共查询到20条相似文献,搜索用时 39 毫秒
1.
Two new neodymium complexes, [Nd2(abglyH)6(2,2′-bipy)2(H2O)2] · 4H2O 1 and {[Nd(abglyH)3(H2O)2] · (4,4′-bipy) · 7H2O}n
2 (abglyH2 = N-P-acetamidobenzenesulfonyl-glycine acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been synthesized and
their structures have been measured by X-ray crystallography. In 1, nine-coordinated Nd(III) ions are bridged by two syn–syn bidentate and two tridentate bridging carboxylate groups from four different abglyH− anions to form dinuclear motifs, which are further connected into a 3-D supramolecular framework via hydrogen bonds between
the binuclear motifs and the uncoordinated water molecules. In 2, eight-coordinated Nd(III) ions are linked by six carboxylate groups adopting a syn–syn bidentate bridging fashion to form a 1-D inorganic–organic alternating linear chain. These polymeric chains generate microchannels
extending along the a direction, and these cavities are occupied by discrete tetradecameric water clusters, which interact with their surroundings
and finally furnish the 3-D supramolecular network via hydrogen bonds. At the same time, π–π stacking interactions between
benzene rings from abglyH− anions also play an important role in stabilizing the network. 相似文献
2.
Abstract Two new Keggin-polyoxometalate hybrids, {[Cu2(4,4′-bpy)2][PW10VIW2VO40]}[Cu2(obpy)2]4 · 2 H2O (1) and {[Cu4(2,2′-bpy)4(4,4′-bpy)3][SiW12O40]} · 2H2O (2) (4,4′-/2,2′-bpy = 4,4′-/2,2′-bipyridyl, Hobpy = 6-hydroxy-2,2′-bipyridyl), were hydrothermally synthesized and structurally
characterized. Gillard type hydration of 2,2′-bipy is observed during the synthesis of 1, resulting in a new obpy ligand in situ. X-ray structural analyses show that 1 consists of 1D hybrid chain {[Cu2(4,4′-bpy)2][PW10VIW2VO40]}∞ and [Cu2(obpy)2] dimer, whereas 2 possesses 1D hybrid structure based on Keggin-type [SiW12O40]4− anions and tetra-nuclear copper complexes [Cu4(2,2′-bpy)4(4,4′-bpy)3]4+. Both compounds present interesting supramolecular architectures based on π–π stacking and hydrogen bonds.
Graphical Abstract Compounds {[Cu2(4,4′-bpy)2][PW12O40]}[Cu2(obpy)2]4 · 2H2O (1) and [Cu4(2,2′-bpy)4(4,4′-bpy)3][SiW12O40] · 2H2O (2) were hydrothermally synthesized. 1 features that the [Cu2(obpy)2] dimers based on in situ generated obpy ligands are stumped between the layers where 1D hybrid chain {[Cu2(4,4′-bpy)2][PW12O40]}∞ locates, while 2 exhibits 1D chain-like structure based on anions [SiW12O40]4− and tetra-copper complexes [Cu4(2,2′-bpy)4(4,4′-bpy)3]4+.
相似文献
3.
Yan Ding Hongli Chen Weilin Chen Enbo Wang Jingxin Meng 《Transition Metal Chemistry》2009,34(3):281-288
Four novel organic–inorganic hybrid compounds [Cu5
I(4,4′-bpy)3(2,2′-bpy)4][BW12O40] · H2O (1), [Ni0.5(2,2′-bpy)1.25][Ni(2,2′-bpy)3][Ni(2,2′-bpy)2(H2O)(SiW11VIWVO40)] · 0.5H2O (2), [H2bpy]2[Zn(2,2′-bpy)3]2[Si2W18O62] · 1.5H2O (3) and [CuII(2,2′-bpy)2]2[SiW12O40] · 2H2O (4) (2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine) have been synthesized under hydrothermal conditions and characterized
by elemental analysis, IR spectroscopy, thermal gravimetric analysis, electrochemical measurements and single-crystal X-ray
diffraction. Compound (1) is a novel [BW12O40]5− polyoxoanion bisupported by copper(I) coordination cations with mixed 2,2′-bpy and 4,4′-bpy ligands. Compound (2) is constructed from the [SiW11VIWVO40]5− polyoxoanions supported by [Ni(2,2′–bpy)2]2+. Compound (3) is composed of a novel [Si2W18O62]8− cluster and [Zn(2,2′–bpy)3]2+ complexes, which held together into a three-dimensional (3D) supramolecular network through hydrogen-bonding interactions.
Compound (4) shows a 2D layer framework constructed from a bisupporting Keggin polyoxoanion cluster and [Cu(2,2′–bpy)2]2+ coordination polymer fragments, resulting in 3D networks via supramolecular interactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Xinxin Xu Xiaoguang Sang Xiaoxia Liu Xia Zhang Ting Sun 《Transition Metal Chemistry》2010,35(4):501-506
Two new supramolecular metal–organic complexes have been synthesized under hydrothermal conditions. Complex 1 exhibits a three-dimensional supramolecular network, constructed from [Co2(H3BPTC)2(phen)2] (H4BPTC = 3,3′4,4′-benzophenone tetracarboxylate acid, phen = 1,10-phenanthroline) discrete units. Complex 2 similarly exhibits discrete [Cu2(DPA)2(bipy)2(H2O)2] (DPA = 1,1′-biphenyl-2,2′-dicarboxylate acid, bipy = 2,2′-bipyridine) units, which are linked to form a three-dimensional
supramolecular network through π–π interactions. It is interesting that during the synthesis of complex 1, the H4BPTC ligands undergo partial decomposition to give 1,2,4-benzenetricarboxylate (H3BTC) ligands, which react with Co to form [Co3(BTC)2]n (3). Complex 3 shows a three-dimensional covalent network. The magnetic properties of complexes 1 and 2 have been studied. 相似文献
5.
Zi-Lu Chen Wei Xiong Zhong Zhang Fu-Pei Liang Bing-Chang Luo 《Transition Metal Chemistry》2010,35(8):991-997
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
6.
Xuemei Han Wansheng You Limei Dai Lijun Qi Yong Fang Weiwei Li 《Journal of Cluster Science》2009,20(4):707-716
Two coordination polymers based on vanadium-substituted Keggin polyoxotungstophosphates as bridging ligands, {[Ni(4,4′-bipy)1.5(OH)(H2O)]2[H3PW10V2O40]}·4H2O (4,4′-bpy = 4,4′-bipyridine) 1 and {[Ni(dpa)2][Ni(dpa)(H2O)3]2[PW9V3O40]}·4H2O (dpa = 2,2′-dipyridylamine) 2, have been obtained by hydrothermal reactions and characterized by elemental analysis, IR, XRD, TGA and single-crystal X-ray
Diffraction analysis. Compound 1 is a 2D layered structure built from 1D infinite zigzag {Ni2(4,4′-bipy)3(OH)2(H2O)2}n2+ chains bridged via [H3PW10V2O40]2− anions. Compound 2 exhibits a one-dimensional chain-like structure constructed from [Ni(dpa)2]2+ fragments bridged via bis-supported Keggin polyoxoanions [Ni(dpa)(H2O)3]2[PW9V3O40]2−. The two examples demonstrate that vanadium-substituted Keggin polyoxometalates have greater coordination capability. 相似文献
7.
Guo-Cheng Liu Yong-Qiang Chen Wen-Yan Zheng Hong-Yan Lin 《Transition Metal Chemistry》2009,34(7):739-744
A novel organic–inorganic hybrid compound [Cu(2,2′-bipy)(C6H5NO2)(H2O)]2[Mo8O26]·5H2O (1), (2,2′-bipy = 2,2′-bipyridine; C6H5NO2 = pyridine-4-carboxylic acid) has been prepared and characterized by elemental analyses, IR spectrum, thermal stability analysis,
and single-crystal X-ray diffraction. Compound 1 is a discrete cluster, constructed from β-[Mo8O26]4− subunits covalently bonded to two [Cu(2,2′- bipy)(C6H5NO2)(H2O)]24+ coordination cations via terminal oxo groups that connect one molybdenum site. A 3D supramolecular network is further formed
by extensive hydrogen bonding interactions and π–π interactions of the 2,2′-bipy and pyridine-4-carboxylic acid ligands. EPR
and magnetic susceptibility studies have been used to elucidate the electronic properties of the Cu2+ centres, and the results are in good agreement with the structural features of the compound. 相似文献
8.
Four new [P4Mo6] cluster-based extended structures containing cadmium complexes, [Cd3(4,4′-Hbpy)2(4,4′-bpy)2(H2O)8][Cd(H2PO4)2(HPO4)4(PO4)2(MoO2)12(OH)6]·7H2O 1, (4,4′-Hbpy)2[Cd(4,4′-bpy)3(H2O)3][Cd(4,4′-bpy)(H2O)]2[Cd(H2PO4)2(HPO4)4 (PO4)2(MoO2)12(OH)6]·H2O 2, [Cd4(phen)2(H2O)4][Cd(phen)(H2O)]2[Cd(HPO4)4 (HPO4)4(MoO2)12(OH)6]·5H2O 3 and [Cd4(2,2′-bpy)2(H2O)4][Cd(2,2′-bpy)(H2O)]2 [Cd(HPO4)4(HPO4)4(MoO2)12(OH)6]·3H2O 4 (4,4′-bpy=4,4′-bpyridine, phen=1,10-phenanthroline, 2,2′-bpy=2,2′-bpyridine), have been synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. The structure of compound 1 is constructed from the Cd[P4Mo6]2 dimers linked by [Cd3(4,4′-Hbpy)2(4,4′-bpy)2(H2O)8] subunits to generate a plane layer. Compound 2 consists of the positive 2D sheets that constructed from Cd[P4Mo6]2 dimers linked by [Cd(4,4′-bpy)(H2O)] complexes, then the 2D sheets are further linked up together to form a 3D supramolecular framework via extensive hydrogen-bonding interactions among the [P4Mo6] clusters, free 4,4′-bpy molecules, dissociated [Cd(4,4′-bpy)3(H2O)3]2+ complexes and water molecules. Compounds 3 and 4 show new 2D layered structure, with Cd[P4Mo6]2 building blocks connected by tetra-nuclear [Cd4{(phen)2/(2,2′-bpy)2}(H2O)4] clusters and [Cd(phen/2,2′-bpy)(H2O)] complexes. The fluorescent activities of compounds 3 and 4 are reported. 相似文献
9.
《Journal of Coordination Chemistry》2012,65(15):2659-2668
Two lanthanide coordination polymers, [Tm2·(5-IPA)4·(2,2′-Hbipy)2]·3H2O (1, 5-H2IPA?=?5-hydroxyisophthalic acid, 2,2′-bipy?=?2,2′-bipyridine) and [Er·(5-HIPA)3·(4,4′-bipy)3·(H2O)2]·3H2O (2, 4,4′-bipy?=?4,4′-bipyridine), have formed by hydrothermal synthesis. Complex 1 exhibits a 2-D coordination network containing parallelepiped-shaped voids occupied by guest 2′2-bipy molecules. Complex 2 possesses a 1-D linear chain structure. The 1-D chains are linked by 4,4′-bipy molecules to form a 3-D supramolecular framework. IR spectroscopy, elemental analysis, and thermogravimetric analysis were also investigated. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(16):2563-2569
Two new supramolecular compounds [M(4,4′-bipy)2 (H2O)4] ·?(4,4′-bipy)2 ·?(3,5-daba)2 ·?8H2O (M=Zn(1) or Mn(2), 4,4′-bipy =?4,4′-bipyridine, 3,5-daba =?3,5-diaminobenzoic acid anion) were synthesized and characterized by elemental analysis and X-ray crystal diffraction. In [M(4,4′-bipy)2(H2O)4]2+, the M(II) is coordinated by two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four waters to form an octahedral configuration. There exist uncoordinated 4,4′-bipy molecules, 3,5-diaminobenzolate counterions and water guests in the compounds. The 3D structures of the title supramolecular compounds are constructed by rich hydrogen bonds among [M(4,4′-bipy)2(H2O)4]2+, uncoordinated 4,4′-bipy molecules, water molecules and 3,5-daba, containing a diverting hexa-member water ring. 相似文献
11.
《Journal of Coordination Chemistry》2012,65(21):3903-3917
Four metal(II) complexes with benzene-1,2,3-triyltris(oxy)triacetic acid (H3L), {[Co1.5(L)(H2O)6]·6H2O}n (1), {[Co1.5(L)(4,4′-bipy)1.5(H2O)4]·4H2O}n (2), {[Co(HL)(2,2′-bipy)(H2O)2]·1.5H2O}n (3), and {[Cu(HL)(phen)(H2O)2]·H2O}n (4) (4,4′-bipy = 4,4′-bipyridine; 2,2′-bipy = 2,2′-bipyridine; phen = phenanthroline), were prepared and structurally characterized. Complex 2 displays a 1-D structure, while 1, 3, and 4 reveal 0-D structures, which further extend to 3-D supramolecular networks by hydrogen bonding interactions, of which 1 and 4 contain double-helical chains, 2 includes meso-helices, and 3 comprises single-helices. Furthermore, the thermal stabilities and antibacterial activities of the complexes were studied. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(7):1035-1050
Two new organic-inorganic hybrids, (4,4′-bipy)[CuI(2,2′-bipy)2]2[W6O19] (2,2′-bipy = 2,2′-bipyrine, 4,4′-bipy = 4,4′-bipyrine) (1) and (C6H5NO2)4{MnIII(H2O)}[AsIIIW9O33]2{W(OH)}- {W(H2O)}?~18H2O (2), have been synthesized and characterized by elemental analysis, IR, TG, UV–Vis, XRPD, XPS, electrochemical analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction analysis shows that 1 is a new Lindqvist-type polyoxoanion bisupported by copper(I) coordination cations and 2,2′-bipy ligands and exhibits a three-dimensional (3-D) supermolecular framework by aromatic π–π stacking interactions. Compound 2 is constructed from a manganese(III)-substituted sandwich-type polyoxoanion based on [α-AsW9O33]9? units and dissociative, protonated pyridine-4-carboxylic acid molecules, which act as the charge compensation cations. The cyclic voltammogram of 2 shows an irreversible redox process for Mn3+ ions. 相似文献
13.
Ji-Wen Cui Yan Chen Hai-Hui Yu Jia-Ning Xu Wei-Jie Duan 《Journal of solid state chemistry》2009,182(7):1913-1920
Two new supramolecular compounds based on tungsten-vanadium polyoxoanions formulated as [Cu(2,2′-bipy)3]2H14[PW2.2V9.8O40(VO)2[Cu(2,2′-bipy)2H2O]2][PW2.2V9.8O40(VO)2]·10H2O (1) and [Cu4(2,2′-bipy)4(H2O)2(PO4)2]H6.5[PW8.4V3.6O40]·2H2O (2) (2,2′-bipy=2,2′-bipyridine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compounds 1 and 2 exhibit novel 2D supramolecular layer structures constructed from tungsten-vanadium polyoxoanions and different types of secondary building units (SBUs), respectively, the different SBUs are formed by [Cu(2,2′-bipy)2H2O]2+ and [Cu(2,2′-bipy)3]2+ cations in compound 1 and [Cu4(2,2′-bipy)4(H2O)2(PO4)2]2+ cations in 2, respectively. Study of magnetic properties indicated the presence of antiferromagnetic behaviors for both compound 1 and 2. 相似文献
14.
Zhi-hong Xu Pin-xian Xi Feng-juan Chen Zheng-zhi Zeng 《Transition Metal Chemistry》2008,33(2):237-241
A novel organic–inorganic hybrid tungstotellurate [Na(H2O)3]2[{Cu(2,2′-bipy)2}2(TeW6O24)] · 4H2O, has been synthesized and characterized by elemental analyses, IR spectra, TG analyses, and single-crystal X-ray diffraction.
The saturated Anderson-type polyoxoanions are covalently bonded with two [Cu(2,2′-bipy)2]2+, and linked by Na+ into an infinite one-dimensional chain. Furthermore, the three-dimensional supramolecular architectures are formed by π–π
stacking interactions of the 2,2′-bipyridine groups between adjacent layers and the hydrogen-bonding interactions respectively. 相似文献
15.
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16.
Cai-Hong Zhan Xiao-Juan Wang Zhan-Guo Jiang Ling-Xian Chen Yun-Long Feng 《Structural chemistry》2010,21(6):1195-1201
Abstract
p-Thioacetatebenzoic acid (H2L) and a combination of N-donor ligand of 4,4′-bipyridine (4,4′-bipy) with metal(II) ions give rise to three 3D supramolecules of general formula [M(HL)2(4,4′-bipy)2(H2O)2] · H2O, M = CoII (1), ZnII (2), NiII (3), which were characterized by crystallographic methods. The crystals are isostructural and belong to the triclinic P[`1] P\bar{1} space group. The structure can be considered to construct from 1D chains and further linked by hydrogen bonds into the final 3D supramolecular networks. The electrochemical behavior of complexes 1 and 3 were studied by cyclic voltammetry, indicating that the electron transfers in the electrode reaction are irreversible. Meanwhile, complex 2 exhibits significantly red-shifted emission in solid state at room temperature. 相似文献17.
Abstract
Four complexes of 3,3-diphenylpropanoate (L) and 4,4′-bipyridine as auxiliary bridging ligands were synthesized and characterized, namely [Zn(L)2(4bpy)(EtOH)2]∞ (1), [Co(L)2(4bpy)(EtOH)2]∞ (2), [Ni(L)2(4bpy)(EtOH)2]∞ (3), and [Cu(L)2(4bpy)(H2O)]∞ (4) (4bpy = 4,4′-bipyridine). X-ray single-crystal diffraction analyses show that complexes 1–4 all take one-dimensional (1D) fishbone-like structures incorporating bridging 4bpy ligands. The complexes show different supramolecular frameworks interlinked via intermolecular hydrogen bonds, π···π stacking, and/or C–H···π supramolecular interactions. Complex 3 only has a simple one-dimensional fishbone-like chain, whereas complexes 1 and 2 show two-dimensional supramolecular structures by interchain C–H···O hydrogen bonds. Complex 4 is assembled into two-dimensional layers and then an overall three-dimensional framework by a combination of interchain O–H···O hydrogen bonds and C–H···π supramolecular interactions. The luminescent properties of the ligands and their complexes were investigated. 相似文献18.
Two new Ni(II) coordination polymers, namely [Ni3(Hsdac)2(sdac)2(2,2′-bipy)2] (1) and [Ni2(sdac)2(4,4′-bipy)2]·2H2O (2) (sdba = 4,4′-sulfonyldibenzoate, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction analyses. Compound 1 possesses an interesting chain structure. Adjacent chains are further linked through H-bond interactions between Hsdac ligands to give a two-dimensional (2D) supramolecular architecture. Compound 2 displays an unusual 2D polyrotaxane-like network. 相似文献
19.
A series of new oxo-vanadium(IV) complexes, [VOCl0.69(OH)0.31 (2,2′-bipy)2]Cl·2H2O (1, 2,2′-bipy?=?2,2′-bipyridine) [(VO)2Cl4(4,4'-bipy)3 (H2O)2] (2, 4,4'-bipy?=?4,4'-bipyridine), [VO(ida)(H2O)]n (3, H2ida?=?iminodiacetic acid), and [(VO)2(oa)4]n·4n(H3O)·n(H2O) (4, H2oa?=?oxalic acid), have been synthesized and structurally characterized. 1 contains a [VOCl0.69(OH)0.31(2,2′-bipy)2]+ cation, Cl – anion and two free H2O molecules. 2 exhibits a binuclear centrosymmetric moiety built up from two [VOCl2(4,4'-bipy)(H2O)] units and one bridging 4,4'-bipy ligand, which provides a rare example of a 4,4'-bipy molecule acting as monodentate ligand. 3 displays a neutral chain [VO(ida)(H2O)]n constructed by the linkages of [VO(H2O)]2+ units and ida2? bridging ligands, while 4 offers the only example of three kinds of oa2- ligands coexisting within the same anionic chain [(VO)2(oa)44-]n. Their spectroscopic properties were investigated, and the magnetic susceptibility of 4 shows antiferromagnetic behavior. 相似文献
20.
Ying Ma Yangguang Li Enbo Wang Ying Lu Cao Qin Xinxin Xu 《Journal of Cluster Science》2006,17(2):167-181
Two new materials built from reduced molybdenum (V) phosphates as building blocks and zinc coordination complexes as linkers, (H3O)2[Zn(2,2′-bpy)]4[Zn(H2O)]2[Zn(HPO4)2 (PO4)6(MoO2)12(OH)6] · 6H2O (2,2′-bpy=2,2′-bpyridine) 1 and [Zn(phen)(H2O)2]2[Zn(phen) (H2O)]2[Zn(H2O)]2[Zn(HPO4)4 (PO4)4(MoO2)12 (OH)6] · 7H2O (phen=1,10-phenanthroline) 2, have been synthesized and characterized by elemental analyses, IR, TG, and single crystal X-ray diffraction. Compound 1 is a new 3-D structure which constructed from Zn[P4Mo6]2 dimers bonded together with [Zn(2,2′-bpy)] coordination complexes and [Zn(H2O)] fragments. In compound 2, the Zn[P4Mo6]2 dimeric units are linked by [Zn(phen)(H2O)] coordination complexes and [Zn(H2O)] fragments to form a new 2-D framework. The fluorescent activities of compounds 1 and 2 were reported. The crystal data for the two compounds are the following: 1, triclinic, P−1, a=13.036(3) ?, b=13.765(3) ?, c=14.459(3) ?,
, Z=1; 2, triclinic, P−1, a=12.708(3) ?, b=14.016(3) ?, c=14.646(3) ?,
, Z=1.Dedicated to Professor Michael T. Pope on the occasion of his retirement. 相似文献