An official website of the United States government
The title compound, C8H7Cl2NO2, crystallizes in the triclinic space groupP1with three molecules in the asymmetric unit. Two of them are essentially planar, with mean deviations of 13 non-hydrogen atoms of 0.029 and 0.030 Å, and differ only in the conformation of the O—H hydrogen atom. The third molecule is quite nonplanar, with the CCNO acetamide plane forming a dihedral angle of 67.56 (5)° with the remainder of the molecule. In the extended structure, the two almost planar molecules form antiparallel hydrogen-bonded chains through N—H...O interactions of the acetamide substituents. The N—H group of the nonplanar molecule donates a bifurcated hydrogen bond to the O—H group and a Cl substituent of one of the planar molecules. The O—H groups of all molecules form intermolecular hydrogen bonds to other O—H groups or carbonyl O atoms. Together, the hydrogen bonds generate a three-dimensional network.
more »
« less
Conformational control through co-operative nonconventional C—H...N hydrogen bonds
We report the design, synthesis, and crystal structure of a conjugated aryleneethynyl molecule, 2-(2-{4,5-dimethoxy-2-[2-(2,3,4-trifluorophenyl)ethynyl]phenyl}ethynyl)-6-[2-(pyridin-2-yl)ethynyl]pyridine, C 30 H 17 F 3 N 2 O 2 , that adopts a planar rhombus conformation in the solid state. The molecule crystallizes in the space group P -1, with Z = 2, and features two intramolecular sp 2 -C—H...N hydrogen bonds that co-operatively hold the arylethynyl molecule in a rhombus conformation. The H atoms are activated towards hydrogen bonding since they are situated on a trifluorophenyl ring and the H...N distances are 2.470 (16) and 2.646 (16) Å, with C—H...N angles of 161.7 (2) and 164.7 (2)°, respectively. Molecular electrostatic potential calculations support the formation of C—H...N hydrogen bonds to the trifluorophenyl moiety. Hirshfeld surface analysis identifies a self-complementary C—H...O dimeric interaction between adjacent 1,2-dimethoxybenzene segments that is shown to be common in structures containing that moiety.
more »
« less
- PAR ID:
- 10292184
- Date Published:
- Journal Name:
- Acta Crystallographica Section C Structural Chemistry
- Volume:
- 77
- Issue:
- 8
- ISSN:
- 2053-2296
- Page Range / eLocation ID:
- 485 to 489
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The molecular structure of the title compound, C 11 H 15 NO 2 S, features a sulfonamide group with S=O bond lengths of 1.4357 (16) and 1.4349 (16) Å, an S—N bond length of 1.625 (2) Å, and an S—C bond length of 1.770 (2) Å. When viewing the molecule down the S—N bond, both N—C bonds of the pyrrolidine ring are oriented gauche to the S—C bond with torsion angles of −65.6 (2)° and 76.2 (2)°. The crystal structure features both intra- and intermolecular C—H...O hydrogen bonds, as well as intermolecular C—H...π and π–π interactions, leading to the formation of sheets parallel to the ac plane.more » « less
-
In an attempt to grow 8-hydroxyquinoline–acetaminophen co-crystals from equimolar amounts of conformers in a chloroform–ethanol solvent mixture at room temperature, the title compound, C 9 H 7 NO, was obtained. The molecule is planar, with the hydroxy H atom forming an intramolecular O—H...N hydrogen bond. In the crystal, molecules form centrosymmetric dimers via two O—H...N hydrogen bonds. Thus, the hydroxy H atoms are involved in bifurcated O—H...N hydrogen bonds, leading to the formation of a central planar four-membered N 2 H 2 ring. The dimers are bound by intermolecular π–π stacking [the shortest C...C distance is 3.2997 (17) Å] and C—H...π interactions into a three-dimensional framework. The crystal grown represents a new monoclinic polymorph in the space group P 2 1 / n . The molecular structure of the present monoclinic polymorph is very similar to that of the orthorhombic polymorph (space group Fdd 2) studied previously [Roychowdhury et al. (1978). Acta Cryst. B 34 , 1047–1048; Banerjee & Saha (1986). Acta Cryst. C 42 , 1408–1411]. The structures of the two polymorphs are distinguished by the different geometries of the hydrogen-bonded dimers, which in the crystal of the orthorhombic polymorph possess twofold axis symmetry, with the central N 2 H 2 ring adopting a butterfly conformation.more » « less
-
In the title compound, 3-[(2-acetamidophenyl)imino]butan-2-one, C 12 H 14 N 2 O 2 , the imine C=N bond is essentially coplanar with the ketone C=O bond in an s-trans conformation. The benzene ring is twisted away from the plane of the C=N bond by 53.03 (14)°. The acetamido unit is essentially coplanar with the benzene ring. In the crystal, molecules are connected into chains along the c axis through C—H...O hydrogen bonds, with two adjacent chains being hinged by C—H...O hydrogen bonds.more » « less
-
The title hydrated molecular salt, C19H15N4+·Cl−·2.5H2O, has two triphenyltetrazolium cations, two chloride anions and five water molecules in the asymmetric unit. The cations differ in the conformations of the phenyl rings with respect to the heterocyclic core, most notably for the C-bonded phenyl ring, for which the N—C—C—C torsion angles differ by 36.4 (3)°. This is likely a result of one cation accepting an O—H...N hydrogen bond from a water molecule [O...N = 3.1605 (15) Å], while the other cation accepts no hydrogen bonds. In the extended structure, the water molecules are involved in centrosymmetric (H2O)2Cl2rings as well as (H2O)4chains. An unusual O—H...π interaction and weak C—H...O and C—H...Cl hydrogen bonds are also observed.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1107/S2053229621007427
