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 750 毫秒
1.
Two coordination polymers, namely {[Mn(2,4′‐bpdc)(bimb)(H2O)0.5] · 0.5H2O}n ( 1 ) and [Mn(4,4′‐bpdc)(bimb)]n · 2.5H2O ( 2 ) [2,4′‐bpdc = biphenyl‐2,4′‐dicarboxylate, 4,4′‐bpdc = biphenyl‐4,4′‐dicarboxylate, and bimb = 1,4‐bis(1‐imidazol‐yl)‐2,5‐dimethyl benzene], were hydrothermally synthesized by reactions of manganese(II) salt with the rigid ligand 1,4‐bis(1‐imidazol‐yl)‐2,5‐dimethyl benzene and isomeric biphenyl dicarboxylate ligands. Complex 1 has an unusual 6‐connected three‐dimensional (3D) architecture with point symbol (44.611). Complex 2 has also a 3D structure with two‐interpenetrated pcu topology with point symbol (412.63). Structural comparisons show that the positions of the carboxylate groups in the ligand backbone play an important role in governing the structural topologies of these complexes.  相似文献   

2.
Two new Zn2+‐based metal–organic frameworks (MOFs) based on biphenyl‐2,2′,5,5′‐tetracarboxylic acid, i.e. H4(o,m‐bpta), and N‐donor ligands, namely, poly[[(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] dimethylformamide monosolvate dihydrate], {[Zn2(C16H6O8)(C14H14N4)2]·C3H7NO·2H2O}n or {[Zn2(o,m‐bpta)(1,3‐bimb)2]·C3H7NO·2H2O}n ( 1 ) {1,3‐bimb = [1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}, and poly[[(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] monohydrate], {[Zn2(C16H6O8)(C14H14N4)2]·H2O}n or {[Zn2(o,m‐bpta)(1,4‐bimb)2]·H2O}n ( 2 ) {1,4‐bimb = [1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}, have been synthesized under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction analysis. Structurally, the (o,m‐bpta)4? ligands are fully deprotonated and combine with Zn2+ ions in μ4‐coordination modes. Complex 1 is a (3,4)‐connected porous network with honeycomb‐like [Zn2(o,m‐bpta)]n sheets formed by 4‐connected (o,m‐bpta)4? ligands. Complex 2 exhibits a (2,4)‐connected network formed by 4‐connected (o,m‐bpta)4? ligands linking Zn2+ ions in left‐handed helical chains. The cis‐configured 1,3‐bimb and 1,4‐bimb ligands bridge Zn2+ ions to form multi‐membered [Zn2(bimb)2] loops. Optically, the complexes show strong fluorescence and display larger red shifts compared to free H4(o,m‐bpta). Complex 2 shows ferroelectric properties due to crystallizing in the C2v polar point group.  相似文献   

3.
ZnII and CdII coordination polymers with dicarboxylate and imidazole‐containing ligands, namely, [Cd (2,3‐PDC)(L)]n ( 1 ) and {[Zn(3,4‐PDC) (L)0.5] · H2O}n ( 2 ), [2,3‐H2PDC = 2,3‐pyridine dicarboxylate, 3,4‐H2PDC = 3,4‐pyridine dicarboxylate, and L = 1,4‐bis(2‐methylimidazol‐3‐ium‐1‐yl)biphenyl], were prepared and characterized by elemental analysis, IR spectroscopy, and X‐ray diffraction. Complex 1 shows a three‐dimensional (3D) structure with threefold interpenetrating diamond topology. Complex 2 features a 3D framework with twofold interpenetrating dmc topology. Moreover, the luminescent properties of complexes 1 and 2 were also investigated.  相似文献   

4.
A novel three‐dimensional (3D) ZnII coordination polymer, namely, poly[[[1,4‐bis(pyridin‐4‐yl)benzene](μ3‐3,3′‐{[1,3‐phenylenebis(methylene)]bis(oxy)}dibenzoato)zinc(II)] 1,4‐bis(pyridin‐4‐yl)benzene], {[Zn(C22H16O6)(C16H12N2)]·C16H12N2}n or {[Zn(PMBD)(DPB)]·DPB}n, 1 , where H2PMBD is 3,3′‐{[1,3‐phenylenebis(methylene)]bis(oxy)}dibenzoic acid and DPB is 1,4‐bis(pyridin‐4‐yl)benzene, has been synthesized by self‐assembly using zinc nitrate, a semi‐rigid dicarboxylic acid and a nitrogen‐containing ligand. The single‐crystal X‐ray structure determination indicates that 1 possesses an intriguing 3D architecture with a 4‐connected uninodal cds topology, which is constructed from dinuclear {Zn2} clusters and V‐shaped PMBD2? linkers. Compound 1 exhibits excellent photocatalytic activity on the degradation of the organic dyes Rhodamine B (RhB), Rhodamine 6G (Rh6G) and Methyl Red (MR).  相似文献   

5.
Two new coordination polymers (CPs) formed from 5‐iodobenzene‐1,3‐dicarboxylic acid (H2iip) in the presence of the flexible 1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb) auxiliary ligand, namely poly[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ3‐5‐iodobenzene‐1,3‐dicarboxylato‐κ4O1,O1′:O3:O3′)cobalt(II)], [Co(C8H3IO4)(C10H14N4)]n or [Co(iip)(bimb)]n, (1), and poly[[[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′](μ2‐5‐iodobenzene‐1,3‐dicarboxylato‐κ2O1:O3)zinc(II)] trihydrate], {[Zn(C8H3IO4)(C10H14N4)]·3H2O}n or {[Zn(iip)(bimb)]·3H2O}n, (2), were synthesized and characterized by FT–IR spectroscopy, thermogravimetric analysis (TGA), solid‐state UV–Vis spectroscopy, single‐crystal X‐ray diffraction analysis and powder X‐ray diffraction analysis (PXRD). The iip2− ligand in (1) adopts the (κ11‐μ2)(κ1, κ1‐μ1)‐μ3 coordination mode, linking adjacent secondary building units into a ladder‐like chain. These chains are further connected by the flexible bimb ligand in a transtranstrans conformation. As a result, a twofold three‐dimensional interpenetrating α‐Po network is formed. Complex (2) exhibits a two‐dimensional (4,4) topological network architecture in which the iip2− ligand shows the (κ1)(κ1)‐μ2 coordination mode. The solid‐state UV–Vis spectra of (1) and (2) were investigated, together with the fluorescence properties of (2) in the solid state.  相似文献   

6.
Two new metal–organic frameworks (MOFs), namely, three‐dimensional poly[diaquabis{μ2‐1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene}bis(μ2‐glutarato)dinickel(II)] monohydrate], {[Ni2(C5H6O4)2(C16H18N4)2(H2O)2]·H2O}n or {[Ni2(Glu)2(1,4‐mbix)2(H2O)2]·H2O}n, ( I ), and two‐dimensional poly[[{μ2‐1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene}(μ2‐glutarato)zinc(II)] tetrahydrate], {[Zn(C5H6O4)(C16H18N4)]·4H2O}n or {[Zn(Glu)(1,4‐mbix)]·4H2O}n ( II ), have been synthesized hydrothermally using glutarate (Glu2?) mixed with 1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene (1,4‐mbix), and characterized by single‐crystal X‐ray diffraction, IR and UV–Vis spectroscopy, powder X‐ray diffraction, and thermogravimetric and photoluminescence analyses. NiII MOF ( I ) shows a 4‐connected 3D framework with point symbol 66, but is not a typical dia network. ZnII MOF ( II ) displays a two‐dimensional 44‐ sql network with one‐dimensional water chains penetrating the grids along the c direction. The solid‐state photoluminescence analysis of ( II ) was performed at room temperature and the MOF exhibits highly selective sensing toward Fe3+ and Cr2O72? ions in aqueous solution.  相似文献   

7.
The new asymmetrical organic ligand 2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole ( L , C17H13N5O), containing pyridine and imidazole terminal groups, as well as potential oxdiazole coordination sites, was designed and synthesized. The coordination chemistry of L with soft AgI, CuI and CdII metal ions was investigated and three new coordination polymers (CPs), namely, catena‐poly[[silver(I)‐μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole] hexafluoridophosphate], {[Ag( L )]PF6}n, catena‐poly[[copper(I)‐di‐μ‐iodido‐copper(I)‐bis(μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole)] 1,4‐dioxane monosolvate], {[Cu2I2( L )2]·C4H8O2}n, and catena‐poly[[[dinitratocopper(II)]‐bis(μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole)]–methanol–water (1/1/0.65)], {[Cd( L )2(NO3)2]·2CH4O·0.65H2O}n, were obtained. The experimental results show that ligand L coordinates easily with linear AgI, tetrahedral CuI and octahedral CdII metal atoms to form one‐dimensional polymeric structures. The intermediate oxadiazole ring does not participate in the coordination interactions with the metal ions. In all three CPs, weak π–π interactions between the nearly coplanar pyridine, oxadiazole and benzene rings play an important role in the packing of the polymeric chains.  相似文献   

8.
A novel twofold interpenetrating two‐dimensional (2D) ZnII coordination framework, poly[[(μ‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene‐κ2N3:N3)(μ‐naphthalene‐2,6‐dicarboxylato‐κ2O2:O6)zinc(II)] dimethylformamide monosolvate], {[Zn(C12H6O4)(C14H14N4)]·C3H7NO}n or {[Zn(1,3‐BMIB)(NDC)]·DMF}n (I), where H2NDC is naphthalene‐2,6‐dicarboxylic acid, 1,3‐BMIB is 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and DMF is dimethylformamide, was prepared and characterized through IR spectroscopy, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. Single‐crystal X‐ray diffraction analysis revealed that (I) exhibits an unusual twofold interpenetrating 2D network. In addition, it displays strong fluorescence emissions and a high photocatalytic activity for the degradation of Rhodamine B (RhB) under UV‐light irradiation.  相似文献   

9.
Two coordination polymers (CPs), {[Zn2(BMB)(5‐AIPA)2] · 2H2O}n( 1 ) and [Zn(BMB)(5‐NIPA)]n( 2 ) {BMB = 1, 4‐bis[(2‐methyl‐imidazol‐1‐yl)methyl]benzene, 5‐AIPA = 5‐aminoisophthalic acid, 5‐NIPA = 5‐nitroisophthalic acid}, were synthesized under hydrothermal conditions. Compound 1 displays a 2D double‐layer structure, which is packed into a 3D supramolecule by interlayer hydrogen bonds and π–π stacking interactions. Compound 2 displays a threefold interpenetrating 3D network, which is composed of left‐handed helical chains and two types of meso‐helical chains along different directions.  相似文献   

10.
A new three‐dimensional interpenetrated CdII–organic framework based on 3,3′‐azodibenzoic acid [3,3′‐(diazenediyl)dibenzoic acid, H2azdc] and the auxiliary flexible ligand 1,4‐bis(1H‐imidazol‐1‐yl)butane (bimb), namely poly[[bis[μ2‐1,4‐bis(1H‐imidazol‐1‐yl)butane‐κ2N3:N3′][μ2‐3,3′‐(diazenediyl)dibenzoato‐κ2O:O′]cadmium(II)] monohydrate], {[Cd(C14H8N2O4)(C10H14N2)2]·H2O}n, (1), was obtained by a typical solution reaction in mixed solvents (water and N,N′‐dimethylformamide). Each CdII centre is six‐coordinated by two O atoms of bis‐monodentate bridging carboxylate groups from two azdc2− ligands and by four N atoms from four bimb ligands, forming an octahedral coordination environment. The CdII ions are connected by the bimb ligands, resulting in two‐dimensional (4,4) layers, which are further pillared by the azdc2− ligands, affording a threefold interpenetrated three‐dimensional α‐Po topological framework with the Schläfli symbol 41263. The thermal stability and solid‐state fluorescence properties of (1) have been investigated.  相似文献   

11.
Abstract. The 3D cobalt(II) coordination polymers [Co1.5(HDDB)(1,4‐bib)1.5(H2O)]n ( 1 ), and {[Co2(DDB)(1,3‐bib)22‐H2O)] · H2O}n ( 2 ) were assembled by mixed‐ligand synthetic strategy [H4DDB = 1,3‐bis(2,4‐dicarboxyphenyl) benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and 1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene]. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric (TG) analyses. Single X‐ray diffraction analysis reveals that complex 1 is an interestingly 3D (3,3.6)‐connected (63)4(65 · 88 · 102) net, and complex 2 is an unprecedented dinuclear [Co2(COO)(μ2‐H2O)] SBUs based 3D (3,6)‐connected (3 · 6 · 7)(32 · 43 · 54 · 63 · 7 · 82) net. Additionally, the magnetic properties of 2 were investigated.  相似文献   

12.
The coordination polymers, {[Co(bbim)2(H2O)2](tcbdc) · 2H2O}n ( 1 ), {[Ni(tcbdc)(bbim)(H2O)2] · 2DMF}n ( 2 ), and {[Cu2(tcbdc)2(bbim)4] · 4H2O}n ( 3 ) [bbim = 1,1′‐(1,4‐butanediyl)bis(imidazole) and tcbdc2– = tetrachlorobenzene‐1,4‐dicarboxylate] were synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, luminescence, and single‐crystal X‐ray diffraction analysis. Complex 1 has a double‐stranded chain structure through doubly bridged [Co(bbim)2] units. Complex 2 exhibits two‐dimensional square grid, whereas complex 3 has a three‐dimensional porous network structure with an unprecedented 44 · 611 topological structure through interpenetrating square grid. The water molecules in complex 3 occupy the vacancy through three kinds of hydrogen bond interactions. Upon excitation at 370 nm, complexes 1 – 3 present solid‐state luminescence at room temperature.  相似文献   

13.
The combination of cobalt, 3,5‐di‐tert‐butyldioxolene (3,5‐dbdiox) and 1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane (tpch) yields two coordination polymers with different connectivities, i.e. a one‐dimensional zigzag chain and a two‐dimensional sheet. Poly[[bis(3,5‐di‐tert‐butylbenzene‐1,2‐diolato)bis(1,5‐di‐tert‐butyl‐4‐oxocyclohexa‐2,5‐dien‐1‐yl‐3‐olato)[μ4‐1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane]cobalt(III)]–ethanol–water 1/7/5], {[Co2(C14H20O2)4(C26H24N4O)]·7C2H5OH·5H2O}n or {[Co2(3,5‐dbdiox)4(tpch)}·7EtOH·5H2O}n, is the second structurally characterized example of a two‐dimensional coordination polymer based on linked {Co(3,5‐dbdiox)2} units. Variable‐temperature single‐crystal X‐ray diffraction studies suggest that catena‐poly[[[(3,5‐di‐tert‐butylbenzene‐1,2‐diolato)(1,5‐di‐tert‐butyl‐4‐oxocyclohexa‐2,5‐dien‐1‐yl‐3‐olato)cobalt(III)]‐μ‐1‐hydroxy‐1,2,4,5‐tetrakis(pyridin‐4‐yl)cyclohexane]–ethanol–water (1/1/5)], {[Co(C14H20O2)2(C26H24N4O)]·C2H5OH·5H2O}n or {[Co(3,5‐dbdiox)2(tpch)]·EtOH·5H2O}n, undergoes a temperature‐induced valence tautomeric interconversion.  相似文献   

14.
Three structurally related flexible bis(imidazole) ligands reacted with Co(NO3)2 · 6H2O and succinic acid (L1) to yield three new metal‐organic frameworks {[Co(L1)(L2)] · (H2O)}n ( 1 ) [L2 = 2‐bis(imidazol‐1‐yl)ethane], {[Co(L1)(L3)](H2O)}n ( 2 ) [L3 = 1,4‐bis(imidazol‐1‐yl) butane], and {[Co(L1)(L4)] · (H2O)}n ( 3 ) [L4 = 1,4‐bis(2‐methyl‐imidazol‐1‐yl)butane], respectively. These complexes were synthesized under solvothermal conditions and characterized by elemental analysis, IR spectroscopy, single‐crystal and powder X‐ray diffraction, as well as thermal analyses. Interestingly, the ligands in these complexes exhibit different conformations and further cause three different configurations. Complex 1 shows a three‐dimensional (3D) framework, which is connected by two‐dimensional (2D) layer structures through hydrogen bonds. Complex 2 is a diamond structure with threefold interpenetration. Complex 3 is a 3D framework linked by hydrogen bonds like complex 1 .  相似文献   

15.
Three copper(II) coordination polymers (CuCPs), namely, [Cu0.5(1,4‐bib)(SO4)0.5]n ( 1 ), {[Cu(1,3‐bib)2(H2O)] · SO4 · H2O}n ( 2 ), and [Cu(bpz)(SO4)0.5]n ( 3 ), were assembled from the reaction of three N‐donors [1,4‐bib = 1,4‐bis(1H‐imidazol‐4‐yl)benzene, 1,3‐bib = 1,3‐bis(1H‐imidazol‐4‐yl)benzene, and Hbpz = 3‐(2‐pyridyl)pyrazole] with copper sulfate under hydrothermal conditions. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectroscopy, powder X‐ray diffraction (PXRD), and thermogravimetric analyses (TGA). Structure analyses reveal that complex 1 is a 3D 6‐connected {412 · 63}‐ pcu net, complex 2 is a fourfold 3D 4‐connected 66‐ dia net, whereas complex 3 is a 1D snake‐like chain, which further expanded into 3D supramolecular architectures with the help of C–H ··· O hydrogen bonds. Moreover, the photocatalytic tests demonstrate that the obtained CuCPs are photocatalysts in the degradation of MB with the efficiency is 86.4 % for 1 , 75.3 % for 2 , and 91.3 % for 3 after 2 h, respectively.  相似文献   

16.
Three coordination complexes, namely, [Zn(btbp)(3‐npa)]n ( 1 ), [Co(btbh)(3‐npa)]n ( 2 ), and {[Co(btbb)(5‐nipa)(H2O)] · H2O}n ( 3 ) (btbp = 1,3‐bis(thiabendazole)propane, btbh = 1,6‐bis(thiabendazole)hexane, btbb = 1,4‐bis(thiabendazole)butane, 3‐H2npa = 3‐nitrophthalic acid and 5‐H2nipa = 5‐nitroisophthalic acid) were synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single‐crystal X‐ray diffraction. Complex 1 features a fascinating meso‐helical chain, which is further extended into a 2D supramolecular framework involving π ··· π stacking interactions. Complexes 2 and 3 show dinuclear structures. Complex 2 is further connected through C–H ··· O hydrogen bonding interactions to afford a 2D supramolecular layer, whereas complex 3 is further extended to a rare 2‐nodal (3,4)‐connected supramolecular sheet with a point symbol of {3.42.5.6.7}2{3.82} by O–H ··· O hydrogen bonding interactions. The electrochemical behaviors of the two cobalt complexes 2 and 3 were reported. Moreover, the luminescent properties for 1 and the photocatalytic properties for the complexes were investigated.  相似文献   

17.
Two cobalt(II) coordination polymers, namely {[Co(HO‐BDC)(bbe)] · (H2O)}n ( 1 ), and {[Co(O‐BDC)(bbp)] · (H2O)}n ( 2 ) (HO‐H2BDC = 5‐hydroxyisophthalic acid, bbe = 1, 2‐bis(benzoimidazol‐2‐yl)ethane, and bbp = 1, 3‐bis(benzoimidazol‐2‐yl)propane) were synthesized under hydrothermal conditions, and characterized by elemental analyses, IR spectroscopy, single‐crystal X‐ray diffraction, and thermogravimetric analyses. Compound 1 is a 1D chain, whereas 2 is a (3, 3)‐connected 2D network with (63) topology. These two 1D and 2D complexes are further connected by hydrogen bonds to form the 3D supramolecular architectures. The electrochemical lithium‐ion storage properties of the as‐made Co3O4 by calcination of 1 are investigated in detail.  相似文献   

18.
Two coordination polymers based on 1, 6‐bis(2‐methyl‐imidazole‐1‐yl)‐hexane (bimh), namely {[Zn3(BTC)2(bimh)] · (bimh)}n ( 1 ) and {[Zn(IPA)(bimh)] · (CH3CH2OH)0.5}n ( 2 ) (H3BTC = trimesic acid, H2IPA = isophthalic acid), were synthesized through hydrothermal reactions. In compound 1 , the zinc(II) ions are bridged by BTC3– ligands to form an undulating infinite two‐dimensional (2D) polymeric network. The 3D networks of 1 show a twofold interpenetrating net. In compound 2 , zinc(II) ions are bridged by IPA2– ligands to form one‐dimensional (1D) helical structures. The 2D structures of 2 are further assembled into 3D networks through aromatic π–π stacking interactions. Both compounds exhibit strong photoluminescence at room temperature and may be good candidates for potential luminescence materials.  相似文献   

19.
Two CoII‐based coordination polymers, namely poly[(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato){μ2‐1,3‐bis[(1H‐imidazol‐1‐yl)methyl]benzene}dicobalt(II)], [Co2(C16H6O8)(C14H14N4)2]n or [Co2(o,m‐bpta)(1,3‐bimb)2]n ( I ), and poly[[aqua(μ4‐biphenyl‐2,2′,5,5′‐tetracarboxylato){1,4‐bis[(1H‐imidazol‐1‐yl)methyl]benzene}dicobalt(II)] dihydrate], {[Co2(C16H6O8)(C14H14N4)2(H2O)2]·4H2O}n or {[Co2(o,m‐bpta)(1,4‐bimb)2(H2O)2]·4H2O}n ( II ), were synthesized from a mixture of biphenyl‐2,2′,5,5′‐tetracarboxylic acid, i.e. [H4(o,m‐bpta)], CoCl2·6H2O and N‐donor ligands under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction analysis. The bridging (o,m‐bpta)4? ligands combine with CoII ions in different μ4‐coordination modes, leading to the formation of one‐dimensional chains. The central CoII atoms display tetrahedral [CoN2O2] and octahedral [CoN2O4] geometries in I and II , respectively. The bis[(1H‐imidazol‐1‐yl)methyl]benzene (bimb) ligands adopt trans or cis conformations to connect CoII ions, thus forming two three‐dimensional (3D) networks. Complex I shows a (2,4)‐connected 3D network with left‐ and right‐handed helical chains constructed by (o,m‐bpta)4? ligands. Complex II is a (4,4)‐connected 3D novel network with ribbon‐like chains formed by (o,m‐bpta)4? linkers. Magnetic studies indicate an orbital contribution to the magnetic moment of I and II due to the longer Co…Co distances. An attempt has been made to fit the χMT results to the magnetic formulae for mononuclear CoII complexes, the fitting indicating the presence of weak antiferromagnetic interactions between the CoII ions.  相似文献   

20.
Abstract. Two new coordination polymers {[Cd2(BDC)2(3‐bpmp)(H2O)2] · 2H2O}n ( 1 ) and [Cd2(BDC)2(4‐bpmp)]n ( 2 ) [H2BDC = 5‐hydroxy‐isophthalic acid, 3‐bpmp = 1,4‐bis(3‐pyridylmethy)piperazine, and 4‐bpmp = 1,4‐bis(4‐pyridylmethy) piperazine] were synthesized via hydrothermal synthesis, and further characterized by IR spectroscopy, elemental analysis, XRD, and X‐ray crystallography. Complex 1 shows a two‐dimensional (4,4) sql topology and complex 2 features an 8‐connected hex topology. Moreover, the luminescent properties of complexes 1 and 2 were investigated in the solid state at room temperature.  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