Decachloro­hexa-1,5-diene

The title compound, C6Cl10, cystallizes in a nearly C2-symmetrical gauche conformation. Both trichloro­vinyl groups are nearly planar [Cl—C—C—Cl torsion angles = −178.47 (12) and −179.93 (11)°] and the lengths of their C—Cl bonds increase from the terminal trans and cis C—Cl bonds to the inter­nal bonds. The Cl—C—Cl bond angles of the terminal dichloro­methyl­ene units are compressed to 111.75 (11) and 111.40 (11)°

5-Pentyl-1H-tetra­zole

The title compound C6H12N4, is one of a few known tetra­zoles with an alkyl chain in the 5-position. The asymmetric unit contains two independent mol­ecules. The mol­ecules are linked by N—H⋯N inter­actions into chains with graph-set notation D(2) and C 2 2(8) along [010]. The two independent mol­ecules form a layered structure, the layers being composed of inter­digitating strands of alternatingly oriented and nearly identical mol­ecules

5-Benzyl-5H-pyrido[3,2-b]indole

The title compound, C18H14N2, was prepared by twofold Pd-catalyzed aryl­amination of a cyclic pyrido–benzo–iodo­lium salt. In the crystal, two mol­ecules of 9-benzyl-δ-carboline form centrosymmetrical dimers with distances of 3.651 (2) Å between the centroids of the pyridine rings and 3.961 (2) Å between the centroids of the pyrrole and pyridine rings. The phenyl rings point to the other mol­ecule in the dimer and the carboline core is essentially planar [maximum deviation of 0.027 (2) Å]

4-Diethyl­amino-3,5-diisopropyl­benzalde­hyde

The title benzaldehyde, C17H27NO, was prepared via lithia­tion of bromoaniline and reaction with DMF. In the crystal, the molecule adopts a C2-symmetrical conformation; nevertheless, two modes of disorder are present: the orientation of the aldehyde group (occupancy ratio 0.5:0.5) and of symmetry-equivalent ethyl groups [occupancy ratio 0.595 (7):0.405 (7)]. The phenyl­ene ring and the carbonyl group are essentially coplanar [C—C—C—O torsion angle = −179.0 (4)°] but the dihedral angle between the mean planes of the phenyl­ene ring and the amino group = 67.5 (2)°. This and the long [1.414 (3) Å] aniline C—N bond indicate electronic decoupling between the carbonyl and amino groups. The angle sum of 359.9 (2)° around the N atom results from steric compression-induced rehybridization

(E,E,E,E)-2,3,5,6-Tetra­kis{2-[4-(dimethyl­amino)­phen­yl]ethen­yl}pyrazine

In the title compound, C44H48N6, the essentially planar mol­ecule [maximum deviation from the mean plane of the π system of 0.271 (3) Å] is located on a crystallographic centre of inversion. The almost planar (angle sums at N atoms = 357.6 and 357.1°) dimethyl­amino groups and short C—N bonds of the aniline groups [both 1.379 (4) Å] indicate strong electronic coupling between these groups and the central pyrazine ring

2,5-Bis[4-(dimethyl­amino)­phen­yl]-3,6-dimethyl­pyrazine

The title compound, C22H26N4, was prepared from p-dimethyl­amino­propiophenone in six steps. The mol­ecule has no crystallographic symmetry. The dihedral angles between the pyrazine ring and the phenyl rings are 35.81 (6) and 37.11 (8)°. The dimethyl­amino groups are essentially planar (sum of the bond angles at N = 359.3 and 359.9°) and nearly coplanar with the adjacent aromatic ring [dihedral angles = 5.54 (11) and 7.40 (3)°]. This effect and the short aniline C—N bonds can be rationalised in terms of charge transfer from the amino groups to the central pyrazine ring

N,N-Dihexyl-4-[2-(4-nitro­phen­yl)vin­yl]aniline

The title compound, C26H36N2O2, was prepared by Horner olefination of p-dihexyl­amino­benzaldehyde and diethyl p-nitro­benzyl­phospho­nate. It crystallizes with two independent mol­ecules in the asymmetric unit. Both have similar geometries of the π-systems but the conformations of all hexyl chains are different. Whereas one hexyl chain of the first mol­ecule shows the typical all-anti conformation, the second is arranged in a gauche-anti-gauche-anti conformation with N—C—C—C, C—C—C—C, C—C—C—C and C—C—C—C torsion angles of −65.1 (4), 167.3 (3), 63.3 (4), and 179.4 (3)°. One of the hexyl chains in the other mol­ecule has an anti-anti-gauche-anti conformation [N—C—C—C, C—C—C—C, C—C—C—C and C—C—C—C torsion angles = 179.6 (3), −179.8 (3), −68.7 (5) and −178.8 (4)°], the other starts with an anti-gauche-gauche sequence. Molecules A and B are composed of five planar subunits. The angle sums around the N atoms are in the range 356 (2)–360.0 (2)°. Torsion angles between these segments do not exceed 4.9 (4)°, except for one of the alkyl chains each [molecule A = 26.2 (4)°; molecule B = −6.0 (4)°]. The high planarity of the molecules and the short aniline C—N bonds [1.385 (3) Å in molecule A and 1.378 (3) Å in molecule B] indicate a strong electronic coupling through the stilbene unit. One methylene group is disordered over two positions with an occupancy ratio of 0.72:0.28

5-Pentyl-1H-tetra­zole

The title compound C6H12N4, is one of a few known tetra­zoles with an alkyl chain in the 5-position. The asymmetric unit contains two independent mol­ecules. The mol­ecules are linked by N—H⋯N inter­actions into chains with graph-set notation D(2) and C 2 2(8) along [010]. The two independent mol­ecules form a layered structure, the layers being composed of inter­digitating strands of alternatingly oriented and nearly identical mol­ecules

5-Methyl-3-(3-methyl­phen­yl)-7-phenyl-1,2,4-triazolo[4,3-c]pyrimidine

The title compound, C19H16N4, is one of the few known 3,7-diaryl-1,2,4-triazolo[4,3-c]pyrimidines. The triazolopyrimidine unit is essentially planar (r.m.s. deviation = 0.048 Å). The phenyl ring and the heterocyclic core subtend a dihedral angle of only 15.09 (6)°, whereas the m-tolyl ring is twisted by 71.80 (6)° out of the plane of the triazole ring. Two C—H⋯N hydrogen bonds and π–π stacking inter­actions [centroid–centroid distance = 3.7045 (8) Å] stabilize the crystal packing