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Jiang-Gao Mao

Publications and source records attributed to Jiang-Gao Mao.

At least 19 recordsLinked to original sources

Origin of the single chain magnet behavior of the Co(H2L)(H2O) compound with a 1D structure.

The paper is aimed at the elucidation of the main factors responsible for the single-chain magnet behavior of the cobalt(II) disphosphonate compound Co(H2L)(H2O) with a 1D structure. The model takes into account the spin-orbit interaction, the axial component of the octahedral crystal field acting on the ground-state cubic 4T1 terms of the Co(II) ions, the antiferromagnetic exchange interaction between Co(II) ions as well as the difference in the crystallographic positions of these ions. The conditions that favor the single-chain magnet behavior based on spin canting in a 1D chain containing inequivalent Co(II) centers are discussed. The peculiarities of this behavior in chains containing orbitally degenerate ions are revealed. The qualitative explanation of the experimental data is given.

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Rational design of 0D, 1D, and 3D open frameworks based on tetranuclear lanthanide(III) sulfonate-phosphonate clusters.

Hydrothermal reactions of lanthanide(III) salts with m-sulfophenylphosphonic acid (H3L1) and 1,10-phenanthroline (phen) or N,N'-piperazinebis(methylenephosphonic acid) (H4L2) afforded six novel lanthanide(III) sulfonate-phosphonates based on tetranuclear clusters, namely, [La(2)(L1)2(phen)4(H2O)].4.5H2O (1), [Ln2(L1)2(phen)2(H2O)5].3H2O (Ln = Nd, 2; Eu, 3; Er, 4), and [Ln2(HL1)(H2L2)2(H2O)4].8H2O (Ln = La, 5; Nd, 6). Compounds 2-4 contain discrete tetranuclear lanthanide(III) cluster units in which four lanthanide(III) ions are bridged by two tridentate and two tetradentate phosphonate groups. In compound 1, the tetranuclear clusters are further interconnected into a 1D chain through the coordination of the sulfonate groups. The structures of compounds 5 and 6 can be viewed as a 3D architecture based on a different types of tetranuclear cluster units that are interconnected by bridging H2L2 anions. In the tetranuclear clusters of compounds 5 and 6, the four lanthanide(III) centers are interconnected by only two HL1 ligands. Compound 2 is a luminescent material in the near-IR region, whereas compound 3 displays a strong luminescent emission band in the red-light region. Magnetic property measurements of compounds 2-4 and 6 indicate that there are strong antiferromagetic interactions between magnetic centers within the cluster units.

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Syntheses, structural studies, and magnetic properties of divalent Cu and Co selenites with organic constituents.

Six new divalent metal selenites have been synthesized by hydro-/solvothermal methods which leads to the incorporation of the organic template as a cation or a ligand. The structure of [H(2)pip][Cu(SeO(3))(2)] (1) (pip=piperazine) features 1D anionic chains of [Cu(SeO(3))(2)](2-) which are cross-linked by the template cations through hydrogen bonds into a 2D layer. In [Cu(C(3)H(4)N(2))(SeO(3))] (2) the organic template is coordinated to the copper(II) ion of the inorganic Cu(SeO(3)) layer. The isostructural compounds [H(2)en][M(HSeO(3))(2)Cl(2)] (en=ethylenediamine; M=Cu (3), Co (4)) contain layers of [MCl(2)(HSeO(3))(2)](2-) units (M=Cu, Co), which are cross-linked by the template cations via hydrogen bonds into a 3D network. The structure of [H(2)en][Cu(2)(SeO(3))(2)(HSeO(3))](2)H(2)O (5), consists of a pillared layered architecture in which the Cu(SeO(3)) layers are further interconnected by bridging hydrogen selenite groups (the pillar). The compound [H(2)pip][Cu(2)(Se(2)O(5))(3)] (6), which crystallizes as a 3D open framework represents the first organically templated metal diselenite. These new compounds are thermally stable up to at least 170 degrees C. All of the compounds exhibit fairly strong antiferromagnetic interactions. More interestingly, compounds 3 and 4 behave as a weak ferromagnets below the critical temperatures of T(c)=12 and 8 K, respectively, and both of them exhibit spin-flop phase transitions around 800+/-100 Oe.

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New members in the Ni(n+1)(QO3)nX2 family: unusual 3D network based on Ni4ClO3 cubane-like clusters in Ni7(TeO3)6Cl2.

Three new members in the family of nickel(II) tellurium(IV)/selenium(IV) oxyhalides generally formulated as Ni(n+1)(QO3)nX2 (Q = Te, X = Cl, n = 6, 10; Q = Se, X = Br, n = 4) have been synthesized by solid-state reactions of NiX2, QO2, and NiO (or Ni2O3) at high temperature. The structure of Ni7(TeO3)6Cl2 features a novel 3D network based on Ni4ClO3 cubane-like clusters with Te atoms located at the cavities of the network. Ni4ClO3 clusters are interconnected into a hexagonal layer through additional O...O edges. The neighboring two layers are further interconnected, via sharing of common Ni(II) atoms, into a novel 3D network. The 3D open framework of Ni5(SeO3)4Br2 is built from 2D nickel(II) oxybromide layers bridged by Se and additional Ni atoms. The structure of Ni11(TeO3)10Cl2 features a condensed 3D network based on NiO5Cl, NiO6, and NiO5 polyhedra interconnected via corner and edge sharing, as well as O-Te-O bridges. The results of magnetic property measurements indicate that all three compounds display antiferromagnetic interactions between nickel(II) centers.

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Three novel zinc(II) sulfonate-phosphonates with tetranuclear or hexanuclear cluster units.

Hydrothermal reactions of zinc(II) carbonate with m-sulfophenylphosphonic acid (m-HO3S-Ph-PO3H2) and 1,10-phenanthroline (phen) or 4,4'-bipyridine (bipy) lead to three novel zinc(II) sulfonate-phosphonates, namely, [Zn(phen)3]2[Zn4(m-O3S-Ph-PO3)4(phen)4].20H2O (1), [Zn6(m-O3S-Ph-PO3)4(phen)8].11H2O (2), and [Zn6(m-O3S-Ph-PO3)4(bipy)6(H2O)4].18H2O (3). Compound 1 contains a tetranuclear zinc(II) cluster anion in which four Zn(II) ions are bridged by two tetradentate and two bidentate phosphonate groups, and the four negative charges of the cluster are compensated by two [Zn(phen)3]2+ cations. Compound 2 features a hexanuclear zinc(II) cluster in which the same tetranuclear cluster of 1 is bridged with two additional Zn(II) ions. The structure of 3 features a porous 3D network based on hexanuclear zinc(II) units of [Zn6(m-O3S-Ph-PO3)4] interconnected by 4,4'-bipy ligands. The hexanuclear cluster in 3 is different from that in 2 in that all four phosphonate groups in 3 are tridentate bridging. Compounds 1, 2, and 3 exhibit broad blue fluorescent emission bands at 378, 409, and 381 nm, respectively.

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Se2(B2O7): a new type of second-order NLO material.

Exploration on the compounds in the selenite-borate system led to the discovery of a new second-order NLO material, Se2B2O7, with a SHG efficiency of about 2.2 times that of KDP (KH2PO4). Its structure features a 3D network with helical tunnels, and it is transparent in the UV and visible region. The compound is a wide band gap semiconductor.

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[Cd2(Te6O13)][Cd2Cl6] and Cd7Cl8(Te7O17): novel tellurium(IV) oxide slabs and unusual cadmium chloride architectures.

Initial attempts to prepare new Ln-Cd-Te-O-Cl compounds led to the isolation of two novel cadmium tellurium(IV) oxychlorides with two different types of structures, namely, [Cd(2)(Te(6)O(13))][Cd(2)Cl(6)] and Cd(7)Cl(8)(Te(7)O(17)). Both compounds feature novel polymeric tellurium(IV) oxide anions and unusual cadmium chloride substructures. The structure of [Cd(2)(Te(6)O(13))][Cd(2)Cl(6)] is composed of 1D [Cd(2)Cl(6)](2)(-) double chains and (002) [Cd(2)(Te(6)O(13))](2+) layers. The 1D Te(6)O(13)(2)(-) slab of the [Cd(2)(Te(6)O(13))](2+) layer is formed by TeO(3), TeO(4), and TeO(5) groups via corner- and edge-sharing, and it contains six- and seven-membered tellurium(IV) polyhedral rings. The structure of Cd(7)Cl(8)(Te(7)O(17)) features a 3D network with long-narrow tunnels along the b axis. The two types of structural building blocks are 1D [Te(7)O(17)](6)(-) anions and unusual corrugated [Cd(7)Cl(8)](6+) layers based on "cyclohexane-like" Cd(3)Cl(3) rings.

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Ca6Cu2Sn7: novel 3D open framework with unusual Sn4 tetramers.

The new ternary polar intermetallic phase, Ca6Cu2Sn7, has been synthesized by the solid-state reaction of the stoichiometric mixture of the pure elements in welded Ta tubes at high temperature. Its structure was established by single-crystal X-ray diffraction studies. Ca6Cu2Sn7 crystallizes in the monoclinic space group C2/m (No. 12) with cell parameters of a=14.257(7), b=4.564(2), and c=12.376(7) A, beta=93.979(6) degrees, V=803.3(7) A3, and Z=2. The structure of Ca6Cu2Sn7 belongs to a new structure type and features a 3D anionic open-framework composed of [Cu2Sn3] layers interconnected by unusual Sn4 tetramers, forming large tunnels along the b axis which are composed of Cu4Sn12 16-membered rings. The calcium atoms are located in these large tunnels. Ca6Cu2Sn7 is metallic and exhibits temperature-independent paramagnetism.

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Luminescent lanthanide selenites and tellurites decorated by MoO4 tetrahedra or MoO6 octahedra: Nd2MoSe2O10, Gd2MoSe3O12, La2MoTe3O12, and Nd2MoTe3O12.

Solid state reactions of lanthanide oxide, MoO3 and SeO2 (or TeO2) at high temperature in an evacuated quartz tube lead to four new Ln-Mo-Se(Te)-O quaternary phases with four different types of structures, namely, Nd2MoSe2O10, Gd2MoSe3O12, La2MoTe3O12, and Nd2MoTe3O12. The structure of Nd2MoSe2O10 features a 3D architecture built by the intergrowth of the Nd-Se-O layers with the Nd-Mo-O layers. The structure of Gd2MoSe3O12 contains a 3D network of gadolinium selenite with the MoO6 octahedra occupying the cavities of the structure. The structure of La2MoTe3O12 features a 3D network of La2(Te3O8)2+ with the tunnels along the a axis occupied by the MoO4 tetrahedra. Nd2MoTe3O12 features a 2D layer built by the lanthanide ions interconnected by tellurite groups and ditellurite groups, with the MoO4 tetrahedra as the interlayer pendant groups. Room temperature and low temperature luminescent studies indicate that Nd2MoSe2O10 and Nd2MoTe3O12 exhibit strong luminescence in the near-IR region.

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Novel corrugated In9 anionic layer in Li2Y5In9: square pyramidal In5 clusters interconnected by unusual butterfly In4 clusters.

The new ternary polar intermetallic phase, Li2Y5In9, was obtained by high-temperature solid-state reactions of the corresponding elements inwelded Ta tubes. Its crystal structure was established by a single-crystal X-ray diffraction study. Li2Y5In9 crystallizes in the tetragonal space group P4/nmm (No. 129) with cell parameters of a = b = 10.1242(4), c = 15.1091(10) A and Z = 4. The structure of Li2Y5In9 features a two-dimensional corrugated anionic In9 layer composed of two types of square pyramidal In5 units and butterfly In4 units. There are two types of square pyramidal In5 units: one with normal In-In bonds and another one with greatly elongated In-In separations within its In4 square. Packing of these 2D In9 layers resulted in cavities and tunnels that are occupied by Y and Li atoms. Extended-Hückel tight-binding calculations indicate that Li2Y5In9 is metallic.

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Syntheses, crystal structures, and properties of six new lanthanide(III) transition metal tellurium(IV) oxyhalides with three types of structures.

Solid-state reactions of lanthanide(III) oxide (and lanthanide(III) oxyhalide), transition metal halide (and transition metal oxide), and TeO(2) at high temperature lead to six new lanthanide transition metal tellurium(IV) oxyhalides with three different types of structures, namely, DyCuTe(2)O(6)Cl, ErCuTe(2)O(6)Cl, ErCuTe(2)O(6)Br, Sm(2)Mn(Te(5)O(13))Cl(2), Dy(2)Cu(Te(5)O(13))Br(2), and Nd(4)Cu(TeO(3))(5)Cl(3). Compounds DyCuTe(2)O(6)Cl, ErCuTe(2)O(6)Cl, and ErCuTe(2)O(6)Br are isostructural. The lanthanide(III) ion is eight-coordinated by eight oxygen atoms, and the copper(II) ion is five-coordinated by four oxygens and a halide anion in a distorted square pyramidal geometry. The interconnection of Ln(III) and Cu(II) ions by bridging tellurite anions results in a three-dimensional (3D) network with tunnels along the a-axis; the halide anion and the lone-pair electrons of the tellurium(IV) ions are oriented toward the cavities of the tunnels. Compounds Sm(2)Mn(Te(5)O(13))Cl(2) and Dy(2)Cu(Te(5)O(13))Br(2) are isostructural. The lanthanide(III) ions are eight-coordinated by eight oxygens, and the divalent transition metal ion is octahedrally coordinated by six oxygens. Two types of polymeric tellurium(IV) oxide anions are formed: Te(3)O(8)(4)(-) and Te(4)O(10)(4)(-). The interconnection of the lanthanide(III) and divalent transition metal ions by the above two types of polymeric tellurium(IV) oxide anions leads to a 3D network with long, narrow-shaped tunnels along the b-axis. The halide anions remain isolated and are located at the above tunnels. Nd(4)Cu(TeO(3))(5)Cl(3) features a different structure. All five of the Nd(III) ions are eight-coordinated (NdO(8) for Nd(1), Nd(2), Nd(4), and Nd(5) and NdO(7)Cl for Nd(3)), and the copper(I) ion is tetrahedrally coordinated by four chloride anions. The interconnection of Nd(III) ions by bridging tellurite anions resulted in a 3D network with large tunnels along the b-axis. The CuCl(4) tetrahedra are interconnected into a 1D two-unit repeating (zweier) chain via corner-sharing. These 1D copper(I) chloride chains are inserted into the tunnels of the neodymium(III) tellurite via Nd-Cl-Cu bridges. Luminescent studies show that ErCuTe(2)O(6)Cl and Nd(4)Cu(TeO(3))(5)Cl(3) exhibit strong luminescence in the near-IR region. Magnetic measurements indicate the antiferromagnetic interactions between magnetic centers in these compounds.

Crystallography, X-Ray↗

New types of blue, red or near IR luminescent phosphonate-decorated lanthanide oxalates.

Hydrothermal reactions of the lanthanide chlorides with MeN(CH2CO2H)(CH2PO3H2), (H3L1) (or Me2NCH2PO3H2, H2L2) and sodium oxalate lead to seven new lanthanide oxalate phosphonate hybrids with three types of 3D network structures, namely, [Ln(C2O4){MeNH(CH2CO2)(CH2PO3H)}]0.5 H2O (Ln=Nd: 1; Eu: 2; Gd: 3), [Ln4(C2O4)5(Me2NHCH2PO3)2(H2O)4]2 H2O (Ln=La: 4, Nd: 5), [Ln3(C2O4)4(Me2NHCH2PO3)(H2O)6]6 H2O (Gd: 6, Er: 7). Their structures have been established by X-ray single-crystal diffraction. Complexes 1-3 are isostructural and feature a 3D network formed by the interconnection of 3D network of {Ln(H2L1)}2+ with 1D chains of {Ln(C2O4)}+. Complexes 4 and 5 are isostructural and feature a complex 3D network built from 3D network of lanthanide oxalate and {Ln4(HL2)2} units. The isostructural 6 and 7 form another type of 3D network composed of porous lanthanide-oxalate network inserted by 1D chains of lanthanide-oxalate phosphonate. Compounds 1, 5 and 7 are luminescent materials in the near IR region. Compounds 3 and 6 exhibit a broad blue fluorescent emission band at 451 and 467 nm, respectively. Compound 2 displays very strong and sharp emission bands at 592, 616 and 699 nm with a long luminescent lifetime of 1.13 ms.

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New types of metal squarato-phosphonates: condensation of aminodiphosphonate with squaric acid under hydrothermal conditions.

The syntheses and crystal structures of the first copper(I) phosphonate, Cu2(H3L)(bipy)(2).2H2O 1 (H5L = C4HO3N(CH2PO3H2)2), which is also the first example of metal phosphonates formed by a type of organic reaction, and a novel luminescent Mn(II) squarate diphosphonate, {Mn[NH(CH2PO3H)2](H2O)2}2{Mn(C4O4)(H2O)4}.(C4H2O4) 2, have been reported. The structure of 1 features a layer architecture in which the Cu(I) centers are three coordinated, and the newly formed ligand acts as a bidentate metal linker. Compound 2 is composed of 1D chains of Mn[NH(CH2PO3H)2](H2O)2, 1D chains of {Mn(C4O4)(H2O)4}, as well as the neutral squaric acid molecules. These three types of building units are interconnected via hydrogen bonding.

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Syntheses, crystal structures, and luminescent properties of novel layered lanthanide sulfonate-phosphonates.

Hydrothermal reactions of lanthanide metal salts with MeN(CH(2)CO(2)H)(CH(2)PO(3)H(2)) (H(3)L) and 5-sulfoisophthalic acid monosodium salt (NaH(2)BTS) lead to four isomorphous lanthanide carboxylate-phosphonate-sulfonate hybrids, namely, Ln(H(2)L)(HBTS)(H(2)O)(2).H(2)O (Ln = La (1), Pr (2), Nd (3), Gd (4)). Their structures have been established by X-ray single-crystal diffraction. The interconnection of the lanthanide(III) ions by carboxylate-phosphonate ligands results in a 1D double chain; these double chains are further bridged by bidentate bridging carboxylate-sulfonate ligands to form a <011> layer. The luminescent properties of compounds 3 and 4 have also been studied.

Alkanesulfonates↗

Li17Ag3Sn6: a polar intermetallic pi-system with carbonate-like [AgSn3]11- anions and trefoil aromatic [Ag2Sn3]6- layers.

A new lithium silver stannide, Li17Ag3Sn6, was synthesized from high-temperature reactions of the pure elements in tantalum containers. Its crystal structure, in the space group, P31m, with a = 8.063(3) A, c = 8.509(4) A, Z = 1, features two distinct AgSn-based anionic layers. Defect graphitic layers of Ag2Sn3, with ordered vacancies at one-third of the Ag sites, are alternately stacked with Kagome-like nets of isolated trigonal planar AgSn3 units. Double layers of Li ions are sandwiched between the stacked AgSn-based layers. Theoretical calculations show unusual pi-interactions within both anionic layers, with the trigonal planar [AgSn3]11- units being isoelectronic with CO(3)2-. In addition, the chemical bonding of the layered [Ag2Sn3]6- pi-network features incompletely filled lone-pair Sn states involved in in-plane trefoil aromatic interactions. Transport and magnetic susceptibility measurements on Li17Ag3Sn6 indicate excellent metallic behavior and temperature-independent paramagnetism consistent with results from band structure calculations. The "trefoil" aromaticity, previously postulated for aromatic molecular systems, is finally observed, albeit in a polar intermetallic solid-state structure that lies at the border between metals and nonmetals.

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The role of sequestering agents in the formation and structure of germanium anion cluster polymers.

Large blue-green, transparent crystalline needles of [K-(2,2)diaza-[18]-crown-6]KGe(9).3en are prepared, in high yield, from the reaction of (2,2)diaza[18]-crown-6 in toluene with a solution of "KGe(4)" in ethylenediamine (en). The compound crystallizes in the orthorhombic space group Pnma (a = 10.9763(12) A, b = 27.265(3) A, c = 13.880(1) A; Z = 4). The crystal structure of [K-(2,2)diaza-[18]-crown-6]KGe(9).2en features one-dimensional [KGe(9)](-) bare intermetallic chains formed from the linking, via exo-bonds, of nido-Ge(9)(2-) clusters. Uncomplexed K atoms effectively cap the square bases of the monocapped square antiprismatic [Ge(9)](2-) clusters. The optical band gap of the title compound is 1.25 eV. The use of weaker sequestering agents in the isolation of Ge cluster anions from en solutions provides an additional handle in a controlled molecular route to preparing new low-dimensional Zintl phases.

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A novel organic-inorganic hybrid based on an 8-electron-reduced Keggin polymolybdate capped by tetrahedral, trigonal bipyramidal, and octahedral zinc: synthesis and crystal structure of (CH3NH3)(H2bipy)[Zn4(bipy)3(H2O)2MoV8MoVI4O36)(PO4)].4H2O.

Hydrothermal reaction of H(3)PO(3), CH(3)NH(2), zinc(II) acetate, 4,4'-bipyridine (bipy), and (NH(4))(6)Mo(7)O(24).4H(2)O at 180 degrees C led to a novel organic-inorganic layered hybrid, [CH(3)NH(3)][H(2)bipy][Zn(4)(bipy)(3)(H(2)O)(2)Mo(V)(8)Mo(VI)O(36)(PO(4))].4H(2)O (1). Its structure was established by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2(1)/c with cell parameters of a = 17.3032(2), b = 17.8113(3), and c = 23.4597 (4) A, beta = 106.410(1) degrees, V = 6935.6(2) A(3), and Z = 4. The structure of compound 1 features a novel 2D layer built from the 8e-reduced tetracapped Keggin [Zn(4)Mo(12)O(36)(PO(4))](3)(-) anions, which are further interconnected by bridging bipy ligands. The four zinc(II) ions are in tetrahedral, trigonal bipyramidal, and octahedral coordination geometries, respectively.

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Synthesis, characterization, and crystal structures of three new divalent metal carboxylate-sulfonates with a layered and one-dimensional structure.

Hydrothermal reactions of 5-sulfoisophthalic acid (HO(3)SC(6)H(3)-1,3-(CO(2)H)(2), H(3)L) with M(II) carbonate (or oxide) and 4,4'-bipyridine (4,4'-bipy) (or 2,2'-bipyridine, 2,2'-bipy) resulted in three new metal carboxylate-sulfonate hybrids, namely, [CdL(H-4,4'-bipy)] (1) and [Cd(3)L(2)(2,2-bipy)(4)(H(2)O)(2)].2H(2)O (2) with layered structures and [ZnL(H-4,4'-bipy)(H(2)O)].2H(2)O (3), whose structure features a one-dimensional double chain. The cadmium(II) ion in complex 1 is seven-coordinated by five carboxylate oxygen atoms and one sulfonate oxygen atom from four ligands and a unidentate 4,4'-bipyridine. The interconnection of the cadmium(II) ions through bridging carboxylate-sulfonate ligands resulted in the formation of a <002> double layer with the bipyridyl rings orientated toward the interlayer space. Complex 2 has a different layered structure. Cd(1) is seven-coordinated by two bidentate chelating carboxylate groups from two ligands, a bidentate chelating 2,2'-bipy and an aqua ligand, and Cd(2) is octahedrally coordinated by two bidentate chelating 2,2'-bipy's, a sulfonate oxygen, and an aqua ligand. The coordination geometry around Cd(3) is similar to that of Cd(1) with the aqua ligand being replaced by an oxygen atom from the sulfonate group. The carboxylate-sulfonate ligand acts as pentadentate ligand, bridging with three cadmium(II) ions. The bridging of cadmium(II) ions through the carboxylate-sulfonate ligands resulted in the formation of <006> and <003> layers; the 2,2'-bipy molecules and [Cd(2)(2,2'-bipy)(2)(H(2)O)] cations are orientated to the interlayer space. Complex 3 features a 1D metal carboxylate-sulfonate double chain along the diagonal of the a- and b-axes. The zinc(II) ion is octahedrally coordinated by four carboxylate O atoms from three ligands, a unidentate 4,4'-bipy, and an aqua ligand. Each pair of zinc(II) ions is bridged by two carboxylate groups from two ligands to form a dimer, and such dimeric units are interconnected by bridging ligands to form a double chain. The sulfonate group of the carboxylate sulfonate ligand remains noncoordinated and forms a number of hydrogen bonds with aqua ligands as well as lattice water molecules.

Journal Article↗