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1.
The 2D CuII metal‐organic framework [Cu2(bptc)(H2O)4]n · 4nH2O ( 1 ) (H4bptc = biphenyl‐2,2′,4,4′‐tetracarboxylic acid) was hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction and magnetic measurements. In the structure, bptc4– serves as a twisted Π‐shaped organic building block to connect paddlewheel [Cu2(COO)4] dinuclear units and mononuclear units through 2‐/2′‐carboxylate and 4‐/4′‐carboxylate, respectively. According to the magnetic analysis using a dimer‐plus‐monomer model, strong antiferromagnetic coupling is operative within the dinuclear unit (J = –311 cm–1 based on H = –J S 1 S 2), and the compound behaves like a mononuclear molecule at low temperature.  相似文献   

2.
Three 1H‐benzimidazole‐5‐carboxylate (Hbic)‐based coordination polymers, {[Ni(H2O)(Hbic)2] · 2H2O}n ( 1 ), {[Ni(H2O)2(Hbic)2] · 3H2O}n ( 2 ), and {[Co2(H2O)4(Hbic)4] · 4DMF · 3H2O}n ( 3 ) were obtained by reactions of the ligand H2bic and NiII or CoII salts in the presence of different structure directing molecules. They were structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermal stability, luminescent, and magnetic measurements. Structural analysis suggests that the three polymers exhibit a 2D (4, 4) layer for 1 and 1D linear double chains for both 2 and 3 due to the variable binding modes and the specific spatial orientation of the Hbic ligand towards the different paramagnetic metal ions, which were further aggregated into different 3D supramolecular architectures by popular hydrogen‐bonding interactions. Weak and comparable antiferromagnetic couplings mediating by Hbic bridge are observed between the neighboring spin carriers for 2 and 3 , respectively. Additionally, complexes 1 – 3 also display different luminescence emissions at room temperature due to the ligand‐to‐metal charge transfer.  相似文献   

3.
Two metal‐organic frameworks, [Co2(ABTC)(bimh)(OH)] · 2H2O ( 1 ) and [Co3(ABTC)2(dimb)4]n ( 2 ) [H3ABTC = 3,4′,5‐azobenzenetricarboxylic acid, bimh = 1,1′‐(1,4‐hexanediy)bis(imidazole), dimb = 1,4‐bis(1H‐imidazol‐1‐yl)benzene], were prepared under solvothermal conditions and structurally characterized. Complex 1 demonstrates a complicated 3D (3,8)‐connected tfz‐d net with (43)2(46.617.85) topology. The framework of 2 can be classified as a rare 3D (3,6,6)‐connected net with the Schäfli symbol of (4.62)2(42.610.83)(44.610.8), and exhibits an intriguing self‐penetrating motif. Meanwhile, the thermal stabilities and magnetic properties for 1 and 2 were also probed.  相似文献   

4.
Four new complexes, {[M(NAIP)(H2O)4]·2H2O}n (M = Co (1), M = Mn (2)), {[Zn(NAIP)]·0.5H2O}n (3) and {Cd(NAIP)(H2O)2]·1.5H2O}n (4) [H2NAIP = 5-(nicotinamido)-isophthalic acid] have been prepared and structurally characterized. The ligand NAIP2− exhibits different coordination modes and leads to the formation of various architectures. Complexes 1 and 2 show a one-dimensional (1D) zigzag chain, where hydrogen-bonding interactions further link these chains to a three dimensional (3D) supramolecular structure. For complex 3, a 3D coordination network with a four-coordinated Zn(II) and NAIP2− as a SBU was observed. Complex 4 presents a three-connected 2-fold interpenetrated 3D network with a (10, 3)-b net topology. Their luminescent and magnetic properties have been investigated in the solid state.  相似文献   

5.
Two 5‐methyl‐tetrazolate (mtz)‐based paramagnetic metal coordination polymers, {[Cu2(H2O)2(mtz)(μ3‐OH)(nip)] · H2O}n ( 1 ) and [Cu(H2O)(mtz)2]n ( 2 ), were obtained in the presence and absence of aromatic 5‐nitroisophathalate (nip2–) coligand by varying the preparation methods. Structural determinations reveal that 1 is a three‐dimensional (3D) framework with corner‐sharing triangular ribbons infinitely extended by ditopic nip2– connectors. In contrast, 2 is a coplanar (4,4) layer constructed from square‐pyramidal CuII ions and μ‐N1,N4‐mtz linkers, which is further assembled into a 3D supramolecular network by interlayer hydrogen‐bonding interactions. Magnetically, spin‐frustrated antiferromagnetic ordering is observed in the 3D framework of 1 and canted antiferromagnetic behavior with a slight spin‐flop transition is presented in 2 , which are structurally resulting from the locally Δ‐ribbon in 1 and asymmetric magnetic superexchange mediated by the μ‐N1,N4‐mtz bridge of 2 .  相似文献   

6.
The three‐dimensional (3D) porous cobalt(II) metal‐organic framework (MOF), [Co3(L)2(DMA)2(MeOH)2 · 4(DMA) · 6(MeOH)]n ( 1 ) [L = fully deprotonated 2,7‐bis(4‐benzoic acid)‐N‐(4‐benzoic acid) carbazole, DMA = N,N‐dimethylacetamide], was synthesized by hydrothermal reaction. Based on X‐ray single‐crystal diffraction, structural analysis indicates that complex 1 crystallizes in the monoclinic C2/c space group. Complex 1 possesses a 3,6‐connected three‐dimensional (3D) topological structure with a point symbol of {42 · 6}2{44 · 62 · 87 · 102} when a trinuclear CoII cluster was regarded as 6‐connected node and the organic ligands could be regarded as 3‐connected linkers between the 6‐connected nodes. The framework structure exhibits a one‐dimension (1D) channel with an accessible void of 4223.0 Å3, amounting to 42.8 % of the total unit‐cell volume (9862.0 Å3). Moreover, the magnetic properties of complex 1 were studied.  相似文献   

7.
Four new complexes of [Cu(bpm)(ox)(H2O)] ( 1 ), [Cu(tpd)(dca)(H2O)] ( 2 ), [Cu(bppz)(N3)2] ( 3 ), and [Cu(bpm)21,3‐N3)(N3)] ( 4 ) (bpm = 2,2′‐bipyrimidine, bppz = 2,3‐bis(2‐pyridyl)pyrazine, tpd = 4‐terpyridone, dca = dicyanamide, ox = oxalate) have been prepared and characterized by X‐ray single‐crystal analysis and variable‐temperature magnetic measurements. Compounds 1–4 are essentially mononuclear Cu(II) complexes. However, in complex 1 , Cu(II) it was found that intermolecular hydrogen bonding through between H2O and ox formed 1‐D chain structure. In complex 2 it was found that the hydrogen bonding between H2O and tpd of the next molecule led to for a binuclear Cu(II) complex. In complex 3 , two nitrogen atoms, one of the pyridyl group of bppz and one of N3? ligands, are weakly coordinated to neighbor Cu(II) ion thus leading to formation of a 1‐D chain structure. In complex 4 , one nitrogen atom of terminated N3? is weakly coordinated to the neighbor Cu(II) site to form a 1‐D polymeric structure. The magnetic susceptibility measurements indicate that complex 1 and 4 exhibit a weak antiferromagnetic interaction whereas a ferromagnetic coupling has been established for complexes 2 and 3 .  相似文献   

8.
Three coordination polymers, namely {[Cu(5‐nipa)(L22)](H2O)2}n ( 1 ), [Zn(5‐nipa)(L22)(H2O)]n ( 2 ), and {[Cd2(5‐nipa)2(L22)(H2O)3](H2O)3.6}n ( 3 ), were prepared under similar synthetic method based on 1,2‐(2‐pyridyl)‐1,2,4‐triazole (L22) and ancillary ligand 5‐nitro‐isophthalic acid (5‐H2nipa) with CuII, ZnII, and CdII perchlorate, respectively. All the complexes were characterized by IR spectroscopy, elemental analysis, and powder X‐ray diffraction (PXRD) patterns. Single‐crystal X‐ray diffraction indicates that complexes 1 and 2 show similar 1D chain structures, whereas complex 3 exhibits the 2D coordination network with hcb topology. The central metal atoms show distinct coordination arrangements ranging from distorted square‐pyramid for CuII in 1 , octahedron for ZnII in 2 , to pentagonal‐bipyramid for CdII in 3 . The L22 ligand adopts the same (η32) coordination fashion in complexes 1 – 3 , while the carboxyl groups of co‐ligand 5‐nipa2– adopt monodentate fashion in 1 and 2 and bidentate chelating mode in 3 . These results indicate that the choice of metal ions exerts a significant influence on governing the target complexes. Furthermore, thermal stabilities of complexes 1 – 3 and photoluminescent properties of 2 and 3 were also studied in the solid state.  相似文献   

9.
Reaction of copper halides CuX (X=Cl, Br, I) with tri(2‐pyridylmethyl)amine) (TPMA) in THF under N2 affords a series of monomeric copper(I) complexes CuX(TPMA) (X=Cl ( 1 ), Br ( 2 ) and I ( 3 )). Treatment of [CuCl(TPMA)] ( 1 ) with 0.5 equivalent of 1,4‐diisocyanobenzene following by equimolar amount of NaBF4 affords a novel binuclear complex [(TPMA)Cu(μ‐1,4‐CNC6H4NC)Cu(TPMA)](BF4)2 ( 4 ). The copper(I) halide TPMA complexes show interesting fluxional behaviors in temperature dependence in the 1H NMR spectrum that can be explained by the dissociation and reassociation of the pyridyl group and alkylamine nitrogen of TPMA ligand. The crystal structures of 1 , 3 and 4 are determined by an X‐ray diffractometer. Complexes 1 and 3 are distorted tetrahedral coordinates with strong bonding between three pyridyl N atoms and the corresponding halide donor. Crystallographic results of 4 clearly indicates two Cu(I) ions are bridged by 1,4‐diisocyanobenzene, forming a centro‐symmetrical homobinuclear complex with a “dangling” uncoordinated pyridyl group.  相似文献   

10.
Two rare earth metal‐organic framework compounds [Ybsip(H2O)5] · 3H2O ( 1 ) and [Dysip(H2O)4] ( 2 ) (NaH2sip: 5‐sulfoisophthalic acid sodium salt) were synthesized hydrothermally, and characterized by single‐crystal X‐ray diffraction, elemental analysis, and FT‐IR spectroscopy. In complex 1 , each YbIII atom is nine‐coordinate with a distorted monocapped tetragonal prismatic arrangement. Two carboxylate groups of each sip3– molecule adopt the same μ1‐η11 chelating coordination model connecting two YbIII atoms. The oxygen atoms of the sulfonate group do not participate in coordination with YbIII. The whole sip3– molecule acts as a μ2 bridge to form an one‐dimensional (1D) chain structure. The 1D chains are linked by hydrogen bonding to generate two‐dimensional layers, and are further combined together to form a three‐dimensional structure. In complex 2 , the DyIII atom is nine‐coordinate with a distorted monocapped tetragonal antiprismatic arrangement. In each sip3– anion, two carboxylate groups take the same μ1‐η11 chelating coordination mode, only an oxygen atom of sulfonate group bond to DyIII ion. The whole ligand sip3– acts as a μ3 bridge linking three different DyIII ions to generate a wave‐like two‐dimensional network with (6,3) topological structure. The two‐dimensional networks are further linked by O–H ··· O hydrogen bonds to form a three‐dimensional structure. The thermal and luminescent properties of both complexes are investigated.  相似文献   

11.
《中国化学会会志》2017,64(5):481-485
5‐Carboxanilide‐dihydropyrimidinone derivatives were synthesized in good yield in a three‐component and efficient process by the condensation reaction of acetoacetanilide, aldehyde and urea/thiourea in the presence of cobalt(II) nitrate hexahydrate as catalyst in ethanol at ambient condition.  相似文献   

12.
The synthesis, characterization and crystal structures of substituted imidazolate bridged binuclear copper(II) complexes, [Cu2(dien)2(L)](ClO4)3, where dien = diethylenetriamine, L = imidazolate (im) ( 1 ), 2‐methylimidazolate (mim) ( 2 ) and benzimidazolate (bim) ( 3 ), are reported. The copper(II) ions of 1 — 3 posses a square planar coordination environment with dien coordinating as a tridentate ligand and the fourth position being occupied by a nitrogen atom of the bridging μ‐imidazolato group. In all three compounds the tendency to form additional long apical bonds at the copper(II) ions to the oxygen atoms of the perchlorate anions is observed. Temperature depended susceptibility data of polycrystalline samples reveal an antiferromagnetic coupling of the copper(II) atoms in 1 — 3 with J = —63.8, —75.4 and —36.8 cm—1, respectively. Significant changes for these coupling constants could not be observed for measurements on frozen aqueous solutions. ESR spectra for solids and frozen solutions are consistent with intramolecular antiferromagnetic exchange interaction between the metal ions. From the data reported it can be concluded that the predominate mechanism for transmitting exchange coupling through the imidazolate bridge is due to a σ exchange pathways.  相似文献   

13.
The series of binuclear Cu(II) and Ni(II) complexes with an asymmetrical exchange fragment based on 2,6‐diformyl‐4‐methylphenol bishydrazone has been synthesized for the first time. The compositions and structures of both ligands and its complexes have been established with the data of IR, 1H NMR, and extended X‐ray absorption fine structure (EXAFS) spectroscopical studies as well as magnetic measurements. The structure of [Ni2L3(μ‐Pz)] · 2CH3OH (L = triply deprotonated form of bishydrazone, Pz = pyrazol) was confirmed by X‐ray crystallographic analysis. In this complex, the coordination environment of two nickel ions is quite different, one nickel atom is square‐planar and the other is distorted octahedral coordinated. The values of exchange parameter calculated in terms of HDVV theory have been compared with the features of an asymmetrical exchange fragment's electronic and geometrical structure.  相似文献   

14.
The stable dinuclear [Cu(μ‐C2O4)Cu]2+ entity is facially coordinated at each end by a N‐nitrile functionalized triazamacrocycle, 1, 4, 7‐tris(cyanomethyl)‐1, 4, 7‐triazacyclononane ( L ), to generate a centrosymmetric compound [Cu2 L 2(μ‐C2O4)](ClO4)2 · 4DMF ( 1 ) containing a bis‐bidentate oxalate bridge. The variable‐temperature magnetic measurement for the crystallographically characterized compound exhibits quite strong antiferromagnetic coupling interaction between two oxalate‐linked CuII atoms separated by 5.149 Å with a singlet‐triplet energy gap of –345.5 cm–1. On the other hand, a mononuclear CoIII compound [Co L (N3)3] · 2.5H2O ( 2 ) with monodentate azide terminal groups was synthesized. Structural elucidation by X‐ray diffraction shows that the compound has crystallographically imposed C3 symmetry. Enantiomerically pure crystals were obtained upon crystallization indicated by a Flack parameter of 0.04(5).  相似文献   

15.
Four metal‐organic coordination polymers [Co2(L)3(nipa)2]·6H2O ( 1 ), [Cd(L)(nipa)]·3H2O ( 2 ), [Co(L) (Hoxba)2] ( 3 ) and [Ni2(L)2(oxba)2(H2O)]·1.5L·3H2O ( 4 ) were synthesized by reactions of the corresponding metal(II) salts with the rigid ligand 1,4‐bis(1H‐imidazol‐4‐yl)benzene (L) and different derivatives of 5‐nitroisophthalic acid (H2nipa) and 4,4′‐oxybis(benzoic acid) (H2oxba), respectively. The structures of the complexes were characterized by elemental analysis, FT‐IR spectroscopy and single‐crystal X‐ray diffraction. Complexes 1 and 3 have the same one‐dimensional (1D) chain while 2 is a 6‐connected twofold interpenetrating three‐dimensional (3D) network with α ‐Po 412·63 topology based on the binuclear CdII subunits. Compound 4 features a puckered two‐dimensional (2D) (4,4) network, and the large voids of the packing 2D nets have accommodated the uncoordinated L guest molecules. An abundant of N–H···O, O–H···O and C–H···O hydrogen bonding interactions exist in complexes 1–4 , which contributes to stabilize the crystal structure and extend the low‐dimensional entities into high‐dimensional frameworks. Lastly, the photoluminiscent properties of compounds 2 were also investigated.  相似文献   

16.
Four new dinuclear copper(II) complexes have been synthesized and have the general formula [Cu2(L)(H2O)2], where L = GLYDTO [N,N′‐bis(carboxymethyl)dithiooxamide], ALADTO [N,N′‐bis(carboxyethyl)dithiooxamide], VALDTO [N,N′‐bis(1‐carboxy‐2‐methylpropyl)dithiooxamide] and LEUDTO [N,N′‐bis(1‐carboxy‐3‐methylbutyl)dithiooxamide]. The complexes were characterized by elemental analysis as well as by IR, electronic and EPR spectroscopy. These techniques provided evidence for the presence of the CuNO2S chromophore. Magnetic susceptibility measurements on all the complexes in the range 4–300 K show the existence of a dominant antiferromagnetic interaction with ?J values greater than 300 cm?1. Thermal decomposition behaviour of the complexes was studied by thermogravimetry.  相似文献   

17.
Three new μ‐oxamido‐bridged heterodinuclear copper (II)‐chromium (III) complexes formulated [Cu(Me2oxpn)Cr‐(L)2](NO3)3, where Me2oxpn denotes N,N'‐bis(3‐amino‐2, 2‐dimethylpropyl)oxamido dianion and L represents 5‐methyl‐1,10‐phenanthroline (Mephen), 4,7‐diphenyl‐1,10‐phenanthroline (Ph2phen) or 2,2′‐bipyridine (bpy), have been synthesized and characterized by elemental analyses, IR and electronic spectral studies, magnetic moments of room‐temperature and molar conductivity measurements. It is proposed that these complexes have oxamido‐bridged structures consisting of planar copper (II) and octahedral chromium (III) ions. The variable temperature magnetic susceptibilities (4.2–300 K) of complexes [Cu(Me2oxpn)Cr(Ph2phen)2](NO3)3 (1) and [Cu(Me2oxpn)Cr(Mephen)2] (NO3)3 (2) were further measured and studied, demonstrating the ferromagnetic interaction between the adjacent chromium (III) and copper (II) ions through the oxamido‐bridge in both complexes 1 and 2. Based on the spin Hamiltonian, ? = ‐ 2J?1 · ?2, the exchange integrals J were evaluated as + 21.5 an?1 for 1 and + 22.8 cm?1 for 2.  相似文献   

18.
Three new complexes: [M(L)(H2O)] [M = Zn ( 1 ), Co ( 2 ), Ni ( 3 ); H2L = 5‐(pyridin‐2‐ylmethyl)aminoisophthalic acid] were synthesized under hydrothermal conditions at 180 °C and were characterized by elemental analysis, FT‐IR spectroscopy, single‐crystal X‐ray diffraction, and thermogravimetric analysis (TGA). The results of X‐ray diffraction analysis reveal that complexes 1 – 3 are isostructural and crystallize in the monoclinic system with space group P21/c. Each of the complexes displays a (3,3′)‐connected two‐dimensional (2D) wave‐like network with (4,82) topology, within which five‐membered uncoplanar N,N‐chelated metallacycles are shaped. Delicate N–H ··· O and O–H ··· O hydrogen bonding interactions exist in complexes 1 – 3 . Adjacent 2D layers are linked by intermolecular interactions, resulting in the construction of extended metal‐organic frameworks (MOFs) in complexes 1 and 2 .  相似文献   

19.
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   

20.
Two cobalt complexes, [Co3(L)2(CH3OH)23‐OH)2] ( 1 ) and [Co(L)(bpe)0.5] · H2O ( 2 ) [H2L = 5‐(4‐carboxyphenoxy)‐pyridine‐2‐carboxylic acid; bpe = 1, 2‐bis(4‐pyridyl)ethylene] were synthesized and fully characterized by elemental analyses, IR spectroscopy, single‐crystal X‐ray diffraction, thermogravimetric analysis (TGA), and magnetic analysis. Complex 1 has a two‐dimensional (2D) structure with puckered Co–O–Co chains, and 2 displays a three‐dimensional (3D) network containing one‐dimensional rectangular channels with dimensions of 9.24 × 13.84 Å. In complex 1 , variable‐temperature magnetic susceptibility measurements indicate antiferromagnetic interactions between cobalt magnetic centers.  相似文献   

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