Syntheses, Crystal Structures and Fluorescence of Cadmium(Ⅱ) Coordination Polymers with Pyrazine-1,4-dioxide, 2-Methylpyrazine-1,4-dioxide and Thiocyanate as Mixed Bridge Ligands

Two Cd(Ⅱ) coordination polymers have been synthesized with pyrazine-1,4-dioxide(L1), 2-methylpyrazine-1,4-dioxide (L2), and thiocyanate anion as mixed bridge ligands. Crystal data for complex 1 [Cd(μ13-SCN-)2(L1)]n: monoclinic system, space group P21/n with a =6.8342(11), b = 14.349(2), c = 10.5443(16) (A), β = 98.534(2)°, V = 1022.5(3) (A)3, Z = 4,C6H4CdN4O2S2, Mr = 340.65, Dc. = 2.213 g/cm3, F(000) = 656 andμ = 2.527 mm-1; and those for2: triclinic system, space group P1 with a = 7.877(3), b = 8.693(3), c = 8.754(3) (A), α =102.297(6), β= 102.464(6), γ= 98.480(6)°, V = 560.0(3) (A)3, Z = 2, C7H6CdN4O2S2, Mr = 354.68,Dc = 2.103 g/cm3, F(000) = 344 and μ = 2.311 mm-1. 1 shows a three-dimensional network structure, and along the c direction a one-dimensional chain is constructed by the coordination of Cd(Ⅱ) ions withμ1,3-SCN- ligands, and the L1 bridging ligands made the chains connect each other leading to the formation of a three-dimensional structure. For 2, the one-dimensional chains along the b axis are generated by the coordination of L2 bridging ligands with Cd(Ⅱ) ions, and the chains are further joined byμ1,3-SCN- bridging ligands forming a two-dimensional sheet structure on the (1 0 -1) plane. Both complexes 1 and 2 exhibit strong fluorescence emission.     

Syntheses and Crystal Structures of Two Two-dimensional Coordination Polymers with 2,3-Dimethylpyrazine-1,4-dioxide and Thiocyanate as Mixed Bridge Ligands

Two two-dimensional coordination polymers,[Cd(μ1,3-SCN-)2(μ1,6-L)]n 1 and [Co(μ1,3-SCN-)2(μ1,6-L)]n 2,have been synthesized with 2,3-dimethylpyrazine-1,4-dioxide (L) and thiocyanate as mixed bridging ligands,and their crystal structures were determined by X-ray crystallography.Both crystals belong to monoclinic system,space group C2/c.The other crystal parameters are as follows:for complex 1:a = 9.732(3),b = 14.658(5),c = 8.811(3) (A),β =102.935(4)°,Z = 4,V = 1225.1(7)(A)3,CsHsCdN4O2S2,Mr = 368.71,Dc.-- 1.999 g/cm3,F(000) =720 andμ = 2.117 mm-1;for complex 2:a = 9.528(7),b = 14.563(11),c = 8.415(6) (A),β =102.195(9)°,V= 1141.3(14) (A)3,Z = 4,C8H8CoN4O2S2,Mr = 315.23,Dc = 1.835 g/cm3,F(000) =636 andμ = 1.863 mm-1.The two complexes show similar two-dimensional sheet structures.Along the c axis one-dimensional chains are constructed by the coordination of Cd(Ⅱ) (or Co(Ⅱ))ions with μ1,6-L bridging ligand,and the μ1,3-SCN- bridging ligands make the chains connect to each other,resulting in the formation of a two-dimensional sheet on the ac plane.     

Synthesis, Crystal Structure and Fluorescence of a Three-dimensional Cd(Ⅱ) Coordination Polymer [Cd(μ1,3-SCN-)2(μ-dmpo)]n (dmpo = 3,5-Dimethylpyridine N-Oxide)

A three-dimensional complex [Cd(μ1,3-SCN)2(dmpo)]n has been synthesized with μ1,3-SCN- and dmpo as mixed bridge ligands. The crystal belongs to monoclinic, space group C2/c with a = 15.648(2), b = 15.126(2), c = 11.9773(15) (A), β= 112.416(2)°, V= 2620.7(6) (A)3, Z= 8,C9H9CdN3OS2, Mr = 351.71, Dc = 1.783 g/cm3, F(000) = 1376 and μ = 1.967 mm-1. The structure was refined to R = 0.0260 and wR = 0.0647 for 2186 observed reflections (1 ＞ 2σ(Ⅰ)). In the crystal the Cd(Ⅱ) ions are coordinated byμ1,3-SCN- bridge ligands to form the crossing chains on the adjacent planes, and these chains are further joined by μ-dmpo mono-dentate bridge ligands leading to a three-dimensional structure. The complex exhibits strong fluorescent emission property.     

Synthesis and Crystal Structure of a Three-dimensional Cd(Ⅱ) Coordination Polymer [Cd(μ1,3-SCN)(μ3-pco)]n (pco = Pyrazine-2-carboxylate 4-oxide Anion)

The three-dimensional complex [Cd(μ1,3-SCN)(μ3-pco)]n has been synthesized with μ1,3-SCN- and pco as mixed bridged ligands. The crystal belongs to monoclinic, space group P21/n with a = 10.3777(16), b = 6.2592(9), c = 13.150(2) (A), β= 97.317(2)°, V=847.2(2) (A)3, Z= 4,C6H3CdN3O3S, Mr = 309.575, Dc = 2.427 g/cm3, F(000) = 592 and μ = 2.804 mm-1. The structure was refined to R = 0.0255 and wR = 0.0550 for 1712 observed reflections (I＞2σ(I)). In the crystal the Cd(Ⅱ) ions are coordinated by μ1,3-SCN- and μ3-pco bridge ligands to form a three-dimensional structure.     

A Novel Copper(II) Coordination Polymer with Figure-of-eight-shaped Channels Occupied by Flexible Monodentate and Bidentate N,N′-bipyrdyl Ligands

A copper(II) coordination polymer, [Cu3(HOA)2(bpp)4]n (1, H4OA = 3,3′,4,4′-oxidiphthalic acid, bpp = 1,3-bis(4-pyridyl) propane), has been hydrothermally synthesized. The crystal structure is of monoclinic, space group P21/c with a = 11.544(3), b = 16.129(4), c = 21.181(6) , β = 98.848(5), V = 3897.0(2) 3, C84O18N8H70Cu3, Mr = 1670.13, Z = 2, Dc = 1.423 g/cm3, F(000) = 1722, μ = 0.887 mm-1 , R = 0.0878 and wR = 0.2583 for 8496 observed reflections (I > 2σ(I)). Single-crystal X-ray structural analysis reveals that 1 is a three-dimensional (3D) framework based on a two-dimensional (2D) mesomeric layer of alternating left-and right-handed helical chains. The monodentate terminal and bidentate bridging bpp ligands in the same conformation are all encapsulated in the figure-of-eight-shaped channels, thus further stabilizing the whole three-dimen-sional framework.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)2]·2CH3OH}n Generated from Cadmium(Ⅱ) and Carbamyldicyanomethanide Anion Bridging Ligand

The three-dimensional coordination polymer {[Cd(cda)2](2CH3OH}n has been syn- thesized by Na(cda) (cda = carbamyldicyanomethanide anion) and hydrated cadmium perchlorate in methanol solution. The crystal belongs to monoclinic, space group C2/c with a = 15.686(3), b = 8.1650(18), c = 13.119(3) (A), β= 119.334(2)°, V = 1464.8(6) (A)3, Z = 4, C10H12CdN6O4, Mr = 392.66, Dc = 1.780 g/cm3, F(000) = 776 and μ = 1.516 mm-1. The structure was refined to R = 0.0248 and wR = 0.0628 for 1176 observed reflections (I ＞ 2σ(I)). The Cd(II) ion is coordinated by two amide- oxygen and four nitrile-nitrogen atoms from six different cda bridging ligands, forming a three- dimensional structure.     

Synthesis,Crystal Structure and Fluorescence of a Three-dimensional Cd(II) Coordination Polymer [Cd(μ_(1,3)- SCN~-)_2(μ-dmpo)]_n (dmpo = 3,5-Dimethylpyridine N-Oxide)

1 INTRODUCTION For a long time much research interest has been focused on coordination polymeric compounds[1] be- cause they may afford new materials with useful properties, such as catalytic activity, micro-porosity, electrical conductivity, non-linear optical activity, magnetic coupling behavior and so on[2]. Thiocya- nate anion, pyridine N-oxide and its derivatives be- long to very useful bridge ligands and many com- plexes[3～5] with one of them as bridge ligand exhibit special propert…     

Synthesis,crystal structures and fluorescence of cadmium(II) coordination polymers with derivatives of pyrazine-1,4-dioxide and thiocyanate as mixed-bridging ligands

Two Cd(II) coordination polymers have been synthesized with derivatives of pyrazine-1,4-dioxide and thiocyanate anion as bridging ligands and structurally determined by X-ray crystallography. Complex 1, [Cd(μ_1,3-SCN^?)₂(μ_1,6-L1)] _n (L1?=?2,5-dimethylpyrazine-1,4-dioxide), belongs to the triclinic, space group P 1 with a?=?5.7627(18)?Å, b?=?7.182(2)?Å, c?=?7.509(2)?Å, α?=?74.042(3)°, β?=?84.766(4)°, γ?=?88.162(4)°; complex 2, [Cd₂(μ_1,3-SCN^?)₄(μ₄-L2)] _n (L2?=?2,3,5,6-tetramethylpyrazine-1,4-dioxide), crystallizes in a monoclinic system with space group C2/m with a?=?10.194(4)?Å, b?=?13.491(6)?Å, c?=?8.140(3)?Å, β?=?120.372(4)°. Complex 1 shows a two-dimensional sheet structure, and in a direction the Cd(II) ions were coordinated by μ_1,3-SCN^? forming the one-dimensional chain and the L1 bridging ligand made the chains connect in the c direction leading to formation of a two-dimensional sheet on the ac plane. For 2 the one-dimensional chains in the a axis were constructed by coordination of μ_1,3-SCN^? bridging ligands with the Cd(II) ions, and in b and c directions the chains were joined by L2 bridging ligands leading to a three-dimensional structure. In 2 L2 displays a μ₄-bridging coordination mode. Both complexes exhibit strong fluorescence emission.     

Syntheses and Crystal Structures of Two Coordination Polymers with Aromatic Dioxide as Bridge Ligands

Two coordination polymers, namely, two-dimensional complex 1 {[Cu(μ- L)1.5(ClO4)2(H2O)].(H2O)0.5}n (L = pyrazine-1,4-dioxide) and one-dimensional complex 2 [Co(μ-L)Br2(H2O)2]n, have been synthesized with pyrazine-1,4-dioxide as bridging ligands, and their crystal structures were determined by X-ray crystallography. Crystal data for complex 1: monoclinic system, space group C2/c, with a = 23.310(3), b = 12.2338(17), c = 10.6075(15) , β = 110.487(2)°, V = 2833.6(7) 3, Z = 8, C6H9Cl2CuN3O12.5, Mr = 457.60, Dc = 2.145 g/cm3, F(000) = 1832 and μ = 1.998 mm-1; and those for 2: monoclinic system, space group C2/c, with a = 11.012(3), b = 7.483(2), c = 11.451(3) , β = 101.654(4)°, V = 924.2(4) 3, Z = 4, C4H8Br2CoN2O4, Mr = 366.87, Dc = 2.637 g/cm3, F(000) = 700 and μ = 10.487 mm-1. 1 shows a two-dimensional sheet structure on the ac plane through the coordination of μ-L bridging ligands with Cu(II) ions, while 2 displays a zigzag one-dimensional chain along the c axis via the coordination of μ-L bridging ligand with Co(II) ions. Hydrogen bonds in 1 and 2 make the sheets (or chains) connect each other to form a three-dimensional structure.     

Synthesis and Crystal Structure of a Three-dimensional Coordination Polymer {[Cd(cda)_2]·2CH_3OH}_n Generated from Cadmium(II) and Carbamyldicyanomethanide Anion Bridging Ligand

1 INTRODUCTION The polynitrile-ligands, such as TCNE, TCNB, TCNQ, TCNP, tcm, dca and so on, are of ideal multi-functional bridging ligands. Many complexes with poly-nitriles as bridging ligands and uncoor- dinated ligand (electron acceptors) display dist…     

Synthesis and Crystal Structure of [Cd(NBA)(μ_3-OH)(4,4′-bipy)_(1/2)]_n

A new cadmium polymer [Cd(NBA)(μ3-OH)(4,4′-bipy)1/2]n 1 (NBA = m-nitrobenzoic acid and 4,4′-bipy = 4,4-bipyridine) has been synthesized by hydrothermal reaction. Its structure was determined by single-crystal X-ray diffraction method, and characterized by elemental analysis and IR spectrum. The crystal is of monoclinic, space group C2/c, with a = 15.6912(9), b = 25.9394(15), c = 6.7332(4) ′, β = 114.7700(10)°, V = 2488.4(3) 3, C12H9CdN2O5, Mr = 373.61, Z = 8, Dc = 1.995 g/cm3, μ = 1.776 mm-1, F(000) = 1464, R = 0.0411 and wR = 0.1128 for 2130 observed reflections (I > 2σ(I)). X-ray diffraction studies reveal that the compound features a layered structure, in which 4,4′-bipy ligands bridge Z type of double chains [Cd(μ3-OH)]n and NBA ligands locate at the two sides of the layer. The π-π interactions between the benzene rings of NBA ligands of two adjacent layers lead to the 3D framework.     

Synthesis and Crystal Structure of a Three-dimensional Cd(II) Coordination Polymer [Cd(μ_(1,3)-SCN)(μ_3-pco)]_n(pco=Pyrazine-2-carboxylate 4-oxide Anion)

1 INTRODUCTION For a long time much research interest has been focused on coordination polymeric compounds[1] because these new coordination polymers may afford new materials with useful properties, such as catalytic activity, micro-porosity, electrical conduc- tivity, non-linear optical activity, magnetic coupling behavior and so on[2]. Thiocyanate anion is a very useful bridging ligand, and many complexes[3～5] are synthesized with it as bridging ligand and some of them exhibit interesti…     

Synthesis and Crystal Structure of a Novel 2D Cadmium(II) Complex Constructed from N-(3-Carboxyphenyl)-4,4ˊ-bipyridinium and Benzene-1,4-dicarboxylic Acid

A novel redox-active bipyridinium ligand N-(3-carboxyphenyl)-4,4ˊ-bipyridinium chloride (HCPBPyCl) and its coordination polymer {[Cd2(CPBPy)2(BDC)(H2O)2Cl2]·6H2O}n 1 (H2BDC = benzene-1,4-dicarboxylic acid) were synthesized and characterized. Crystallographic data for 1: C42H44Cd2Cl2N4O16, Mr = 1156.51, monoclinic, space group C2/c, a = 21.046(3), b = 11.0036(15), c = 20.012(3) , β = 98.694(8)°, Z = 4, V = 4581.1(11) 3, Dc = 1.677 g/cm3, F(000) = 2280 and μ = 1.120 mm-1. Complex 1 possesses a thick and undulated two-dimensional layer with (6,3) topology, which interpenetrates with two others (above and below) to extend into a three-di-mensional supramolecular framework.     

Structure and Fluorescence Property of a 2D Bilayer Cd(Ⅱ) Coordination Polymer Induced by H-bonding and π-π Interaction

Solvothermal reactions of 4,4'-oxybis(benzoic acid) (H2oba) with 1,3-dipyridyl benzene (1,3-dpb) produced a two-dimensional (2D) cadmium(Ⅱ) coordination polymer {[Cd(oba)(dpb)]·H2O}n (1). The complex was characterized by elemental analysis, IR spectroscopy, and X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group C2/c with a = 13.6692(9), b = 25.9647(17), c = 8.7912(6) , α = 125.0370(10), γ = 2544.7(3)°, V = 2544.7(3) 3, C30H22N2O6Cd, Mr = 618.91, Dc =1.609 g/cm3, F(000) = 1248, μ = 0.904 mm-1 and Z = 4. The neighboring Cd(Ⅱ) ions are linked by oba2-anions and 1,3-dpb to form an infinitely 2D wavelike sheet, and two such 2D sheets are interlocked with each other by H-bonding to form a 2D → 2D structure. The adjacent two groups of interlocked structures are further linked to form a bilayer 2D supramolecular network by π-π interactions. In addition, the fluorescence property of 1 was also studied.     

Synthesis,Crystal Structure and Luminescence of a Novel Cadmium（Ⅱ） Coordination Polymer with 5-Connected nov Net

A novel interesting coordination polymer,[Cd(HSSA)(2-bimb)2].3H2O(1,H3SSA = 5-sulfosalicylic acid,2-bimb = 1,2-bis(imidazol-1-ylmethyl)-benzene),has been synthesized and structurally characterized.Compound 1 crystallizes in the monoclinic system,space group P21/n with a = 10.8653(10),b = 19.4100(17),c = 17.4414(17) ,β = 91.944(2)°,V = 3676.2(6) 3,Z = 4,C35H38CdN8O9S,Mr = 859.19,Dc = 1.552 g/cm3,μ = 0.717 mm-1,S = 0.999,F(000) = 1760,R = 0.0531 and wR = 0.1078.The compound features a rare three-dimensional(3D) 5-connected nov topology.In addition,compound 1 exhibits strong photoluminescent emission at room temperature.     

Synthesis,Structure,Electrochemistry and Fluorescence Properties of a One-dimensional Coordination Polymer {[Cd[μ-(4,4′-dps)]_2(H_2O)_2]·(4-abs)_2(H_2O)_2}_n

A new cadmium(II) compound, {[Cd[μ-(4,4'-dps)]2(H2O)2]·(4-abs)2(H2O)2}n 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) , V = 3831.8(8) 3, Z = 4, C32H36CdN6O10S4, Mr = 905.31, F(000) = 1848, μ = 0.850 mm-1, Dc = 1.569 Mg/m3 , the final R = 0.0238 and wR = 0.0589 for 3080 observed reflections with I > 2σ(I). Complex 1 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(II) 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.     

Hydrothermal Synthesis and Crystal Structure of a Cadmium(II) Polymer with One-dimensional Chain Structure: [Cd(bpy)(BDC)]_n·nbpy

A metal-organic coordination polymer [Cd(bpy)(BDC)]n·nbpy (bpy = 2,2-bipyri- dine, H2BDC = terephthalic acid) has been hydrothermally synthesized and structurally characteri- zed by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group C2/c with a = 15.723(5), b = 21.695(5), c = 7.576(5) , β = 116.171(7)o, V = 2319.3(18) 3, C28H20CdN4O4, Mr = 588.88, Dc = 1.686 g/cm3, μ(MoKα) = 0.987 mm-1, F(000) = 1184, Z = 4, the final R = 0.0464 and wR = 0.0831 for 1882 observed reflections (I > 2σ(I)). It exhibits a three-dimensional network with channels constructed from one-dimensional coordination chains via C–H···O hydrogen bonds and significant aromatic π-π stacking interactions.     

Syntheses, Crystal Structures and Characterization of Layered and Layer-pillared Zinc Arsonates

Two zinc arsonate coordination polymers, Zn(4-apa)·H2O (1, 4-apaH2 = 4-amino- phenylarsonatic acid) and Zn(4-apa) (2), have been hydrothermally synthesized and characterized by elemental analysis, IR and single-crystal and powder X-ray diffraction. Crystal data for 1: monoclinic, space group C2/c with a = 23.056(5), b = 5.4224(11), c = 15.027(3) , β = 121.22(3)°, V = 1606.6(6) ?3, Dc = 2.468 g·cm-3, F(000) = 1168, μ = 7.122 mm-1, Z = 8, the final R = 0.0309 and wR = 0.0752 for 1763 observed reflections with I > 2σ(I). For 2: monoclinic, space group P21/c with a = 8.7852(18), b = 9.2744(19), c = 9.752(2) , β = 103.45(3)°, V = 772.7(3)3, Dc = 2.410 g·cm-3, F(000) = 544, μ = 7.387 mm-1, Z = 4, the final R = 0.0321 and wR = 0.0741 for 1696 observed reflections with I > 2σ(I). The structure of 1 shows a two-dimensional (4,4)-network composed of an inorganic ladder chain bridged by the phenyl-linkers of 4-apa ligands. Compound 2 exhibits a 3D layer-pillared framework with crb net, in which inorganic (4-82)-networks are joined by the phenyl-linkers.     

Synthesis, Crystal Structure and Magnetic Properties of a Novel Azide-bridged Copper（Ⅱ） Coordination Polymers Containing Nitroxy Nitroxide

A novel azide-bridged copper(Ⅱ) coordination polymer, [Cu3(NITpPy)4(N3)6]n (NITpPy = 4-pyridyl-4,4,5,5-tetramethylimidazline-3-oxide-1-oxyl), was structurally and magnetically characterized. It crystallizes in the triclinic space group P with a = 7.6932(10), b = 14.5556(19), c = 16.122(2) , α = 108.443(2), β = 95.251(2), γ = 104.236(2)°, V = 1631.7(4) 3, C48H64Cu3N30O8, Mr = 1379.87, Z = 1, Dc = 1.404 g/cm3, μ(MoKα) = 1.041 mm-1, F(000) = 713, the R = 0.0510 and wR = 0.1185 for 4285 observed reflections with I > 2σ(I). X-ray analysis reveals that the Cu(Ⅱ) ions are linked by nitrogen atom of μ1,1 azido ligands to form a Cu-Cu-Cu unit. The units are linked by μ1,3 azido ligands through a bridging style to form a one-dimensional coordination polymer. The variable-temperature magnetic susceptibility data of the complex show ferromagnetic interactions in the complex.     

Synthesis and Crystal Structure of μ_(1,1,3) Formic Bridging 3D Microporous Ni(II) Complex

A μ1,1,3 formic bridging Ni2+ complex [Ni3(HCOO)6·H2O]]n 1 has been synthesi- zed under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 exhibits a 3D open microporous tube formed by covalent and coordination bonds. Complex 1 crystallizes in the monoclinic system, space group P21/c with a = 11.1487(13), b = 9.7763(11), c =17.9685(17) , β = 126.948(6)o, C6H6Ni3O13, Mr = 462.02, V = 1565.2(3) 3, Z = 4, Dc = 1.961 g/cm3, μ = 3.630 mm-1, F(000) = 917.7, Rint = 0.0234, the final R = 0.0234 and wR = 0.0734 for 3469 observed reflections (I>2σ(I)).