System-pH-dependent supramolecular isomers of puckered three-dimensional layered hydrogen-bonded networks: Syntheses, characterization and fluorescent properties

2006 ◽  
Vol 179 (8) ◽  
pp. 2656-2662 ◽  
Author(s):  
Pang-Kuan Chen ◽  
Yun-Xia Che ◽  
Yu-Mei Li ◽  
Ji-Min Zheng
2015 ◽  
Vol 71 (3) ◽  
pp. 222-228 ◽  
Author(s):  
Mohamed Abdellatif Bensegueni ◽  
Aouatef Cherouana ◽  
Slimane Dahaoui

Two alkaline earth–tetrazole compounds, namelycatena-poly[[[triaquamagnesium(II)]-μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N5] hemi{bis[μ-5,5′-(azanediyl)ditetrazolato-κ3N1,N1′:N2]bis[triaquamagnesium(II)]} monohydrate], {[Mg(C2HN9)(H2O)3][Mg2(C2HN9)2(H2O)6]0.5·H2O}n, (I), and bis[5-(pyrazin-2-yl)tetrazolate] hexaaquamagnesium(II), (C5H3N6)[Mg(H2O)6], (II), have been prepared under hydrothermal conditions. Compound (I) is a mixed dimer–polymer based on magnesium ion centres and can be regarded as the first example of a magnesium–tetrazolate polymer in the crystalline form. The structure shows a complex three-dimensional hydrogen-bonded network that involves magnesium–tetrazolate dimers, solvent water molecules and one-dimensional magnesium–tetrazolate polymeric chains. The intrinsic cohesion in the polymer chains is ensured by N—H...N hydrogen bonds, which formR22(7) rings, thus reinforcing the propagation of the polymer chain along theaaxis. The crystal structure of magnesium tetrazole salt (II) reveals a mixed ribbon of hydrogen-bonded rings, of typesR22(7),R22(9) andR24(10), running along thecaxis, which are linked byR24(16) rings, generating a 4,8-cflunet.


Author(s):  
Nives Politeo ◽  
Mateja Pisačić ◽  
Marijana Đaković ◽  
Vesna Sokol ◽  
Boris-Marko Kukovec

A 6-chloronicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4′-bipyridine (4,4′-bpy), namely, catena-poly[[[tetraaquanickel(II)]-μ-4,4′-bipyridine-κ2 N:N′] bis(6-chloronicotinate) tetrahydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O} n or {[Ni(4,4′-bpy)(H2O)4](6-Clnic)2·4H2O} n , (1), was prepared by the reaction of nickel(II) sulfate heptahydrate, 6-chloronicotinic acid and 4,4′-bipyridine in a mixture of water and ethanol. The molecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4′-bpy)(H2O)4]2+} n cation, two 6-chloronicotinate anions and four water molecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octahedrally coordinated by four water molecule O atoms and by two 4,4′-bipyridine N atoms in the trans position. The 4,4′-bipyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4′-bpy)(H2O)4]2+} n , the 6-chloronicotinate anions and the water molecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetrameric R 2 4(8) and R 4 4(10) loops, a dimeric R 2 2(8) loop and a pentameric R 4 5(16) loop.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5955
Author(s):  
Qi-Ying Weng ◽  
Ya-Li Zhao ◽  
Jia-Ming Li ◽  
Miao Ouyang

A pair of cobalt(II)-based hydrogen-bonded organic frameworks (HOFs), [Co(pca)2(bmimb)]n (1) and [Co2(pca)4(bimb)2] (2), where Hpca = p-chlorobenzoic acid, bmimb = 1,3-bis((2-methylimidazol-1-yl)methyl)benzene, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene were hydrothermally synthesized and characterized through infrared spectroscopy (IR), elemental and thermal analysis (EA), power X-ray diffraction (PXRD), and single-crystal X-ray diffraction (SCXRD) analyses. X-ray diffraction structural analysis revealed that 1 has a one-dimensional (1D) infinite chain network through the deprotonated pca− monodentate chelation and with a μ2-bmimb bridge Co(II) atom, and 2 is a binuclear Co(II) complex construction with a pair of symmetry-related pca− and bimb ligands. For both 1 and 2, each cobalt atom has four coordinated twisted tetrahedral configurations with a N2O2 donor set. Then, 1 and 2 are further extended into three-dimensional (3D) or two-dimensional (2D) hydrogen-bonded organic frameworks through C–H···Cl interactions. Topologically, HOFs 1 and 2 can be simplified as a 4-connected qtz topology with a Schläfli symbol {64·82} and a 4-connected sql topology with a Schläfli symbol {44·62}, respectively. The fluorescent sensing application of 1 was investigated; 1 exhibits high sensitivity recognition for Fe3+ (Ksv: 10970 M−1 and detection limit: 19 μM) and Cr2O72− (Ksv: 12960 M−1 and detection limit: 20 μM). This work provides a feasible detection platform of HOFs for highly sensitive discrimination of Fe3+ and Cr2O72− in aqueous media.


2016 ◽  
Vol 72 (10) ◽  
pp. 1412-1416
Author(s):  
Monserrat Alfonso ◽  
Helen Stoeckli-Evans

The title isotypic complexes, bis[μ-5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylato]-κ4N1,O2,N6:O3;κ4O3:N1,O2,N6-bis[diaquamanganese(II)] tetrahydrate, [Mn2(C16H8N4O4)2(H2O)4]·4H2O, (I), and bis[μ-5,6-bis(pyridin-2-yl)pyrazine-2,3-dicarboxylato]-κ4N1,O2,N6:O3;κ4O3:N1,O2,N6-bis[diaquairon(II)] tetrahydrate, [Fe2(C16H8N4O4)2(H2O)4]·4H2O, (II), are, respectively, the manganese(II) and iron(II) complexes of the ligand 5,6-bis(pyridin-2-yl)-pyrazine-2,3-dicarboxylic acid. The complete molecule of each complex is generated by inversion symmetry. Each metal ion is coordinated by a pyrazine N atom, a pyridine N atom, two carboxylate O atoms, one of which is bridging, and two water O atoms. The metal atoms haveMN2O4coordination geometries and the complexes have a cage-like structure. In the crystals of both compounds, the complexes are linked by O—H...O and O—H...N hydrogen bonds involving the coordinating water molecules, forming chains along [100]. These chains are linked by O—H...O hydrogen bonds involving the non-coordinating water molecules, forming layers parallel to (011). The layers are linked by pairs of C—H...O hydrogen bonds and offset π–π interactions, so forming a hydrogen-bonded three-dimensional framework.


2020 ◽  
Vol 124 (42) ◽  
pp. 22959-22971
Author(s):  
Ioannis Skarmoutsos ◽  
Emmanuel N. Koukaras ◽  
George E. Froudakis ◽  
Guillaume Maurin ◽  
Emmanuel Klontzas

Crystals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 408 ◽  
Author(s):  
Ruo-Yan Li ◽  
Xiao-Xin An ◽  
Juan-Li Wu ◽  
You-Peng Zhang ◽  
Wen-Kui Dong

An unexpected trinuclear Co(II) complex, [Co3(L2)2(μ-OAc)2(CH3OH)2]·2CH3OH (H2L2 = 4,4′-dibromo-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol) constructed from a half-Salamo-based ligand (HL1 = 2-[O-(1-ethyloxyamide)]oxime-4-bromophenol) and Co(OAc)2·4H2O, has been synthesized and characterized by elemental analyses, infrared spectra (IR), UV-Vis spectra, X-ray crystallography and Hirshfeld surface analysis. The Co(II) complex contains three Co(II) atoms, two completely deprotonated (L2)2− units, two bridged acetate molecules, two coordinated methanol molecules and two crystalline methanol molecules, and finally, a three-dimensional supramolecular structure with infinite extension was formed. Interestingly, during the formation of the Co(II) complex, the ligand changed from half-Salamo-like to a symmetrical single Salamo-like ligand due to the bonding interactions of the molecules. In addition, the antimicrobial activities of HL1 and its Co(II) complex were also investigated.


2021 ◽  
Author(s):  
Wen-Yuan Wu ◽  
Tie-Huan Tang ◽  
Yi Li ◽  
Shuang Xu

Versatile bridging oxalates build up the delicate 3D structure, leaving the cavity for a hydrogen-bonded water molecule.


2006 ◽  
Vol 59 (5) ◽  
pp. 320 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth ◽  
Peter C. Healy ◽  
Jonathan M. White

The 1:1 proton-transfer brucinium compounds from the reaction of the alkaloid brucine with 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, and 5-sulfosalicylic acid, namely anhydrous brucinium 5-nitrosalicylate (1), brucinium 3,5-dinitrosalicylate monohydrate (2), and brucinium 5-sulfosalicylate trihydrate (3) have been prepared and their crystal structures determined by X-ray crystallography. All structures further demonstrate the selectivity of brucine for meta-substituted benzoic acids and comprise three-dimensional hydrogen-bonded framework polymers. Two of the compounds (1 and 3) have the previously described undulating brucine sheet host-substructures which incorporate interstitially hydrogen-bonded salicylate anion guest species and additionally in 3 the water molecules of solvation. The structure of 2 differs in having a three-centre brucinium–salicylate anion bidentate N+–H···O(carboxyl) hydrogen-bonding association linking the species through interstitial associations involving also the water molecules of solvation. A review of the crystallographic structural literature on strychnine and brucine is also given.


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