共查询到20条相似文献,搜索用时 15 毫秒
1.
Olha Sereda Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(6):m221-m223
The structure of the title compound, [NiCu(CN)4(C10H8N2)(H2O)2]n or [{Cu(H2O)2}(μ‐C10H8N2)(μ‐CN)2{Ni(CN)2}]n, was shown to be a metal–organic cyanide‐bridged framework, composed essentially of –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains (4,4′‐bpy is 4,4′‐bipyridine) linked by [Ni(CN)4]2− anions. Both metal atoms sit on special positions; the CuII atom occupies an inversion center, while the NiII atom of the cyanometallate sits on a twofold axis. The 4,4′‐bpy ligand is also situated about a center of symmetry, located at the center of the bridging C—C bond. The scientific impact of this structure lies in the unique manner in which the framework is built up. The arrangement of the –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains, which are mutually perpendicular and non‐intersecting, creates large channels running parallel to the c axis. Within these channels, the [Ni(CN)4]2− anions coordinate to successive CuII atoms, forming zigzag –Cu—N[triple‐bond]C—Ni—C[triple‐bond]N—Cu– chains. In this manner, a three‐dimensional framework structure is constructed. To the authors' knowledge, this arrangement has not been observed in any of the many copper(II)–4,4′‐bipyridine framework complexes synthesized to date. The coordination environment of the CuII atom is completed by two water molecules. The framework is further strengthened by O—H...N hydrogen bonds involving the water molecules and the symmetry‐equivalent nonbridging cyanide N atoms. 相似文献
2.
Antony Bulanov Igor N. Shcherbakov Leonid D. Popov E. Y. Shasheva P. A. Belikov Zoya A. Starikova 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(3):o85-o88
The structures of new oxaindane spiropyrans derived from 7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐carbaldehyde (SP1), namely N‐benzyl‐2‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]hydrazinecarbothioamide, C27H25N3O3S, (I), at 120 (2) K, and N′‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]‐4‐methylbenzohydrazide acetone monosolvate, C27H24N2O4·C3H6O, (II), at 100 (2) K, are reported. The photochromically active Cspiro—O bond length in (I) is close to that in the parent compound (SP1), and in (II) it is shorter. In (I), centrosymmetric pairs of molecules are bound by two equivalent N—H...S hydrogen bonds, forming an eight‐membered ring with two donors and two acceptors. 相似文献
3.
Daniel E. Vicentes Ricaurte Rodríguez Patricia Ochoa Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(10):1405-1416
A concise and efficient synthesis of a series of amino‐substituted benzimidazole–pyrimidine hybrids has been developed, starting from the readily available N4‐(2‐aminophenyl)‐6‐methoxy‐5‐nitrosopyrimidine‐2,4‐diamine. In each of N5‐benzyl‐6‐methoxy‐4‐(2‐phenyl‐1H‐benzo[d]imidazol‐1‐yl)pyrimidine‐2,5‐diamine, C25H22N6O, (I), 6‐methoxy‐N5‐(4‐methoxybenzyl)‐4‐[2‐(4‐methoxyphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidine‐2,5‐diamine, C27H26N6O3, (III), 6‐methoxy‐N5‐(4‐nitrobenzyl)‐4‐[2‐(4‐nitrophenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidine‐2,5‐diamine, C25H20N8O5, (IV), the molecules are linked into three‐dimensional framework structures, using different combinations of N—H…N, N—H…O, C—H…O, C—H…N and C—H…π hydrogen bonds in each case. Oxidative cleavage of 6‐methoxy‐N5‐(4‐methylbenzyl)‐4‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidine‐2,5‐diamine, (II), with diiodine gave 6‐methoxy‐4‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidine‐2,5‐diamine, which crystallized as a monohydrate, C19H18N6O·H2O, (V), and reaction of (V) with trifluoroacetic acid gave two isomeric products, namely N‐{5‐amino‐6‐methoxy‐6‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidin‐2‐yl}‐2,2,2‐trifluoroacetamide, which crystallized as an ethyl acetate monosolvate, C21H17F3N6O2·C4H8O2, (VI), and N‐{2‐amino‐6‐methoxy‐4‐[2‐(4‐methylphenyl)‐1H‐benzo[d]imidazol‐1‐yl]pyrimidin‐5‐yl}‐2,2,2‐trifluoroacetamide, which crystallized as a methanol monosolvate, C21H17F3N6O2·CH4O, (VIIa). For each of (V), (VI) and (VIIa), the supramolecular assembly is two‐dimensional, based on different combinations of O—H…N, N—H…O, N—H…N, C—H…O and C—H…π hydrogen bonds in each case. Comparisons are made with some related structures. 相似文献
4.
Katarzyna
lepokura Tadeusz Lis Magorzata Bogucka Joanna Lutomska Adam Kraszewski Krzysztof Sierosawski 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(7):o405-o409
The crystal structures of triethylammonium adenosine cyclic 2′,3′‐phosphate {systematic name: triethylammonium 4‐(6‐aminopurin‐9‐yl)‐6‐hydroxymethyl‐2‐oxido‐2‐oxoperhydrofurano[3,4‐c][1,3,2]dioxaphosphole}, Et3NH(2′,3′‐cAMP) or C6H16N+·C10H11N5O6P−, (I), and guanosine cyclic 2′,3′‐phosphate monohydrate {systematic name: triethylammonium 6‐hydroxymethyl‐2‐oxido‐2‐oxo‐4‐(6‐oxo‐1,6‐dihydropurin‐9‐yl)perhydrofurano[3,4‐c][1,3,2]dioxaphosphole monohydrate}, [Et3NH(2′,3′‐cGMP)]·H2O or C6H16N+·C10H11N5O7P−·H2O, (II), reveal different nucleobase orientations, viz. anti in (I) and syn in (II). These are stabilized by different inter‐ and intramolecular hydrogen bonds. The structures also exhibit different ribose ring puckering [4E in (I) and 3T2 in (II)] and slightly different 1,3,2‐dioxaphospholane ring conformations, viz. envelope in (I) and puckered in (II). Infinite ribbons of 2′,3′‐cAMP− and helical chains of 2′,3′‐cGMP− ions, both formed by O—H⋯O, N—H⋯X and C—H⋯X (X = O or N) hydrogen‐bond contacts, characterize (I) and (II), respectively. 相似文献
5.
Xiu‐Yan Wang Jia‐Jun Wang Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(12):m401-m404
The ZnII compounds, μ‐4,4′‐ethylenedibenzoato‐bis[acetatoaqua(dipyrido[3,2‐a:2′,3′‐c]phenazine)zinc(II)] dihydrate, [Zn2(C2H3O2)2(C16H10O4)(C18H10N4)2(H2O)2]·2H2O, (I), and catena‐poly[[[aqua(pyrazino[2,3‐f][1,10]phenanthroline)zinc(II)]‐μ‐4,4′‐ethylenedibenzoato] N,N‐dimethylformamide hemisolvate], {[Zn(C16H10O4)(C14H8N4)(H2O)]·0.5C3H7NO}n, (II), display very different structures because of the influence of the N‐donor chelating ligands. In (I), the coordination geometry of each ZnII centre is distorted octahedral, involving two N atoms from one dipyrido[3,2‐a:2′,3′‐c]phenazine (L1) ligand, and four O atoms from one bis‐chelating acetate anion, one bridging 4,4′‐ethylenedibenzoate (bpea) ligand and one water molecule. Adjacent ZnII atoms are bridged by one bpea ligand to form a dinuclear complex, and the dinuclear species is centrosymmetric. Two types of π–π interactions between neighbouring dinuclear species have been found: one is between the L1 ligands, and the second is between the L1 and bpea ligands. In this way, an interesting two‐dimensional supramolecular layer is formed. The layers are further linked by O—H...O and O—H...N hydrogen bonds, generating a three‐dimensional supramolecular network. In (II), each ZnII atom is square‐pyramidally coordinated by two N atoms from one pyrazino[2,3‐f][1,10]phenanthroline ligand, three O atoms from two different bpea ligands and one water molecule. The two bpea dianions are situated across inversion centres. The bpea dianions bridge neighbouring ZnII centres, giving a one‐dimensional chain structure in the ab plane. As in (I), two types of π–π interactions between neighbouring chains complete a three‐dimensional supramolecular structure. The results indicate that the structures of the N‐donor chelating ligands are the dominant factors determining the final supramolecular structures of the two compounds. 相似文献
6.
Nada Kouti‐Hulita Aleksandar Danilovski Miroslav Maleevi Marina Orei Miljenko Dumi 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1144-1145
The 2,8‐dihydroxy‐1,3,7,9‐tetramethyl‐6,12‐dihydrodipyrido[1,2‐a:1′,2′‐d]pyrazinediylium dication possesses 2/m symmetry and lies in the mirror plane together with a chloride anion and the water O atom. The dication also lies on an inversion centre, i.e. C16H20N2O22+·2Cl?·2H2O. Due to these symmetry constrictions the dication adopts an unexpected planar conformation. Molecules are linked by O—H?O and O—H?Cl hydrogen bonds to form chains, which are cross‐connected by C—H?Cl attractive interactions forming a complex three‐dimensional hydrogen‐bond network. 相似文献
7.
Silvia Cruz Jorge Trilleras Justo Cobo John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(12):o637-o642
3‐tert‐Butyl‐7‐(4‐chlorobenzyl)‐4′,4′‐dimethyl‐1‐phenyl‐4,5,6,7‐tetrahydro‐1H‐pyrazolo[3,4‐b]pyridine‐5‐spiro‐1′‐cyclohexane‐2′,6′‐dione ethanol hemisolvate, C30H34ClN3O2·0.5C2H6O, (I), its 7‐(4‐bromobenzyl)‐ analogue, C30H34BrN3O2·0.5C2H6O, (II), and its 7‐(4‐methylbenzyl)‐ analogue, C31H37N3O2·0.5C2H6O, (III), are isomorphous, with the ethanol component disordered across a twofold rotation axis in the space group C2/c. In the corresponding 7‐[4‐(trifluoromethyl)benzyl]‐ compound, C31H34F3N3O2·0.5C2H6O, (IV), the ethanol component is disordered across a centre of inversion in the space group P. In each of (I)–(IV), the reduced pyridine ring adopts a half‐chair conformation. The heterocyclic components in (I)–(III) are linked into centrosymmetric dimers by a single C—H...π interaction, with the half‐occupancy ethanol component linked to the dimer by a combination of C—H...O and O—H...π(arene) hydrogen bonds. The heterocyclic molecules in (IV) are linked into chains of centrosymmetric rings by C—H...O and C—H...π hydrogen bonds, again with the half‐occupancy ethanol component pendent from the chain. The significance of this study lies in the isomorphism of the related derivatives (I)–(III), in the stoichiometric hemisolvation by ethanol, where the disordered solvent molecule is linked to the heterocyclic component by a two‐point linkage, and in the differences between the crystal structures of (I)–(III) and that of (IV). 相似文献
8.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(12):1109-1115
Two spiro[indoline‐3,3′‐pyrrolizine] derivatives have been synthesized in good yield with high regio‐ and stereospecificity using one‐pot reactions between readily available starting materials, namely l ‐proline, substituted 1H‐indole‐2,3‐diones and electron‐deficient alkenes. The products have been fully characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry and crystal structure analysis. In (1′RS ,2′RS ,3SR ,7a′SR )‐2′‐benzoyl‐1‐hexyl‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine]‐1′‐carboxylic acid, C28H32N2O4, (I), the unsubstituted pyrrole ring and the reduced spiro‐fused pyrrole ring adopt half‐chair and envelope conformations, respectively, while in (1′RS ,2′RS ,3SR ,7a′SR )‐1′,2′‐bis(4‐chlorobenzoyl)‐5,7‐dichloro‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine], which crystallizes as a partial dichloromethane solvate, C28H20Cl4N2O3·0.981CH2Cl2, (II), where the solvent component is disordered over three sets of atomic sites, these two rings adopt envelope and half‐chair conformations, respectively. Molecules of (I) are linked by an O—H…·O hydrogen bond to form cyclic R 66(48) hexamers of (S 6) symmetry, which are further linked by two C—H…O hydrogen bonds to form a three‐dimensional framework structure. In compound (II), inversion‐related pairs of N—H…O hydrogen bonds link the spiro[indoline‐3,3′‐pyrrolizine] molecules into simple R 22(8) dimers. 相似文献
9.
Zarife Sibel ahin Fatma Sevindi Hasan budak amil Ik 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(10):m314-m318
The title compounds, trans‐bis(trans‐cyclohexane‐1,2‐diamine)bis(6‐methyl‐2,2,4‐trioxo‐3,4‐dihydro‐1,2,3‐oxathiazin‐3‐ido)copper(II), [Cu(C4H4NO4S)2(C6H14N2)2], (I), and trans‐diaquabis(cyclohexane‐1,2‐diamine)zinc(II) 6‐methyl‐2,2,4‐trioxo‐3,4‐dihydro‐1,2,3‐oxathiazin‐3‐ide dihydrate, [Zn(C6H14N2)2(H2O)2](C4H4NO4S)2·2H2O, (II), are two‐dimensional hydrogen‐bonded supramolecular complexes. In (I), the CuII ion resides on a centre of symmetry in a neutral complex, in a tetragonally distorted octahedral coordination environment comprising four amine N atoms from cyclohexane‐1,2‐diamine ligands and two N atoms of two acesulfamate ligands. Intermolecular N—H...O and C—H...O hydrogen bonds produce R22(12) motif rings which lead to two‐dimensional polymeric networks. In contrast, the ZnII ion in (II) resides on a centre of symmetry in a complex dication with a less distorted octahedral coordination environment comprising four amine N atoms from cyclohexane‐1,2‐diamine ligands and two O atoms from aqua ligands. In (II), an extensive two‐dimensional network of N—H...O, O—H...O and C—H...O hydrogen bonds includes R21(6) and R44(16) motif rings. 相似文献
10.
Jonathan D. Woodward Rnal Backov Khalil A. Abboud Daniel R. Talham 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1027-1029
The one‐dimensional chain catena‐poly[[aqua(2,2′:6′,2′′‐terpyridyl‐κ3N)nickel(II)]‐μ‐cyano‐κ2N:C‐[bis(cyano‐κC)nickelate(II)]‐μ‐cyano‐κ2C:N], [Ni(terpy)(H2O)]‐trans‐[Ni‐μ‐(CN)2‐(CN)2]n or [Ni2(CN)4(C15H11N3)(H2O)], consists of infinite linear chains along the crystallographic [10] direction. The chains are composed of two distinct types of nickel ions, paramagnetic octahedral [Ni(terpy)(H2O)]2+ cations (with twofold crystallographic symmetry) and diamagnetic planar [Ni(CN)4]2? anions (with the Ni atom on an inversion center). The [Ni(CN)4]2? units act as bidentate ligands bridging through two trans cyano groups thus giving rise to a new example of a trans–trans chain among planar tetracyanonickelate complexes. The coordination geometry of the planar nickel unit is typical of slightly distorted octahedral nickel(II) complexes, but for the [Ni(CN)4]2? units, the geometry deviates from a planar configuration due to steric interactions with the terpyridine ligands. 相似文献
11.
Ericsson D. Coy‐Barrera Luis E. Cuca‐Surez Michael Sefkow Uwe Schilde 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(8):o320-o322
The structure of naturally‐occurring cinerin C [systematic name: (7S,8R,3′R,4′S,5′R)‐Δ8′‐4′‐hydroxy‐5,5′,3′‐trimethoxy‐3,4‐methylenedioxy‐2′,3′,4′,5′‐tetrahydro‐2′‐oxo‐7.3′,8.5′‐neolignan], isolated from the ethanol extract of leaves of Pleurothyrium cinereum (Lauraceae), has previously been established by NMR and HRMS spectroscopy, and its absolute configuration established by circular dichroism measurements. For the first time, its crystal strucure has now been established by single‐crystal X‐ray analysis, as the monohydrate, C22H26O7·H2O. The bicyclooctane moiety comprises fused cyclopentane and cyclohexenone rings which are almost coplanar. An intermolecular O—H...O hydrogen bond links the 4′‐OH and 5′‐OCH3 groups along the c axis. 相似文献
12.
Ahmet Karadag Hümeyra Paaoglu Gkhan Kata Orhan Büyükgüngr 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(11):m581-m583
The title compound, catena‐poly[[μ‐cyano‐1:2κ2C:N‐dicyano‐1κ2C‐trans‐bis[N‐(2‐hydroxyethyl)ethane‐1,2‐diamine‐2κ2N,N′]cadmium(II)nickel(II)]‐μ‐cyano‐1:2′κ2C:N], [CdNi(CN)4(C4H12N2O)2], consists of alternating square‐planar Ni(CN)4 fragments, formally dianionic, and Cd(hydet‐en)2 moieties [hydet‐en is N‐(2‐hydroxyethyl)ethylenediamine], with the two bridging cyanide ligands in a mutually trans disposition at the Ni atom and cis at the Cd atom. The resulting one‐dimensional zigzag chain structure has the Ni atom on an inversion center, while the distorted octahedron centered on the Cd atom lies on a twofold axis. The polymer chains are connected into undulating sheets by weak interchain N—H⋯N, N—H⋯O and O—H⋯N hydrogen bonds, which are also present between successive sheets. 相似文献
13.
Wenqing Lin Kuiying Xu Henning Eickmeier Frank Seela 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):o195-o197
In the title compound, 4‐amino‐3‐propynyl‐1‐(β‐d ‐ribofuranosyl)‐1H‐pyrazolo[3,4‐d]pyrimidine methanol solvate, C13H15N5O4·CH3OH, the torsion angle of the N‐glycosylic bond is between anti and high‐anti [χ = −101.8 (5)°]. The ribofuranose moiety adopts the C3′‐endo (3T2) sugar conformation (N‐type) and the conformation at the exocyclic C—C bond is +sc (gauche, gauche). The propynyl group is out of the plane of the nucleobase and is bent. The compound forms a three‐dimensional network which is stabilized by several hydrogen bonds (O—H·O and O—H·N). The nucleobases are stacked head‐to‐tail. The methanol solvent molecule forms hydrogen bonds with both the nucleobase and the sugar moiety. 相似文献
14.
B. de Castro C. Freire M. Teresa Duarte M. F. Minas da Piedade I. C. Santos 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(4):370-372
In the title complex, trans‐{2,2′‐[cyclohexane‐1,2‐diylbis(nitrilomethylidyne)]diphenolato‐κ4O,N,N′,O′}nickel(II)–chloroform (1/1), [Ni(C20H20N2O2)]·CHCl3, the Ni atom has a square‐planar geometry, slightly tetrahedrally distorted. The Ni—N and Ni—O bonding distances are within the expected ranges for Ni–Schiff base derivatives. The diimine bridge has a gauche conformation with the cyclohexyl ring almost coplanar with the NiN2O2 plane. The complex molecules pack in dimers with an Ni?Ni distance of 3.59 (1) Å and form a three‐dimensional structure displaying a herring‐bone configuration. Channels are occupied by solvent molecules, which are involved in C—H?O hydrogen bonds with the ligand O atoms. 相似文献
15.
Ze‐Bao Zheng Xue Zhao Ji‐Kun Li Yin‐Feng Han Ning‐Ning Ji 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(11):o569-o573
The title compounds, dimethylammonium 2‐{4‐[1‐(4‐carboxymethoxyphenyl)‐1‐methylethyl]phenoxy}acetate, C2H8N+·C19H19O6−, (I), and 2,2′‐[isopropylidenebis(p‐phenyleneoxy)]diacetic acid–4,4′‐bipyridine (1/1), C19H20O6·C10H8N2, (II), are 1:1 adducts of 2,2′‐[isopropylidenebis(p‐phenyleneoxy)]diacetic acid (H2L) with dimethylammonium or 4,4′‐bipyridine. The component ions in (I) are linked by N—H...O, O—H...O and C—H...O hydrogen bonds into continuous two‐dimensional layers parallel to the (001) plane. Adjacent layers are stacked via C—H...O hydrogen bonds into a three‐dimensional network with an –ABAB– alternation of the two‐dimensional layers. In (II), two H2L molecules, one bipy molecule and two half bipy molecules are linked by O—H...N hydrogen bonds into one‐dimensional chains and rectanglar‐shaped rings. They are assembled viaπ–π stacking interactions and C—H...O hydrogen bonds into an intriguing zero‐dimensional plus one‐dimensional poly(pseudo)rotaxane motif. 相似文献
16.
Mwaffak Rukiah Mahmoud M. Al-Ktaifani Mohammad K. Sabra 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(2):112-118
The design of new organic–inorganic hybrid ionic materials is of interest for various applications, particularly in the areas of crystal engineering, supramolecular chemistry and materials science. The monohalogenated intermediates 1‐(2‐chloroethyl)pyridinium chloride, C5H5NCH2CH2Cl+·Cl−, (I′), and 1‐(2‐bromoethyl)pyridinium bromide, C5H5NCH2CH2Br+·Br−, (II′), and the ionic disubstituted products 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dichloride dihydrate, C12H14N22+·2Cl−·2H2O, (I), and 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dibromide, C12H14N22+·2Br−, (II), have been isolated as powders from the reactions of pyridine with the appropriate 1,2‐dihaloethanes. The monohalogenated intermediates (I′) and (II′) were characterized by multinuclear NMR spectroscopy, while (I) and (II) were structurally characterized using powder X‐ray diffraction. Both (I) and (II) crystallize with half the empirical formula in the asymmetric unit in the triclinic space group P. The organic 1,1′‐(ethylene‐1,2‐diyl)dipyridinium dications, which display approximate C2h symmetry in both structures, are situated on inversion centres. The components in (I) are linked via intermolecular O—H…Cl, C—H…Cl and C—H…O hydrogen bonds into a three‐dimensional framework, while for (II), they are connected via weak intermolecular C—H…Br hydrogen bonds into one‐dimensional chains in the [110] direction. The nucleophilic substitution reactions of 1,2‐dichloroethane and 1,2‐dibromoethane with pyridine have been investigated by ab initio quantum chemical calculations using the 6–31G** basis. In both cases, the reactions occur in two exothermic stages involving consecutive SN2 nucleophilic substitutions. The isolation of the monosubstituted intermediate in each case is strong evidence that the second step is not fast relative to the first. 相似文献
17.
Eric P. Kelson Proma P. Phengsy Atta M. Arif 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):517-519
The aldehyde moiety in the title complex, chloro(2‐pyridinecarboxaldehyde‐N,O)(2,2′:6′,2′′‐terpyridine‐κ3N)ruthenium(II)–chloro(2‐pyridinecarboxylic acid‐N,O)(2,2′:6′,2′′‐terpyridine‐κ3N)ruthenium(II)–perchlorate–chloroform–water (1.8/0.2/2/1/1), [RuCl(C6H5NO)(C15H11N3)]1.8[RuCl(C6H5NO2)(C15H11N3)]0.2(ClO4)2·CHCl3·H2O, is a structural model of substrate coordination to a transfer hydrogenation catalyst. The title complex features two independent RuII complex cations that display very similar distorted octahedral coordination provided by the three N atoms of the 2,2′:6′,2′′‐terpyridine ligand, the N and O atoms of the 2‐pyridinecarboxaldehyde (pyCHO) ligand and a chloride ligand. One of the cation sites is disordered such that the aldehyde group is replaced by a 20 (1)% contribution from a carboxylic acid group (aldehyde H replaced by carboxyl O—H). Notable dimensions in the non‐disordered complex cation are Ru—N 2.034 (2) Å and Ru—O 2.079 (2) Å to the pyCHO ligand and O—C 1.239 (4) Å for the pyCHO carbonyl group. 相似文献
18.
Choudhury M. Zakaria George Ferguson Alan J. Lough Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m1-m4
In the adduct ferrocene‐1,1′‐diylbis(diphenylmethanol)–1,2‐bis(4‐pyridyl)ethene (1/1), [Fe(C18H15O)2]·C12H10N2, there is an intramolecular O—H?O hydrogen bond in the ferrocenediol component and a single O—H?N hydrogen bond linking the diol to the diamine, which is disordered over two sets of sites, so forming a finite monomeric adduct. In the adduct ferrocene‐1,1′‐diylbis(diphenylmethanol)–1,6‐diaminohexane (2/1), 2[Fe(C18H15O)2]·C6H16N2, the amine lies across a centre of inversion in space group P. There is an intramolecular O—H?O hydrogen bond in the ferrocenediol, and the molecular components are linked by O—H?N and N—H?O hydrogen bonds, one of each type, into a C(13)[R(12)] chain of rings. 相似文献
19.
Ying Fu Yin‐Xia He Hong‐Xia Hou Wen‐Bo Zhu Hu‐Lin Li Chao Wu Fang‐Yan Xian 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):282-284
2,2′‐Anhydro‐1‐(3′,5′‐di‐O‐acetyl‐β‐D‐arabinofuranosyl)uracil, C13H14N2O7, was obtained by refluxing 2′,3′‐O‐(methoxymethylene)uridine in acetic anhydride. The structure exhibits a nearly perfect C4′‐endo (4E) conformation. The best four‐atom plane of the five‐membered furanose ring is O—C—C—C, involving the C atoms of the fused five‐membered oxazolidine ring, and the torsion angle is only −0.4 (2)°. The oxazolidine ring is essentially coplanar with the six‐membered uracil ring [r.m.s. deviation = 0.012 (5) Å and dihedral angle = −3.2 (3)°]. The conformation at the exocyclic C—C bond is gauche–trans which is stabilized by various C—H...π and C—O...π interactions. 相似文献
20.
Jorge Trilleras Jairo Quiroga Justo Cobo John N. Low Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(12):o665-o670
3‐tert‐Butyl‐7‐(4‐methoxybenzyl)‐4′,4′‐dimethyl‐1‐phenyl‐4,5,6,7‐tetrahydro‐1H‐pyrazolo[3,4‐b]pyridine‐5‐spiro‐1′‐cyclohexane‐2′,6′‐dione, C31H37N3O3, (I), 3‐tert‐butyl‐7‐(2,3‐dimethoxybenzyl)‐4′,4′‐dimethyl‐1‐phenyl‐4,5,6,7‐tetrahydro‐1H‐pyrazolo[3,4‐b]pyridine‐5‐spiro‐1′‐cyclohexane‐2′,6′‐dione, C32H39N3O4, (II), 3‐tert‐butyl‐4′,4′‐dimethyl‐7‐(3,4‐methylenedioxybenzyl)‐1‐phenyl‐4,5,6,7‐tetrahydro‐1H‐pyrazolo[3,4‐b]pyridine‐5‐spiro‐1′‐cyclohexane‐2′,6′‐dione, C31H35N3O4, (III), and 3‐tert‐butyl‐4′,4′‐dimethyl‐1‐phenyl‐7‐(3,4,5‐trimethoxybenzyl)‐4,5,6,7‐tetrahydro‐1H‐pyrazolo[3,4‐b]pyridine‐5‐spiro‐1′‐cyclohexane‐2′,6′‐dione ethanol 0.67‐solvate, C33H41N3O5·0.67C2H6O, (IV), all contain reduced pyridine rings having half‐chair conformations. The molecules of (I) and (II) are linked into centrosymmetric dimers and simple chains, respectively, by C—H...O hydrogen bonds, augmented only in (I) by a C—H...π hydrogen bond. The molecules of (III) are linked by a combination of C—H...O and C—H...π hydrogen bonds into a chain of edge‐fused centrosymmetric rings, further linked by weak hydrogen bonds into supramolecular arrays in two or three dimensions. The heterocyclic molecules in (IV) are linked by two independent C—H...O hydrogen bonds into sheets, from which the partial‐occupancy ethanol molecules are pendent. The significance of this study lies in its finding of a very wide range of supramolecular aggregation modes dependent on rather modest changes in the peripheral substituents remote from the main hydrogen‐bond acceptor sites. 相似文献