An experimental measurement was performed us- ing time-resolved particle image velocimetry (TRPIV) to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer ad...An experimental measurement was performed us- ing time-resolved particle image velocimetry (TRPIV) to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer additive solu- tion. The fully developed near-wall turbulent flow fields with and without polymer additives at the same Reynolds number were measured by TRPIV in a water channel. The compar- isons of turbulent statistics confirm that due to viscoelastic structure of long-chain polymers, the wall-normal velocity fluctuation and Reynolds shear stress in the near-wall region are suppressed significantly. Furthermore, it is noted that such a behavior of polymers is closely related to the decease of the motion of the second and forth quadrants, i.e., the ejection and sweep events, in the near-wall region. The spa- tial topological mode of coherent structures during bursts has been extracted by the new mu-level criteria based on locally averaged velocity structure function. Although the general shapes of coherent structures are unchanged by polymer additives, the fluctuating velocity, velocity gradient, velocity strain rate and vorticity of coherent structures during burst events are suppressed in the polymer additive solution com- pared with that in water. The results show that due to the polymer additives the occurrence and intensity of coherent structures are suppressed, leading to drag reduction.展开更多
Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-((pyridin-3-ylmethyl)thio)-5-(6-quinolinyl)-1,3,4-oxadiazole(L),obtained by the condensation reaction of 5-(6-quinolinyl)-1,3,4-...Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-((pyridin-3-ylmethyl)thio)-5-(6-quinolinyl)-1,3,4-oxadiazole(L),obtained by the condensation reaction of 5-(6-quinolinyl)-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2(CF_3SO_3)_2](I) and a coordination polymer [Ag L(PF_6)]_n(Ⅱ),respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.展开更多
In order to perform a study on the structural modulation in the Cd(Ⅱ)-L architecture(HL =(E)-2-[2-(3-pyridyl)ethenyl]-8-hydroxyquinoline), two different dicarboxylic acids, namely, 2-aminoterephthalic acid(H...In order to perform a study on the structural modulation in the Cd(Ⅱ)-L architecture(HL =(E)-2-[2-(3-pyridyl)ethenyl]-8-hydroxyquinoline), two different dicarboxylic acids, namely, 2-aminoterephthalic acid(H_2ATA) and 4,4¢-biphenyldicarboxylic acid(H_2BPDC), are employed as the secondary auxiliary ligands. Two new complexes [Cd_2L_2(ATA)](1) and [Cd_2L_2(BPDC)·2MeO H· 4H_2O](2) with distinct 3D frameworks were obtained. In complex 1, ligands ATA bridge the 1D Cd(Ⅱ)-L infinite chains into a 3D polymeric coordination network. Complex 2 is a 3D porous framework, in which adjacent 2D Cd(Ⅱ)-L coordination layers were linked together by the coor- dinated BPDC ligands. The variant structures of two complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. In addition, the photoluminescent properties(fluorescent emission, lifetime, and quantum yield) of polymers 1 and 2 were also investigated in the solid state.展开更多
The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y(N(Si Me3)2)3 with one equivalent of H3bptd(H3bptd = 1,9-bis(2-pyrrolyl)-2,...The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y(N(Si Me3)2)3 with one equivalent of H3bptd(H3bptd = 1,9-bis(2-pyrrolyl)-2,5,8-triazanona-1,8-diene) in THF gave a complex of composition [Y(bptd)(THF)]2(1). Reaction of Y(N(Si Me3)2)3 with one equivalent of H3tpa(H3tpa = tris(pyrrolyl-α-methyl)amine) in THF generated [Y(tpa)(THF)3](2) in good yield. Complexes 1and 2 have been characterized by single-crystal X-ray diffraction, elemental analyses and NMR spectroscopy. Complex 1 is dinuclear. The two metal centers are doubly bridged by two amine nitrogen atoms to form a Y–N–Y–N four-membered rhombus ring. The geometries of Y^3+ ions in 1and 2 are well described as pentagonal bipyramid and capped octahedron, respectively. The ring-opening polymerization reactions of ε-caprolactone initiated by 1 and 2, respectively, were investigated. They both exhibited good catalytic activity for the polymerization of ε-caprolactone. All of the obtained polymers have high molecular weights and relatively narrower PDIs. The polymers generated by 2 possessed polydispersity close to 1.1. The good catalytic activities of 1 and 2 reveal their potential applications in polymer industry.展开更多
Reaction of (NH_4)_2MoS_4 with AgI in α-MePy gives the title com- pound,an X-ray analysis of which shows that the molecule forms a one-dimensional polymeric chain with continuous metal-metal bonds.
A novel tetrazylphosphonate ligand, namely ethyl 4-(2-ethyl-2H-1,2,3,4-tetrazol-5-yl) benzylphosphonate(Et-L), was designed and successfully achieved from p-cyano benzyl chloride, based on which a zinc coordinatio...A novel tetrazylphosphonate ligand, namely ethyl 4-(2-ethyl-2H-1,2,3,4-tetrazol-5-yl) benzylphosphonate(Et-L), was designed and successfully achieved from p-cyano benzyl chloride, based on which a zinc coordination polymer(1) with a 2D layer structure has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TGA and X-ray single-crystal diffraction. The colorless block crystals of H_2L·H_2O were also obtained under the same hydrothermal conditions, which belongs to monoclinic system, space group P2_1/c with a = 13.3141(7), b = 5.1650(3), c = 21.9839(18) A, β = 115.307(5)°, V = 1366.69(15)A3, Z = 4, D_c = 1.391 mg/cm^(-3), Mr = 349.58, F(000) = 600, R = 0.0748 and wR = 0.1917 for 2392 observed reflections(I 〉 2σ(I)). The colorless block crystals of complex 1([Zn(L)(H_2O)]_n) also belong to monoclinic system, space group P2_1/c with a = 22.7464(10), b = 6.0430(3), c = 9.7704(4) ?, β = 92.525(4)°, V = 1341.70(10)A3, Z = 4, D_c = 1.731 mg/cm_(-3), M_r = 349.58, F(000) = 712, R = 0.0596 and wR = 0.1688 for 2357 observed reflections(I 〉 2σ(I)). Only the oxygen atoms of phosphonic group are coordinated with the metal zinc probably because the hydrogen atom of tetrazole has been substituted by ethyl group. Photoluminescence properties of the complex are also investigated.展开更多
Two new coordination polymers containing rigid bis(triazole), namely, [Ni(btb)_(0.5)(nph)(H_2O)]_n(1) and [Zn(btb)(SO_4)]_n(2)(btb = 4,4a-bis(1,2,4-triazolyl-1-yl)-biphenyl, H_2nph = 3-nitrophthal...Two new coordination polymers containing rigid bis(triazole), namely, [Ni(btb)_(0.5)(nph)(H_2O)]_n(1) and [Zn(btb)(SO_4)]_n(2)(btb = 4,4a-bis(1,2,4-triazolyl-1-yl)-biphenyl, H_2nph = 3-nitrophthalic acid) have been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a 3D trinodal(3,4,4)-connected sqc69 topology. Complex 2 presents a 2D uninodal 4-connected sql network, which is further packed into a 3D supramolecular framework by C-H···O hydrogen bonds. Thermal stabilities and fluorescence properties of two complexes have been discussed in detail.展开更多
Two mixed-ligand polymeric complexes formulated as {[Zn(pda)(bpy)]·0.5H2O}n (pda = 1,4-phenylenediacetate, bpy = 2,2'-bipyridine) 1 and {[Cd(pda)(bpy)]·1.5H2O}n 2 have been hydrothermally synthesi...Two mixed-ligand polymeric complexes formulated as {[Zn(pda)(bpy)]·0.5H2O}n (pda = 1,4-phenylenediacetate, bpy = 2,2'-bipyridine) 1 and {[Cd(pda)(bpy)]·1.5H2O}n 2 have been hydrothermally synthesized. Single-crystal X-ray diffraction analyses reveal that the structures of complexes 1 and 2 possess similar one-dimensional zigzag chains. Crystal data for compound 1: monoclinic, space group P21/c, a = 15.965(2), b = 8.305(1), c= 14.856(2) °A, β= 111.048(2)°, Mr = 422.73, V = 1838.2(4)°A^3, Z = 4, Dc = 1.528 g/cm^3, μ= 1.368 mm^-1, F(000) = 868, the final R = 0.0783 and wR = 0.1469 (w =1/[σ^2(Fo^2) + (0.0351P)^2+ 8.0014P], where P = (Fo^2 + 2Fc^2)/3) based on 2025 observed reflections with I〉 2σ(I); and those for compound 2: monoclinic, space group C2/c, a = 29.921 (7), b = 8.5400(17), c = 15.320(3) °A,β= 99.59(3)°, Mr = 487.75, V = 3859.9(14) °A^3, Z = 8, Dc = 1.668 g/cm^3, μ= 1.169 mm^-1, F(000) = 1936, the final R = 0.0723 and wR = 0.1612 (w = 1/[σ^2(Fo^2) + (0.0681P)^2 + 55.9577P], where P = (Fo^2 + 2Fc^2)/3) based on 2130 observed reflections with I〉 2σ(I). Fluorescent analyses show that both complexes exhibit intense blue luminescence (λmax = 485 nm for 1 and 475 nm for 2) upon excitation at 330 nm.展开更多
A new coordination polymer, [Zn2(m-bix)(p-bdc)2] (1), was synthesized under hydrothermal conditions by a reaction of 1,3-bis(imidazol-l-ylmethyl)benzene (m-bix), 1,3-benzene- dicarboxylic acid (H2p-bdc) an...A new coordination polymer, [Zn2(m-bix)(p-bdc)2] (1), was synthesized under hydrothermal conditions by a reaction of 1,3-bis(imidazol-l-ylmethyl)benzene (m-bix), 1,3-benzene- dicarboxylic acid (H2p-bdc) and Zn(NO3)2. The colorless block crystals of complex 1 (C30H22N408Zn2) belong to the triclinic system, space group P1 with a = 10.213(2), b = 12.052(2), c = 12.392(3) A, a = 82.97(3), β = 76.04(3), y = 78.02(3)°, V= 1443.8(5) A3, Z = 2, Dc = 1.604 g/cm3, Mr = 697.26, F(000) = 708, R = 0.0403 and wR = 0.0907 for 4886 observed reflections (1 〉 2σ(I)). In 1, the tetrahedral Zn11 cations are linked by [p-bdc]2- anions into 2D sql networks, which are further connected by bix ligands forming an interesting 2-fold 4,4-connected mog-type 3D network with a point symbol of {4·6^4·8}^2{4^2·6^2·8^2}. Complex 1 was characterized by elemental, IR spectroscopy, powder X-ray diffractions and thermalgravimetric analysis. In addition, complex 1 exhibits coordination induced photoluminescent property.展开更多
In this work, we synthesized a new two-dimensional Cd(Ⅱ) coordination polymer, [Cd(1,4-NDC)(L)](1), by using mixed 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) and typical chelating N-donor ligands 2-(2-chl...In this work, we synthesized a new two-dimensional Cd(Ⅱ) coordination polymer, [Cd(1,4-NDC)(L)](1), by using mixed 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) and typical chelating N-donor ligands 2-(2-chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline ligand(L). Compound 1 crystallizes in monoclinic, space group P21/n with a = 12.936(5), b = 15.245(5), c = 13.499(5) ?, β = 105.456(5)o, V = 2565.9(16) A^3, Z = 4, C(31)H(16)CdClFN4O4, Mr = 675.33, Dc = 1.748 g/cm^3, F(000) = 1344, μ(MoKa) = 1.011 mm^-1, R = 0.0350 and wR = 0.0926. In 1, each 1,4-NDC anion bridges three adjacent Cd(Ⅱ) atoms to give a two-dimensional layer structure. The L ligands are attached on both sides of the layer in chelating coordination modes. In addition, the N–H···O hydrogen bond between L and 1,4-NDC further stabilizes the layer structure of 1. Moreover, the solid state luminescent property of 1 was also investigated at room temperature.展开更多
The reaction of flexible bis(imidazole) ligand and 1,2-bis(imidazol-l'-yl)methane (bimm) with Co(Ⅱ) salt under ionothermal method resulted in the formation of a new coordination polymer {[Co(bimm)3]·...The reaction of flexible bis(imidazole) ligand and 1,2-bis(imidazol-l'-yl)methane (bimm) with Co(Ⅱ) salt under ionothermal method resulted in the formation of a new coordination polymer {[Co(bimm)3]·(PF6)2}n (1). X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647(6), b = 12.092(9), c = 14.967(1 l) A, α = 88.912(8), β = 81.199(8), ), = 89.395(8)°, V= 1546 (2) A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F(000) = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ(I). In compound 1, the Co(lI) ion is connected to another Co(ll) by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.展开更多
5-(Hydroxymethyl) isophthalic acid (H2HIA) as a novel organic ligand was prepared from 3,5-bis(methoxycarbonyl)benzoic acid by a two-step method. And then, a 3D helical coor- dination polymer with a 3-fold inter...5-(Hydroxymethyl) isophthalic acid (H2HIA) as a novel organic ligand was prepared from 3,5-bis(methoxycarbonyl)benzoic acid by a two-step method. And then, a 3D helical coor- dination polymer with a 3-fold interpenetration structure, namely [Zn1/2(HIA)1/2(DPEE)1/2]n (1), was hydrothermally synthesized at 160 ℃, using H2HIA ligands to assemble with DPEE ligands and Zn2+ ions. Complex 1 crystalizes in orthorhombic system, space group Pnna, with a = 8.2118(5), b = 17.1698(7), c =14.9922(7) ?, V = 2113.82(18) ?3, μ = 1.194 mm-1, Z = 4 and S = 0.967. Moreover, some physical characteristics of complex 1, such as powder X-ray diffraction (PXRD), thermogravimetry analyses (TGA) and photoluminescent properties, were also investigated.展开更多
A one-dimensional chain-like coordination polymer [Mn(phen)(2,4,6-TMBA)2(H2O)]n has been synthesized from 2,4,6-trimethylbenzoic acid, 1,10-phenanthroline and anhydrous manganese(Ⅱ ) sulfate and then characte...A one-dimensional chain-like coordination polymer [Mn(phen)(2,4,6-TMBA)2(H2O)]n has been synthesized from 2,4,6-trimethylbenzoic acid, 1,10-phenanthroline and anhydrous manganese(Ⅱ ) sulfate and then characterized. Crystal data for this complex: tetragonal, space group I41, a = 2.05643(16), b = 2.05643(16), c = 1.3939(2) nm, V = 5.8946(11) nm^3, Mr = 579.54, Z = 8, Dc = 1.306 g/cm^3, μ(MoKα) = 0.490 mm^-1, F(000) = 2424, S = 0.985, the final R = 0.0411 and wR = 0.0950. The Flack factor is -0.01(2). The crystal structure shows that two neighboring man- ganese(Ⅱ ) ions are linked together by one bridge-chelating 2,4,6-trimethylbenzoic group, forming a one-dimensional chain structure. The manganese(Ⅱ ) ion is coordinated with two nitrogen atoms of one 1,10-phenanthroline, three oxygen atoms from three 2,4,6-trimethylbenzoic acids and one water oxygen atom, giving a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex was also investigated.展开更多
The ionothermal reaction of Zn(NO3)2·6H2O with 5-sulfoisophthalic acid monosodium salt(NaH2SIP) and 1,2,4-triazole in 1-ethyl-3-methylimidazolium tetrafluoroborate(EMIM-BF4) ionic liquid has afforded the co...The ionothermal reaction of Zn(NO3)2·6H2O with 5-sulfoisophthalic acid monosodium salt(NaH2SIP) and 1,2,4-triazole in 1-ethyl-3-methylimidazolium tetrafluoroborate(EMIM-BF4) ionic liquid has afforded the compound {(EMIM)[Zn(SIP)]}n(1).The Zn(Ⅱ) ions are linked by the carboxylate groups of SIP^3- ligands to give a two-dimensional layered structure featuring the centrosymmetric dinuclear Zn2(μ2-COO)2 units.The adjacent two-dimensional layers are further linked by the Zn-0 bonds between the Zn(Ⅱ) ions and the sulfonate O atoms to generate a three-dimensional anionic[Zn(SIP)]n^n- framework featuring one-dimensional open channels propagating along the a axis.The imidazolium cations[EMIM]^+ derived from ionic liquid act as extraframework charge-balancing species for the anionic[Zn(SIP)]n^n- framework and occupy the void space of the one-dimensional open channels.The rich ionic environments of the ionic liquid may be particularly helpful in the formation of the ionic compound 1.The roles of the ionic liquid in ionothermal synthesis and crystallization of the compound are briefly discussed.Furthermore,compound 1 displays a photoluminescent emission at 490 nm upon excitation at 406 nm.展开更多
A novel Cd(Ⅱ) coordination polymer with diacylhydrazide ligand N,N?-bis(3-methoxysalicyl)-2,6-pyridinedicarbohydrazide(H_6msphz),[Cd_2(H_2msphz)(Py)_4]_n(1,Py = pyridine) has been synthesized through sol...A novel Cd(Ⅱ) coordination polymer with diacylhydrazide ligand N,N?-bis(3-methoxysalicyl)-2,6-pyridinedicarbohydrazide(H_6msphz),[Cd_2(H_2msphz)(Py)_4]_n(1,Py = pyridine) has been synthesized through solvothermal reaction and structurally characterized by single-crystal X-ray diffraction,IR,TGA and PXRD investigations. It crystallizes in triclinic system,space group P1,with a = 11.0230(11),b = 11.7264(15),c = 17.3395(14) ?,α = 70.520(9),β = 84.806(7),γ = 81.965(9)°,V = 2089.9(4) ?~3,Dc = 1.638 gcm^(–3),μ = 1.083 mm^(-1),F(000) = 1032,Z = 2 and S = 1.040. In complex 1,the H_2msphz4-ligand uses not only its coordinated pocket to catch one Cd(Ⅱ) ion,but also its two terminal groups to chelate other two Cd(Ⅱ) ions,leading to the formation of a chain structure. The adjacent chains are further assembled together by two kinds of π-π interactions between the Py rings,resulting in the finial double layered supramolecular structure. In addition,complex 1 is found to show photoluminescence in the solid state at room temperature,which can be ascribed to the intraligand π→π* transitions.展开更多
The pH /temperature dually responsive microgels of interpenetrating polymer network( IPN) structure composed of poly( N-isopropylacrylamide)( PNIPAM) network and poly( acrylic acid)( PAA) network( PNIPAM /PAA IPN micr...The pH /temperature dually responsive microgels of interpenetrating polymer network( IPN) structure composed of poly( N-isopropylacrylamide)( PNIPAM) network and poly( acrylic acid)( PAA) network( PNIPAM /PAA IPN microgels) were synthesized by seed emulsion polymerization. The results obtained by dynamic laser light scattering( DLLS) show that the microgels have good pH /temperature dual sensitivities. The temperature sensitive component and the pH sensitive component inside the microgels have little interference with each other. The rheological properties of the concentrated PNIPAM /PAA IPN microgel dispersions as a function of temperature at pH 4. 0 or 7. 0 were investigated by viscometer,and the results displayed that only at pH 7. 0 the dispersions presented thermoreversible thickening behavior. Then the PNIPAM /PAA fibers were prepared by self-assembly of the PNIPAM /PAA IPN microgels in the ice-crystal templates formed by unidirectional liquid nitrogen freezing method. Field emission scanning electron microscopy( FESEM) images indicate that the PNIPAM /PAA fibers are rounded,randomly orientated and interweaved.展开更多
A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f]...A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182(8), b = 11.3249(10), c = 12.7326(12) A, α = 77.897(2), β = 81.644(2), γ = 84.491(2)°, V = 1269.0(2) A^3, Z = 2, C_(27)H_(24)FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F(000) = 690, μ(MoKa) = 6.701 mm^(-1), R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb(Ⅱ) atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied.展开更多
The title complex bis{4-chloro-2-[(6-methyl-pyridin-2-ylimino)-methyl]-phenol}-palladium(Ⅱ)(C_(26)H_(20)Cl_2N_4O_2Pd) has been synthesized by the reaction of 4-chloro-2-[(6-methylpyridin- 2-ylimino)-methy...The title complex bis{4-chloro-2-[(6-methyl-pyridin-2-ylimino)-methyl]-phenol}-palladium(Ⅱ)(C_(26)H_(20)Cl_2N_4O_2Pd) has been synthesized by the reaction of 4-chloro-2-[(6-methylpyridin- 2-ylimino)-methyl]-phenol with Pd(CH_3COO)_2, and characterized by IR spectrum and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures. The crystal belongs to the monoclinic system, space group P2_1/c with a = 4.1324(2), b = 23.5432(16), c = 11.8943(8) A, β = 91.238(5)o, V = 1156.93(12) ?~3, C_(26)H_(20)Cl_2N_4O_2Pd, M_r = 597.76, Z = 2, D_c = 1.716 g/cm^3, μ = 1.067 mm^(-1), F(000) = 600, the final R = 0.0247 and w R = 0.0677(I 〉 2σ(I)). In the presence of methylaluminoxane(MAO), the complex exhibits excellent catalytic activities(1.737×10~7 g of PNB(mol of Pd)^(-1)·h^(-1)) in the vinyl polymerization of norbornene.展开更多
A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- ...A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-L)3/3]?H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.展开更多
Two novel copper complexes with methyl or trifluoro-substituted mono-β-diiminato ligands and one acetoxyl anion were synthesized and characterized by IR spectroscopy and elemental analysis for the first time. The str...Two novel copper complexes with methyl or trifluoro-substituted mono-β-diiminato ligands and one acetoxyl anion were synthesized and characterized by IR spectroscopy and elemental analysis for the first time. The structure of complex 2 bearing trifluoro substituents was further confirmed by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.377(4), b = 11.727(6), c = 12.913(7) ?, α = 116.569(6), β = 98.829(7), γ = 96.520(6)°, V = 966.2(8) ?3, Z = 2, Mr = 479.86, Dc = 1.649 g/cm3, F(000) = 482, μ = 1.205 mm-1, the final R = 0.0370 and w R = 0.0903 for 3430 observed reflections with I 〉 2σ(I). These mono-β-diiminato copper complexes can effectively catalyze methacrylate(MA) polymerization when activated by MMAO. The introduction of fluoro groups into the N-aryl ring of β-diiminato ligands can greatly increase the catalytic activity of copper complexes as well as the molecular weight of PMA.展开更多
基金supported by the National Natural Science Foundation of China(11272233)National Key Basic Research and Development Program(2012CB720101)2012 opening subjects of The State Key Laboratory of Nonlinear Mechanics(LNM),Institute of Mechanics,Chinese Academy of Sciences
文摘An experimental measurement was performed us- ing time-resolved particle image velocimetry (TRPIV) to in- vestigate the spatial topological character of coherent struc- tures in wall-bounded turbulence of polymer additive solu- tion. The fully developed near-wall turbulent flow fields with and without polymer additives at the same Reynolds number were measured by TRPIV in a water channel. The compar- isons of turbulent statistics confirm that due to viscoelastic structure of long-chain polymers, the wall-normal velocity fluctuation and Reynolds shear stress in the near-wall region are suppressed significantly. Furthermore, it is noted that such a behavior of polymers is closely related to the decease of the motion of the second and forth quadrants, i.e., the ejection and sweep events, in the near-wall region. The spa- tial topological mode of coherent structures during bursts has been extracted by the new mu-level criteria based on locally averaged velocity structure function. Although the general shapes of coherent structures are unchanged by polymer additives, the fluctuating velocity, velocity gradient, velocity strain rate and vorticity of coherent structures during burst events are suppressed in the polymer additive solution com- pared with that in water. The results show that due to the polymer additives the occurrence and intensity of coherent structures are suppressed, leading to drag reduction.
基金financially supported by the National Natural Science Foundation of China(No.21201112)
文摘Two new Ag~Ⅰ-complexes have been synthesized based on the semi-rigid ligand 2-((pyridin-3-ylmethyl)thio)-5-(6-quinolinyl)-1,3,4-oxadiazole(L),obtained by the condensation reaction of 5-(6-quinolinyl)-1,3,4-oxadiazole-2-thiol and 3-chloromethyl pyridine hydrochloride. Crystallization of L with Ag OTf and Ag PF_6 in a CH_2Cl_2/MeO H mixed solvent system at room temperature affords a novel supramolecular [Ag_2L_2(CF_3SO_3)_2](I) and a coordination polymer [Ag L(PF_6)]_n(Ⅱ),respectively. Two complexes were characterized by TGA,X-ray powder and single-crystal diffraction.
基金supported by the National Natural Science Foundation of China(No.21201002)the Foundation of State Key Laboratory of Structural Chemistry(20130016)+1 种基金Anhui Provincial Natural Science Foundation(1308085QB22)Training Programs of Innovation and Entrepreneurship for Undergraduates(201410360023 and 201410360157)
文摘In order to perform a study on the structural modulation in the Cd(Ⅱ)-L architecture(HL =(E)-2-[2-(3-pyridyl)ethenyl]-8-hydroxyquinoline), two different dicarboxylic acids, namely, 2-aminoterephthalic acid(H_2ATA) and 4,4¢-biphenyldicarboxylic acid(H_2BPDC), are employed as the secondary auxiliary ligands. Two new complexes [Cd_2L_2(ATA)](1) and [Cd_2L_2(BPDC)·2MeO H· 4H_2O](2) with distinct 3D frameworks were obtained. In complex 1, ligands ATA bridge the 1D Cd(Ⅱ)-L infinite chains into a 3D polymeric coordination network. Complex 2 is a 3D porous framework, in which adjacent 2D Cd(Ⅱ)-L coordination layers were linked together by the coor- dinated BPDC ligands. The variant structures of two complexes indicate that the skeleton of dicarboxylate anions plays a great role in the assembly of such different frameworks. In addition, the photoluminescent properties(fluorescent emission, lifetime, and quantum yield) of polymers 1 and 2 were also investigated in the solid state.
基金Supported by NNSFC(21272167)the Priority Academic Program Development of Jiangsu Higher Education Institution,and KLSLRC(KLSLRC-KF-13-HX-1)
文摘The syntheses, structures and catalytic activities of two yttrium complexes supported by pyrrolide ligands are reported. Treatment of Y(N(Si Me3)2)3 with one equivalent of H3bptd(H3bptd = 1,9-bis(2-pyrrolyl)-2,5,8-triazanona-1,8-diene) in THF gave a complex of composition [Y(bptd)(THF)]2(1). Reaction of Y(N(Si Me3)2)3 with one equivalent of H3tpa(H3tpa = tris(pyrrolyl-α-methyl)amine) in THF generated [Y(tpa)(THF)3](2) in good yield. Complexes 1and 2 have been characterized by single-crystal X-ray diffraction, elemental analyses and NMR spectroscopy. Complex 1 is dinuclear. The two metal centers are doubly bridged by two amine nitrogen atoms to form a Y–N–Y–N four-membered rhombus ring. The geometries of Y^3+ ions in 1and 2 are well described as pentagonal bipyramid and capped octahedron, respectively. The ring-opening polymerization reactions of ε-caprolactone initiated by 1 and 2, respectively, were investigated. They both exhibited good catalytic activity for the polymerization of ε-caprolactone. All of the obtained polymers have high molecular weights and relatively narrower PDIs. The polymers generated by 2 possessed polydispersity close to 1.1. The good catalytic activities of 1 and 2 reveal their potential applications in polymer industry.
文摘Reaction of (NH_4)_2MoS_4 with AgI in α-MePy gives the title com- pound,an X-ray analysis of which shows that the molecule forms a one-dimensional polymeric chain with continuous metal-metal bonds.
基金Support by National Natural Science Foundation of China(21371052)the Scientific Research Fund of Heilongjiang Provincial Education Department(12531512)
文摘A novel tetrazylphosphonate ligand, namely ethyl 4-(2-ethyl-2H-1,2,3,4-tetrazol-5-yl) benzylphosphonate(Et-L), was designed and successfully achieved from p-cyano benzyl chloride, based on which a zinc coordination polymer(1) with a 2D layer structure has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TGA and X-ray single-crystal diffraction. The colorless block crystals of H_2L·H_2O were also obtained under the same hydrothermal conditions, which belongs to monoclinic system, space group P2_1/c with a = 13.3141(7), b = 5.1650(3), c = 21.9839(18) A, β = 115.307(5)°, V = 1366.69(15)A3, Z = 4, D_c = 1.391 mg/cm^(-3), Mr = 349.58, F(000) = 600, R = 0.0748 and wR = 0.1917 for 2392 observed reflections(I 〉 2σ(I)). The colorless block crystals of complex 1([Zn(L)(H_2O)]_n) also belong to monoclinic system, space group P2_1/c with a = 22.7464(10), b = 6.0430(3), c = 9.7704(4) ?, β = 92.525(4)°, V = 1341.70(10)A3, Z = 4, D_c = 1.731 mg/cm_(-3), M_r = 349.58, F(000) = 712, R = 0.0596 and wR = 0.1688 for 2357 observed reflections(I 〉 2σ(I)). Only the oxygen atoms of phosphonic group are coordinated with the metal zinc probably because the hydrogen atom of tetrazole has been substituted by ethyl group. Photoluminescence properties of the complex are also investigated.
基金supported by the National Natural Science Foundation of China(No.51474086)Natural Science Foundation-Steel and Iron Foundation of Hebei Province(B2015209299)the Graduate Student Innovation Fund of North China University of Science and Technology(2015S13)
文摘Two new coordination polymers containing rigid bis(triazole), namely, [Ni(btb)_(0.5)(nph)(H_2O)]_n(1) and [Zn(btb)(SO_4)]_n(2)(btb = 4,4a-bis(1,2,4-triazolyl-1-yl)-biphenyl, H_2nph = 3-nitrophthalic acid) have been synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a 3D trinodal(3,4,4)-connected sqc69 topology. Complex 2 presents a 2D uninodal 4-connected sql network, which is further packed into a 3D supramolecular framework by C-H···O hydrogen bonds. Thermal stabilities and fluorescence properties of two complexes have been discussed in detail.
基金This work was supported by the National Natural Science Foundation of China (No. 20231020) and Natural Science Foundation of Fujian Province
文摘Two mixed-ligand polymeric complexes formulated as {[Zn(pda)(bpy)]·0.5H2O}n (pda = 1,4-phenylenediacetate, bpy = 2,2'-bipyridine) 1 and {[Cd(pda)(bpy)]·1.5H2O}n 2 have been hydrothermally synthesized. Single-crystal X-ray diffraction analyses reveal that the structures of complexes 1 and 2 possess similar one-dimensional zigzag chains. Crystal data for compound 1: monoclinic, space group P21/c, a = 15.965(2), b = 8.305(1), c= 14.856(2) °A, β= 111.048(2)°, Mr = 422.73, V = 1838.2(4)°A^3, Z = 4, Dc = 1.528 g/cm^3, μ= 1.368 mm^-1, F(000) = 868, the final R = 0.0783 and wR = 0.1469 (w =1/[σ^2(Fo^2) + (0.0351P)^2+ 8.0014P], where P = (Fo^2 + 2Fc^2)/3) based on 2025 observed reflections with I〉 2σ(I); and those for compound 2: monoclinic, space group C2/c, a = 29.921 (7), b = 8.5400(17), c = 15.320(3) °A,β= 99.59(3)°, Mr = 487.75, V = 3859.9(14) °A^3, Z = 8, Dc = 1.668 g/cm^3, μ= 1.169 mm^-1, F(000) = 1936, the final R = 0.0723 and wR = 0.1612 (w = 1/[σ^2(Fo^2) + (0.0681P)^2 + 55.9577P], where P = (Fo^2 + 2Fc^2)/3) based on 2130 observed reflections with I〉 2σ(I). Fluorescent analyses show that both complexes exhibit intense blue luminescence (λmax = 485 nm for 1 and 475 nm for 2) upon excitation at 330 nm.
基金Support by the National Natural Science Foundation of China(21371052)
文摘A new coordination polymer, [Zn2(m-bix)(p-bdc)2] (1), was synthesized under hydrothermal conditions by a reaction of 1,3-bis(imidazol-l-ylmethyl)benzene (m-bix), 1,3-benzene- dicarboxylic acid (H2p-bdc) and Zn(NO3)2. The colorless block crystals of complex 1 (C30H22N408Zn2) belong to the triclinic system, space group P1 with a = 10.213(2), b = 12.052(2), c = 12.392(3) A, a = 82.97(3), β = 76.04(3), y = 78.02(3)°, V= 1443.8(5) A3, Z = 2, Dc = 1.604 g/cm3, Mr = 697.26, F(000) = 708, R = 0.0403 and wR = 0.0907 for 4886 observed reflections (1 〉 2σ(I)). In 1, the tetrahedral Zn11 cations are linked by [p-bdc]2- anions into 2D sql networks, which are further connected by bix ligands forming an interesting 2-fold 4,4-connected mog-type 3D network with a point symbol of {4·6^4·8}^2{4^2·6^2·8^2}. Complex 1 was characterized by elemental, IR spectroscopy, powder X-ray diffractions and thermalgravimetric analysis. In addition, complex 1 exhibits coordination induced photoluminescent property.
基金Supported by Science and Technology Development Projects of Jilin Province(No.20150101007JC)
文摘In this work, we synthesized a new two-dimensional Cd(Ⅱ) coordination polymer, [Cd(1,4-NDC)(L)](1), by using mixed 1,4-naphthalenedicarboxylic acid(1,4-H2NDC) and typical chelating N-donor ligands 2-(2-chloro-6-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline ligand(L). Compound 1 crystallizes in monoclinic, space group P21/n with a = 12.936(5), b = 15.245(5), c = 13.499(5) ?, β = 105.456(5)o, V = 2565.9(16) A^3, Z = 4, C(31)H(16)CdClFN4O4, Mr = 675.33, Dc = 1.748 g/cm^3, F(000) = 1344, μ(MoKa) = 1.011 mm^-1, R = 0.0350 and wR = 0.0926. In 1, each 1,4-NDC anion bridges three adjacent Cd(Ⅱ) atoms to give a two-dimensional layer structure. The L ligands are attached on both sides of the layer in chelating coordination modes. In addition, the N–H···O hydrogen bond between L and 1,4-NDC further stabilizes the layer structure of 1. Moreover, the solid state luminescent property of 1 was also investigated at room temperature.
基金supported by the Natural Science Foundation of Henan Province(132300410326)the Foundation of the Education Department of Henan Province(13A150801 and 14A150040)
文摘The reaction of flexible bis(imidazole) ligand and 1,2-bis(imidazol-l'-yl)methane (bimm) with Co(Ⅱ) salt under ionothermal method resulted in the formation of a new coordination polymer {[Co(bimm)3]·(PF6)2}n (1). X-ray single-crystal diffraction determination reveals that 1 crystallizes in the triclinic Pi space group, with α = 8.647(6), b = 12.092(9), c = 14.967(1 l) A, α = 88.912(8), β = 81.199(8), ), = 89.395(8)°, V= 1546 (2) A3, Z = 2, Mr = 793.39, Dc= 1.704 Mg/m3,μ = 0.768 mm-1 F(000) = 798, the final R = 0.0626 and wR = 0.1634 for 4319 observed reflections with I〉 2σ(I). In compound 1, the Co(lI) ion is connected to another Co(ll) by two bimm ligands to form 1D double chains which are further linked by bimm ligands to form a 2D wavelike layer. Topologically, the structure of 1 represents a uninodal 2D 4-connected sq1/Shubnikov tetragonal plane net. Moreover, thermogravimetric analyses and photocatalytic property for 1 have also been investigated.
基金supported by the Natural Science Foundation of Guizhou Province(20122344)125 program of Guizhou Education Department(2012015)the Doctoral Scientific Fund of Zunyi Normal College(2012BSJJ12)
文摘5-(Hydroxymethyl) isophthalic acid (H2HIA) as a novel organic ligand was prepared from 3,5-bis(methoxycarbonyl)benzoic acid by a two-step method. And then, a 3D helical coor- dination polymer with a 3-fold interpenetration structure, namely [Zn1/2(HIA)1/2(DPEE)1/2]n (1), was hydrothermally synthesized at 160 ℃, using H2HIA ligands to assemble with DPEE ligands and Zn2+ ions. Complex 1 crystalizes in orthorhombic system, space group Pnna, with a = 8.2118(5), b = 17.1698(7), c =14.9922(7) ?, V = 2113.82(18) ?3, μ = 1.194 mm-1, Z = 4 and S = 0.967. Moreover, some physical characteristics of complex 1, such as powder X-ray diffraction (PXRD), thermogravimetry analyses (TGA) and photoluminescent properties, were also investigated.
基金Supported by the Construct Program of the Key Discipline in Hunan Province and the Foundation of Education Committee of Hunan Province (06C195)
文摘A one-dimensional chain-like coordination polymer [Mn(phen)(2,4,6-TMBA)2(H2O)]n has been synthesized from 2,4,6-trimethylbenzoic acid, 1,10-phenanthroline and anhydrous manganese(Ⅱ ) sulfate and then characterized. Crystal data for this complex: tetragonal, space group I41, a = 2.05643(16), b = 2.05643(16), c = 1.3939(2) nm, V = 5.8946(11) nm^3, Mr = 579.54, Z = 8, Dc = 1.306 g/cm^3, μ(MoKα) = 0.490 mm^-1, F(000) = 2424, S = 0.985, the final R = 0.0411 and wR = 0.0950. The Flack factor is -0.01(2). The crystal structure shows that two neighboring man- ganese(Ⅱ ) ions are linked together by one bridge-chelating 2,4,6-trimethylbenzoic group, forming a one-dimensional chain structure. The manganese(Ⅱ ) ion is coordinated with two nitrogen atoms of one 1,10-phenanthroline, three oxygen atoms from three 2,4,6-trimethylbenzoic acids and one water oxygen atom, giving a distorted octahedral coordination geometry. The cyclic voltametric behavior of the complex was also investigated.
基金the National Natural Science Foundation of China(21101081)the Project of the Science Funds of Jiangxi Education Office(GJJ14235)+1 种基金Science Founds of StateK ey Laboratory of Structural Chemistry(20130011)Hunan Province Project of Science and Technology(2014FJ6032)
文摘The ionothermal reaction of Zn(NO3)2·6H2O with 5-sulfoisophthalic acid monosodium salt(NaH2SIP) and 1,2,4-triazole in 1-ethyl-3-methylimidazolium tetrafluoroborate(EMIM-BF4) ionic liquid has afforded the compound {(EMIM)[Zn(SIP)]}n(1).The Zn(Ⅱ) ions are linked by the carboxylate groups of SIP^3- ligands to give a two-dimensional layered structure featuring the centrosymmetric dinuclear Zn2(μ2-COO)2 units.The adjacent two-dimensional layers are further linked by the Zn-0 bonds between the Zn(Ⅱ) ions and the sulfonate O atoms to generate a three-dimensional anionic[Zn(SIP)]n^n- framework featuring one-dimensional open channels propagating along the a axis.The imidazolium cations[EMIM]^+ derived from ionic liquid act as extraframework charge-balancing species for the anionic[Zn(SIP)]n^n- framework and occupy the void space of the one-dimensional open channels.The rich ionic environments of the ionic liquid may be particularly helpful in the formation of the ionic compound 1.The roles of the ionic liquid in ionothermal synthesis and crystallization of the compound are briefly discussed.Furthermore,compound 1 displays a photoluminescent emission at 490 nm upon excitation at 406 nm.
基金Supported by the National Natural Science Foundation of China(Nos.51572050,21271050 and 21261004)the Guangxi Natural Science Foundation(Nos.2015GXNSFDA139007,2014GXNSFBA118055 and 2013GXNSFGA019008)
文摘A novel Cd(Ⅱ) coordination polymer with diacylhydrazide ligand N,N?-bis(3-methoxysalicyl)-2,6-pyridinedicarbohydrazide(H_6msphz),[Cd_2(H_2msphz)(Py)_4]_n(1,Py = pyridine) has been synthesized through solvothermal reaction and structurally characterized by single-crystal X-ray diffraction,IR,TGA and PXRD investigations. It crystallizes in triclinic system,space group P1,with a = 11.0230(11),b = 11.7264(15),c = 17.3395(14) ?,α = 70.520(9),β = 84.806(7),γ = 81.965(9)°,V = 2089.9(4) ?~3,Dc = 1.638 gcm^(–3),μ = 1.083 mm^(-1),F(000) = 1032,Z = 2 and S = 1.040. In complex 1,the H_2msphz4-ligand uses not only its coordinated pocket to catch one Cd(Ⅱ) ion,but also its two terminal groups to chelate other two Cd(Ⅱ) ions,leading to the formation of a chain structure. The adjacent chains are further assembled together by two kinds of π-π interactions between the Py rings,resulting in the finial double layered supramolecular structure. In addition,complex 1 is found to show photoluminescence in the solid state at room temperature,which can be ascribed to the intraligand π→π* transitions.
基金National Natural Science Foundations of China(Nos.51073033,51373030)the Fundamental Research Funds for the Central Universities,China(No.2232014D3-43)
文摘The pH /temperature dually responsive microgels of interpenetrating polymer network( IPN) structure composed of poly( N-isopropylacrylamide)( PNIPAM) network and poly( acrylic acid)( PAA) network( PNIPAM /PAA IPN microgels) were synthesized by seed emulsion polymerization. The results obtained by dynamic laser light scattering( DLLS) show that the microgels have good pH /temperature dual sensitivities. The temperature sensitive component and the pH sensitive component inside the microgels have little interference with each other. The rheological properties of the concentrated PNIPAM /PAA IPN microgel dispersions as a function of temperature at pH 4. 0 or 7. 0 were investigated by viscometer,and the results displayed that only at pH 7. 0 the dispersions presented thermoreversible thickening behavior. Then the PNIPAM /PAA fibers were prepared by self-assembly of the PNIPAM /PAA IPN microgels in the ice-crystal templates formed by unidirectional liquid nitrogen freezing method. Field emission scanning electron microscopy( FESEM) images indicate that the PNIPAM /PAA fibers are rounded,randomly orientated and interweaved.
文摘A new Pb(Ⅱ) coordination polymer, [Pb(1,4-chdc)(L)]_n·nH_2O(1), was synthesized under hydrothermal condition(1,4-H2 chdc = 1,4-cyclohexanedicarboxylic acid and L = 2-(3-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by singlecrystal X-ray diffraction. Compound 1 crystallizes in triclinic, space group P1 with a = 9.1182(8), b = 11.3249(10), c = 12.7326(12) A, α = 77.897(2), β = 81.644(2), γ = 84.491(2)°, V = 1269.0(2) A^3, Z = 2, C_(27)H_(24)FN_4O_5Pb, M_r = 710.69, D_c = 1.860 g/cm^3, F(000) = 690, μ(MoKa) = 6.701 mm^(-1), R = 0.0349 and wR = 0.0746. In 1, each 1,4-chdc anion bridges two neighboring Pb(Ⅱ) atoms in a bidentate chelating coordination mode to give a chain structure. The L ligands are attached on one side of the chain through chelating the Pb(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. The O-H···O and N-H···O hydrogen bonding interactions further stabilize the supramolecular layer structure of 1. Moreover, solid state luminescent property of 1 was also studied.
基金Supported by the Ministry of Education of China(No.208066)the Education Department of Fujian Province(JA07029)the State Key Laboratory of Structural Chemistry(No.20130013)
文摘The title complex bis{4-chloro-2-[(6-methyl-pyridin-2-ylimino)-methyl]-phenol}-palladium(Ⅱ)(C_(26)H_(20)Cl_2N_4O_2Pd) has been synthesized by the reaction of 4-chloro-2-[(6-methylpyridin- 2-ylimino)-methyl]-phenol with Pd(CH_3COO)_2, and characterized by IR spectrum and elemental analysis. Single-crystal X-ray diffraction analysis results further confirmed the molecular structures. The crystal belongs to the monoclinic system, space group P2_1/c with a = 4.1324(2), b = 23.5432(16), c = 11.8943(8) A, β = 91.238(5)o, V = 1156.93(12) ?~3, C_(26)H_(20)Cl_2N_4O_2Pd, M_r = 597.76, Z = 2, D_c = 1.716 g/cm^3, μ = 1.067 mm^(-1), F(000) = 600, the final R = 0.0247 and w R = 0.0677(I 〉 2σ(I)). In the presence of methylaluminoxane(MAO), the complex exhibits excellent catalytic activities(1.737×10~7 g of PNB(mol of Pd)^(-1)·h^(-1)) in the vinyl polymerization of norbornene.
基金This work was supported by the Science and Technology Bureau of Jinhua City (No 2003-01-179)
文摘A novel pyrazine-2,3-dicarboxylic acid bridged Co(II) phen complex 2 ∞ [Co- (phen)(μ-L)3/3]?H2O (H2L = pyrazine-2,3-dicarboxylic acid) has been hydrothermally synthesized, and X-ray single-crystal diffraction analysis shows that it crystallizes in the monoclinic system, space group P21/n with a = 11.480(2), b = 11.885(2), c = 12.939(3) ?, β = 110.55(3)°, V = 1653.1(6) ?3, Mr = 423.25, Dc = 0.425 g/cm3, Z = 4, R = 0.0361 and wR = 0.1011. The title complex consists of 2D 2 ∞ [Co(phen)(μ-L)3/3] layers and crystal water molecules. Each Co atom is octahedrally coordinated by three N atoms and three O atoms to form 2D 2 ∞ [Co(phen)(μ-L)3/3] polymeric layers. Furthermore, such 2D layers are stacked into 3D supramolecular frameworks via Van der Waals’ intermolecular forces, strong and weak hydrogen-bond interactions. The coordination phen and crystal water molecules are resided into cavities of the frameworks.
基金Supported by the National Natural Science Foundation of China(21172269)the Applied Fundamental Research Project of Wuhan City(2015011701011598)
文摘Two novel copper complexes with methyl or trifluoro-substituted mono-β-diiminato ligands and one acetoxyl anion were synthesized and characterized by IR spectroscopy and elemental analysis for the first time. The structure of complex 2 bearing trifluoro substituents was further confirmed by single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.377(4), b = 11.727(6), c = 12.913(7) ?, α = 116.569(6), β = 98.829(7), γ = 96.520(6)°, V = 966.2(8) ?3, Z = 2, Mr = 479.86, Dc = 1.649 g/cm3, F(000) = 482, μ = 1.205 mm-1, the final R = 0.0370 and w R = 0.0903 for 3430 observed reflections with I 〉 2σ(I). These mono-β-diiminato copper complexes can effectively catalyze methacrylate(MA) polymerization when activated by MMAO. The introduction of fluoro groups into the N-aryl ring of β-diiminato ligands can greatly increase the catalytic activity of copper complexes as well as the molecular weight of PMA.