首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 11 毫秒
1.
Copper(II)–Schiff base complexes have attracted extensive interest due to their structural, electronic, magnetic and luminescence properties. The title novel monomeric CuII complex, [Cu(C10H11N2O4)2], has been synthesized by the reaction of 3‐{[(3‐hydroxypropyl)imino]methyl}‐4‐nitrophenol (H2L ) and copper(II) acetate monohydrate in methanol, and was characterized by elemental analysis, UV and IR spectroscopies, single‐crystal X‐ray diffraction analysis and a photoluminescence study. The CuII atom is located on a centre of inversion and is coordinated by two imine N atoms, two phenoxy O atoms in a mutual trans disposition and two hydroxy O atoms in axial positions, forming an elongated octahedral geometry. In the crystal, intermolecular O—H…O hydrogen bonds link the molecules to form a one‐dimensional chain structure and π–π contacts also connect the molecules to form a three‐dimensional structure. The solid‐state photoluminescence properties of the complex and free H2L have been investigated at room temperature in the visible region. When the complex and H2L are excited under UV light at 349 nm, the complex displays a strong green emission at 520 nm and H2L displays a blue emission at 480 nm.  相似文献   

2.
In the title compound, [Pb(C12H8NO2)2]n, the Pb atom sits on a crystallographic C2 axis and is six‐coordinate, ligated by two chelating carboxylate groups from two 3‐(pyridin‐4‐yl)benzoate (L) ligands and by two N atoms from another two ligands. Each ligand bridges two PbII centres, extending the structure into a corrugated two‐dimensional (4,4) net. The ligand L is conformationally chiral, with a torsion angle of 27.9 (12)° between the planes of its two rings. The torsion angle has the same sense throughout the structure, so that the extended two‐dimensional polymer is homochiral. Investigation of the thermal stability shows that the network is stable up to 613 K. In the absence of any stereoselective factor in the preparation of the compound, the enantiomeric purity of the crystal studied, based only on the torsional conformation of the ligand, implies that the bulk sample is a racemic conglomerate.  相似文献   

3.
Single crystals of (1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)lithium(I) diiodide dihydrate, [Li(C6H16N3O3)(C6H15N3O3)]I2·2H2O or [Li(Htaci)(taci)]I2·2H2O (taci is 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol), (I), bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)sodium(I) iodide, [Na(C6H15N3O3)2]I or [Na(taci)2]I, (II), and bis(1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol‐κ3O2,O4,O6)potassium(I) iodide, [K(C6H15N3O3)2]I or [K(taci)2]I, (III), were grown by diffusion of MeOH into aqueous solutions of the complexes. The structures of the Na and K complexes are isotypic. In all three complexes, the taci ligands adopt a chair conformation with axial hydroxy groups, and the metal cations exhibit exclusive O‐atom coordination. The six O atoms of the resulting MO6 unit define a centrosymmetric trigonal antiprism with approximate D3d symmetry. The interligand O...O distances increase significantly in the order Li < Na < K. The structure of (I) exhibits a complex three‐dimensional network of R—NH2—H...NH2R, R—O—H...NH2R and R—O—H...O(H)—H...NH2R hydrogen bonds. The structures of the Na and K complexes consist of a stack of layers, in which each taci ligand is bonded to three neighbours via pairwise O—H...NH2 interactions between vicinal HO—CH—CH—NH2 groups.  相似文献   

4.
In the title compound, C31H29N3O2, the reduced pyridine ring adopts a conformation intermediate between the envelope and half‐chair forms. The aryl rings of the benzyl and phenyl substituents are nearly parallel and overlap, indicative of an intramolecular π–π stacking interaction. A combination of two C—H...O hydrogen bonds and one C—H...N hydrogen bond links the molecules into a bilayer having tert‐butyl groups on both faces.<!?tpb=19.5pt>  相似文献   

5.
The reaction of 4,4′‐bipyridine with copper acetate in the presence of 4‐nitrophenol led to the formation of the title compound, {[Cu(CH3COO)2(C10H8N2)]·C6H5NO3·2H2O}n. The complex forms a double‐stranded ladder‐like coordination polymer extending along the b axis. The double‐stranded polymers are separated by 4‐nitrophenol and water solvent molecules. The two CuII centres of the centrosymmetric Cu2O2 ladder rungs have square‐pyramidal coordination environments, which are formed by two acetate O atoms and two 4,4′‐bipyridine N atoms in the basal plane and another acetate O atom at the apex. The ladder‐like double strands are separated from each other by one unit‐cell length along the c axis, and are connected by the water and 4‐nitrophenol molecules through a series of O—H...O and C—H...O hydrogen‐bonding interactions and two unique intermolecular π–π interactions.  相似文献   

6.
In the title monohydrated cocrystal, namely 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol iodide–1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol–water (1/1/1), C6H16N3O3+·I·C6H15N3O3·H2O, the neutral 1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol (taci) molecule and the monoprotonated 1,3‐diamino‐5‐azaniumyl‐1,3,5‐trideoxy‐cis‐inositol cation (Htaci+) both adopt a chair conformation, with the three O atoms in axial and the three N atoms in equatorial positions. The cation, but not the neutral taci unit, exhibits intramolecular O—H...O hydrogen bonding. The entire structure is stabilized by a complex three‐dimensional network of intermolecular hydrogen bonds. The neutral taci entities and the Htaci+ cations are each aligned into chains along [001]. In these chains, two O—H...N interactions generate a ten‐membered ring as the predominant structural motif. The rings consist of vicinal 2‐amino‐1‐hydroxyethylene units of neighbouring molecules, which are paired via centres of inversion. The chains are interconnected into undulating layers parallel to the ac plane, and the layers are further held together by O—H...N hydrogen bonds and additional interactions with the iodide counter‐anions and solvent water molecules.  相似文献   

7.
The title compound, [Cu(C9H8BrClNO2)2], is a square‐planar complex. The potentially tridentate dibasic 2‐bromo‐4‐chloro‐6‐{[(2‐hydroxyethyl)imino]methyl}phenolate ligand coordinates in a trans‐bis fashion to the CuII centre via the imine N and phenolate O atoms. The CuII atom lies on the centre of inversion of the molecule. The potentially coordinating hydroxyethyl group remains protonated and uncoordinated, taking part in intermolecular hydrogen bonds with vicinal groups, leading to the formation of a two‐dimensional hydrogen‐bond network with sheets parallel to the (10) plane. Substituent effects on the crystal packing and coordination modes of the ligand are discussed.  相似文献   

8.
The polyfluorinated title compounds, [MBr2(C18H16F8N2O2)] or [4,4′‐(HCF2CF2CH2OCH2)2‐2,2′‐bpy]MBr2, ( 1 ) (M = Pd and bpy is bipyridine) and ( 2 ) (M = Pt), have –CH(α)2OCH(β)2CF2CF2H side chains with methylene H‐atom donors at the α and β sites, and methine H‐atom donors at the terminal sites, in addition to aromatic H‐atom donors. In contrast to the original expectation of isomorphous structures, ( 1 ) crystallizes in the space group C2/c and ( 2 ) in P21/n, with similar unit‐cell volumes and Z = 4. The asymmetric unit of ( 1 ) is one half of the molecule, which resides on a crystallographic twofold axis. Both ( 1 ) and ( 2 ) display stacking of the molecules, indicating a planar (bpy)MBr2 skeleton in each case. The structure of ( 1 ) exhibits columns with C—H(β)…Br hydrogen bonds between consecutive layers which conforms to a static (β,β) linkage between layers. In the molecular plane, ( 1 ) shows double C—H(α)…Br hydrogen bonds self‐repeating along the b axis, the planar molecules being connected into infinite belts. Compound ( 2 ) has no crystallographic symmetry and forms π‐dimer pairs as supermolecules, which then stack parallel to the a axis. The π‐dimer‐pair supermolecules exhibit (Pt—)Br…Br(—Pt) contacts [3.6937 (7) Å] to neighbouring π‐dimer pairs crosslinking the columns. The structure of ( 2 ) reveals many C—H…F(—C) interactions between F atoms and aromatic C—H groups, in addition to those between F atoms and methylene C—H groups.  相似文献   

9.
The title compound, [Dy2(C2H3O2)6(H2O)4]·4H2O, crystallizes in the form of dimeric units related by an inversion centre. Each cation is nine‐coordinate, binding to two water mol­ecules and three acetate groups, two of which are bidentate and the third tridentate. This last acetate group acts as a bridge between neighbouring metal atoms, leading to an intradimer Dy?Dy separation of 4.170 (1) Å.  相似文献   

10.
The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5′‐dmbpy)2]ClO4·H2O (where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′‐dmbpy–KClO4 system. Within the complex cation, the NiII atom is hexacoordinated by two chelating 5,5′‐dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen‐bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single‐ion anisotropy, D, which arises from the reduced local symmetry of the cis‐NiO2N4 chromophore. The fitting of the variable‐temperature magnetic data (2–300 K) gives giso = 2.134 and D/hc = 3.13 cm−1.  相似文献   

11.
The polyfluorinated title compounds, [M Cl2(C16H16F4N2O2)] or [4,4′‐(HCF2CH2OCH2)2‐2,2′‐bpy]M Cl2 [M = Pd, ( 1 ), and M = Pt, ( 2 )], have –C(Hα)2OC(Hβ)2CF2H side chains with H‐atom donors at the α and β sites. The structures of ( 1 ) and ( 2 ) are isomorphous, with the nearly planar (bpy)M Cl2 molecules stacked in columns. Within one column, π‐dimer pairs alternate between a π‐dimer pair reinforced with C—H…Cl hydrogen bonds (α,α) and a π‐dimer pair reinforced with C—Hβ…F(—C) interactions (abbreviated as C—Hβ…F—C,C—Hβ…F—C). The compounds [4,4′‐(CF3CH2OCH2)2‐2,2′‐bpy]M Cl2 [M = Pd, ( 3 ), and M = Pt, ( 4 )] have been reported to be isomorphous [Lu et al. (2012). J. Fluorine Chem. 137 , 54–56], yet with disorder in the fluorous regions. The molecules of ( 3 ) [or ( 4 )] also form similar stacks, but with alternating π‐dimer pairs between the (α,β; α,β) and (β,β) forms. Through (C—)H…Cl hydrogen‐bond interactions, one molecule of ( 1 ) [or ( 2 )] is expanded into an aggregate of two inversion‐related π‐dimer pairs, one pair in the (α,α) form and the other pair in the (C—Hβ…F—C,C—Hβ…F—C) form, with the plane normals making an interplanar angle of 58.24 (3)°. Due to the demands of maintaining a high coordination number around the metal‐bound Cl atoms in molecule ( 1 ) [or ( 2 )], the ponytails of molecule ( 1 ) [or ( 2 )] bend outward; in contrast, the ponytails of molecule ( 3 ) [or ( 4 )] bend inward.  相似文献   

12.
The title bimolecular structure, [Cu4Cl6O(C4H8O)3(H2O)]2[Cu4Cl6O(C4H8O)4]·4C4H8O, at 100 K has monoclinic (P21/c) symmetry. The structure contains nine symmetry‐independent molecules expressed in simplest molecular form as 6[Cu4Cl6O(C4H8O)3(H2O)·2(C4H8O)]:3Cu4Cl6O(C4H8O)4. The compound exhibits a supercell (smaller than the unit cell based on weak reflections) structure due to pseudotranslational symmetry. The structure displays O—H...O hydrogen bonding between bound water ligands and tetrahydrofuran (THF) solvent molecules. The structure exhibits disorder for 12 of the THF molecules, of which seven are ligated to Cu and five are hydrogen bonded to H2O ligands.  相似文献   

13.
The structure of the ionic title compound, (C5H7N6)2[Nd2(C5O5)4(H2O)8], consists of anionic dimers built around an inversion centre and is made up of an NdIII cation, two croconate (croco) dianions and four water molecules (plus their inversion images), with two noncoordinated symmetry‐related 2,6‐diamino‐1H‐purin‐3‐ium (Hdap+) cations providing charge balance. Each NdIII atom is bound to nine O atoms from four water and three croco units. The coordination polyhedron has the form of a rather regular monocapped square antiprism. The croconate anions are regular and the Hdap+ cation presents a unique, thus far unreported, protonation state. The abundance of hydrogen‐bonding donors and acceptors gives rise to a complex packing scheme consisting of dimers interlinked along the three crystallographic directions and defining anionic `cages' where the unbound Hdap+ cations lodge, linking to the mainframe via (N—H)Hdap...Owater/croco and (O—H)water...NHdap interactions.  相似文献   

14.
A novel neutral polymer, {[Co2(C7H3NO4)2(H2O)4]·2H2O}n, was hydrothermally synthesized using pyridine‐2,5‐dicarboxylate (2,5‐PDC2−) as the organic linker. It features a two‐dimensional layer structure constructed from one‐dimensional {[Co(2,5‐PDC)2]2−}n chains interlinked by [Co(H2O)4]+ units. The two CoII cations occupy special positions, sitting on inversion centres. Each 2,5‐PDC2− anion chelates to one CoII cation via the pyridine N atom and an O atom of the adjacent carboxylate group, and links to two other CoII cations in a bridging mode via the O atoms of the other carboxylate group. In this way, the 2,5‐PDC2− ligand connects three neighbouring CoII centres to form a two‐dimensional network. The two‐dimensional undulating layers are linked by extensive hydrogen bonds to form a three‐dimensional supramolecular structure, with the uncoordinated solvent molecules occupying the interlamellar region.  相似文献   

15.
In the title compound, [Cu(C9H5N4O)Cl(C12H8N2)]n or [Cu(tcnoet)Cl(phen)]n, where phen is 1,10‐phenanthroline and tcnoet is 1,1,3,3‐tetracyano‐2‐ethoxypropenide, the axially elongated (4 + 2) coordination polyhedron around the CuII centre contains N atoms from three different tcnoet ligands. The resulting coordination polymer takes the form of sheets which are linked in pairs by a single C—H...N hydrogen bond to form bilayers. The bond lengths provide evidence for significant bond fixation in the phen ligand and extensive electronic delocalization in the tcnoet ligand, where the two –C(CN)2 units are rotated, in conrotatory fashion, out of the plane of the central C3O fragment.  相似文献   

16.
Hydrogen bonding between urea functionalities is a common structural motif employed in crystal‐engineering studies. Crystallization of 1,3‐bis(3‐fluorophenyl)urea, C13H10F2N2O, from many solvents yielded concomitant mixtures of at least two polymorphs. In the monoclinic form, one‐dimensional chains of hydrogen‐bonded urea molecules align in an antiparallel orientation, as is typical of many diphenylureas. In the orthorhombic form, one‐dimensional chains of hydrogen‐bonded urea molecules have a parallel orientation rarely observed in symmetrically substituted diphenylureas.  相似文献   

17.
Racemic 2,4(6)‐di‐O‐benzoyl‐myo‐inositol 1,3,5‐orthoformate, C21H18O8, (1) , shows a very efficient intermolecular benzoyl‐group migration reaction in its crystals. However, the presence of 4,4′‐bipyridine molecules in its cocrystal, C21H18O8·C10H8N2, (1)·BP , inhibits the intermolecular benzoyl‐group transfer reaction. In (1) , molecules are assembled around the crystallographic twofold screw axis (b axis) to form a helical self‐assembly through conventional O—H...O hydrogen‐bonding interactions. This helical association places the reactive C6‐O‐benzoyl group (electrophile, El) and the C4‐hydroxy group (nucleophile, Nu) in proximity, with a preorganized El...Nu geometry favourable for the acyl transfer reaction. In the cocrystal (1)·BP , the dibenzoate and bipyridine molecules are arranged alternately through O—H...N interactions. The presence of the bipyridine molecules perturbs the regular helical assembly of the dibenzoate molecules and thus restricts the solid‐state reactivity. Hence, unlike the parent dibenzoate crystals, the cocrystals do not exhibit benzoyl‐transfer reactions. This approach is useful for increasing the stability of small molecules in the crystalline state and could find application in the design of functional solids.  相似文献   

18.
In bis(2‐aminoanilinum) fumarate, 2C6H9N2+·C4H2O42−, (I), the asymmetric unit consists of two aminoanilinium cations and one fumarate dianion, whereas in 3‐methylanilinium hydrogen fumarate, C7H10N+·C4H3O4, (II), and 4‐chloroanilinium hydrogen fumarate, C6H7ClN+·C4H3O4, (III), the asymmetric unit contains two symmetry‐independent hydrogen fumate anions and anilinium cations with a slight difference in their geometric parameters; the two salts are isostructural. In (II) and (III), the carboxylic acid H atoms of the anions are disordered across both ends of the anion, with equal site occupancies of 0.50. Both the 4‐chloroanilinium cations of (III) are disordered over two orientations with major occupancies fixed at 0.60 in each case. The hydrogen fumarate anions of (II) and (III) form one‐dimensional anionic chains linked through O—H...O hydrogen bonds. Salts (II) and (III) form two‐dimensional supramolecular sheets built from R44(16), R44(18), R55(25) and C22(14) motifs extending parallel to the (010) plane, whereas in (I), an (010) sheet is formed built from two R43(13) motifs, two R22(9) motifs and an R44(18) motif.  相似文献   

19.
<!?tlsb=‐0.2pt>Nitrogen‐based polydentate ligands are of interest owing to their flexible complexation to transition metal atoms. For the title compound, [Ni(C15H17N2)2], a transition metal complex formed by the coordination of two identical N,N′‐bidentate mono(imino)pyrrolyl ligands to an NiII centre, an X‐ray crystal diffraction study indicates that the two ligands show an inverted arrangement with respect to one another around the NiII centre, which is located on a crystallographic inversion centre. The planes of the aromatic substituents at the imine N atoms of the ligands show dihedral angles of 85.91 (5)° with respect to the NiN4 plane. The Ni—N bond lengths are in the range 1.9072 (15)–1.9330 (15) Å and the Nimino—Ni—Npyrrole bite angles are 83.18 (6)°. The Ni—Npyrrole bond is substantially shorter than the Ni—Nimino bond. Molecules are linked into an extensive network by means of intermolecular C—H...π(arene) hydrogen bonds in which every molecule acts both as hydrogen‐bond donor and acceptor. The supramolecular assembly takes the form of an infinite two‐dimensional sheet.  相似文献   

20.
A new inorganic–organic hybrid zinc phosphite, [Zn(HPO3)(C6H11NO2)]n, has been synthesized hydrothermally. Protonated piperidin‐1‐ium‐4‐carboxylate (PDCA) was generated in situ by hydrolysis of the piperidine‐4‐carboxamide precursor. The P atom possesses a typical PO3H pseudo‐pyramidal geometry. The crystal structure features an unusual (3,4)‐connected two‐dimensional inorganic zinc–phosphite layer, with organic PDCA ligands appended to the sheets and protruding into the interlayer region. Helical chains of opposite chirality are involved in the construction of a puckered sheet structure.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号