X-Ray Structure Determinations of Bromo- and/or Bromomethylsubstituted Benzenes: C–H···Br, C–Br···Br, and C–Br···π Interactions

2012 ◽  
Vol 67 (12) ◽  
pp. 1273-1281 ◽  
Author(s):  
Peter G. Jones ◽  
Piotr Kuś ◽  
Ina Dix

The structures of seven benzene derivatives [1,2,3-tri(bromomethyl)benzene, (1); 3,5- di(bromomethyl)bromobenzene, (2); 2,5-di(bromomethyl)bromobenzene, (3); 4-(bromomethyl)-2,5- dibromotoluene, (4); 4-(bromomethyl)bromobenzene, (5); 2,3-di(bromomethyl)bromobenzene, (6) and (bromomethyl)-p-dibromobenzene, (7)] with bromo and bromomethyl (and in one case methyl) substituents are presented and analysed in terms of Br···Br interactions up to 4.0 A° , supported by hydrogen bonds H···Br. Some interactions of the type Br···π and π···π are encountered and play a subordinate role in the packing. Despite the close chemical similarity of the compounds, some of which are isomers with permuted substituent positions, the packing motifs are highly variable. Compounds 2-5 are based on layer structures with Brn (n=3, 4) and/or mixed Br/C rings. Compounds 1, 6 and 7 display three-dimensional packings of differing complexity, but with interpretable substructures; 1 can be analysed in terms of ribbons of linked Br3 and Br4 rings; 6 displays chains of linked Br3 triangles; 7 consists of ribbons of linked Br4 quadrilaterals.

2002 ◽  
Vol 57 (8) ◽  
pp. 914-921 ◽  
Author(s):  
P. G. Jones ◽  
J. Ossowski ◽  
P. Kus

N,N′-Dibutyl-terephthaldiamide (1), N,N′-dihexyl-terephthaldiamide (2), N,N′-di(tert-butyl)- terephthaldiamide (3), N,N,N′,N′-tetrabutyl-terephthaldiamide (4), 1,1′-terephthaloylbis- pyrrolidine (5), 1,1′-terephthaloyl-bis-piperidine (6), and 4,4′-terephthaloyl-bis-morpholine (7) have been synthesised and physicochemically characterised. The X-ray structure determinations reveal imposed inversion symmetry for compounds 1-6; compound 3 has two independent molecules with inversion symmetry in the asymmetric unit. Compounds 1-3 form classical hydrogen bonds of the type N-H···O=C, leading to a ribbon-like arrangement of molecules (1 and 2) or a layer structure (3). Compound 3 also displays a very short C-H···O interaction, a type of hydrogen bond that is also observed in compounds 4-7, which lack classical donors; thereby compounds 4-6 form layer structures and 7 a complex threedimensional network.


2003 ◽  
Vol 58 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Rainer Mattes ◽  
Jörg Ebbing ◽  
Annette Grüss ◽  
Jens Köppe ◽  
Krystyna Majcher

Abstract The synthesis and single crystal X-ray structures of four adducts of squaric acid with cyclic nitrogen bases are reported. Extensive hydrogen bonding, ionic interactions and (in one case) π-π-interactions lead to layered, and to two- and three-dimensional assemblies. [Pyrimidinium][ hydrogenquadratate] (1) has a layer structure, consisting of head-to-tail infinite chains of pyrimidinium and [HC4O4]− ions, which are cross-linked by short N-H···O and C-H···O hydrogen bonds. [C9H11N2][HC4O4] ・0.5H2C4O4 (2), the adduct of a benzodiazepin and squaric acid, has a ladder-structure. Chains of [HC4O4]− ions and H2C4O4 molecules in alternating order form the ladder-beam. Layers of cations and anions in the ratio 2:1 build the crosspieces at an angle of 49° to the beam. The layers contain dimers of [HC4O4]− ions. [H2L2][HC4O4]2 (3) with L2 = 5,6,7,8,9,14,15,16,17,18-decahydrodibenzo[e,l]-1,4,8,11-tetraaza-cyclotetradecine shows zigzag chains made of [HC4O4]− ions. Between the [H2L2]2+ and the [HC4O4]− ions π-π interactions exist besides up to four N-H···O hydrogen bonds. The [H2L2]2+ ions possess two different conformations. [H2cyclam][C2O4] ·4H2O (4) contains strongly undulated layers of the composition [C4O4 ·4H2O]2−. The cations, which show two intramolecular N-H···N hydrogen bonds with N···N distances of 2.870 (3) Å , are interlinked at an angle of 41.5°.


IUCrJ ◽  
2014 ◽  
Vol 1 (2) ◽  
pp. 136-150 ◽  
Author(s):  
Palash Sanphui ◽  
Geetha Bolla ◽  
Ashwini Nangia ◽  
Vladimir Chernyshev

Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR),p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM) hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior stability, faster dissolution rate and is able to overcome the hydration tendency of the reference drug.


Author(s):  
R. A. Nagalakshmi ◽  
J. Suresh ◽  
S. Maharani ◽  
R. Ranjith Kumar ◽  
P. L. Nilantha Lakshman

The title compound, C23H21N3, comprises a 2-amino-3-cyanopyridine ring fused with a cyclopentane ring. The later adopts an envelope conformation with the central methylene C atom as the flap. The benzyl and andp-tolyl rings are inclined to one another by 56.18 (15)°, and to the pyridine ring by 81.87 (14) and 47.60 (11)°, respectively. In the crystal, molecules are linked by pairs of N—H...Nnitrilehydrogen bonds, forming inversion dimers with anR22(12) ring motif. The dimers are linked by C—H...π and π–π interactions [centroid–centroid distance = 3.7211 (12) Å], forming a three-dimensional framework.


2011 ◽  
Vol 396-398 ◽  
pp. 2338-2341
Author(s):  
Xing Chuan Wei ◽  
Zhi Li Liu ◽  
Kun Zhang ◽  
Zhi Yun Du ◽  
Xi Zheng

In this paper, (2E,6E)-2,6-Bis(2,3,4-tri-methoxy -benzylidene)cyclohexanone (omitted as tmbcho) (1) was obtained by the reaction of acetic acid, tetrahydrofuran, cyclohexanone and 2,3,4-tri-methoxy-benzaldehyde. Three non-classic hydrogen bonds were observed in the compound. X-ray crystallography shows that the crystal structure is stabilized by intermolecular C-H•••π interactions and it contains plenty of conjugated double bonds. The title compound was characterized by UV-vis and fluorescent spectral studies.


2012 ◽  
Vol 68 (6) ◽  
pp. o1711-o1711 ◽  
Author(s):  
Vandavasi Koteswara Rao ◽  
Matthias Zeller ◽  
Sherri R. Lovelace-Cameron

The asymmetric unit of the title compound, C10H8N2·C8H6O4, consists of one half-molecule of each moiety, 4,4′-bipyridine (bpy) and terephthalic acid (bdc), both being located on crystallographic inversion centers. They are linked together via strong intermolecular O—H...N hydrogen bonds, forming infinite chains propagating along [1-21]. The chains are further connected through C—H...O interactions giving sheets in (012). The sheets are linked via π–π interactions between the bpy rings and the bdc–bpy rings [centroid–centroid distances = 3.690 (2) and 3.869 (2) Å], resulting in the formation of a three-dimensional supramolecular layer-like structure.


Author(s):  
Robert A. Toro ◽  
Analio Dugarte-Dugarte ◽  
Jacco van de Streek ◽  
José Antonio Henao ◽  
José Miguel Delgado ◽  
...  

The structure of racemic (RS)-trichlormethiazide [systematic name: (RS)-6-chloro-3-(dichloromethyl)-1,1-dioxo-3,4-dihydro-2H-1λ6,2,4-benzothiadiazine-7-sulfonamide], C8H8Cl3N3O4S2 (RS-TCMZ), a diuretic drug used in the treatment of oedema and hypertension, was determined from laboratory X-ray powder diffraction data using DASH [David et al. (2006). J. Appl. Cryst. 39, 910–915.], refined by the Rietveld method with TOPAS-Academic [Coelho (2018). J. Appl. Cryst. 51, 210–218], and optimized using DFT-D calculations. The extended structure consists of head-to-tail dimers connected by π–π interactions which, in turn, are connected by C—Cl...π interactions. They form chains propagating along [101], further connected by N—H...O hydrogen bonds to produce layers parallel to the ac plane that stack along the b-axis direction, connected by additional N—H...O hydrogen bonds. The Hirshfeld surface analysis indicates a major contribution of H...O and H...Cl interactions (32.2 and 21.7%, respectively). Energy framework calculations confirm the major contribution of electrostatic interactions (E elec) to the total energy (E tot). A comparison with the structure of S-TCMZ is also presented.


IUCrData ◽  
2016 ◽  
Vol 1 (10) ◽  
Author(s):  
S. Naveen ◽  
Seranthimata Samshuddin ◽  
Manuel Rodrigues ◽  
Dandavathi Arunkumar ◽  
N. K. Lokanath ◽  
...  

In the title hydrated hydrazine compound, C12H17N3O·H2O, the C=N bond adopts an E conformation. In the crystal, water molecules bridge the hydrazine molecules, via N—H...O and O—H...O hydrogen bonds, forming sheets parallel to the bc plane. There are C—H...π interactions present within the sheets, and further C—H...π interactions link the sheets to form a three-dimensional structure.


2013 ◽  
Vol 68 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Muhammad Monim-ul-Mehbooba ◽  
Muhammad Ramzan ◽  
Tobias Rüffe ◽  
Heinrich Lang ◽  
Shafqat Naddem ◽  
...  

A cyanido-bridged Zn(II)-Ag(I) bimetallic coordination polymer, {[Zn(phen)2(H2O){Ag(CN)2}] [Ag(CN)2]·MeOH}n (1), was prepared using ZnCl2, 1,10-phenanthroline (phen) and K[Ag(CN)2] and characterized by IR spectroscopy, thermal analysis and X-ray crystallography. The crystal structure of 1 consists of dinuclear [Zn(phen)2(H2O){Ag(CN)2}]+ cations, [Ag(CN)2]- anions and a methanol molecule. The non-coordinated [Ag(CN)2]- anions are linked to the [Zn(phen)2(H2O){Ag(CN)2}]+ complex cations through argentophilic interactions leading to the formation of chains. The chains are connected by hydrogen bonds and π-π interactions to give a 3D network.


2016 ◽  
Vol 72 (10) ◽  
pp. 1412-1416
Author(s):  
Monserrat Alfonso ◽  
Helen Stoeckli-Evans

The title isotypic complexes, bis[μ-5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylato]-κ4N1,O2,N6:O3;κ4O3:N1,O2,N6-bis[diaquamanganese(II)] tetrahydrate, [Mn2(C16H8N4O4)2(H2O)4]·4H2O, (I), and bis[μ-5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylato]-κ4N1,O2,N6:O3;κ4O3:N1,O2,N6-bis[diaquairon(II)] tetrahydrate, [Fe2(C16H8N4O4)2(H2O)4]·4H2O, (II), are, respectively, the manganese(II) and iron(II) complexes of the ligand 5,6-bis(pyridin-2-yl)-pyrazine-2,3-dicarboxylic acid. The complete molecule of each complex is generated by inversion symmetry. Each metal ion is coordinated by a pyrazine N atom, a pyridine N atom, two carboxylate O atoms, one of which is bridging, and two water O atoms. The metal atoms haveMN2O4coordination geometries and the complexes have a cage-like structure. In the crystals of both compounds, the complexes are linked by O—H...O and O—H...N hydrogen bonds involving the coordinating water molecules, forming chains along [100]. These chains are linked by O—H...O hydrogen bonds involving the non-coordinating water molecules, forming layers parallel to (011). The layers are linked by pairs of C—H...O hydrogen bonds and offset π–π interactions, so forming a hydrogen-bonded three-dimensional framework.


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