H...

Distribution by Scientific Domains


Selected Abstracts


1,1,-Fc(4-C6H4CO2Et)2 and its unusual salt derivative with Z, = 5, catena -[Na+]2[1,1,-Fc(4-C6H4CO2,)2]0.6H2O [1,1,-Fc = (,5 -(C5H4)2Fe]

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2010
John F. Gallagher
The neutral diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate, Fe[,5 -(C5H4)(4-C6H4CO2Et)]2 (I), yields (II) (following base hydrolysis) as the unusual complex salt poly[disodium bis[diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate] 0.6-hydrate] or [Na+]2[Fe{,5 -(C5H4)-4-C6H4CO}2]0.6H2O with Z, = 5. Compound (I) crystallizes in the triclinic system, space group , with two molecules having similar geometry in the asymmetric unit (Z, = 2). The salt complex (II) crystallizes in the orthorhombic system, space group Pbca, with the asymmetric unit comprising poly[decasodium pentakis[diethyl 4,4,-(ferrocene-1,1,-diyl)dibenzoate] trihydrate] or [Na+]10[Fe{,5 -(C5H4)-4-C6H4CO}2]53H2O. The five independent 1,1,-Fc[(4-C6H4CO2),]2 dianions stack in an offset ladder (stepped) arrangement with the ten benzoates mutually oriented cisoid towards and bonded to a central layer comprising the ten Na+ ions and three water molecules [1,1,-Fc = ,5 -(C5H4)2Fe]. The five dianions differ in the cisoid orientations of their pendant benzoate groups, with four having their ,C6H4, groups mutually oriented at interplanar angles from 0.6,(3) to 3.2,(3) (as ,..., stacked C6 rings) and interacting principally with Na+ ions. The fifth dianion is distorted and opens up to an unprecedented ,C6H4, interplanar angle of 18.6,(3) through bending of the two 4-C6H4CO2 groups and with several ionic interactions involving the three water molecules (arranged as one-dimensional zigzag chains in the lattice). Overall packing comprises two-dimensional layers of Na+ cations coordinated mainly by the carboxylate O atoms, and one-dimensional water chains. The non-polar Fc(C6H4)2 groups are arranged perpendicular to the layers and mutually interlock through a series of efficient C,H..., stacking contacts in a herringbone fashion to produce an overall segregation of polar and non-polar entities. [source]


Probing the shapes of chiral bis-(o -naphthalimidobenzoyl) systems using X-ray and circular dichroism methods

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 1 2009
Urszula Rychlewska
CD (circular dichroism) and X-ray investigations have been carried out in order to identify the prevalent conformations and define the forces that determine the molecular and supramolecular organization of the alkyl-bridged bichromophoric [NAB, ortho -(1,8-naphthalimido)benzoyl] units, each consisting of the benzoyl substituted in the ortho position with the 1,8-naphthalimide group. The results reveal that NAB bichromophores incorporated into the same molecule exist in a variety of conformation/helicity combinations. The molecular structures are largely stabilized by local 1,3-CH/CO dipole,dipole interactions, while the crystal packing besides dispersive H...H interactions is mostly governed by multiple C,H...O(=C) and C,H..., interactions. The relatively small contribution of ,..., interactions comes from a pairwise off-face stacking between naphthalimide rings or from pairwise carbonyl..., interactions. All these types of intermolecular interactions have been summarized quantitatively by means of a Hirshfeld surface analysis. [source]


Monitoring structural transformations in crystals.

ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2008

Variations in crystal and molecular structures, brought about by the intramolecular [4,+,4] photocycloaddition of bi(anthracene-9,10-dimethylene), were monitored using X-ray diffraction. The cell volume increased by 0.8% until the reaction was ca 40% complete, and afterwards decreased by 1.6% during the remainder of the photoreaction. The changes of the a and b lattice parameters were correlated with the changes of the molecular shape and packing. The distance between the directly reacting C atoms varied in a manner not observed for other photochemical reactions in crystals. It was constant until ca 20% photoreaction progress, then decreased, and later stabilized from ca 40% photoreaction progress. This phenomenon was explained by interplay between stress resulting from the presence of product molecules and the rigidity of reactant molecules. Changes of the orientation of molecules during the photoreaction were smaller than in the case of other monitored photochemical reactions in crystals owing to similarities in the shape and packing of reactant and product molecules. Weak C,H..., hydrogen bonds exist among reactant molecules in the pure reactant and partly reacted crystals. [source]


Green chemistry synthesis: 2-amino-3-[(E)-(2-pyridyl)methylideneamino]but-2-enedinitrile monohydrate and 5-cyano-2-(2-pyridyl)-1-(2-pyridylmethyl)-1H -imidazole-4-carboxamide

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 9 2010
Muhammad Altaf
The title compounds, C10H9N5OH2O (L1H2O) and C16H12N6O (L2), were synthesized by solvent-free aldol condensation at room temperature. L1, prepared by grinding picolinaldehyde with 2,3-diamino-3-isocyanoacrylonitrile in a 1:1 molar ratio, crystallized as a monohydrate. L2 was prepared by grinding picolinaldehyde with 2,3-diamino-3-isocyanoacrylonitrile in a 2:1 molar ratio. By varying the conditions of crystallization it was possible to obtain two polymorphs, viz. L2-I and L2-II; both crystallized in the monoclinic space group P21/c. They differ in the orientation of one pyridine ring with respect to the plane of the imidazole ring. In L2-I, this ring is oriented towards and above the imidazole ring, while in L2-II it is rotated away from and below the imidazole ring. In all three molecules, there is a short intramolecular N,H...N contact inherent to the planarity of the systems. In L1H2O, this involves an amino H atom and the C=N N atom, while in L2 it involves an amino H atom and an imidazole N atom. In the crystal structure of L1H2O, there are N,H...O and O,H...O intermolecular hydrogen bonds which link the molecules to form two-dimensional networks which stack along [001]. These networks are further linked via intermolecular N,H...N(cyano) hydrogen bonds to form an extended three-dimensional network. In the crystal structure of L2-I, symmetry-related molecules are linked via N,H...N hydrogen bonds, leading to the formation of dimers centred about inversion centres. These dimers are further linked via N,H...O hydrogen bonds involving the amide group, also centred about inversion centres, to form a one-dimensional arrangement propagating in [100]. In the crystal structure of L2-II, the presence of intermolecular N,H...O hydrogen bonds involving the amide group results in the formation of dimers centred about inversion centres. These are linked via N,H...N hydrogen bonds involving the second amide H atom and the cyano N atom, to form two-dimensional networks in the bc plane. In L2-I and L2-II, C,H..., and ,,, interactions are also present. [source]


(9E)-9-Benzylidene-3-methyl-2-methylsulfanyl-5-phenyl-5,6,7,8,9,10-hexahydropyrimido[4,5- b]quinolin-4(3H)-one: polarized molecules within hydrogen-bonded bilayers

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Diana Becerra
The molecules of the title compound, C26H25N3OS, which was prepared by means of an acid-catalysed cyclocondensation reaction between a 6-aminopyrimidinone and 2,6-dibenzylidenecyclohexanone, exhibit a polarized electronic structure, namely (9E)-9-benzylidene-3-methyl-2-methylsulfanyl-5-phenyl-3,5,6,7,8,9-hexahydropyrimido[4,5- b]quinolin-10-ium-4-olate, involving charge separation in the vinylogous amide portion. Four hydrogen bonds, two each of the C,H...O and C,H...,(arene) types, link the molecules into bilayers comprising inversion-related pairs of sheets, each containing a single type of R43(36) ring. [source]


Forced twin-chair conformation in 7-benzoyl- and 7-phenylacetyl- r -2,c -4,t -6,t -8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonanes with 1,3-diaxial phenyl groups in the piperidine ring: single- and double-layered supramolecular sheets built from C,H...O and C,H...,(arene) hydrogen bonds

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Chinniah Sakthivel
The crystal structures of 7-benzoyl- r -2,c -4,t -6,t -8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonane, C38H33NOS, (I), and r -2,c -4,t -6,t -8-tetraphenyl-7-phenylacetyl-3-thia-7-azabicyclo[3.3.1]nonane [systematic name: 2-phenyl-1-(r -2,c -4,t -6,t -8-tetraphenyl-3-thia-7-azabicyclo[3.3.1]nonan-7-yl)ethanone], C39H35NOS, (II), both reveal a forced twin-chair conformation with the 1,3-diaxial phenyl groups in the piperidine ring, and flattening at the N-atom end of the piperidine ring of the bicyclic system. In the crystal structure of (I), molecules are linked into sheets by a combination of two weak C,H...O and one C,H...,(arene) hydrogen bond, while in the crystal structure of (II), the molecules extend into double-layered sheets assisted by three C,H...,(arene) hydrogen bonds. [source]


4-Methoxyanilinium tetrafluoroborate,dibenzo-18-crown-6 (1/1)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2010
Xue-qun Fu
In the structure of the complex of dibenzo-18-crown-6 [systematic name: 2,5,8,15,18,21-hexaoxatricyclo[20.4.0.09,14]hexacosa-1(26),9,11,13,22,24-hexaene] with 4-methoxyanilinium tetrafluoroborate, C7H10NO+BF4,C20H24O6, the protonated 4-methoxyanilinium (MB-NH3+) cation forms a 1:1 supramolecular rotator,stator complex with the dibenzo-18-crown-6 molecule via N,H...O hydrogen bonds. The MB-NH3+ group is attached from the convex side of the bowl-shaped crown, in contrast with similar ammonium cations that nest in the curvature of the bowl. The cations are associated via C,H..., interactions, while the cations and anions are linked by weak C,H...F hydrogen bonds, forming cation,crown,anion chains parallel to [011]. [source]


25-Allyloxy-5,11,17,23-tetra- tert -butyl-26,27,28-trihydroxycalix[4]arene chloroform disolvate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010
Tobias Gruber
In the title solvated calixarene, C47H60O42CHCl3, the host chalice displays an almost undistorted cone conformation, stabilized by three strong O,H...O hydrogen bonds at the calixarene's lower rim. One chloroform solvent molecule is fixed in the calixarene cavity by C,H..., interactions, while the second is accommodated in a clathrate-like mode in elliptical packing voids. These voids are spanned by six host molecules connected via C,H..., contacts and van der Waals interactions. Within the crystal structure, one tert -butyl group of the calixarene host is disordered over two orientations, with occupancies of 0.884,(4) and 0.116,(4). Furthermore, both solvent molecules show disorder, with occupancies of 0.857,(2) and 0.143,(2) for the cavitate-type, and 0.9359,(17) and 0.0641,(17) for the clathrate-type chloroform solvent molecules. [source]


Two similarly substituted benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-diones: supramolecular structures in two and three dimensions

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010
Yurina Daz
The molecules of 8-methyl-7,10-diphenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C27H17N3O2, (I), are weakly linked into chains by a single C,H...O hydrogen bond, and these chains are linked into sheets by a ,,, stacking interaction involving pyridyl and aryl rings. In 8-methyl-7-(4-methylphenyl)-10-phenyl-5H -benzo[h]pyrazolo[3,4- b]quinoline-5,6(10H)-dione, C28H19N3O2, (II), the molecules are linked into a three-dimensional framework structure by a combination of C,H...N, C,H...O and C,H...,(arene) hydrogen bonds, together with a ,,, stacking interaction analogous to that in (I). [source]


Intermolecular C,H..., interactions in 1,5-diphenyl-3-(2-pyridyl)-2-pyrazoline

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2010
Miquel Barcel-Oliver
The title compound, C20H17N3, is a derivative of 1,3,5-triaryl-2-pyrazoline and can act as an N,N,-bidentate ligand. This molecule features strong fluorescence that can be explained by an extended pyridyl,C=N,N,phenyl system. The three-dimensional structure is formed by means of an extended network of weak C,H..., hydrogen bonds supported by ,,, interactions. [source]


Poly[bis(,-4-benzoyl-1-isonicotinoylthiosemicarbazide-,2N:S)dichloridocadmium(II)]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010
Yu-Bo Wang
The asymmetric unit of the title complex, [CdCl2(C14H12N4O2S)2]n, consists of one CdII ion located on the crystallographic inversion centre, one 4-benzoyl-1-isonicotinoylthiosemicarbazide ligand and one chloride ligand. The central CdII ion adopts a distorted octahedral coordination geometry formed by two pyridyl N atoms of two ligands, two S atoms of two other ligands and two chloride ligands. The thiosemicarbazide ligands act as bridges, linking the metal ions into a two-dimensional layered structure parallel to the bc plane. Intermolecular N,H...O hydrogen bonds and C,H..., interactions exist between adjacent layers. [source]


(E)- N2 -{4-[(E)-2-(4-Chlorobenzoyl)ethenyl]-3-methyl-1-phenyl-1H -pyrazol-5-yl}- N1,N1 -dimethylformamidine: polarized molecules within sheets of ,-stacked hydrogen-bonded chains

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010
Jairo Quiroga
The molecules of the title compound, C22H21ClN4O, are conformationally chiral, and in the space group P212121 each crystal contains only one conformational enantiomer. The intramolecular dimensions provide evidence for polarization of the electronic structure. Molecules are linked by a single C,H...,(arene) hydrogen bond into chains, which are themselves weakly linked into sheets by an aromatic ,,, stacking interaction. [source]


A novel oxazolidinone antibiotic: RWJ-416457

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 5 2010
Eugene Y. Cheung
The crystal structure of the antibiotic drug candidate RWJ-416457 (systematic name: N -{(5S)-3-[4-(5,6-dihydro-2H,4H -2-methylpyrrolo[3,4- c]pyrazol-5-yl)-3-fluorophenyl]-2-oxo-1,3-oxazolidin-5-yl}acetamide), C18H20FN5O3, which belongs to the first new class of antibiotics discovered in the past 30 years, has been determined at 150,K. Each molecule of this drug donates one hydrogen bond to a neighboring molecule and accepts one hydrogen bond to give (O=C,R,N,H...O=C,R,N,H...)n linkages along the b -axis direction. The compound contains a pyrrolopyrazole ring, which, owing to its uncommon structure, has been shown to have particular effectiveness against multi-drug-resistant bacteria. [source]


5-Amino-1-benzoyl-3-methylpyrazole: complex sheets built from N,H...N, C,H...O and C,H...,(arene) hydrogen bonds

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Jairo Quiroga
Molecules of the title compound [systematic name: (5-amino-3-methylpyrazol-1-yl)(phenyl)methanone], C11H11N3O, contain an intramolecular hydrogen bond. The molecules are linked into sheets by a combination of N,H...N, C,H...O and C,H...,(arene) hydrogen bonds. Comparisons are made with the hydrogen-bonded structures of some related compounds. [source]


A hydrogen-bonded dimer in 6-(4-bromophenyl)-3-methyl-1-phenyl-4,5-dihydro-1H -pyrazolo[3,4- b]pyridine and a chain of rings built from N,H...N and C,H...,(pyridine) hydrogen bonds in 3-(4-nitrophenyl)-4-phenyl-1H -pyrazolo[3,4- b]pyridine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Jairo Quiroga
In 6-(4-bromophenyl)-3-methyl-1-phenyl-4,5-dihydro-1H -pyrazolo[3,4- b]pyridine, C19H16BrN3, the reduced pyridine ring adopts a conformation that is close to a screw-boat form. Molecules are linked by pairs of symmetry-related C,H...,(arene) hydrogen bonds into cyclic centrosymmetric dimers. Molecules of 3-(4-nitrophenyl)-4-phenyl-1H -pyrazolo[3,4- b]pyridine, C18H12N4O2, are linked into centrosymmetric R22(8) dimers by pairs of symmetry-related N,H...N hydrogen bonds, and these dimers are linked by pairs of C,H...,(pyridine) hydrogen bonds to form a chain of edge-fused rings, or a molecular ladder, along [100]. The molecular aggregation in this compound is completed by two weak C,H...O hydrogen bonds, one of which links the chains along [100] into sheets. [source]


Hydrogen-bonding patterns in three substituted N -benzyl- N -(3- tert -butyl-1-phenyl-1H -pyrazol-5-yl)acetamides

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Gerson Lpez
The molecules of N -(3- tert -butyl-1-phenyl-1H -pyrazol-5-yl)-2-chloro- N -(4-methoxybenzyl)acetamide, C23H26ClN3O2, are linked into a chain of edge-fused centrosymmetric rings by a combination of one C,H...O hydrogen bond and one C,H...,(arene) hydrogen bond. In N -(3- tert -butyl-1-phenyl-1H -pyrazol-5-yl)-2-chloro- N -(4-chlorobenzyl)acetamide, C22H23Cl2N3O, a combination of one C,H...O hydrogen bond and two C,H...,(arene) hydrogen bonds, which utilize different aryl rings as the acceptors, link the molecules into sheets. The molecules of S -[N -(3- tert -butyl-1-phenyl-1H -pyrazol-5-yl)- N -(4-methylbenzyl)carbamoyl]methyl O -ethyl carbonodithioate, C26H31N3O2S2, are also linked into sheets, now by a combination of two C,H...O hydrogen bonds, both of which utilize the amide O atom as the acceptor, and two C,H...,(arene) hydrogen bonds, which utilize different aryl groups as the acceptors. [source]


C,H..., interactions in cocrystals of bis(trimethylsilyl)acetylene and diphenylacetylene with benzene

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Frank Meyer-Wegner
We present here the crystal structures of two acetylene derivatives cocrystallized with benzene, namely bis(trimethylsilyl)acetylene benzene solvate, C8H18Si2C6H6, (I), and diphenylacetylene benzene solvate, C14H10C6H6, (II). In (I), both molecules belong to the symmetry point group C2h and are located about special positions with site symmetry 2/m. In (II), both molecules show crystallographic inversion symmetry. In both structures, there are C,H..., contacts between aromatic H atoms and the ,-electrons of the triple bond. In addition to these, in (II) there are C,H..., contacts between aromatic H atoms and the ,-electron cloud of the benzene molecules. [source]


A three-dimensional hydrogen-bonded framework in (2S*,4R*)-7-fluoro-2- exo -[(E)-styryl]-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Lina M. Acosta
Molecules of the title compound, C18H16FNO, are linked into a three-dimensional framework structure by a combination of two C,H...O hydrogen bonds and three C,H...,(arene) hydrogen bonds. Comparisons are made with the (2R,4R) diastereoisomer and with the corresponding pair of diastereoisomeric 7-chloro analogues. [source]


Hydrogen-bonded dimers, chains and rings in six differently substituted 2-vinyltetrahydro-1,4-epoxy-1-benzazepines

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Lina M. Acosta
In (2SR,4RS)-2- exo -vinyl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C12H13NO, (I), the molecules are linked by two independent C,H...,(arene) hydrogen bonds to form sheets, such that all of the molecules in a given sheet are of the same configuration. The molecules of (2SR,4RS)-7-chloro-2- exo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C14H16ClNO, (II), are linked by a C,H...O hydrogen bond into C(4) chains, where all the molecules in a given chain are of the same configuration, whereas the molecules of (2SR,4RS)-8-chloro-9-methyl-2- exo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C15H18ClNO, (III), are linked into centrosymmetric dimers by pairs of symmetry-related C,H...,(arene) hydrogen bonds. (2RS,4RS)-8-Chloro-9-methyl-2- endo -(2-methylprop-1-enyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C15H18ClNO, (IV), is a diastereoisomer of (III) and, as for (II), a single C,H...O hydrogen bond links the molecules into C(4) chains, each containing molecules of a single configuration. The structure of (2SR,4RS)-8-chloro-9-methyl-2- exo -(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C14H16ClNO, (V), contains a C,H...O hydrogen bond which links pairs of molecules into centrosymmetric R22(6) dimers. (2SR,4RS)-7,9-Dichloro-2- exo -(prop-1-en-2-yl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C13H13Cl2NO, (VI), is an inversion twin containing both the (2S,4R) and (2R,4S) enantiomers in the space group P21, and a C,H...O hydrogen bond links molecules of a given configuration into simple C(3) chains. [source]


Five 2-aryl-substituted tetrahydro-1,4-epoxy-1-benzazepines: isolated molecules and hydrogen-bonded chains and sheets

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2010
Sandra L. Gmez
(2SR,4RS)-2- exo -Phenyl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H15NO, (I), (2SR,4RS)-2- exo -(4-chlorophenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H14ClNO, (II), and (2SR,4RS)-2- exo -(3-methylphenyl)-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C17H17NO, (III), all crystallize with Z, = 2, in the space groups Cc, P21/n and P21/c, respectively. In each of (II) and (III), the conformations of the two independent molecules are significantly different. The molecules in (I) are linked by C,H...,(arene) hydrogen bonds to form two independent chains, each containing only one type of molecule. The molecules in (II) are linked into sheets by a combination of C,H...O, C,H...(N,O) and C,H...,(arene) hydrogen bonds, all of which link pairs of molecules related by inversion, while in (III), the molecules are linked into sheets by a combination of C,H...N, C,H...O and C,H...,(arene) hydrogen bonds. There are no direction-specific intermolecular interactions of any kind in the structure of (2SR,4RS)-7-bromo-2- exo -phenyl-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H14BrNO, (IV), but in the structure of (2SR,4RS)-2- exo -(4-bromophenyl)-7-chloro-2,3,4,5-tetrahydro-1H -1,4-epoxy-1-benzazepine, C16H13BrClNO, (V), a combination of one C,H...N hydrogen bond and one C,H...O hydrogen bond links the molecules into sheets of alternating centrosymmetric R22(14) and R66(22) rings. Comparisons are made with the structures of a number of related compounds. [source]


Tetrakis(,2 -4-aminobenzoato)di-,3 -oxido-tetrakis[dibutyltin(IV)]

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Anthony Linden
The molecule of the title compound, [Sn4(C4H9)8(C7H6NO2)4O2], lies about an inversion centre and is a tetranuclear bis(tetrabutyldicarboxylatodistannoxane) complex containing a planar Sn4O2 core in which two ,3 -oxide O atoms connect an Sn2O2 ring to two exocyclic Sn atoms. Each Sn atom has a highly distorted octahedral coordination. In the molecule, the carboxylate groups of two aminobenzoate ligands bridge the central and exocyclic Sn atoms, while two further aminobenzoate ligands have highly asymmetric bidentate chelation to the exocyclic Sn atoms plus long O...Sn interactions with the central Sn atoms. Each Sn atom is also coordinated by two pendant n -butyl ligands, which extend roughly perpendicular to the plane of the Sn4O10 core. Only one of the four unique hydrogen-bond donor sites is involved in a classic N,H...O hydrogen bond, and the resulting supramolecular hydrogen-bonded structure is an extended two-dimensional network which lies parallel to the (100) plane and consists of a checkerboard pattern of four-connected molecular cores acting as nodes. The amine groups not involved in the hydrogen-bonding interactions have significant N,H..., interactions with neighbouring aminobenzene rings. [source]


The ansa -zirconocene [bis(,5 -cyclopentadienyl)phenylphosphine]dichloridozirconium(IV)

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Susanne Bschel
In the title compound, [Zr(C16H13P)Cl2], the geometry at the metal atom is distorted tetrahedral; the Cl,Zr,Cl angle is 101.490,(16) and the cyclopentadienyl (Cp) centroids subtend an angle of 122.63,(3) at the Zr atom. The P atom lies 0.474,(3) and 0.496,(3), out of the planes of the Cp rings. The C,P,C angle of 91.42,(7) reflects the pincer effect of the two Cp rings. Three C,H...Cl, one C,H...P, one C,H..., and one Cl...P interaction link the molecules to form thick layers parallel to the bc plane. [source]


p -Phenylenediamine and its dihydrate: two-dimensional isomorphism and mechanism of the dehydration process, and N,H...N and N,H..., interactions

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Agnieszka Czapik
p -Phenylenediamine can be obtained as the dihydrate, C6H8N22H2O, (I), and in its anhydrous form, C6H8N2, (II). The asymmetric unit of (I) contains one half of the p -phenylenediamine molecule lying about an inversion centre and two halves of water molecules, one lying on a mirror plane and the other lying across a mirror plane. In (II), the asymmetric unit consists of one molecule in a general position and two half molecules located around inversion centres. In both structures, the p -phenylenediamine molecules are arranged in layers stabilized by N,H..., interactions. The diamine layers in (I) are isostructural with half of the layers in (II). On dehydration, crystals of (I) transform to (II). Comparison of their crystal structures suggests the most plausible mechanism of the transformation process which requires, in addition to translational motion of the diamine molecules, in-plane rotation of every fourth p -phenylenediamine molecule by ca 60. A search of the Cambridge Structural Database shows that the formation of hydrates by aromatic amines should be considered exceptional. [source]


7-Amino-5-methyl-2-phenyl-6-(phenyldiazenyl)pyrazolo[1,5- a]pyrimidine crystallizes with Z, = 2: pseudosymmetry and the formation of complex sheets built from N,H...N and C,H...,(arene) hydrogen bonds

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Jaime Portilla
The title compound, C19H16N6, crystallizes with Z, = 2 in the space group P21/n. The two molecules in the selected asymmetric unit are approximate mirror images of one another; most corresponding pairs of atoms are related by an approximate half-cell translation along [100]. Each molecule contains an intramolecular N,H...N hydrogen bond and the molecules are linked into complex sheets by a combination of two intermolecular N,H...N and four C,H...,(arene) hydrogen bonds. Comparisons are made with some other 7-aminopyrazolo[1,5- a]pyrimidines. [source]


Hydrogen-bonding patterns in two aroylthiocarbamates and two aroylimidothiocarbonates

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2010
Henry Insuasty
In O -ethyl N -benzoylthiocarbamate, C10H11NO2S, the molecules are linked into sheets by a combination of two-centre N,H...O and C,H...S hydrogen bonds and a three-centre C,H...(O,S) hydrogen bond. A combination of two-centre N,H...O and C,H...O hydrogen bonds links the molecules of O -ethyl N -(4-methylbenzoyl)thiocarbamate, C11H13NO2S, into chains of rings, which are linked into sheets by an aromatic ,,, stacking interaction. In O,S -diethyl N -(4-methylbenzoyl)imidothiocarbonate, C13H17NO2S, pairs of molecules are linked into centrosymmetric dimers by pairs of symmetry-related C,H...,(arene) hydrogen bonds, while the molecules of O,S -diethyl N -(4-chlorobenzoyl)imidothiocarbonate, C12H14ClNO2S, are linked by a single C,H...O hydrogen bond into simple chains, pairs of which are linked by an aromatic ,,, stacking interaction to form a ladder-type structure. [source]


Two polymorphs of a lead(II) complex with 8-hydroxy-2-methylquinoline and thiocyanate

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010
Gholamhossein Mohammadnezhad
Two distinct polymorphs of bis(,2 -methylquinolin-8-olato)-,3N,O:O;,3O:N,O -bis[(isothiocyanato-,N)lead(II)], [Pb2(C10H8NO)2(NCS)2], (I), forming dinuclear complexes from a methanolic solution containing lead(II) nitrate, 2-methylquinolin-8-ol (M-Hq) and KSCN, crystallized concomitantly as colourless prisms [form (Ia)] and long thin colourless needles [form (Ib)]. In both cases, the complexes lie across a centre of inversion. The polymorphs differ substantially in their conformation and in their interactions, viz. Pb...S and ,,, for form (Ia) and Pb...S, Pb..., and C,H..., for form (Ib). [source]


N -(3- tert -Butyl-1-phenyl-1H -pyrazol-5-yl)- N -(4-methoxybenzyl)acetamide: a hydrogen-bonded chain of centrosymmetric rings

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010
Juan C. Castillo
The molecule of the title compound, C23H27N3O2, adopts a conformation having no internal symmetry so that the compound exhibits conformational chirality. The molecules are linked by a combination of C,H...O and C,H...,(arene) hydrogen bonds into a chain of rings in which two types of centrosymmetric ring alternate. [source]


Hydrogen-bonding patterns in 3-alkyl-3-hydroxyindolin-2-ones

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2010
Diana Becerra
The molecules of racemic 3-benzoylmethyl-3-hydroxyindolin-2-one, C16H13NO3, (I), are linked by a combination of N,H...O and O,H...O hydrogen bonds into a chain of centrosymmetric edge-fused R22(10) and R44(12) rings. Five monosubstituted analogues of (I), namely racemic 3-hydroxy-3-[(4-methylbenzoyl)methyl]indolin-2-one, C17H15NO3, (II), racemic 3-[(4-fluorobenzoyl)methyl]-3-hydroxyindolin-2-one, C16H12FNO3, (III), racemic 3-[(4-chlorobenzoyl)methyl]-3-hydroxyindolin-2-one, C16H12ClNO3, (IV), racemic 3-[(4-bromobenzoyl)methyl]-3-hydroxyindolin-2-one, C16H12BrNO3, (V), and racemic 3-hydroxy-3-[(4-nitrobenzoyl)methyl]indolin-2-one, C16H12N2O5, (VI), are isomorphous in space group P. In each of compounds (II),(VI), a combination of N,H...O and O,H...O hydrogen bonds generates a chain of centrosymmetric edge-fused R22(8) and R22(10) rings, and these chains are linked into sheets by an aromatic ,,, stacking interaction. No two of the structures of (II),(VI) exhibit the same combination of weak hydrogen bonds of C,H...O and C,H...,(arene) types. The molecules of racemic 3-hydroxy-3-(2-thienylcarbonylmethyl)indolin-2-one, C14H11NO3S, (VII), form hydrogen-bonded chains very similar to those in (II),(VI), but here the sheet formation depends upon a weak ,,, stacking interaction between thienyl rings. Comparisons are drawn between the crystal structures of compounds (I),(VII) and those of some recently reported analogues having no aromatic group in the side chain. [source]


(E)-4,4,-Bis(1,3-benzoxazol-2-yl)stilbene at 150 and 375,K

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2010
M. Amine Fourati
The title compound, a chromophore of formula C28H18N2O2, crystallizes with the molecule lying on an inversion centre to give one-half of a crystallographically independent molecule in the asymmetric unit. The molecule is almost planar, with slight deviation of the benzene rings from the mean molecular plane. The structure is characterized by a herringbone packing arrangement arising from C,H..., and ,,, intermolecular interactions. The benzoxazole group is disordered between two orientations, with occupancy factors of 0.669,(10) and 0.331,(10) at 150,K [0.712,(7) and 0.288,(7) at 375,K]. [source]


2-Cyano- N -(2,6-dimethoxypyrimidin-4-yl)-3-[4-(dimethylamino)phenyl]acrylamide and dimethylammonium 6-cyano-1,3-dimethyl-2,4,5-trioxo-1,2,3,4,5,8-hexahydropyrido[2,3- d]pyrimidin-8-ide: a ,-stacked dimer and a hydrogen-bonded ribbon containing three types of ring

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2010
Jairo Quiroga
The bond distances in 2-cyano- N -(2,6-dimethoxypyrimidin-4-yl)-3-[4-(dimethylamino)phenyl]acrylamide, C18H19N5O3, (I), and in the anionic component of the salt dimethylammonium 6-cyano-1,3-dimethyl-2,4,5-trioxo-1,2,3,4,5,8-hexahydropyrido[2,3- d]pyrimidin-8-ide, C2H8N2+C10H7N4O3,, (II), provide evidence for the occurrence of electronic polarization. There are no hydrogen bonds in the structure of (I), instead pairs of molecules are linked into centrosymmetric dimers by a single ,,, stacking interaction. In (II), a combination of a two-centre N,H...O hydrogen bond, a three-centre N,H...(O)2 hydrogen bond, together utilizing all three O atoms, and a two-centre C,H...N hydrogen bond, link the components into a ribbon containing R12(6), R22(10) and R66(30) rings. [source]