Density Functional Theory Study of Cyanoetheneselenol: A Molecule of Astrobiological Interest.

The interstellar medium has a rich chemistry which involves a wide variety of molecules. Of particular interest are molecules that have a link to prebiotic chemistry which hold the key to understanding of our origins. On the basis of suggestions that selenium may have been involved in the origin and evolution of life, we have studied the selenium analogue of cyanoethenethiol, namely the novel cyanoetheneselenol. Cyanoetheneselenol exhibits conformational and geometrical isomerism. This theoretical work deals with the study of four forms of cyanoetheneselenol in terms of their structural, spectroscopic and thermodynamic parameters. All computations were performed using density functional theory method with the B3LYP functional and the Pople basis set, 6-311 + G(d,p), for all atoms. The relative stability of the four isomers of cyanoetheneselenol was obtained and interpreted. The infrared spectra were generated and assignment of the normal modes of vibration was performed. Probable regions of detection, proposed on the basis of parameters obtained from this study for the four isomers, include comets, the molecular cloud: Sagittarius B2(N), and planetary atmospheres. The molecular and spectroscopic parameters should be useful for future identification of the astrobiological molecule cyanoetheneselenol and the development of the Square Kilometre Array. Graphical Abstract E and Z isomers of cyanoetheneselenol.

2-[1-(Phenylsulfonyl)ethyl]benzoic acid and 2-[1-(phenylsulfonyl)propyl]benzoic acid.

In the title acids, C(15)H(14)O(4)S, (I), and C(16)H(16)O(4)S, (II), respectively, the angle between the planes of the benzene ring and the carboxyl group is 13.7 (1) degrees for (I) and 21.3 (1) degrees for (II). The molecular structures are stabilized by intramolecular C-H.O hydrogen bonds. The crystal packing is stabilized by a single O-H.O hydrogen bond in both compounds, in which the O and H atoms are ordered; H.O 1.87 A for (I) and 1.83 A for (II), O.O 2.680 (2) A for (I) and 2.652 (3) A for (II), and O-H.O 172 degrees for (I) and 175 degrees for (II). The hydrogen bond forms a cyclic dimer, with graph-set descriptor R(2)(2)(8), about a centre of symmetry.

Ethyl beta-[2-[4-(dimethylamino)phenyliminomethyl]-1-(phenylsulfonyl)indol-3-yl]acrylate.

The title compound, C(28)H(27)N(3)O(4)S, crystallizes in the centrosymmetric space group P2(1)/n, with one molecule in the asymmetric unit. In the indole ring, the dihedral angle between the fused rings is 3.6 (1) degrees. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 79.2 (1) degrees with the best plane of the indole moiety. The phenyl ring of the dimethylaminophenyl group is orthogonal to the phenyl ring of the phenylsulfonyl group. The dihedral angle formed by the weighted least-squares planes through the pyrrole ring and the phenyl ring of the dimethylaminophenyl group is 7.8 (1) degrees. The molecular structure is stabilized by C-H.O and C-H.N interactions.

A donor-acceptor compound composed of a dinuclear zinc(II) complex of a robson macrocycle with 8-methylquinoline

A donor-acceptor compound, diaqua-1kappaO,2kappaO-[&mgr;-11, 23-dimethyl-3,7,15,19-tetraazatricyclo[19.3.1.1(9,13)]hexacosa-1(25), 2,7,9,11,13(26),14,19,21,23-decaene-25,26-diolato-1kappa(4)N(3),N(7), O(25),O(26):2kappa(4)N(15),N(19),O(25),O(26)]dizinc(II) diperchlorate bis(8-methylquinoline) ethanol disolvate, [Zn(2)(C(24)H(26)N(4)O(2))(H(2)O)(2)](ClO(4))(2).2C(10)H(9)N. 2C(2)H(6)O, obtained by the reaction of a dinuclear zinc(II) complex of a Robson macrocycle (acceptor) and 8-methylquinoline (donor), lies about an inversion centre and the coordination about the unique Zn atom is a distorted square pyramid. The fifth coordination site is occupied by the water molecule, Zn-O = 2.016 (2) A, and the average macrocyclic Zn-O and Zn-N distances are 2.059 (6) and 2.059 (3) A, respectively.

trans-cis S-benzyl dithiocarbazate

In the crystal structure of the title compound, C(8)H(10)N(2)S(2), the molecules are linked by N-H.S hydrogen bonds between the imino group and the thione-S atoms to form a chain along the b axis. The dithiocarbazate moiety is rotated by 85.8 (2) degrees with respect to the phenyl ring.

4-(N-Hydroxyethyl-N-methylamino)benzaldehyde thiosemicarbazone

In the crystal structure of the title compound, C(11)H(16)N(4)OS, the phenyl ring and the thiosemicarbazone moiety from a dihedral angle of 7.7 (1) degrees. The crystal structure is governed by N-H.O and O-H.S hydrogen bonds leading to the formation of a two-dimensional network.

Two benzoylaminoacridinedione derivatives

The title compounds, 10-benzoylamino-1,2,3,4,5,6,7,8,9, 10-decahydroacridine-1,8-dione monohydrate, C(20)H(20)N(2)O(3).H(2)O, and 10-p-toluoylamino-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1, 8-dione monohydrate, C(21)H(22)N(2)O(3).H(2)O, consist of partially hydrogenated acridine moieties with one benzoylamino substituent on the central ring. The acridine moiety suffers considerable deviations from planarity. The central ring in the acridine moiety is a boat, while the outer rings adopt sofa conformations.

2-(Nitromethylene)-1,3-dithietane

In the crystal structure of the title compound, C(3)H(3)NO(2)S(2), the four-membered C(2)S(2) ring is planar, as is the whole molecule. The short intramolecular S.O distance of 2.687 (2) A shows the five-atom system to be conjugated. The molecules pack as a two-dimensional network in the (010) plane through short intermolecular S.O [2.900 (2) and 3.077 (2) A] interactions.

(N,N-Diisopropyldithiocarbamato-S, S')bis(triphenylphosphine-P)gold(I) butane solvate

In the crystal structure of the title complex, [Au(C(7)H(14)NS(2))(C(18)H(15)P)(2)].C(4)H(10), the Au atom is in a distorted tetrahedral environment consisting of the two P atoms of the triphenylphosphine ligands and the two S atoms of the diisopropylthiocarbamate ligand. The molecular structure and packing are stablized by van der Waals interactions.

trans-Dichloro(1,5,9,13-tetramethyl-1,5,9, 13-tetrazacyclohexadecane-kappa4N)ruthenium(III) triiodide

In the title complex, [RuCl(2)(C(16)H(36)N(4))]I(3), the overall symmetry of the centrosymmetric cation is approximately C(2h) and the I(-3) anions are slightly asymmetric. The I.I distance is 4.313 (1) A. The cations and the linear anions are arranged in alternate layers and thus form the intercalating structure.

1,2-Dibenzoylhydrazine

In the crystal structure of the title compound, C(14)H(12)N(2)O(2), the molecule lies about a twofold axis; two carbonyl groups and the H atoms of the N-N bond are in a trans orientation with respect to each other. In the crystal, each molecule is linked to the other and vice versa by intermolecular N-H.O hydrogen bonds between the amide hydrogen and the O atoms of neighbouring molecules to form two ten-membered rings, each of which has the graph-set motif C4R(2)(2)(10). This extends as a polymeric chain along the c axis.

p-methoxybenzaldehyde benzoylhydrazone monohydrate

The crystal structure of the title compound, C(15)H(14)N(2)O(2). H(2)O, is in the keto tautomeric form and the configuration at the azomethine C=N double bond is E. The molecule is non-planar, with a dihedral angle of 27.3 (1) degrees between the aromatic rings. The crystal structure is stabilized by extensive hydrogen bonding involving the water molecule and hydrazone moiety.

4-Hydroxy-3-methoxybenzaldehyde 4,5-diazafluoren-9-ylidenehydrazone

The whole molecule of the title compound, C(19)H(14)N(4)O(2), is essentially planar, with a highly conjugated pi system. In the crystal, the molecules are packed as chains along the [011] direction connected by O-H.N intermolecular hydrogen bonds.