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 15 毫秒
1.
A new copper(II) complex Cu2(L)a(2,2'-bipy)2(H2O)2 (1) has been synthesized with 2-benzoylbenzoic acid (HL) and 2,2'-bipyridin as ligands. The crystal belongs to a monoclinic system with space group Cc, a = 13.9979(II), b = 15.9888(13), c = 30.306(3) A, β = 100.8700(10)°, V= 6661.1(10) A3, Dc= 1.372 g/cm3, Z = 8, F(000) = 2840, the final GOOF = 1.018, R= 0.0685, and wR= 0.1731. There are two mononuclear Cu(L)2(2,2'-bipy)(H20) units in the crystal of 1. Each Cu(II) cation is coordinated by five atoms. The magnetic and fluorescent properties of 1 were studied. The results show that 1 exhibits weak paramagnetism, and when the excitation wavelength is at 616 nm, it has an intense fluorescent emission band around 482 nm.  相似文献   

2.
Three new inorganic-organic composite polyoxotungstates [Cu(2,2'-bpy)2]5[α-PW11.5Cu0.5O40]·2H2O 1, [Co(2,2'-bpy)2(N3)2]4H3[α-PW12O40]·3H2O 2 and [Cu(2,2'-bpy)2(4,4'-bpy)]2[α-GeW12O40]-4H2O 3 (2,2'-bpy = 2,2'-bipyridine, 4,4'-bpy = 4,4'-bipyridine) have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the orthorhombic space group Pna21 with a = 27.847(3), b = 21.597(2), c = 20.1179(19)A, V= 12099(2)A^3, Z= 4, GOF= 1.038, R = 0.0427 and wR = 0.1035; 2 belongs to the triclinic space group P1^- with a = 12.31150(10), b = 16.1954(4), c = 19.36290(10)A, α = 99.366(11), β =105.168(8), γ = 111.836(8)°, V = 3309.98(9)A3, Z = l, GOF = 1.024, R = 0.0739 and wR = 0.2216; and 3 crystallizes in the monoclinic space group P21/n with a = 12.858(4), b = 20.943(6), c = 15.598(5)A, β = 102.338(5)°, V= 4103(2)A3, Z = 2, GOF = 1.026, R = 0.0557 and wR = 0.1316. The common structural features of 1-3 are that their molecular structures all consist of a saturated a-Keggin polyoxoanion and several discrete metal-organic moieties. Intriguingly, 2 and 3 are composed of metal-organic coordination moieties with two mixed ligands.  相似文献   

3.
Reactions of M(Ⅱ) acetate (M = Cu, Ni) with disodium 4,4'-biphenyldisulfonate (BPDS) and 2,2'-bipyridine (2,2'-bipy) yielded three new metal sulfonates formulated as {[Cu2(2,2'-bipy)2(H2O)(C2O4)(BPDS)]·2H2O}n 1, [Cu(2,2'-Bipy)(H2O)3](BPDS)'2H2O 2 and [Ni(2,2'-Bipy)(H2O)4](BPDS)·2.5H2O 3. These three compounds were characterized by elemental analyses, FT-IR spectra, TG-DTA analyses and single-crystal X-ray diffraction analyses. Compound 1 belongs to the monoclinic system, space group P21/c with a = 17.7942(2), b = 10.1369(10), c = 19.8681(3) A, β = 104.323(10)°, V = 3472.20(7)A3, Mr = 893.82, Z = 4, F(000) = 1824,μ(CuKa) = 3.295 mm-1, R = 0.0427 and wR = 0.1278. Compound 2 is of orthorhombic system, space group Pca21 with a = 20.1016(7), b = 7.2460(2), c = 17.4802(6)A, V= 2546.10(14)A3, Mr = 622.11, Z= 4, F(000) = 1284,μ (CuKα) = 3.314 mm-1, R = 0.0415 and wR = 0.1291. Compound 3 belongs to the monoclinic system, space group C2/c with a = 15.9204(5), b = 11.7511(4), c = 15.2559(4)A, β = 98.886(3)°, V = 2819.85(15)A3, Mr = 1288.60, Z = 2, F(000) = 1340,μ(CuKa) = 2.957 mm^-1, R = 0.0515 and wR = 0.1454. Compound 1 is composed of one-dimensional helical chains of [Cu2(2,2'-bipy)2(H2O)(C2O4)]2+ fragments bridged alternately by 4,4'-biphenyldisulfonate ligands, along the c axis of the unit cell. In compound 2, 4,4'-biphenyldisulfonate anions are arranged in a zigzag mode and interact with the lattice waters via hydrogen bonds resulting in the formation of infinite chains. Adjacent chains are linked by lattice waters to form 2D extended sheets. The complex cations are located in the interlayer regions and interact with the sheets through hydrogen bonds. In compound 3, the Ni center resides at a crystallographic inversion center and adopts a distorted octahedral coordination sphere. The complex cations interact with 4,4'-biphenyldisulfonate  相似文献   

4.
A new copper(II)-2,2'-biimidazole metal-organic POMs-supported compound [Cu(H2biim)2]{[Cu(H2biim)212[H10W12O44]}'8H2O (H2biim = 2,2'-biimidazole) has been success- fully synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and TG. The crystal adopts space group Pi with a = 11.800(2), b = 13.437(3), c = 13.685(3) A, V = 1922.5(7) A3, D,. = 3.507 g/cm3, C36H62Cu3N24W12O52, M,. = 4059.92, F(000) = 1837,μ = 18.796 mm-1, Z = 1, R = 0.0579 and wR = 0.1465 for 8734 observed reflections (I 〉 2σ(I)). X-ray crystallography analysis exhibits that the title compound consists of one [H10W12044]6- polyanion and three [Cu(H2biim)2] units. And significant π-π stacking interactions and intermolecular O-H-,.O or N-H.'-O hydrogen-bonding interactions lead to a three-dimensional supramolecular framework. Thermal stability and magnetic property of the complex have also been investigated.  相似文献   

5.
A novel hybrid tungstocuprate ( Ⅱ ) [ Cu (2,2'-bpy) 3 ] 2 H4 [ CuW12O40 ] · 6H2O ( 2,2'-bpy = 2,2'-bipyfidine) was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [ CuW12O40 ]^6- and a pair of chiral complex cations [ Cu(2,2'-bpy) 3 ]^+ together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [ Cu (2,2'-bpy)3 ]^+v/a multiple C-H…O hydrogen bonds resulting in a dimer.  相似文献   

6.
A new coordination polymer [Zn3(bpda)3(bpy)] 1 (H2bpda = 2,2'-biphenyldicar- boxylic acid, bpy = 4,4'-bipyridien) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, TG analysis and IR spectrum. 1 Crystallizes in cubic crystal system, space group Ia 3, with a = 20.9687(9) A, V = 9219.7(3) A^3, Z = 8, and R(I 〉 2σ(I)) = 0.0431. Complex 1 is a three-dimensional framework involving a new building block, linear trinuclear {Zn3(CO2)6N2} cluster. In the structure, each bpda coordinates to four zinc atoms via its two bridging bidentate carboxylate groups. To the best of our knowledge, 1 implies a new coordination mode of 2,2'-biphenyldicarboxylic acid. The solid state fluorescent spectra show a strong emission peak at 451 nm (λex= 341 nm).  相似文献   

7.
A novel composite, [C16H36N][Cu(2,2-bipy)3][PW12O40]·CH3CN·H2O based on Keggin-type phosphotungstate, has been synthesized in acetonitrile at moderate temperature and then characterized by IR and single-crystal X-ray structural analysis. The crystal is of monoclinic system, space group P21/n with a = 20.489(4), b = 17.249(3), c = 23.723(4)A, β = 95.114(2)^o, V = 8350(3)A3, Mr = 3710.79, Z = 4, Dc = 2.952 g/cm^3, F(000) = 6676, μ = 16.808 mm^-1, the final R = 0.0551 and wR = 0.1269 for 9460 observed reflections with I 〉 20(I). Interestingly, it is found that the structure unit contains two different cations of [C16H36N]^+ and [Cu(2,2-bipy)3]^2+.  相似文献   

8.
Two new cobalt(II) supramolecular complexes [Co(4,4'-bipy)2(H2O)4]·[Co2(4,4'-bipy)3(H2O)8]·2TST·2(4,4'-bipy)·4H2O 1 and [Co(4,4'-bipy)2(H2O)4]DSNT·4,4'-bipy 2 based upon the assembly of Co(II), 4,4'-bipyridine (4,4'-bipy) and two new multifunctional organic ligands, 2,4,6-tris(4-sulfophenyl- amino)-1,3,5-triazine (H3TST) and 2,4-bis(p-sulfanilato)-6-diethylamino-1,3,5-triazine (H2DSNT), have been prepared by hydrothermal method and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal structure of 1 is of monoclinic, space group P21/n with a = 13.599(4), b = 18.988(6), c = 22.995(7) A, β = 90.273(6)°, V = 5938(3)A^3, Z = 4, C56H59Co1.5N13O17S3, Mr = 1370.74, Dc = 1.533 g/cm^3, μ = 0.613 mm^-1, F(000) = 2842, GOOF = 1.018, the final R = 0.0796 and wR = 0.1498 for 9019 observed reflections with I 〉 2σ(I). The crystal structure of 2 belongs to the monoclinic system, space group C2/c with a = 18.864(6), b = 14.283(5), c = 20.246(7)A, β = 107.799(6)°, V = 5194(3)A^3, Z = 4, C49H52CoN12O10S2, Mr = 1092.08, Dc = 1.397 g/cm^3, μ = 0.480 mm^-1, F(000) = 2276, GOOF = 1.059, the final R = 0.0665 and wR = 0.1900 for 4887 observed reflections with I 〉 2σ(I). The results of X-ray crystal structure analysis revealed that complexes 1 and 2 exhibit layered supramolecular frameworks stabilized by electrostatic interactions, π-π interactions and hydrogen bonds.  相似文献   

9.
The complex [Cu2(H2dhbd)2(tpy)2]·CH3OH·4H2O 1 (H4dhbd =2,3-dihydroxybutanedioic acid, tpy = 2,2':6',2''-terpyridine) has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal is of triclinic, space groups Pi with a= 8.6859(17), b = 11.223(2), c = 12.275(2)A, α = 112.454(3), β= 98.435(3), γ = 105.593(3)°, V= 1022.5(3) A^3, Z = 1, C38H42Cu2N6O18, Mr = 997.86, Dc = 1.621 g/cm^3, μ= 1.127 mm^-1, F(000) = 514, T = 293(2) K, the final R = 0.0539 and wR = 0.1394 for 3550 observed reflections with I 〉 2σ(I). In the dinuclear unit, two Cun atoms are bridged by two H2dhbd chelate anions, forming a 14-membered ring, in which the distance of Cu…Cu atoms is 7.0526(12)A. Adjacent dinuclear units are constituted through π-π interactions and C-H…O hydrogen-bonding interactions, fashioning the final 3-D supramolecular framework with 1-D open channels. Variable-temperature magnetic susceptibility measurement indicates the presence of weak antiferromagnetic exchange interactions between Cu^II ions.  相似文献   

10.
The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757(4), b = 10.663(6), c = 11.727(7)A, α = 94.272(4), β = 104.067(7), γ = 97.400(7)°, V= 927.4(9)A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F(000) = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ(I). The central Cu(II) ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.  相似文献   

11.
A metal-organic coordination compound formulated as [Cd(pzdc)(2,2'-bipy)]n·nH2O 1 (Hzpzdc = pyrazine-2,3-dicarboxylic acid, 2,2'-bipy = 2,2'-bipyridine) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TG fluorescence spectrum and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group P2 1/c with a = 10.8081(13), b = 14.4328(17), c = 10.2530(12) A, β = 98.504(2)°, V= 1581.8(3) ]A3, C16H14CdN4O5, Mr= 454.71, Dc = 1.909 g/cm^3, μ(MoKa) = 1.420 mm^-1, F(000) = 904, Z = 4, the final R = 0.0230 and wR = 0.0554 for 2901 observed reflections (I 〉 2σ(I)). It exhibits an interesting two-dimensional network structure and shows yellow photoluminescent property at room temperature.  相似文献   

12.
A new cadmium(N) compound, {[ CdLu-(4,4'-dps) ]2(H2O)2]'(4'abs )2(H2O)2n 1 (4,4'-dps = 4,4'-dipyridylsulfide, 4-abs = deprotonated 4-amino benzenesulfonic acid), has been synthesized and structurally characterized. It belongs to the orthorhombic system, space group Pbcn with a = 19.950(3), b = 10.6381(13), c = 18.055(2)A, V= 3831.8(8) A3, Z = 4, C32H36CdN6010S4, Mr = 905.31, F(000) = 1848, μ= 0.850 mm^-1, Dc = 1.569 Mg/m^3, the final R = 0.0238 and wR = 0.0589 for 3080 observed reflections with I 〉 2σ(I). Complex I is a one-dimensional linear chain coordination polymer and the repeat unit is comprised of doubly charged cadmium complex cation, uncoordinated 4-aminobenzene sulfonate anions and water molecules. The cadmium(H) ion adopts a six-coordinate distorted octahedral geometry. Complex 1 is stabilized and linked into a three-dimensional layered structure through intermolecular O-H…O and N-H…O hydrogen bonds together with electrostatic force. The cyclic voltammograms and fluorescence spectrum of 1 were also measured. It shows one irreversible redox process and emits a very strong and sharp fluorescent band at about 341 nm.  相似文献   

13.
Compounds [Zn(2,2'-bipy)(L)Cl]2 1 and [Zn(phen)(L2)]2 2 (2,2'-bipy = 2,2'-bipyridine, HL = 3-methylbenzoic acid, phen = 1,10-phenanthroline) have been synthesized under hydrothermal conditions. 1: monoclinic, space group C2/c, a = 20.240(4), b = 9.2960(19), c = 17.904(4)A, β = 92.63(3)°, V = 3365.1(12) A^3, C36H30Cl2N4O4Zn2, Mr = 784.32, Z = 4, Dc = 1.548 g/cm^3, μ = 1.631 mm^-1, F(000) = 1600, the final R = 0.0367 and wR = 0.1289 for 3867 observed reflections (I 〉 2σ(I)). 2: monoclinic, space group C2/c, a = 23.035(5), b = 9.0395(18), c = 23.799(5) A, β = 98.55(3)°, V = 4900.6(17)A^3, C56H44N4O8Zn2, Mr = 1031.73, Z = 4, Dc = 1.398 g/cm^3, μ = 1.039 mm^-1, F(000) = 2128, the final R = 0.0540 and wR = 0.1287 for 5002 observed reflections (I 〉 2σ(I)). The two compounds have the same space group and similar isolated dinuclear structure, but different space packing structures are formed by different weak intermolecular interactions. Mo- reover, IR and luminescence spectra are also employed to study the crystal structures and pro- perties of these two compounds.  相似文献   

14.
The novel mixed-ligand neutral compound [Mo3O4(C2O4)2bipy-(H2O)3]·EtOH·2H2O(bipy = 2,2′-bipyridine) has been prepared by the reaction of oxalic acid elution of Mo(IV) and bipy, and characterized by single-crystal X-ray diffraction analysis and IR. The crystal is of triclinic, space groups P1^- with a = 9.5520(2), b = 10.3730(1), c = 13.5722(2)A, a = 74.940(12),β = 80.772(14),γ= 69.898(11)°, V = 1215.73(11)A^3, Z = 2, C16H24Mo3N2O18, Mr = 820.19, Dc = 2.241 g/cm^3,μ = 1.616 mm^-1, F(000) = 808, T = 293(2) K, the final R = 0.0424 and wR = 0.0939 for 4119 observed reflections with I 〉 2σ(I). The trinuclear unit is coordinated by mixed ligands of oxalate and bipy. The intermolecular hydrogen bonding interactions among adjacent [Mo3O4(C2O4)2·bipy(H2O)3] extend the compound into a three-dimensional supramolecular framework. The uncoordinated water molecules and ethal molecules act as space-fillers and consolidate the whole architecture through hydrogen bonding interactions.  相似文献   

15.
李兵  郑寿添  杨国昱 《结构化学》2009,28(5):531-536
Two new hybrid polyoxotungstates, [Co(2,2'-bipy)3][a-H5PW11CoO40]-3H2O 1 and [Fe(2,2'-bipy)3]2[a-HBW12O40]-2.5H2O 2 (2,2'-bipy = 2,2'-dipyridyl), have been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray structural analyses. The results of X-ray crystallography analyses exhibit that 1 consists of one a-Keggin anion [a-H5PW11CoO40]2- and one isolated [Co(2,2'-bipy)3]2+ complex, while 2 is constructed from one a-Keggin anion [a- HBW12O40]4- and two isolated [Fe(2,2'-bipy)3]2+ cations. The data for 1: orthorhombic system, space group Pbcn, a = 16.062(6), b = 27.278(10), c = 16.951(6)A, V = 7427(5)A3 and Z = 4; and those for 2: triclinic system, space group P1, a = 13.787(3), b = 17.857(5), c = 18.918(5)A, a = 88.009(12), β = 72.768(10), γ = 74.935(10)°, V = 4291(2)A3 and Z = 2.  相似文献   

16.
The title compound [Cu2(μ2-dppm)2(MeCN)2(μ2-MeCN)](ClO4)2·MeCN (dppm = bis(diphenylphosphino)methane) has been prepared and characterized. It crystallizes in the monoclinic system,space group P21/n,with a = 11.904(6),b = 20.755(11),c = 24.744(13)A,β = 98.226(12)°,C58H56Cl2Cu2N4O8P4,Mr = 1258.93,V = 6051(5) A^3,Z = 4,Dc = 1.382 g/cm^3,μ = 9.52 mm^-1,F(000) = 2592,R = 0.0533 and wR = 0.1295 for 6175 observed reflections with I 〉 2σ(I). Each Cu(I) center is tetrahedrally coordinated by two phosphine atoms from two bridging dppm ligands,one nitrogen atom from a terminally coordinated acetonitrile molecule,and another nitrogen atom from a μ2-acetonitrile molecule. The two Cu(I) centers are bridged by two dppm ligands as well as a unique acetonitrile molecule. The full molecule exhibits a 'chair-like' configuration. This dinuclear complex exhibits intense or middle photoluminescence at room temperature in the solid state or actonitrile solution at 486 nm.  相似文献   

17.
The copper(II) compound [Cu(Brzhama)(DMF)]2 (C22H24Br4Cu2N4O10S2, Br2hamaH2 = [(3,5-dibromo-2-hydroxybenzylidene)-amino]-methanesulfonic acid, DMF = N,N'-dimethylformamide) 1 crystallizes in trictinic, space group P1 with a = 8.477(2), b = 10.164(2), c = 10.671(2)A, α= 112.66(3), β = 104.33(3), γ = 96.67(3)°, Z = 1, and R = 0.0789 for 1823 observed reflections with I 〉 2σ(I). The centrosymmetric molecule comprises a pair of copper atoms connected by two anions of [(3,5-dibromo-2-hydroxybenzylidene)-amino]-methanesulfonic acid in a tetradentate coordination mode. The five-coordination of copper(II) is further completed by DME The complex forms a 1-D chain through C-H…π hydrogen bonds. The Cu^II…Cu^II distance is 4.937(1) A.  相似文献   

18.
A new copper(H) complex [Cu2(DMF)(H2O)(C7H4NO4)2(C7H3NO4)]2-3.5DMF has been synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P1^- with a = 10.722(3), b = 18.170(4), c = 20.923(7)A,α = 105.297(9), β = 101.701(10), γ = 105.74(1)°, V= 3615(1)A^3, Z = 2, C58.50H64.50Cu4N1l.50O3150, Mr = 1686.90, Dc = 1.550 g/cm^3,μ= 1.255 mm^-1, F(000) = 1728.00, T = 150(2) K, the final R = 0.0640 and wR = 0.173 for 11310 observed reflections with I 〉 2σ(I). In the crystal, each formular unit consists of two dinuclear copper(H) compounds, between which the O-H…O hydrogen bonds exist. Each Cu^Ⅱ cation is six-coordinated in an octahedral geometry. The intermolecular hydrogenbonding interaction leads to a 3-D framework of the title compound.  相似文献   

19.
An organic-inorganic compound [Cu(2,2'-bpy)2][{Cu(2,2'-bpy)2}2W12O4o(H2)]·4H2O (Mr = 4048.00) was prepared from the hydrothermal reaction of Na2WO4·2H2O, CuCl2·2H2O,2,2'-bipyridine (2,2'-bpy) and H2O at 160 ℃ for 4 days. The compound crystallizes in the monoclinic system, space group P21/n with a = 18.9196(8), b = 20.4212(8), c = 21.8129(9)(A), β=96.992(3)°, V= 8365.0(6) (A)3, Dc= 3.214 g/cm3, Z = 4,μ(MoKα) = 17.269 mm-1 and F(000) = 7324.Of the 119837 total reflections, 17315 were unique (Rint = 0.0489). The final R = 0.0385 and wR =0.0770 for 11142 observed reflections with I > 2σ(I). Single-crystal X-ray diffraction reveals that the structure is composed of [{Cu(2,2'-bpy)2}2W12O40(H2)]2- anions, discrete [Cu(2,2'-bpy)2]2 cations and lattice water molecules, and the anion is made up of a {W12O40(H2)}6- α-Keggin core decorated with two {Cu(2,2'-bpy)2}2 groups through bridging oxygen atoms.  相似文献   

20.
The complex [Eu(3-IBA)3·2,2'-bipy]2 was synthesized from 3-iodobenzoic acid (3-HIBA), 2,2'-bipyridine (2,2‘-bipy) and EuCl3·6H2O by hydrothermal synthesis, and its crystal structure was determined by X-ray single-crystal diffraction. It is of triclinic, space group Pi, with a = 10.958(2), b = 12.311(3), c = 12.556(3) A, α = 81.549(3), β = 82.404(4), γ = 78.348(3)°, Mr = 1049.15, V= 1631.7(6) A3, Z = 1, Dc = 2.135 g/cm^3, F(000) = 980, 2(MoKa) = 0.71073 A,μ(MoKa) = 4.804 mm^-1, the final R = 0.0329 and wR = 0.0723 for 4640 observed reflections with I 〉 2σ(I). The Eu(Ⅲ) ion is eight-coordinated and two Eu(Ⅲ) ions are held together by four 3-iodobenzoate groups in the bidentate bridging mode. The complex was characterized by DTA-TG, IR, UV and fluorescence spectra.  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