, C15H15NO3, derived from the condensation of dehydroacetic acid and p-toluidine, crystallizes in a zwitterionic form with cationic iminium and anionic enolate groups, which complete a six-membered pseudocycle via an intramolecular N—H...O hydrogen bond. C—H...O interactions link the molecules into a two-dimensional network.


2012 ◽  
Vol 68 (6) ◽  
pp. o1636-o1636
Author(s):  
Er-Qun Yang ◽  
Jun-Tao Zhang ◽  
Xiao-Ping Cao ◽  
Jin-Zhong Gu

The title compound, C18H17NO4, was obtained accidentally through acid-catalysed aromatization of a phthalimide-substituted 2-(1-hydroxyethyl)cyclohex-2-enone. It exhibits an intramolecular O—H...Oc (c = carbonyl) hydrogen bond and forms a three-dimensional network structure via π–π stacking interactions between adjacent benzene rings (phthalimide-to-phenylene and phthalimide-to-phthalimide), with centroid–centroid distances of 3.8262 (6) and 3.6245 (5) Å.


Author(s):  
Sevim Türktekin Çelikesir ◽  
Mehmet Akkurt ◽  
Aliasghar Jarrahpour ◽  
Habib Allah Shafie ◽  
Ömer Çelik

In the title compound, C22H18N2O5, the central β-lactam ring (r.m.s. deviation = 0.002 Å) makes dihedral angles of 64.21 (14), 82.35 (12) and 20.66 (13)° with the phenyl ring and the nitro- and methoxybenzene rings, respectively. The molecular structure is stabilized by an intramolecular C—H...O hydrogen bond. In the crystal, molecules are linkedviaC—H...O hydrogen bonds, forming slabs lying parallel to (111). The slabs are linkedviaC—H...π interactions, forming a three-dimensional network.


2015 ◽  
Vol 71 (6) ◽  
pp. o416-o416 ◽  
Author(s):  
Muhammad Salim ◽  
Muhammad Nawaz Tahir ◽  
Munawar Ali Munawar ◽  
Muhammad Shahid ◽  
Hazoor Ahmad Shad

In the title compound, C15H14ClNO, which is isostructural with its bromo analogue [Tahiret al.(2012).Acta Cryst., E68, o2730], the dihedral angle between the planes of the aromatic rings is 2.71 (7)° and an intramolecular O—H...N hydrogen bond closes anS(6) ring. In the crystal, extremely weak C—H...π interactions link the molecules into a three-dimensional network.


2012 ◽  
Vol 68 (6) ◽  
pp. o1765-o1765 ◽  
Author(s):  
Durga Prasad Singh ◽  
Seema Pratap ◽  
Ray J. Butcher ◽  
Sushil K. Gupta

The title compound, C13H11NO3S, was synthesized from methyl anthranilate, triethylamine and 2-thiophenoyl chloride in benzene. The molecular conformation is stabilized by an intramolecular N—H...O hydrogen bond. The dihedral angle between the rings is 2.74 (12)°. In the crystal, C—H...O interactions link neighbouring molecules into a three-dimensional network.


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