Molecular chains in the structure of a Zinc(Ii) Complex with Pyrazine-2,6-Dicarboxylate and Water Ligands

Crystals of catena-[diaqua-(μ-pyrazine-2,6-dicarboxylato-N,O,O′-μ-N′)]zinc(II) contain molecular chains in which the Zn(II) ions are bridged by pyrazine-2,6-dicarboxylate ligands via two symmetry-related oxygen atoms, each donated by a different carboxylic group [Zn–O(1) and O(1) ^I : 2.182(2)?Å] and the hetero-ring nitrogen atom [Zn–N(1): 2.049(3)?Å] situated between them on one side and the second hetero-ring nitrogen atom [Zn–N(2) ^II 2.118(3)?Å] from the adjacent ligand on the other. The Zn(II) ion and four coordinating atoms are coplanar. Two symmetry related water molecules [Zn–O3 and O: 2.116(2)?Å] situated above and below this plane complete the coordination around the Zn(II) ion to six atoms forming a distorted octahedron.     

Dimeric Molecules in the Crystals of a Calcium(II) Complex with Pyridine-2,6-Dicarboxylate and Water Ligands

The crystals of bis[ w -pyridine-2,6-dicarboxylato-O,N,O')]bis[trisaqua-calcium(II)] di(pyridine-2,6-dicarboxylic acid) contain dimeric molecules composed of two calcium(II) ions and two ligand molecules. Calcium ions are bridged by two bidentate oxygen atoms each donated by one carboxylic group of the ligand [Ca―N 2.467(2)Å], a monodentate oxygen atom of the second carboxylate group of the ligand [Ca―N 2.484(2)Å] and three oxygen atoms donated by the water molecules [mean Ca―O 2.388(2)Å]. The coordination polyhedron is a distorted pentagonal bipyramid. Acid molecules were found to be located in the space between dimers and involved in an extended network of hydrogen bonds.     

Hydrothermal Synthesis,Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of _∞~2[Co(phen)(μ-L)_(3/3)]·H_2O (H_2L = Pyrazine-2,3-dicarboxylic Acid)

1 INTRODUCTION Molecular assembly and supramolecular che-mistry are young and rapidly growing subjects andhave attracted great attention. Microporous materialsbuilt up by organic ligands and metal ions have po-tential applications in catalysis, chemical absorption,magnetism and electronic conductivity[1～3]. Multi-dentate organic ligands are good building blocks,such as 1,2,4,5-benzene tetracarboxylic acid (BT-CA), 1,3,5-benzene tricarboxylic acid, terephthalicacid, 1,10-phenanthrol…     

Hydrothermal Synthesis, Crystal Structure and Thermal Analyses of Pyrazine-2,3-dicarboxylic Acid Bridged Co(II) Coordination Polymer of 2∞[Co(phen) (μ-L)3/3]·H2O (H2L = Pyrazine-2,3-dicarboxylic Acid)

A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex2∞[Co- (phen)(μ-L)3/3]·H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) (A), β = 110.55(3)°, V = 1653.1(6) (A)3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2∞[Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals' intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.     

The Crystal Structures of Two Calcium(II) Complexes with Pyrazine- 2,6-Dicarboxylate and Water Ligands

The structure of catena-{bis[(μ-aqua)(diaqua)(pyrazine-2,6-dicarboxylato-O,N-μ-O')](calcium(II)} consists of dimeric units composed of two calcium(II) ions, two ligand molecules and six water molecules. The calcium ions are bridged by two bidentate oxygen atoms, each donated by one carboxylic group of the ligand. The Ca(II) ion is also coordinated by one oxygen atom of the second carboxylate group and the hetero-ring nitrogen atom belonging to the same ligand molecule. Both calcium ions in a dimer are bridged to the Ca(II) ions in adjacent dimers by a pair of water molecules forming infinite molecular ribbons. In addition, each Ca(II) ion is coordinated by three water molecules; one of them is used for bridging the adjacent dimer. The coordination polyhedron around the Ca(II) ion is a pentagonal bipyramid with two apices above and one apex below the equatorial plane. The same molecular pattern is observed in the structure of catena-{bis[(μ-aqua)(diaqua)(pyrazine-2,6-dicarboxylato-O,N-μ-O')](calcium(II)} dihydrate which, in addition, contains two solvation water molecules per unit cell. In both compounds the molecular ribbons are held together by extended systems of hydrogen bonds.     

Synthesis and Crystal Structure of [Zn(HPDB)_2(H_2O)_2]n·2nDMSO·2nH_2O (H_2-PDB = Pyridine-3,4-dicarboxylic Acid)

1 INTRODUCTION Metal-organic coordination polymers are currently of considerable interest and importance because they can be used as new functional materials applicable in adsorption, luminescent and NLO materials fields[1, 2]. Due to the manifold N- and O-donors of pyridine- (bi)carboxylic ligands, metal pyridine-(bi)carboxyla- tes can construct versatile structural motifs, which finally aggregate to generate various supramolecular architectures with interesting properties[3, 4]. The d…     

Synthesis and Crystal Structure of Diaquabis{2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]-phenolato}nickel(Ⅱ) Dinitrate Diacetonitrile

The title mononuclear Schiff base nickel(Ⅱ) complex [Ni(C11H14Br2N2O)2(H2O)2]· 2NO3·2C2H3N was prepared and characterized by elemental analysis,IR spectrum,and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system,space group P21/n with a=15.534(2),b=7.647(1),c=16.435(2),β=103.252(2)o,V=1900.3(4)3,Z=2,Dc=1.750 g/cm3,Mr=1000.99,λ(MoKα)=0.71073,μ=4.776 mm-1,F(000)=996,the final R=0.0368 and wR=0.0724. A total of 3988 unique reflections were collected,of which 2764 with I > 2σ(I) were observed. The complex consists of a mononuclear [Ni(C11H14Br2N2O)2(H2O)2]2+ cation,two nitrate anions and two acetonitrile molecules. The Ni atom,lying on the inversion centre,is six-coordinated by two Schiff bases and two water molecules to assume an octahedral coordination geometry. The molecules in the crystal are linked through intermolecular hydrogen bonds of N–H…O,N–H…Br,O–H…O,O–H…N and C–H…O to form layers.     

Crystal structure of pharmaceutical cocrystals of 2,6‐diaminopyridine with piracetam and theophylline

Pharmaceutical cocrystals are crystalline solids formed by an active pharmaceutical ingredient and a cocrystal former. The cocrystals 2,6‐diaminopyridine (DAP)–piracetam [PIR; systematic name: 2‐(2‐oxopyrrolidin‐1‐yl)acetamide] (1/1), C₅H₇N₃·C₆H₁₀N₂O₂, (I), and 2,6‐diaminopyridine–theophylline (TEO; systematic name: 1,3‐dimethyl‐7H‐purine‐2,6‐dione) (1/1), C₅H₇N₃·C₇H₈N₄O₂, (II), were prepared by the solvent‐assisted grinding method and were characterized by IR spectroscopy and powder X‐ray diffraction. Cocrystal (I) crystallized in the orthorhombic space group Pbca and showed a 1:1 stoichiometry. The DAP and PIR molecules are linked by an N—H…O hydrogen‐bond interaction. Self‐assembly of PIR molecules forms a sheet of C (4) and C (7) chains. Cocrystal (II) crystallized in the monoclinic P 2₁/c space group and also showed a 1:1 stoichiometry. The DAP and TEO molecules are connected by N—H…N and N—H…O hydrogen bonds, forming an R ₂²(9) heterosynthon. A bidimensional supramolecular array is formed by interlinked DAP–TEO tetramers, producing a two‐dimensional sheet.     

Characterization and crystal structure study of a new Cu(II) complex of pyridine-2,6-dicarboxylic acid and aniline containing a water cluster

A new monoclinic Cu(II) salt complex (C₆H₆N₂) ₂ ⁺ [Cu(2,6-dipico)₂]^2?·6H₂O, (2,6-dipico=pyridine-2,6-dicarboxylic acid) is synthesized and characterised by CHN analyses, IR, UV-Vis, magnetic susceptibility measurements, and single crystal X-ray crystallography. The structure contains two pyridine-2,6-dicarboxylate species as tridentate ligands with protonated aniline acting as a counter cation and six uncoordinated water molecules. The complex crystallizes in the monoclinic space group C2/c with unit cell parameters a = 20.9393(4) Å, b = 7.94330(10) Å, c = 19.9093(4) Å, V(ų) = 2932.32(9), Z = 4. Crystal packing is stabilized by N-H…O, O-H…O intermolecular hydrogen bonds and weak π…π interactions. The water molecules are trapped by a cooperative association of coordination interactions forming water clusters as well as by a hydrogen bond to the Cu (II) complex.     

二维层状磷酸亚磷酸钒(Ⅳ)化合物[V2O2(OH)(HPO3)(HPO3)0.7(PO3OH)0.3].(C6N2H16)0.5的水热合成与结构表征

迄今, 在中温水热条件下已合成了大量具有空旷骨架结构的过渡金属磷酸盐微孔材料[1], 这类材料在非线性光学材料、磁性材料、超导材料及催化等诸多方面具有潜在的应用前景[2～5].     

一种新的有机胺为模板剂的稀土硫酸钐合成，结构表征以及荧光性质

本文采用正丁醇与水的混合溶剂合成一种新的以有机胺为模板剂的硫酸钐盐:[C2N2H10]1.5[Sm(SO4)3(H2O)].2H2O(1),并通过X-射线衍射、红外、热重及元素分析对其进行了表征。该化合物晶体属于单斜晶系,P21/c空间群。其中a=0.65515(9)nm,b=2.648 3(4)nm,c=0.996 15(13)nm,β=104.067 0(10)°,V=1.676 5(4)nm3,Z=4。晶体结构分析显示化合物1中的波浪形层状结构由SmO9多面体与SO4多面体构成,同时非配位水与乙二胺通过氢键连接相邻的两个层。化合物1具有较强的荧光。     

Doubly bridged molecular ribbons in the structure of an ionic complex,hydronium zinc(II) pyrazine-2,3-dicarboxylate

The structure of dihydronium [catena-bis(μ-pyrazine-2,3-dicarboxylato-N,O,O′)zinc(II)], (H3O)2[Zn(2,3PZDC)2], is composed of polyanionic ribbons of zinc(II) ions linked by double bridging 2,3-PZDC ligand molecules. Each ligand uses an N,O bonding moiety formed by one carboxylic group [Zn–O 2.071(2)?Å; Zn–N 2.184(2)?Å] and a monodentate oxygen atom of the other carboxylate group [Zn–O 2.092(2)?Å]. Coordination around the zinc(II) ion is strongly distorted octahedral. Hydronium cations (H₃O)¹⁺ link the ribbons by hydrogen bonds.     

Synthesis and Crystal Structure of Diaquabis{2,4-dibromo-6-[(2-ethylaminoethylimino)methyl]phenolato}nickel(Ⅱ) Dinitrate Diacetonitrile

The title mononuclear Schiff base nickel(Ⅱ) complex [Ni(C11H14Br2N2O)2(H2O)2]·2NO3·2C2H3N was prepared and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 15.534(2), b = 7.647(1), c = 16.435(2) (A), β = 103.252(2)o, V = 1900.3(4) (A)3, Z = 2, Dc = 1.750 g/cm3, Mr = 1000.99, λ(MoKα) = 0.71073 (A), μ = 4.776 mm-1, F(000) = 996, the final R = 0.0368 and wR = 0.0724. A total of 3988 unique reflections were collected, of which 2764 with I＞2σ(I) were observed. The complex consists of a mononuclear [Ni(C11H14Br2N2O)2(H2O)2]2 cation, two nitrate anions and two acetonitrile molecules. The Ni atom, lying on the inversion centre, is six- coordinated by two Schiff bases and two water molecules to assume an octahedral coordination geometry. The molecules in the crystal are linked through intermolecular hydrogen bonds of N-H…O, N-H…Br, O-H…O, O-H…N and C-H…O to form layers.     

Synthesis and Crystal Structure of a Novel Hetero-bimetallic Complex with a Three-dimensional Network Structure: Bis(malonato)tetra(aqua)calcum(II)cobalt(II)

1INTRODUCTION There has been considerable interest in the designand synthesis of transition metal complexes withcarboxylate ligands in coordination chemistry due tothe fact that this type of complexes has potentialapplications in molecule-based magnets,catalysis,supramolecular chemistry and biological systems[1～3].As an important flexibility dicarboxylate ligand,malonate dianion may act as momodentate,chelatedbidentate and tridentate bridging ligands to formvarious1D,2D and3D structures[…     

Synthesis,Properties and Crystal Structure of A New 12-Molybdogermanic Salt of Lanthanum Coordinated to N -Methyl-2-Pyrrolidone

A new compound [La(NMP) 4 (H 2 O) 4 ][HGeMo 12 O 40 ]·2NMP·3H 2 O (NMP = N -methyl-2-pyrrolidone), 1 , was synthesized and characterized. The compound crystallizes in the monoclinic space group P 2 1 / c with a = 17.3428(4), b = 18.3258(5), c = 23.0387(7) Å, g = 107.088(1)°, V = 6998.9(3) Å 3 and Z = 4. The structure was characterized crystallographically with final R 1 = 0.0589, wR 2 = 0.1596. The crystal structure contains [GeMo 12 O 40 ] 4 m anions combining with [La(NMP) 4 (H 2 O) 4 ] 3+ cations through hydrogen bonds. The La 3+ ion exhibits eight-coordination with four water molecules and four carbonyl oxygen atoms of the organic ligands. Hydrogen bonds are formed between [GeMo 12 O 40 ] 4 m anions and coordinated water molecules, coordinating to water molecules. The anti-tumor activity of 1 was estimated against Hela and P c -3m cancer cells.     

Synthesis and Crystal Structure of [Zn(HPDB)2(H2O)2]n·2nDMSO·2nH2O (H2-PDB = Pyridine-3,4-dicarboxylic Acid)

The title complex [Zn(HPDB)2(H2O)2]n·(2nDMSO(2nH2O(H2-PDB is pyridine-3, 4-dicarboxylic acid and DMSO the dimethyl sulphoxide) was synthesized under traditional solution condition. Its crystal (C18H28N2O14S2Zn) belongs to monoclinic system, space group P21/c with a = 8.2791(6), b = 12.5495(10), c = 13.6519(11)(A), β = 105.294(2)°, V = 1368.18(18)(A)3, Z = 2, Mr = 625.91, Dx = 1.514 g/cm3, μ = 1.117 mm-1, F(000) = 648, R = 0.0654 and wR = 0.1654 for 2414 observed reflections (I > 2σ(I)). It has a 2-D planar network, in which the Zn atom is six-coor- dinated and hydrogen bonds between carboxylate groups, DMSO and water molecules result in the final 3D structure.     

Structures of 1-（3,4-Dihydroxyphenyl）-2-（3,4-dimethoxyphenyl） ethanone and Its Hydrate Complex

The title compounds, C16H16O5 (I) and C16H16O5·H2O (II), were structurally characterized by single-crystal X-ray diffraction. Compound I crystallizes in monoclinic space group P21/c with a = 10.5574(10), b = 8.3576(9), c = 16.5528(16) , β = 91.762(3)°, Z = 4, R = 0.0524 and wR = 0.1084. The molecules are jointed into a chain by intermolecular O-H···O and C-H···O hydrogen bonds, which form layers parallel to (001). The chains run along the [110] and [110] directions alternatively layer by layer, and are assembled into a network by intermolecular O-H···O (carboxyl) hydrogen bonds. On the other hand, the hydrate complex (II) crystallizes in the triclinic space group P1 with a = 5.1451(2), b = 10.4583(4), c = 14.8267(5) , α = 70.900(2), β = 82.478(2), γ = 81.359(2)°, Z = 2, R = 0.0393 and wR = 0.0983. The molecules are linked into infinite two-dimensional ribbons by O-H···O (carbonyl) and solvent-bridged O-H···O hydrogen bonds.     

2‐Ethyl‐6‐methylpyridin‐3‐ol and its salt bis(2‐ethyl‐3‐hydroxy‐6‐methylpyridinium) succinate

The title compounds, C₈H₁₁NO, (I), and 2C₈H₁₂NO⁺·C₄H₄O₄²⁻, (II), both crystallize in the monoclinic space group P2₁/c. In the crystal structure of (I), intermolecular O—H...N hydrogen bonds combine the molecules into polymeric chains extending along the c axis. The chains are linked by C—H...π interactions between the methylene H atoms and the pyridine rings into polymeric layers parallel to the ac plane. In the crystal structure of (II), the succinate anion lies on an inversion centre. Its carboxylate groups interact with the 2‐ethyl‐3‐hydroxy‐6‐methylpyridinium cations via intermolecular N—H...O hydrogen bonds with the pyridine ring H atoms and O—H...O hydrogen bonds with the hydroxy H atoms to form polymeric chains, which extend along the [01] direction and comprise R₄⁴(18) hydrogen‐bonded ring motifs. These chains are linked to form a three‐dimensional network through nonclassical C—H...O hydrogen bonds between the pyridine ring H atoms and the hydroxy‐group O atoms of neighbouring cations. π–π interactions between the pyridine rings and C—H...π interactions between the methylene H atoms of the succinate anion and the pyridine rings are also present in this network.     

Synthesis and Crystal Structure of Copper(Ⅱ) Compound with Didentate Schiff-base Ligand

1INTRODUCTIONTransitionmetalcomplexesofSchiff-baseligandswhichbindtwoormoremetalcentersincloseproximityareimportantaspotentialcatalysts[1]andasmodelsforanumberofmetalloproteins[2]duetotheopportunitytheyprovidefortheinvesti-gationofmagneticinteractions.The…     

Influence of hydrogen bonding on the assembly of six-membered vanadium borophosphate cluster anions: synthesis and structures of (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12](6)10H2O, (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12](6)17H2O, and (NH4)3(C4H14N2)4 5[Sr(H2O)5]2[Sr(H2O)4][V2P2BO12]6 10H2O

Three new strontium vanadium borophosphate compounds, (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12]6 10H2O (Sr-VBPO1) (1), (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12]6 17H2O (Sr-VBPO2) (2), and (NH4)3(C4H14N2)4.5[Sr(H2O)5]2[Sr(H2O)4][V2P2BO12]6 10H2O (Sr-VBPO3) (3) have been synthesized by interdiffusion methods in the presence of diprotonated ethylenediamine, 1,3-diaminopropane, and 1,4-diaminobutane. Compound 1 has a chain structure, whereas 2 and 3 have layered structures with different arrangements of [(NH4) [symbol: see text] [V2P2BO12]6] cluster anions within the layers. Crystal data: (NH4)2(C2H10N2)6[Sr(H2O)5]2[V2P2BO12]6 10H2O, monoclinic, space group C2/c (no. 15), a = 21.552(1) A, b = 27.694(2) A, c = 20.552(1) A, beta = 113.650(1) degrees, Z = 4; (NH4)2(C3H12N2)6[Sr(H2O)4]2[V2P2BO12]6 17H2O, monoclinic, space group I2/m (no. 12), a = 15.7618(9) A, b = 16.4821(9) A, c = 21.112(1) A, beta = 107.473(1) degrees, Z = 2; (NH4)3(C4H14N2)4.5[Sr(H2O)5]2[Sr(H2O)4] [V2P2BO12]6 10H2O, monoclinic, space group C2/c (no. 15), a = 39.364(2) A, b = 14.0924(7) A, c = 25.342(1) A, beta = 121.259(1) degrees, Z = 4. The differences in the three structures arise from the different steric requirements of the amines that lead to different amine-cluster hydrogen bonds.