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1.
Reaction of [MoOCl5]2− with in situ generated H2Se under hydrothermal conditions (4M HCl, 140 °C) leads to reduction of Mo(V) to Mo(IV) with the formation of a triangular cluster Mo33-Se)(μ-O)34+ in high yield. It is present in HCl solutions as aqua chlorocomplex [Mo33-Se)(μ-O)3(H2O)6Cl3]+ which was isolated and structurally characterized as supramolecular adduct with cucurbit[6]uril (CB[6]), {[Mo33-Se)(μ-O)3(H2O)6Cl3]2CB[6]}Cl2·15H2O. Dedicated to Professor Dieter Fenske on the Occasion of his 65th Birthday  相似文献   

2.

Abstract  

p-Thioacetatebenzoic acid (H2L) and a combination of N-donor ligands such as 4,4′-bipyridine (4,4′-bipy) and 1,3-bi(4-pyridyl)propane (bpp) with metal ions Mn(II) and Ni(II) give rise to two coordination polymers, namely, [Mn(HL)2(bpp)2(H2O)2] n (1), [NiL (4,4′-bipy)(H2O)3] n ·nH2O (2). 1 features an unusual “8” shaped double layer by hydrogen bonds and two different types of helical chains are arrayed alternatively in the 2D double layer framework, which further extends into a 3D supramolecular structure through C–H···O hydrogen bonds. 2 consists of 1D chains which further connect with each other via hydrogen bonds to form the final 3D framework including two different types of helical structure. Photoluminescence study reveals that 1 displays intense structure-related fluorescent emission bands (λ ex = 369 nm) at 414 nm in the solid state at room temperature. Electrochemical property of 2 reveals that the process of the redox is irreversible.  相似文献   

3.
One reported compound [Co(PDA)(4,4′-bipy)]n·nH2O and one new compound [Co(PDA)(Im)2(H2O)2]n·nH2O were prepared by the reactions of Co(NO3)2·6H2O or Co(OH)2 with 1,4-phenylenediacetic acid (H2PDA) in the presence of the ancillary ligands 4,4′-bipyridine (4,4′-bipy) or imidazole (Im), and their magnetic properties were investigated. The presence of 4,4′-bipy in [Co(PDA)(4,4′-bipy)]n·nH2O results in a μ 3-bridging mode of the PDA2− ligand with one μ 2-carboxylato group and one chelating carboxylato group and the construction of a 2D framework as reported in the literature. The introduction of Im ligand in [Co(PDA)(Im)2(H2O)2]n·nH2O helps to construct a one dimensional chain with the two carboxylato groups of PDA2− ligand in monodentate coordination modes. The magnetic studies reveal the presence of dominant antiferromagnetic interaction in [Co(PDA)(4,4′-bipy)]n·nH2O with a field-induced magnetic transition due to spin-flop. Magnetically, [Co(PDA)(Im)2(H2O)2]n·nH2O presents a mononuclear structure. This work reveals that the introduction of ancillary ligands in the Co(II)-PDA system adjusts the linking modes of PDA2− and therefore the resulting frameworks and their magnetic properties.  相似文献   

4.
Three novel coordination polymers, namely, [Mn(ndc)(bpy)] n  · n(H2O) (1), [Mn(ndc)(phen)] n (2), and [Mn3(ndc)3(bpy)2] n (3) (H2ndc = 2,6-naphthalenedicarboxylic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been hydrothermally synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Complexes 13 exhibit three-dimensional metal-organic frameworks (MOFs); 1 and 2 are assemblies of the same secondary building units (SBUs), linear infinite chains {Mn(CO2)2} n , forming one-dimensional channel, while complex 3 is constructed by trinuclear clusters {Mn3(CO2)6} SBUs. Magnetic properties of complexes 1 and 3 are also discussed with respect to the bridging mode of the carboxylate groups.  相似文献   

5.
Two new Mn(II) coordination polymers formed with molecular formula [Mn(H2O)2(HBTC)·(H2O)] 1 and [Mn(H2O)2(4,4′bipy)(HBTC)2]·(H4,4′bipy)2 2, where BTC = 1,2,4-benzenetricarboxylate and 4,4′bipy = 4,4′bipydine, have been synthesized via hydrothermal approach and characterized by single crystal X-ray diffraction techniques. 1 is composed of Mn–H2O–Mn 1D chains and further the chains are linked by HBTC ligands to form a 2D network in the ab plane; 2 is constructed by Mn–4,4′bipy–Mn 1D chains along the b direction with Mn2+ ions coordinated to H2BTC and water as terminal ligands to form a 2D network. We also prepared a third compound with the molecular formula of [Mn(H2O)(HBTC)·(H2O)] which has been recently structurally reported elsewhere. The magnetic properties of the three compounds have been studied in detail under variable temperatures.  相似文献   

6.
Three new coordination polymers with formula [Gd(bta)(H2O)·1.39H2O] n (1), [Dy(bta)(H2O)·1.35H2O] n (2) and [Y(bta)(H2O)2·0.5H2O] n (3) were synthesized by using corresponding rare earth nitrates and 1,3,5-benzenetriacetic acid (H3bta) under hydrothermal/solvothermal reaction conditions, and characterized by single-crystal X-ray diffraction. In these complexes, the carboxylate groups of bta3− adopt different coordination modes, namely one carboxylate group adopts μ211-bridging and each of the other two carboxylate groups adopts μ221-bridging coordination modes in 1 and 2, and one carboxylate group adopts a μ221-bridging coordination mode and each of the other two carboxylate groups adopts a μ211-bridging mode for the major component and one carboxylate group adopts a μ221-bridging coordination mode, one has a μ211-bridging mode and the third has a monodentate mode for the minor component in 3. The magnetic properties of the complexes 1 and 2 were investigated in the temperature range of 1.8–300 K.  相似文献   

7.
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(ClO4nH2O ( 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   

8.
The coordination polymers (CPs), [Ni(L)(H2O)4]n ( 1 ), [Co(HL)2(H2O)2]n ( 2 ), {[Cu(L)(H2O)3] · H2O}n ( 3 ), [Mn(L)(H2O)2]n ( 4 ), [Cd(L)(H2O)2]n ( 5 ), and {[Zn2(L)2] · H2O}n ( 6 ), were solvothermally synthesized by employing the imidazol‐carboxyl bifunctional ligand 4‐(1H‐imidazol‐1‐yl) phthalic acid (H2L). Single‐crystal X‐ray diffraction indicated that the L2–/HL ligands display various coordination modes with different metal ions in 1 – 6 . Complexes 1 and 2 show one‐dimensional (1D) chain structures, whereas complexes 3 – 6 show 2D layered structures. The magnetic properties of these complexes were investigated. Complexes 1 and 3 indicate weak ferromagnetic interactions, whereas complexes 2 and 4 demonstrate antiferromagnetic interactions. In addition, luminescence properties of 5 and 6 were measured and studied in detail.  相似文献   

9.
We report the basis set dependencies and the basis set superposition errors for the hydrated complexes of K+ and Na+ ions in relation to the recent studies of the KcsA potassium channel. The basis set superposition errors are estimated by the geometry optimizations at the counterpoise-corrected B3LYP level. The counterpoise optimizations alter the hydration distances by about 0.02–0.03 Å. The enthalpies and free energies for K+ + n(H2O) → [K(H2O)n]+ and Na+ + n(H2O) → [Na(H2O)n]+ (n = 1–6) are compared between the theoretical and experimental values. The results show that the addition of diffuse functions to K, Na, and O species are effective. However, it is also found that the counterpoise corrections using diffuse functions work so as to underestimate the free energies for the complexes with increasing the hydration number. The stabilization energies in aqueous solution are larger for a Na+ ion than for a K+ ion, suggesting the contributions of their dehydration processes to the ion selectivity of the KcsA potassium channel. The changes in coordination distance between the isolated [K(H2O)8]+ and the [K(H2O)8]+ in the KcsA potassium channel indicate the importance of hydrogen bondings between the first hydration shell and the outer hydration shells.  相似文献   

10.
The reaction of neodymium diiodide NdI2 with excess methanol in acetonitrile produced the tetranuclear neodymium cluster [Nd42-I)1.13-I)(μ2-OMe)4.94-O)(MeCN)12]I3 (1). In the latter, the isomorphic substitution of one methoxy group by an I anion with site occupancies (%) of 90 and 10, respectively, was observed. Due to the isomorphic substitution in the crystal, cluster 1 can be considered as a superposition of two complexes, [Nd42-I)(μ3-I)(μ2-OMe)54-O)(MeCN)12]I3 and [Nd42-I)23-I)(μ2-OMe)44-O)(MeCN)12]I3. The characteristic feature of cluster 1 is that the center of the Nd4 cage is occupied by the μ4-coordinated O2− anion, which is indicative of the partial O-C bond cleavage in methanol. The reaction of NdI2 with an equimolar amount of MeOH in an acetonitrile solution produced methoxide NdI2(OMe)(MeCN)4 in 49% yield. Dedicated to Professor W. J. Evans on the occasion of his 60th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1894–1897, October, 2007.  相似文献   

11.
Two Mn(II) coordination polymers, namely [Mn(bpda)] n (1) and [Mn(bpda)(bpy)0.5] n (2) (H2bpda = 1,1′-biphenyl-3,3′-dicarboxylic acid and bpy = 4,4′-bipyridine), have been synthesized from H2bpdc, bpy, and MnSO4·2H2O under hydrothermal conditions. The complexes were characterized by physicochemical and spectroscopic methods, as well as by X-ray crystallography. Compound 1 possesses a 3D structure consisting of carboxylate-bridged edge-sharing Mn–O–Mn double chains. Compound 2 features a 3D open structure with a dinuclear Mn(II) secondary building unit. Magnetic susceptibility measurements of compounds 1 and 2 exhibit antiferromagnetic interactions between the nearest Mn(II), with J = –11.3 cm−1 and g = 2.12 for 1, and J = –13.5 cm−1 and g = 2.12 for 2.  相似文献   

12.

Abstract  

A series of 1-D lanthanide coordination polymers [Ln(μ3-OH)(pybz)(pa)] n (Ln = Er (1), Tb (2), Gd (3), Hpybz = 4-pyridin-4-yl-benzoic acid, Hpa = 2-picolinic acid) based on [Ln43-OH)4] cluster units have been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR, elemental analysis, and thermogravimetric analysis. X-ray crystal structure analyses reveal that 1–3 are isomorphous with tetragonal space group P [`4] \overline{4} 21c and comprise tetranuclear Ln–O clusters, in which four Ln3+ centers are joined together by four μ3-bridging hydroxyl groups to form cubane-like [Ln43-OH)4]8+ cores that are further linked by four μ3-pa ligands to produce 1-D chains along the c-axis.  相似文献   

13.
The oxidation of [CrIII(HNTA)(Hist)(H2O)] and [CrIII(HNTA)(Asp)(H2O)] (NTA = nitrilotriacetate, Hist = l-histidinate and Asp = dl-aspartate) by periodate in aqueous medium has been studied spectrophotometrically between 15.0 and 35.0 °C under pseudo-first-order conditions, [IO4 ] ≫ [complex]. The rate increases over the pH range 3.40–4.45 in both cases, but the two complexes give different rate laws. It is proposed that electron transfer proceeds through an inner-sphere mechanism via coordination of IO4 to chromium(III). A common mechanism for the oxidation of some chromium(III) complexes by periodate is proposed, and this is supported by an excellent isokinetic relationship between ΔH* and ΔS* values for these reactions.  相似文献   

14.
合成和表征了5个螺旋配位聚合物{[Cu(Hbpma)(H2O)4]2(SO4)3·3.5H2O}n (1)、{[Ni(Hbpma)(H2O)4]4(SO4)6·10.75H2O}n (2)、{[Mn(Hbpma)(H2O)4](SO4)1.5·3H2O}n (3)、{[Zn(Hbpma)(H2O)4]4(SO4)6·4H2O·4CH3OH}n (4)和{[Cu(Hbpma)2(H2O)2](SO4)2·9H2O}n (5), 其中bpma代表N,N'-双(3-吡啶甲基)胺。晶体结构分析表明配合物1~4为一维链状结构, 配合物5为二维层状结构, 其中金属离子由质子化的bpma配体桥连。值得注意的是, 采取反-反式构象的柔性bpma配体使得配合物12为假螺旋链结构, 配合物34为螺旋链结构, 配合物5为螺旋层结构。同时研究了配合物的磁性和热稳定性。  相似文献   

15.
A series of transition metal coordination polymers [Co(H3L)2(4,4′- bpy)(H2O)2]n?n(4,4′-bpy) (1), [Ni(H2L)(4,4′-bpy)(H2O)2]n (2), [Co2(L)(phen)2(H2O)4]n?(H2O)2n (3), and [Ni2(L)(phen)2(H2O)4]n?(H2O)2n (4) have been assembled from a semirigid multicarboxylate ligand 3,3′-(1,4-phenylenebis(oxy))diphthalic acid (H4L) with the help of 4,4′-bipyridine (4,4′-bpy) ligand or 1,10-phenanthroline (phen) ligand. X-ray single crystal diffraction analysis reveals that complex 1 crystallizes in the space group of P − 1 and displays a one-dimensional (1D) chain structure constructed from 4,4′-bpy ligand and H3L ligand, which was further interlinked to form a three-dimensional network via hydrogen bonds. In complex 2, Ni(II) atoms are coordinated by L ligand in monodentate fashion to form alternate left- and right-helices, which are further bridged together by the coordination interactions between Ni(II) atoms and 4,4′-bpy, leading to a 2-fold (4, 4)-connected interpenetrating network. Isostructural complexes 3 and 4 belong to the space group P − 1 and display a 1D chain structure constructed from phen and L ligands, which was further interlinked to form a 2D plane via π–π interactions. In addition, their thermal and luminescent properties were also investigated.  相似文献   

16.
Three isomorphous coordination polymers of general formula {[M(H2bna)·(DMF)2·(H2O)2]·DMF}n (M = Co for 1, Mn for 2, Ni for 3, respectively, where H4bna = 2,2′-dihydroxy-[1,1′]-binaphthalene-3,3′-dicarboxylate) were synthesized under solvothermal conditions and characterized by FTIR, single crystal X-ray diffraction, thermogravimetric analysis, and X-ray power diffraction analysis. All three polymers crystallize in the same monoclinic space group P21/n. The complexes are assembled into 1D helical chains, and each adjacent helical chain of the same chirality is further connected to form a chiral layer by hydrogen bond interactions. The layers are packed in alternating left-(M) and right-handed (P) chirality arrays. Magnetic studies reveal the presence of antiferromagnetic coupling interactions in complexes 1 and 2.  相似文献   

17.
Polymeric tetracyanonickelate complexes of the type [M(H2O)(2mpz)Ni(μ-CN)4] n (2mpz = 2-methylpyrazine, M = Mn(II) (1) or Cd(II) (2)) have been prepared and characterized by FT-IR, Raman spectroscopy, thermal, and elemental analyses. The crystal structure of supramolecular [Cd(H2O)(2mpz)Ni(CN)4] n complex has been determined by X-ray single crystal diffraction. It crystallizes in the orthorhombic system, space group Pnma. The structure consists of corrugated and cyanide-bridged polymeric two-dimensional networks. In the Hofmann-type complexes, the coordination environment of the M(II) ions can be described as distorted octahedral geometry, whereas around the Ni(II) center has square planar geometry. The spectral features suggest that the 2mpz is coordinated to metal ions of the adjacent layers of [M-Ni(CN)4] n as monodentate ligand. The thermal decomposition of these complexes takes place in three stages: (i) dehydration, (ii) decomposition of the 2-methylpyrazine ligands, and (iii) release of the CN groups and burning of organic residue.  相似文献   

18.
利用四氰基构筑单元和不同位阻的吡啶类配体,合成了3例氰基桥联的Fe2Ni链状化合物。化合物{[Fe(bpy)(CN)4]2[Ni(bp)2]·2H2O}n1)(bpy=2,2''-联吡啶;bp=4-苯基吡啶),{[Fe(bpy)(CN)4]2[Ni(papy)2]·H2O}n2)(papy=4-(苯基氮烯)吡啶)和{[Fe(bpy)(CN)4]2[Ni(azp)]·4H2O}n3)(azp=1,2-二(吡啶-4-基)二氮烯)均为双之字型的链状结构。磁性测试表明化合物1~3均表现为链内的铁磁相互作用。化合物1表现出单链磁体行为,有效能垒为10.9 K。  相似文献   

19.
采用溶剂热的方法,将配位模式丰富的多羧酸有机配体5-(2-硝基-4-羧基苯氧基)-间苯二甲酸(H3ncpoi)与Cd~(2+)离子以及不同的辅助配体原位组装而成4个新的配位聚合物晶体:[Cd(Hncpoi)(2,2′-bpy)(H2O)]n(1),{[Cd2(Hncpoi)2(bpyp)(H2O)4]·3H2O}n(2),{[Cd2(Hncpoi)2(azpy)(H2O)2]·2H2O}n(3),{[Cd2(Hncpoi)2(dpe)(H2O)2]·2H2O}n(4),其中H3ncpoi为5-(2-硝基-4-羧基苯氧基)-间苯二甲酸,2,2′-bpy为2,2′-联吡啶,bpyp为1,4-二-吡啶基-4-亚甲基-哌嗪,azpy为4,4′-偶氮吡啶,dpe为1,2-二-(4-吡啶基)乙烯。对4个配合物进行了X射线单晶衍射、粉末衍射,元素分析、热重、荧光光谱等表征。X射线单晶结构分析表明,配合物1,2具有一维链状结构,而配合物3,4则具有二维(4,4)格子层状结构,一维链和二维层之间通过分子间作用力连接成三维超分子结构。进一步研究表明,辅助配体的构型、配位方式等对晶体结构具有决定性作用。与此同时,对几个配合物的荧光光谱进行分析,发现不同的辅助配体对配合物的荧光性能有着显著的影响。  相似文献   

20.
A new 3D coordination polymer, [LaAg(Pydc)(HPydc)(C2O4)0.5(H2O)2] n (I) (H2Pydc = pyridine-3,5-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analyses and single crystal X-ray diffraction. The X-ray diffraction analysis reveals that I (C15H11AgLaN2O12) crystallizes in triclinic space group P $ \bar 1 $ \bar 1 and features an interesting 3D framework constructed by 2D layers via strong Ag-Ag interactions. Unit cell parameters for I (n = 1): a = 7.749(2), b = 8.316(1), c = 14.239(3) ?, α = 97.64(2)°, β = 100.12(2)°, γ = 94.37(2)°, and Z = 2.  相似文献   

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