Abstract The title compound, with the formula C4H9—C6H10—CH2—C6H10—COO—C6H4CN (CBMC), crystallizes in the monoclinic space group P21/n with a = 6.4075(7) A, b = 18.345(2) A c = 19.423(2) A, β = 98.614(9) A and four molecules per unit cell. The structure was solved by direct methods and refined to R = 0.052. The CBMC molecules adopt an elongated banana-shaped form enabling the formation of a monotropic nematic phase 2 degrees below the melting point. The X-ray experiments were complemented by a conformational analysis of the phenyl-4-cyclohexylmethyl-cyclohexanoate moiety using the EPEN/2 method. The Molecular structure existing in the crystal (and probably also in the mesophase) agrees very well with the most stable conformation indicated by calculation. In the conformational analysis the molecular 1ength:width ratio was also taken into consideration. The synthesis of CBMC, which represents a new type of mesogen, is described.

The first synthesis of substituted 2,2-dioxo-1-phenyl-1H-thieno[3,4-c][1,2]thiazines 2 and some of their reactions are achieved. Compounds 2 were prepared from the 3,5-dimethyl-1,1-dioxo-1,2-thiazine-4-carbaldehydes 1 by reaction with sulfur and triethyl amine in dimethylformamide under mild conditions. They were characterized spectroscopically and by X-ray structure analysis. The formylation, chlorination and oxidation of 2 are reported.

Treatment of bis(4-methoxybenzylthio)acetylene (1) with iodine monochloride yields different products in the presence or absence of nucleophiles such as water or alcohols. Normally, the electrophilic cyclisation of bis(benzylthio)acetylenes produces 1H-2-benzothiopyrans 2 by intramolecular ortho attack on the aromatic ring by a vinyl cation formed in situ (Ar2-6 cyclisation). In the case of 1, however, the high electron density in the ipso position of the aromatic ring favours ipso attack (Ar1-5 route). The fate of the ipso σ complex is determined by the presence or absence of nucleophiles in the reaction medium. When nucleophiles are excluded, the σ complex is stabilised by 1,2-migration and formation of 1H-2-benzothiopyran 2a. In the presence of water, the σ complex yields spirocyclohexadienone dihydrothiophenes 3a and 3d. In the presence of 3-methylbenzyl alcohol, the methoxy substituent of the 2-benzothiopyran ring is exchanged by the 3-methylbenzyloxy group in product 2d. These findings are consistent with the formation of 2a, 2c, 2d and 2f by ipso − and not ortho − attack on the 4-methoxyphenyl ring. Similar results were obtained both with ICl and from a proton-induced cyclisation. In one-pot syntheses, 3a and 3d were transformed into 2-benzothiopyrylium salts 4a and 4b by tritylium tetrafluoroborate, and 3a and 3b were rearranged into the 6-hydroxy-substituted 2-benzothiopyrans 2b and 2g by proton catalysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The crystal and molecular structures of the title compounds have been determined. Ph2P(O)N=C(NH2)NHPh (1) crystallizes in the space group P2(1)2(1)2(1) With four molecules in the unit cell of dimensions: a = 9.183(1), b = 11.699(1), c = 16.554(2) A. Ph2P(S)N=C(NH2)NHPh (2) crystallizes in the space group PI with four molecules in the unit cell of dimensions: a = 9.479(2), b = 13.695(1), c = 14.037(1) Angstrom, alpha = 82.98(1), beta = 89.31(1), gamma = 87.67(1)degrees. The structures were solved by direct methods. The molecules of 1 and 2 are associated via weak intermolecular NH O (1) and NH S (2) hydrogen bonds, respectively. Besides that, weak intramolecular interactions were observed between the NH2 group and the chalcogen atom in both structures. Additionally, hydrogen bonds were characterized by IR spectroscopy in solution as well as in the solid state in dependence on temperature. (C) 2000 Elsevier Science B.V. All rights reserved.

Me-2(Cl)SnCH2CH2PPh2 (1) reacts with Ni-II, pd(II) and Pt-II halides in molar ratio 2:1 forming the complexes [MX2{PPh2CH2CH2Sn(Cl)Me-2}(2)] (M=Ni, Pd, Pt; X=Cl, Br) (3-6, 9, 10) (7, 8: M = Ni; Br instead of Cl). The nickel complexes were isolated and characterized both as the planar (3, 5, 7) and the tetrahedral (4, 6, 8) isomer. Crystal structure analyses and NMR data indicate for the planar nikkel complexes 3, 5, 7 and [MCl2{PPh2CH2CH2Sn(Cl)Me-2}(2)] (9: M = Pd; 10: M = Pt) the existence of intra and intermolecular M-Hal ... Sn bridges. In a ligand:metal molar ratio of 3:1 the complexes [M+Cl{PPh2CH2CH2Sn-Cl2Me2}-{PPh2CH2CH2Sn(Cl)Me-2}(2)] (11: M = Pd; 12: M = Pt) are formed which represent intramolecular ion pairs. By dehaloge nation of [PdCl2{PPh2CH2CH2Sn(Cl)Me-2}(2)] (9) with sodium amalgam and graphite potassium (C8K), respectively, the palladacycles cis-[Pd{PPh2CH2CH2SnMe2}(2)] (13) and trans-[Pd(Cl)PPh2CH2CH2SnMe2{PPh2CH2CH2Sn(Cl)Me-2}] (14) are formed. From the compounds 1, 3, 9, 11, and 12 the crystal structures are determined. All compounds are characterized by H-1, P-31 and Sn-119 NMR spectroscopy.

The crystal and molecular structures of hexyloxy (3a) and heptyloxy homologues (3b) of mesogenic 4,6-dichloro-1,3phenylene bis[4-(4-n-alkyloxy-phenyliminomethyl)benzoates] have been determined by X-ray analyses. Both compounds crystallize in the triclinic space group P (1) over bar with two molecules in unit cells of following dimensions. 3a: a = 8.340(2), b = 13.143(4) and c = 19.364(6) Angstrom; alpha = 96.36(4), beta = 93.33(4) and gamma = 103.07(1)degrees; 3b: a = 8.738(2), b = 15.850(4) and c = 17.618(5) Angstrom; alpha = 115.73(2), beta = 90.82(2) and gamma = 95.49(2)degrees. The structures were solved by direct methods and refined on F-2 to R values of R1 = 0.046 (3a) and 0.094 (3b).The molecular structures of 3a and 3b are discussed in detail, especially in view of the correlation between molecular conformation (banana- or rod-shaped molecules) and liquid crystalline behaviour (observed mesophases). It can be shown for 3a and 3b that the molecules are not strongly bent and not so far from the rod-like shape. Crystal packing of the mesogens is characterized by a parallel arrangement of the strongly interlocked molecules. (C) 2000 Elsevier Science B.V. All rights reserved.

The title compound crystallizes in the monoclinic space group P2(1)/c with four formula units in a unit cell of dimensions a = 10.814(2), b = 8.400(2), c = 11.398(4) Angstrom, beta = 110.86(2)degrees, V = 967.5(5) Angstrom(3). The crystal structure is characterized by almost exactly planar [Me2NC(NH2)Me](+) cations and [O2CNMe2](-) anions which are approximately perpendicular oriented to one another. The amidine N-1-C and N-2-C bond lengths are significantly different (1.341(7) and 1.292(7) Angstrom, respectively) but the C-O distances of the carbamate anion are equal within experimental error (1.263(6) and 1.256(6) Angstrom). An essential feature of the crystal structure are N-H ... O hydrogen bonds between cations and anions.

Terminally alkyl- and alkyloxysubstituted 4,6-dichloro-1,3-phenylene bis[4-(phenyliminomethyl)benzoates] have been synthesized and studied by optical microscopy, differential scanning calorimetry, NMR spectroscopy, X-ray diffraction and dielectric measurements. Surprisingly, nematic and smectic phases are observed, although comparable bisesters of resorcinol and monochlororesorcinol exhibit B phases typical for banana-shaped mesogens. It could be proved by NMR investigations in the liquid crystallinen state that the molecules have a nearly rod-like shape. Dielectric measurements indicate a rotation around the molecular long axis as known from calamitic mesogens, which is clearly distinguished from the behaviour of bent molecules. Obviously, substitution of the central phenyl ring of the bent 1,3-phenylene bis[4-(4-n-alkyloxyphenyliminamethyl)benzoates] by two chlorine atoms causes a markedly change of the molecular shape resulting in nearly calamitic mesogens. These results are supported by single crystal structure studies, which anew the precise determination of the molecular structure and packing in the solid state.

A new synthesis of pyrido[3,2-f][1,4]thiazepine derivatives 3 starting with 2-chloronicotinic acid (1), methylaminoacetonitrile hydrochloride and carbon disulfide is described. As proved by a crystal structure determination, a boat conformation with approximated mirror symmetry can be assigned to the 1,4-thiazepine ring in 3b. 2-Chloro-N-cyanomethyl-N-methyl-5-nitrobenzamide (5) reacts with carbon disulfide in presence of a strong base in DMF or DMSO depending on the temperature to either the benzothiopyran compound 6 or by intramolecular aromatic nucleophilic substitution to a seven-membered ring system as thiolate anion which can be alkylated to give the 1,4-benzothiazepine derivative 7, or to an open-chain amido ketene dithioacetal 8.

Reactions of the 1:1 adduct of dimethylamine and carbon dioxide (dimcarb) with metallic copper and zinc, respectively, are reported. Dimcarb gives with copper in the presence of oxygen the N,N-dimethylcarbamato copper(II) complex [Cu(O2CNMe2)(2)(HNMe2)(2)] (1). Zinc spontaneously dissolves in a dimcarb-acetonitrile mixture under generation of hydrogen and giving (H2NMe2)[Zn-2.(O2CNMe2)(5)]. MeCN (3). The rate of this reaction is strongly depending on the purity of the metal, high purity zinc doesn't react. But 3 can be prepared from it by electrosynthesis. The crystal structures of 1 and 3 were determined by Xray analysis. In I the copper atom has a distorted octahedral coordination sphere in which the two carbamate ligands are chelating. In the homoleptic complex anion of 3 two zinc atoms are bridged by three carbamate ligands whereas the other two carbamate ligands are coordinated monodentately.

Es werden die Kristallstrukturen von Kalium- und Silbercyanamidonitrat beschrieben. Sowohl im Kalium- als auch im Silbersalz gibt es Metall–Anionen-Kontakte über die Atome Cyano–N, Amid–N und Sauerstoff. Die Strukturparameter des Ions [NO2NCN]– werden von den unterschiedlichen Umgebungen (Kalium, Silber) nur wenig beeinflußt. K[NO2NCN] bildet ein Koordinationsgitter, in dem das Kaliumion insgesamt neun N- und O-Atome von sieben verschiedenen Anionen als nächste Nachbarn hat. Im Ag[NO2NCN] liegt eine Schichtstruktur vor; die Silberatome sind in Zickzack-Ketten mit einem Ag–Ag-Abstand von 3,169(1) Å angeordnet, die senkrecht zu den Schichten verlaufen. Pseudoelement Compounds. XV Crystal Structure Analysis of Potassium and Silver Cyanamidonitrate The crystal structures of potassium and silver cyanamidonitrate are reported. In both the potassium and the silver salt metal anion contacts via the atoms cyano-N, amide-N and oxygen are observed. The structural parameters of the ion [NO2NCN]– are only slightly influenced by the different environments (potassium, silver). K[NO2NCN] forms a coordination lattice in which the nearest neighbours of the potassium ion are nine N and O atoms belonging to seven different anions. Ag[NO2NCN] has a layer structure; the silver atoms are arranged in zickzack chains running perpendicular to the layers with an Ag–Ag distance of 3.169(1) Å.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Alkali metal trithiocyanatomanganate (II) hydrates have been prepared and characterized by several analytical methods. The structures of NH4[Mn(NCS)(3)(H2O)] (1a), K[Mn(NCS)(3)(H2O)] (1b) and Na[Mn(NCS)(3)] . 3 H2O (2) could be elucidated by X-ray analysis. 1a and 1b are isotypic and form a polymeric layer structure which is characterized by the ambident nature of the thiocyanate ligand and binding of the water molecule to the octahedrally coordinated Mn atom. In 2 the complex manganate(II) anions form a layer structure with trigonal symmetry in which each Mn atom is connected with three Mn neighbours by thiocyanate double bridges. The cation partial lattice consists of infinite chains of face-sharing [Na(H2O)(6)](+) octahedra running perpendicular to the anion layers.

Complexes of the type [M{N(O)C(CN)(2)}(PPh3)(n)] (M = Cu-1, Ag-1, n = 2, 3) were synthesized by metathesis of K[N(O)C(CN)(2)] and [M(NO3)(PPh3)(n)]. The complexes were characterized by C-13-, P-31-NMR and IR spectroscopy and elemental analyses. The crystal structures of [M{N(O)C(CN)(2)}(PPh3)(2)](2) (M Cu-1, Ag-1) have been determined by X-ray diffraction. Depending on the metal atom in the complexes [M{N(O)C(CN)(2)} (PPh3)(3)] the ionic ligand is coordinated via the central nitrogen (copper) or the oxygen atom (silver). In addition the two copper and silver complexes [M{N(O)C(CN)(2)}(PPh3)(2)](2) are not isostructural but have quite different structures. For M = Gu the two copper atoms are doubly bridged by two NCCN sequences, forming an approximately planar Cu(NCCN)(2)Cu ring. On the other hand, in the homologous silver derivative the metal atoms are also doubly bridged, but by two NO groups, thus forming a planar six-membered ring.

A simple and efficient approach to the 9-thiatricyclo[3.3.1.03,7]nonane ring system (5) has been found by treating cis-bicyclo[3.3.0]octane-3,7-diones (1) with Lawesson's reagent or phosphorus pentasulfide. When dione 1 is treated with Lawesson's reagent tetramethyl 3(4aH)oxo-1,4-dihydrophenanthro[9,10-a]pentalene-1,2,4,4a-tetracarboxylate (6) is obtained as a by-product as shown by X-ray structural analysis.

The absolute configurations of both the enantiomers of the title compound, C15H18BrNO2S2, have been determined. As expected, the molecular dimensions of both forms are insignificantly different. The phenacyl and dithiocarbamate fragments are planar and approximately perpendicular to one another. The short N-C(=S) bond length [1.330 (7) Angstrom] indicates involvement of the N-atom lone pair in the thiocarbonyl pi system.

The crystal structures of potassium and silver cyanamidonitrate are reported. In both the potassium and the silver salt metal anion contacts via the atoms cyano-N, amide-N and oxygen are observed. The structural parameters of the ion [NO2NCN](-) are only slightly influenced by the different environments (potassium, silver). K[NO2NCN] forms a coordination lattice in which the nearest neighbours of the potassium ion are nine N and O atoms belonging to seven different anions. Ag[NO2NCN] has a layer structure; the silver atoms are arranged in ticktack chains running perpendicular to the layers with an Ag-Ag distance of 3.169(1) Angstrom.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.