The cover picture shows a novel dual channel fluorescent probe for Ca2+ and Zn2+ based on a coumarin Schiff base. The probe displays a solvent dependent dual sensing, viz., recognition of Ca2+ in DMF‐H2O (9∶1, V /V ) solution based on C = N isomerization, photoinduced electron transfer (PET ) inhibition and chelation‐enhanced fluorescence (CHEF ) mechanism as well as detection of Zn2+ in H2O‐CH3OH (9∶1, V /V ) solution by excited‐state intramolecular proton transfer (ESIPT ) and CHEF processes. More details are discussed in the article by Guo et al. on page 1263–1269.
A novel fluorescence chemosensor 1 based on (R)‐binaphthyl‐salen can exhibit highly sensitive and selective recognition responses toward Cu2+ by "turn‐off" fluorescence quench type in THF/H2O, and Zn2+ by "turn‐on" fluorescence enhancement type in CHCl3/CH3CN, respectively, suggesting that solvents can dramatically affect the responsive properties of salen‐based chemosensor. In addition, Cu2+ can lead to the most pronounced changes of CD spectra without the influence of solvents, which indicates this kind chemosensor can also be used as a sole Cu2+ probe based on CD spectra. 相似文献
The proton transfer compound LH2 , (phenH+)2(pydc2—), has been prepared from 1, 10‐phenanthroline, phen, and 2, 6‐pyridinedicarboxylic acid, (dipicolinic acid), pydcH2. Characterization was performed using solution and solid phase CP/MAS 13C NMR and IR spectroscopy. The reactions of this adduct with ZnSO4·7H2O and Zn(NO3)2·4H2O give the complexes, [Zn(pydc)2][Zn(phen)2(H2O)2]·7H2O (1) and [Zn(phen)3]4(H(Hpydc)2)(NO3)7·26H2O (2) , respectively. These complexes were characterized by 1H and 13C NMR spectroscopy and single crystal X‐ray analysis. The complexes crystallize in the triclinic space group P1 with Z = 2. The unit cell dimensions for complex 1 and 2 are: a = 9.9838(9) Å, b = 14.7483(13) Å, c = 14.8365(13) Å and a = 12.640(4) Å, b = 15.855(5) Å, c = 21.830(7) Å, respectively. In complex 1 (pydc2—) and phen, are tri‐ and bidentate ligands, respectively, and an anionic [Zn(pydc)2]2— and cationic [Zn(phen)2(H2O)2]2+ complex are formed simultaneously. In complex 2 , three phen participate in complexation leaving hydrogen‐bis(pyridine‐2‐carboxylate), (H(Hpydc)2)— as a supramolecular anion. The fragments (H(Hpydc)2)—, 7 NO3—, and 26 H2O in complex 2 are joined together by extensive and strong H‐bonding; therefore, the structure is composed of [Zn(phen)3]48+, and an anionic hydrogen bond supramolecular assembly with the formula, {(H(Hpydc)2(NO3)7)8— · 26H2O}n. The anionic species (H(Hpydc)2)— has a special position at the inversion center, as well as one of the NO3— anions, which is disordered over the inversion center. Most of the hydrogen bonds in complex 2 represent strong H‐bonding. The protonation constants of the building blocks of the pydc‐phen adduct, the equilibrium constants for the reaction of (pydc2—) with phenanthroline and the stoichiometry and stability of the ZnII complex with LH2 on aqueous solution were determined by potentiometric pH titration. The solution study results support self‐association between (pydc2—) and (phenH+) with a stoichiometry for the Zn(II) complex similar to that observed for the isolated crystalline complex. 相似文献
The hydrothermal reaction of Zn2+ ions with a mixture of two ligands, Hcptpy and H3btc (Hcptpy=4‐(4‐carboxyphenyl)‐2,2′:4′,4′′‐terpyridine; H3btc=1,3,5‐benzenetricarboxylic acid), led to the formation of a 3D metal–organic framework (MOF) with 1D channels, [Zn2(cptpy)(btc)(H2O)]n ( 1 ), which was structurally characterized by using single‐crystal X‐ray diffraction (SXRD). In MOF 1 , two independent Zn2+ ions were interconnected by btc3? ligands to form a 1D chain, whilst adjacent Zn2+ ions were alternately bridged by cptpy? ligands to generate a 2D sheet, which was further linked by 1D chains to form a 3D framework with a new (3,3,4,4)‐connected topology. Furthermore, compound 1 also exhibited excellent stability towards air and water and, more importantly, luminescence experiments indicated that it could serve as a probe for the sensitive detection of paraquat (PAQ) and Fe3+ ions in aqueous solution. 相似文献
Rational self‐assembly of Sb2O3 and Na2WO4, or (NH4)18[NaSb9W21O86] with transition‐metal ions (Mn2+, Cu2+, Co2+), in aqueous solution under controlled conditions yield a series of sandwich type complexes, namely, Na2H2[Mn2.5W1.5(H2O)8(B‐β‐SbW9O33)2]?32 H2O (1) , Na4H7[Na3(H2O)6Mn3(μ‐OAc)2(B‐α‐SbW9O33)2]?20 H2O (OAc=acetate anion) (2) , NaH8[Na2Cu4Cl(B‐α‐SbW9O33)2]?21 H2O (3) , Na8K[Na2K(H2O)2{Co(H2O)}3(B‐α‐SbW9O33)2]? 10 H2O (4) , and Na5H[{Co(H2O)2}3W(H2O)2(B‐β‐SbW9O33)2]?11.5 H2O (5) . These structures are determined by using the X‐ray diffraction technique and further characterized by obtaining IR spectra and performing elemental analysis. Structure analysis reveals that polyoxoanions in 1 and 5 comprise of two [B‐β‐SbW9O33]9? building units, whereas 2 , 3 , and 4 consist of two isomerous [B‐α‐SbW9O33]9? building blocks, which are all linked by different transition‐metal ions (Mn2+, Cu2+, or Co2+) with different quantitative nuclearity. It should be noted that compound 2 represents the first one‐dimensional sinusoidal chain based on sandwich like tungstoantimonate building blocks through the carboxylate‐bridging ligands. Additionally, 3 is constructed from sandwiched anions [Na2Cu4Cl(B‐α‐SbW9O33)2]9? linked to each other to form an infinitely extended 2D network, whereas 5 shows an interesting 3D framework built up from offset sandwich type polyoxoanion [{Co(H2O)2}3W(H2O)2(B‐β‐SbW9O33)2]6? linked by Co2+ and Na+ ions. EPR studies performed at 110 K and room temperature reveal that the metal cations (Mn2+, Cu2+, Co2+) reside in a square‐pyramidal geometry in 2 , 3 , and 4 . The magnetic behavior of 1 – 4 suggests the presence of weak antiferromagnetic coupling interactions between magnetic metal centers with the exchange integral J=?0.552 cm?1 in 2 . 相似文献
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
Two new mononuclear coordination compounds, bis{4‐[(hydroxyimino)methyl]pyridinium} diaquabis(pyridine‐2,5‐dicarboxylato‐κ2N,O2)zincate(II), (C6H7N2O)2[Zn(C7H3NO4)2(H2O)2], (1), and (pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)bis[N‐(pyridin‐4‐ylmethylidene‐κN)hydroxylamine]zinc(II), [Zn(C7H3NO4)(C6H6N2O)2], (2), have been synthesized and characterized by single‐crystal X‐ray diffractometry. The centrosymmetric ZnII cation in (1) is octahedrally coordinated by two chelating pyridine‐2,5‐dicarboxylate ligands and by two water molecules in a distorted octahedral geometry. In (2), the ZnII cation is coordinated by a tridentate pyridine‐2,6‐dicarboxylate dianion and by two N‐(pyridin‐4‐ylmethylidene)hydroxylamine molecules in a distorted C2‐symmetric trigonal bipyramidal coordination geometry. 相似文献
A 1D double‐helical coordination polymer {[Cd(pbbm)2]2(ClO4)4(H2O)2}n ( 1 ) was successfully constructed by the reaction of Cd(ClO4)2 · 6H2O with 1,1′‐(1,5‐pentanediyl)bis‐1H‐benzimidazole (pbbm). Interestingly, polymer 1 exhibits highly selective capacity for the ionic exchange of Zn2+ and Cu2+ over Co2+ and Ni2+ ions in the crystalline solid state when the crystals of 1 are immersed in the aqueous solutions of the perchlorate salts of Cu2+, Zn2+, Co2+, and Ni2+ ions, respectively, which indicates that central CdII ion exchange might be considered as being dominated by the coordination ability of metal ions to free functional groups, ionic radii of exchanged metal ions, and the solution concentration of adsorbed metal salts. The parent material‐ and ion‐exchange‐induced products are identified by FT‐IR spectroscopy, PXRD patterns as well as SEM and EDS measurements. In addition, the thermal stability of 1 was also investigated. 相似文献
Six mono/double‐layered 2D and three 3D coordination polymers were synthesized by a self‐assembly reaction of Zn (II) salts, organic dicarboxylic acids and L1/L2 ligands. These polymeric formulas are named as [Zn(L1)(C4H2O4)0.5 (H2O)]n·0.5n(C4H2O4)·2nH2O ( 1 ), [Zn2(L2)(C4H2O4)2]n·2nH2O ( 2 ), [Zn(L1)(m‐BDC)]n ( 3 ), [Zn2(L2)(m‐BDC)2]n·2nH2O ( 4 ), [Zn3(L1)2(p‐BDC)3(H2O)4]n·2nH2O ( 5 ), [Zn2(OH)(L2) (p‐BDC)1.5]n ( 6 ), [Zn2(L1)(p‐BDC)2]n·5nH2O ( 7 ), [Zn2(L2)(p‐BDC)2]n·3nH2O ( 8 ) and [Zn2(L1)(C4H4O4)1.5(H2O)]n·n(ClO4)·nH2O ( 9 ) [L1 = N,N′‐bis (pyridin‐4‐ylmethyl)propane‐1,2‐diamine, L2 = N,N′‐bis (pyridin‐3‐ylmethyl)propane‐1,2‐ diamine, m‐BDC2? = m‐benzene dicarboxylate, p‐BDC2? = p‐benzene dicarboxylate]. Meanwhile, these polymers have been characterized by elemental analysis, infrared, thermogravimetry (TG), photoluminescence, powder and single‐crystal X‐ray diffraction. Polymers 1–6 present mono‐ and double (4,4)‐layer motifs accomplished by L1/L2 ligands with diverse conformations and organic dicarboxylates, and the layer thickness locates in the range of 5.8–15.0 Å. In three 3D polymers, the L1 and L2 molecules adopt the same cis‐conformations and join adjacent Zn (II) cations together with p‐BDC2? or succinate, giving rise to different binodal (4,4)‐c nets with (4.52.83)(4.53.72) ( 7 ), pts ( 8 ) topology and twofold interpenetrated binodal (5,5)‐c nets with (32.44.52.62)(3.43.52.64) ( 9 ). Therefore, the diverse conformations of the two bis (pyridyl)‐propane‐1,2‐diamines and the feature of different organic dicarboxylate can effectively influence the architectures of these polymers. Powder X‐ray diffraction patterns demonstrate that these bulk solid polymers are pure phase. TG analyses indicate that these polymers have certain thermal stability. Luminescent investigation reveals that the emission maximum of these polymers varies from 402 to 449 nm in the solid state at room temperature. Moreover, 1 , 3 and 5–8 show average luminescence lifetimes from 8.81 to 16.30 ns. 相似文献
Reaction of the flexible phenolic carboxylate ligand 2‐(3,5‐dicarboxylbenzyloxy)benzoic acid (H3L) with nickel salts in the presence of 1,2‐bis(pyridin‐4‐yl)ethylene (bpe) leads to the generation of a mixture of the two complexes under solvolthermal conditions, namely poly[[aqua[μ‐1,2‐bis(pyridin‐4‐yl)ethylene‐κ2N:N′]{μ‐5‐[(2‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato‐κ3O1,O1′:O3}nickel(II)] dimethylformamide hemisolvate monohydrate], {[Ni(C16H10O7)(C12H10N2)(H2O)]·0.5C3H7NO·H2O}n or {[Ni(HL)(bpe)(H2O)]·0.5DMF·H2O}n, 1 , and poly[[diaquatris[μ‐1,2‐bis(pyridin‐4‐yl)ethylene‐κ2N:N′]bis{μ‐5‐[(2‐carboxyphenoxy)methyl]benzene‐1,3‐dicarboxylato‐κ2O1:O5}nickel(II)] dimethylformamide disolvate hexahydrate], {[Ni2(C16H10O7)2(C12H10N2)3(H2O)2]·2C3H7NO·6H2O}n or {[Ni2(HL)2(bpe)3(H2O)2]·2DMF·6H2O}n, 2 . In complex 1 , the NiII centres are connected by the carboxylate and bpe ligands to form two‐dimensional (2D) 4‐connected (4,4) layers, which are extended into a 2D+2D→3D (3D is three‐dimensional) supramolecular framework. In complex 2 , bpe ligands connect to NiII centres to form 2D layers with Ni6(bpe)6 metallmacrocycles. Interestingly, 2D+2D→3D inclined polycatenation was observed between these layers. The final 5‐connected 3D self‐penetrating structure was generated through further connection of Ni–carboxylate chains with these inclined motifs. Both complexes were fully characterized by single‐crystal analysis, powder X‐ray diffraction analysis, FT–IR spectra, elemental analyses, thermal analysis and UV–Vis spectra. Notably, an interesting metal/ligand‐induced crystal‐to‐crystal transformation was observed between the two complexes. 相似文献
Investigations on the Crystal Structure of Lithium Dodecahydro‐closo‐dodecaborate from Aqueous Solution: Li2(H2O)7[B12H12] By neutralization of an aqueous solution of the acid (H3O)2[B12H12] with lithium hydroxide (LiOH) and subsequent isothermic evaporation of the resulting solution to dryness, it was possible to obtain the heptahydrate of lithium dodecahydro‐closo‐dodecaborate Li2[B12H12] · 7 H2O (≡ Li2(H2O)7[B12H12]). Its structure has been determined from X‐ray single crystal data at room temperature. The compound crystallizes as colourless, lath‐shaped, deliquescent crystals in the orthorhombic space group Cmcm with the lattice constants a = 1215.18(7), b = 934.31(5), c = 1444.03(9) pm and four formula units in the unit cell. The crystal structure of Li2(H2O)7[B12H12] can not be described as a simple AB2‐structure type. Instead it forms a layer‐like structure analogous to the well‐known barium compound Ba(H2O)6[B12H12]. Characteristic feature is the formation of isolated cation pairs [Li2(H2O)7]2+ in which the water molecules form two [Li(H2O)4]+ tetrahedra with eclipsed conformation, linked to a dimer via a common corner. The bridging oxygen atom (∢(Li‐ O ‐Li) = 112°) thereby formally substitutes Ba2+ in Ba(H2O)6[B12H12] according to (H2 O )Li2(H2O)6[B12H12]. A direct coordinative influence of the [B12H12]2— cluster anions to the Li+ cations is not noticeable, however. The positions of the hydrogen atoms of both the water molecules and the [B12H12]2— units have all been localized. In addition, the formation of B‐Hδ—···δ+H‐O‐hydrogen bonds between the water molecules and the hydrogen atoms from the anionic [B12H12]2— clusters is considered and their range and strength is discussed. The dehydratation of the heptahydrate has been investigated by DTA‐TG measurements and shown to take place in two steps at 56 and 151 °C, respectively. Thermal treatment leads to the anhydrous lithium dodecahydro‐closo‐dodecaborate Li2[B12H12], eventually. 相似文献
Pamidronate (3‐ammonium‐1‐hydroxypropylidene‐1,1‐bisphosphonate) is used clinically in the treatment of diseases affecting bone tissue. In the salt zinc pamidronate dihydrate, Zn2+·2C3H10NO7P2−·2H2O, pamidronate is a zwitterion with an overall charge of −1. The carbon chain adopts a trans conformation, separating maximally the positively charged N atom from the negative phosphonate groups. The Zn2+ ion lies on an inversion center and is surrounded by a sixfold coordination sphere provided by two bidentate chelating zwitterions and two water molecules. The bidentate O⋯Zn⋯O bond angle is 92.70 (7)°, while the O⋯O bite distance is 3.018 (3) Å. 相似文献
On the Crystal Structures of the Transition‐Metal(II) Dodecahydro‐closo‐Dodecaborate Hydrates Cu(H2O)5.5[B12H12]·2.5 H2O and Zn(H2O)6[B12H12]·6 H2O By neutralization of an aqueous solution of the free acid (H3O)2[B12H12] with basic copper(II) carbonate or zinc carbonate, blue lath‐shaped single crystals of the octahydrate Cu[B12H12]·8 H2O (≡ Cu(H2O)5.5[B12H12]·2.5 H2O) and colourless face‐rich single crystals of the dodecahydrate Zn[B12H12]·12 H2O (≡ Zn(H2O)6[B12H12]·6 H2O) could be isolated after isothermic evaporation. Copper(II) dodecahydro‐closo‐dodecaborate octahydrate crystallizes at room temperature in the monoclinic system with the non‐centrosymmetric space group Pm (Cu(H2O)5.5[B12H12]·2.5 H2O: a = 768.23(5), b = 1434.48(9), c = 777.31(5) pm, β = 90.894(6)°; Z = 2), whereas zinc dodecahydro‐closo‐dodecaborate dodecahydrate crystallizes cubic in the likewise non‐centrosymmetric space group F23 (Zn(H2O)6[B12H12]·6 H2O: a = 1637.43(9) pm; Z = 8). The crystal structure of Cu(H2O)5.5[B12H12]·2.5 H2O can be described as a monoclinic distortion variant of the CsCl‐type arrangement. As characteristic feature the formation of isolated [Cu2(H2O)11]4+ units as a condensate of two corner‐linked Jahn‐Teller distorted [Cu(H2O)6]2+ octahedra via an oxygen atom of crystal water can be considered. Since “zeolitic” water of hydratation is also present, obviously both classical H–Oδ?···+δH–O and non‐classical B–Hδ?···+δH–O hydrogen bonds play a significant role for the stabilization of the structure. A direct coordinative influence of the quasi‐icosahedral [B12H12]2? anions on the Cu2+ cations has not been determined. The zinc compound Zn(H2O)6[B12H12]·6 H2O crystallizes in a NaTl‐type related structure. Two crystallographically different [Zn(H2O)6]2+ octahedra are present, which only differ in their relative orientation within the packing of the [B12H12]2? anions. The stabilization of the crystal structure takes place mainly via H–Oδ?···+δH–O hydrogen bonds, since again the hydrogen atoms of the [B12H12]2? anions have no direct coordinative influence on the Zn2+ cations. 相似文献
Sorption of cations of the Zn2+-Hg2+-NO3--H2O system by the biomass of basidiomycete (line 21 Pl. ostreatus f. florida) and by KB-4(H+) cation exchanger at pH 1.00 was studied. The results are discussed with regard to the state of cations in the solution before contact with the sorbent, sorbent properties, and sorption behavior of cations. 相似文献
In the coordination polymer, poly[[{μ‐1‐[(1H‐benzimidazol‐2‐yl)methyl]‐1H‐imidazole‐κ2N:N′}(μ‐5‐carboxybenzene‐1,3‐dicarboxylato‐κ2O1:O3)zinc(II)] dimethylformamide monosolvate pentahydrate], {[Zn(C9H4O6)(C11H10N4)]·C3H7NO·5H2O}n, the ZnII ion is coordinated by two N atoms from two symmetry‐related 1‐[(1H‐benzimidazol‐2‐yl)methyl]‐1H‐imidazole (bmi) ligands and two O atoms from two symmetry‐related 5‐carboxybenzene‐1,3‐dicarboxylate (Hbtc2−) ligands in a slightly distorted tetrahedral geometry. The ZnII ions are bridged by Hbtc2− and bmi ligands, leading to a 4‐connected two‐dimensional network with the topological notation (44.62). Adjacent layers are further connected by 12 kinds of hydrogen bonds and also by π–π interactions, resulting in a three‐dimensional supramolecular architecture in the solid state. 相似文献
We have previously shown that the nucleobase thymine binding to Zn2+ -cyclen (cyclen=1,4,7,10-tetraazacyclododecane) complex became stronger by appending acridine, naphthalene, or quinoline rings to the cyclen. Amongst these, the pendant bis((1-naphthyl)methyl) or bis((4-quinolyl)methyl) groups yielded the most effective thymine-recognizing Zn2+ -cyclen complexes [J. Am. Chem. Soc., 121 (1999) 5426]. The present study was undertaken to find causes of the bis(aromatic) ring effect by X-ray crystal structure analysis and NMR studies. The crystal structure of the Zn2+ -bis((1-naphthyl)methyl)-cyclen complex with a deprotonated 1-methylthymine (1-MeT) failed to show the anticipated evidence for the double ~ - ~ stacking interactions between the two naphthalenes and the Zn 2+ -bound 1-MeT m (1-MeT m =N(3')-deprotonated 1-MeT). Crystal data: formula C36 H47 N7 O7 Zn, M r =755.19, monoclinic, space group P21/ c (No. 14), a =15.438(2) Å, b =14.093(3) Å, c =16.726(2) Å, g =90.53(1) V =3638.7(8) Å 3 Z =4, R =0.035, Rw =0.049. However, the 1H NMR studies of Zn2= -bis((4-quinolyl)methyl)-cyclen with 1-MeT in varying H2O/CH3 CN solution showed increasing upfield shifts of Me(5') and H(6') of the Zn2+ -bound 1-MeT in more aqueous media, indicating that the double intercalation with the two quinolines became more significant in more protic environments. We conclude that the double ~ - ~ stacking effect accounts for the enhanced recognition of thymine base by the appended bis((1-naphthyl)methyl) or bis((4-quinolinyl)methyl) groups. 相似文献
Many factors, such as temperature, solvent, the central metal atom and the type of coligands, may affect the nature of metal–organic frameworks (MOFs) and the framework formation in the self‐assembly process, which results in the complexity of these compounds and the uncertainty of their structures. Two new isomeric ZnII metal–organic frameworks (MOFs) based on mixed ligands, namely, poly[[μ‐1,5‐bis(2‐methyl‐1H‐imidazol‐1‐yl)pentane‐κ2N 3:N 3′](μ‐5‐methylisophthalato‐κ2O 1:O 3)zinc(II)], [Zn(C9H6O4)(C13H20N4)]n , (I), and poly[[μ‐1,5‐bis(2‐methyl‐1H‐imidazol‐1‐yl)pentane‐κ2N 3:N 3′](μ3‐5‐methylisophthalato‐κ3O 1:O 1′:O 3)(μ3‐5‐methylisophthalato‐κ4O 1:O 1′:O 3,O 3′)dizinc(II)], [Zn2(C9H6O4)2(C13H20N4)]n , (II), have been synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis and thermogravimetric analysis. Complex (I) displays a two‐dimensional layer net, while complex (II) exhibits a twofold interpenetrating three‐dimensional framework. Both complexes show high stability and good fluorescence in the solid state at room temperature. 相似文献
The hexadentate ligand all‐cis‐N1,N2‐bis(2,4,6‐trihydroxy‐3,5‐diaminocyclohexyl)ethane‐1,2‐diamine (Le) was synthesized in five steps with an overall yield of 39 % by using [Ni(taci)2]SO4?4 H2O as starting material (taci=1,3,5‐triamino‐1,3,5‐trideoxy‐cis‐inositol). Crystal structures of [Na0.5(H6Le)](BiCl6)2Cl0.5?4 H2O ( 1 ), [Ni(Le)]‐ Cl2?5 H2O ( 2 ), [Cu(Le)](ClO4)2?H2O ( 3 ), [Zn(Le)]CO3?7 H2O ( 4 ), [Co(Le)](ClO4)3 ( 5 c ), and [Ga(H?2Le)]‐ NO3?2 H2O ( 6 ) are reported. The Na complex 1 exhibited a chain structure with the Na+ cations bonded to three hydroxy groups of one taci subunit of the fully protonated H6(Le)6+ ligand. In 2 , 3 , 4 , and 5 c , a mononuclear hexaamine coordination was found. In the Ga complex 6 , a mononuclear hexadentate coordination was also observed, but the metal binding occurred through four amino groups and two alkoxo groups of the doubly deprotonated H?2(Le)2?. The steric strain within the molecular framework of various M(Le) isomers was analyzed by means of molecular mechanics calculations. The formation of complexes of Le with MnII, CuII, ZnII, and CdII was investigated in aqueous solution by using potentiometric and spectrophotometric titration experiments. Extended equilibrium systems comprising a large number of species were observed, such as [M(Le)]2+, protonated complexes [MHz(Le)]2+z and oligonuclear aggregates. The pKa values of H6(Le)6+ (25 °C, μ=0.10 m ) were found to be 2.99, 5.63, 6.72, 7.38, 8.37, and 9.07, and the determined formation constants (log β) of [M(Le)]2+ were 6.13(3) (MnII), 20.11(2) (CuII), 13.60(2) (ZnII), and 10.43(2) (CdII). The redox potentials (vs. NHE) of the [M(Le)]3+/2+ couples were elucidated for Co (?0.38 V) and Ni (+0.90 V) by cyclic voltammetry. 相似文献
The assembly of metal–organic frameworks (MOFs) with metal ions and organic ligands is currently attracting considerable attention in crystal engineering and materials science due to their intriguing architectures and potential applications. A new three‐dimensional MOF, namely poly[[diaqua(μ8‐para‐terphenyl‐3,3′,5,5′‐tetracarboxylato)dizinc(II)] dimethylformamide disolvate monohydrate], {[Zn2(C22H10O8)(H2O)2]·2C3H7NO·H2O}n, was synthesized by the self‐assembly of Zn(NO3)2·6H2O and para‐terphenyl‐3,3′,5,5′‐tetracarboxylic acid (H4TPTC) under solvothermal conditions. The compound was structurally characterized by FT–IR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction analysis. Each ZnII ion is located in a square‐pyramidal geometry and is coordinated by four carboxylate O atoms from four different TPTC4? ligands. Pairs of adjacent equivalent ZnII ions are bridged by four carboxylate groups, forming [Zn2(O2CR)4] (R = terphenyl) paddle‐wheel units. One aqua ligand binds to each ZnII centre along the paddle‐wheel axis. Each [Zn2(O2CR)4] paddle wheel is further linked to four terphenyl connectors to give a three‐dimensional framework with NBO‐type topology. The thermal stability and solid‐state photoluminescence properties of the title compound have also been investigated. 相似文献
Triclinic single crystals of [(C6H10)(NH3)2][Ni(H2O)4C6H2(COO)4]·4H2O have been prepared in aqueous solution at 55 °C. Space group (Nr. 2), a = 691.23(6), b = 924.84(5), c = 1082.43(7) pm, α = 74.208(6)°, β = 75.558(7)°, γ = 68.251(6)°, V = 0.60985(7) nm3, Z = 1. The Nickel(II) species, located on a crystallographic inversion centre, is coordinated in a trans‐octahedral fashion by two oxygen atoms stemming from the centrosymmetric pyromellitate anions and four from water molecules (Ni–O 205.82(12) – 208.11(13) pm). The connection between Ni2+ and [C6H2(COO)4)]4? leads to infinite chain‐like polyanions extending parallel to with {Ni(H2O)4[C6H2(COO)4]2?}n composition. [(C6H10)(NH3)2]2+‐cations are accomodated between the chains, compensating for the negative charge of the polyanions. Thermogravimetric analysis in air showed that the loss of water of crystallisation occurs in two steps between 102 and 206 °C, corresponding to the loss of 6 and 2 water molecules per formula unit, respectively. The dehydrated sample was stable between 206 and 353 °C. Further decomposition yielded nickel(II) oxide (NiO). 相似文献
