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The novel sulfonate-carboxylate ligand of 5,7-disulfonate-1,4-naphthalenedicarboxylic acid (H4-DSNPDC) was synthesized, and its series of lanthanide compounds {[Ln3(μ2-OH)(DSNPDC)2(H2O)x]·yH2O}n (J...

A novel fluorinated biphenyldicarboxylate ligand of 3,3',5,5'-tetrafluorobiphenyl-4,4'-dicarboxylic acid (H2-TFBPDC) and its terbium metal-organic framework, {[Tb2(TFBPDC)3(H2O)]·4.5DMF·0.5H2O}n (denoted as JXNU-6), were synthesized. JXNU-6 exhibits a three-dimensional (3D) framework built from one-dimensional (1D) terbium carboxylate helical chains bridged by TFBPDC2- linkers. The 3D framework of JXNU-6 features 1D fluorine-lined channels. The gas adsorption experiments show that the activated JXNU-6 (JXNU-6a) displays distinct adsorption behavior for propyne (C3H4) and propylene (C3H6) gases. The effective removal of a trace amount of C3H4 from C3H6 was achieved by JXNU-6a under ambient conditions, which is demonstrated by the column-breakthrough experiments. The modeling studies show that the preferential binding sites for C3H4 are the exposed F atoms on the pore surface in 1D channels. The strong C-H···F hydrogen bonds between C3H4 molecules and F atoms of TFBPDC2- ligands dominate the host-guest interactions, which mainly account for the excellent C3H4/C3H6 separation performance of JXNU-6a. This work provides a strategy for specific recognition toward C3H4 over C3H6 through the C-H···F hydrogen bond associated with the fluorinated organic ligand.

Due to the intrinsic coordination preference of the linear uranyl unit, uranyl-organic frameworks (UOFs) are generally prone to exhibiting low-dimensional structures. Reactions of uranyl nitrate with biphenyl-3,3'-disulfonyl-4,4'-dicarboxylic acid dipotassium salt (K2H2BPDSDC) under different conditions led to three UOFs, namely, {(Me2NH2)[K2(UO2)3(μ3-O)(μ3-OH)2(μ2-OH)(BPDSDC)(H2O)3]·4DMF}n (1), {[K2(UO2)(μ3-O)(BPDSDC)0.5(H2O)2]}n (2), and {(Me2NH2)2.5[K1.5(UO2)(BPDSDC)1.5(H2O)3]}n (3). Compounds 1 and 2 contain one-dimensional (1D) ribbon structures formed from UO22+ units bridged by μ3-O atoms and carboxylate groups. The 1D ribbons in 1 are linked by K+ atoms to form a two-dimensional (2D) layer, which is further pillared by the biphenyl units to give a three-dimensional (3D) framework. For 2, the oxygen atoms of UO22+ units in each 1D ribbon bridge the K+ atoms to form four -[K-O-K]n- infinite chains located above and below the ribbon. The 1D ribbons in 2 are bridged by sulfonate groups to generate a 3D substructure featuring 1D channels occupied by biphenyl moieties. In 3, each mononuclear [(UO2)(COO)3] unit is bridged by three K+ atoms to form a 3D substructure featuring 1D small left-handed and large righted helical channels occluded by biphenyl moieties. Compound 2 exhibits an excellent proton conductivity with the highest conductivity of 1.07 × 10-3 S cm-1. The inner walls of 1D channels of 2 are full of the hydrophilic sulfonate groups, which boost enrichment of the guest water molecules, thus resulting in a high proton conductivity. Finally, temperature dependence of fluorescent studies showed that compounds 1 and 2 display the characteristic uranyl emissions. This work presents the elegant examples of the rarely explored 3D UOFs and expands the potentials of UOFs.

A novel metal-organic framework (MOF) of [Co8(OH)4(TCA)4(H2O)4]n (abbreviation: JXNU-9) based on the unique octanuclear Co8(μ3-OH)4 clusters linked by 4,4',4″-nitrilotribenzoate (TCA3-) ligands featuring small caged structures and one-dimensional channels was prepared and characterized. JXNU-9 shows a high C2H6 uptake capacity of 3.60 mmol g-1 (4.46 mmol cm-3) at 298 K and 1 atm with a small isosteric heat of adsorption (23.6 kJ mol-1) and a moderate C2H6/C2H4 adsorption selectivity of 1.7, resulting in excellent C2H6/C2H4 separation performance. The pore walls decorated by plenty of aromatic rings provide π-electron-cloud-surrounding environments to accommodate the large polarizable C2H6 molecules. The calculations demonstrate that the rich π-systems in JXNU-9 facilitate an adsorption affinity for large C2H6 molecules through multiple C-H···π interactions. Additionally, the open metal sites located in the concave pores with a close Co···Co separation (4.21 A) in octanuclear Co8(μ3-OH)4 clusters make the open metal sites inaccessible for the C2H4 molecule with a kinetic diameter of 4.163 A. Thus, the annihilation of open metal sites in this structure is achieved, which further facilitates the C2H6-selective C2H6/C2H4 separation.

A π-rich aromatic organic ligand, 4'-(3,5-dicarboxyphenyl)-2,2′,6′,2″-terpyridine (H2-DCPTP), and four new lanthanide coordination polymers, {[Ln(DCPTP)(NO3)]·(H2O)}n (Ln = Tb, Eu, Gd) and {[Tb0.9064Eu0.0936(DCPTP)(NO3)]·(H2O)}n (termed Tb0.9064Eu0.0936-DCPTP), were prepared. Compound {[Ln(DCPTP)(NO3)]·(H2O)}n is a 3D framework based on the dinuclear Ln2(μ2-COO)2] units linked by the tridentate DCPTP2− ligands. The H2-DCPTP ligand with an appropriate triplet excited state confirmed by DFT calculations and experiments, is a light-harvesting ligand for efficiently sensitizing of Tb3+ and Eu3+ simultaneously, thus enhancing the overall luminescent properties of Tb0.9064Eu0.0936-DCPTP. The Tb0.9064Eu0.0936-DCPTP behaves as a high-performance luminescent thermometer ranging from 150 to 300 K with a large relative thermal sensitivity (Sm) of 21.5% K−1 and a high energy transfer efficiency (η) of 84% at 300 K.

Two coordination polymers, {[Ln2(BPDSDC)(BDC)(H2O)6]·4H2O}n (Ln = Tb(1) and Eu(2)), constructed from biphenyl-3,3′-disulfonyl-4,4′-dicarboxylate (BPDSDC4–) and 1,4-benzenedicarboxylate (BDC2–) ligands were synthesized and structurally characterized. The solid state structure of {[Ln2(BPDSDC)(BDC)(H2O)6]·4H2O}n consists of one-dimensional (1D) Ln-BPDSDC double chains and two-dimensional (2D) Ln-BDC squares featuring the Ln2(COO)4 paddle-wheel units and the nanosized grids. Each grid of the 2D squares is threaded by a 1D Ln-BPDSDC double chain, wherein the two parts are interacted through coordination bonds between lanthanide centers of the 2D squares and sulfonate oxygen atoms from 1D chains. Thus the 1D Ln-BPDSDC double chains are threaded through the 2D squares stacked in an eclipsed fashion to give a three-dimensional (3D) distinct architecture. The two compounds emit the characteristic Tb(III) and Eu(III) emissions in the solid state, respectively. Temperature-dependent luminescent studies show the emission intensities for both compounds decrease as temperature increases, which indicates these compounds have the potential for sensing temperature.

An inorganic-organic hybrid compound (H2DPA)2(SiF6) (1) constructed from the di(pyridine-4-yl)amine (DPA) ligands and octahedral SiF62− anions was presented. The protonated H2DPA cations and SiF62− anions are linked by the N H⋯F hydrogen bonds to give a one-dimensional (1D) helical chain, which is further linked by the N H⋯F hydrogen bonds to generate a three-dimensional (3D) framework featuring helical chains. Compound 1 crystallizes in an acentric space group and exhibits a phase-matchable second-harmonic-generation (SHG) response of 1.4 times that of potassium dihydrogen phosphate (1.4 × KDP). The nonlinear organic ligand with inherent dipole and the distorted [SiF6] octahedra, as well as the helical chains in a parallel packing mode contribute the SHG activity for 1.

Two thorium–organic frameworks of [Th6O4(OH)4(TFBPDC)6(H2O)6]n (Th-TFBPDC) and [Th6O4(OH)4(TFBPDC)4(HCOO)4(H2O)6]n (Th-TFBPDC-i) constructed from the 3,3′,5,5′-tetrakis(fluoro)biphenyl-4,4′-dicarbo...

Three cadmium(II) coordination polymers constructed from 5,7-disulfonate-1,4-naphthalenedicarboxylate and N-containing ligands, {[Cd2(DSNPDC)(phen)(H2O)4]·2.5H2O}n (1), {[Cd2(DSNPDC)(phen)2(H2O)4]·3H2O}n (2) and [Cd2(DSNPDC)(bpy)2(H2O)4]n (3) (H4-DSNPDC = 5,7-disulfonate-1,4-naphthalenedicarboxylic acid, phen = 1,10-phenanthroline, and bpy = 2,2′-bipyridine), were synthesized and characterized. Compound 1 displays a two-dimensional (2D) layered structure. In 2 and 3, the dinuclear [Cd2(COO)2] units are connected by DSNPDC4– ligands to generate one-dimensional (1D) chains. Due to the presence of the terminal chelating phen/bpy ligands, all compounds show low dimensional structures. Compounds 1–3 exhibit fluorescence emissions centered at 378, 419 and 376 nm, respectively, which are assigned to ligand-centered emissions or ligand-to-metal charge transfer.

Two coordination polymers, [Co2(DPSDSDC)(H2O)6]n (1) and {[Cu4(DPSDSDC)2(bpy)4(H2O)2]·11.5(H2O)}n (2) (H4-DPSDSDC =diphenylsulfone-3,3′disulfo-4,4′-dicarboxylic acid and bpy = 4,4'-bipyridine), were prepared and characterized. Compound 1 shows a two-dimensional (2-D) layered structure featuring hydrophilic interlayered spaces and a moderate proton conductivity of 5.22 × 10−5 S cm−1 at 95% RH and 85 °C. Compound 2 contains the linear trinuclear Cu3 units and mononuclear copper(II) units, which are connected by diphenylsulfone-3,3′-disulfo-4,4′-dicarboxylate and 4,4'-bipyridine ligands to afford a 3-D framework. Compound 2 exhibits low proton conductivity resulting from the hydrophobic aromatic rings on the pore walls.

A 3D coordination polymer [CdK6(μ2-H2O)2(BODSDC)2(H2O)]n (1) based on the novel benzophenone-3,3′-disulfonyl-4,4′-dicarboxylate (BODSDC4−) ligand was synthesized and structurally characterized. The carboxylate and sulfonate groups of the organic ligands as well as the bridging water molecules connect the Cd2+ and K+ ions to produce a 2D layer, which is linked by the benzophenone moieties to give a 3D pillared framework. Compound 1 crystallizes in an acentric space group of Cc and has a large second-harmonic-generation (SHG) response of 1.3 times that of potassium dihydrogen phosphate (KDP) in the particle size of 25–210 μm. Further SHG measurements revealed that the material is type-I phase-matchable. The observed SHG efficiency is associated with the unsymmetrical geometry of the organic ligand and the distorted coordination polyhedrons of metal centers.

Two dinuclear lanthanide(III) complexes, namely, [Ln2(bfa)4L2]·CH2Cl2 (Ln(III) = Gd (1) and Tb (2), bfa = benzoyltrifluoroacetone and HL = 2-[[(4-methylphenyl)imino]methyl]-8-hydroxyquinoline), have been synthesized, structurally and magnetically characterized. 1 and 2 are phenoxo-O bridged dinuclear complexes and each center Ln(III) ion is eight-coordinated with two bidentate bfa and two μ2-O bridging 8-hydroxyquinoline Schiff base ligands. Magnetic studies reveal that 1 displays cryogenic magnetic refrigeration property (−ΔSm = 18.5 J kg−1 K−1 for ΔH = 7 T at 2 K); while 2 exhibits single-molecule magnet behavior with the anisotropic barriers (ΔE/kB) of 9.93 K.

Reactions of Cd(NO3)2·4H2O with 2-quinolinecarboxylic acid (H-QLC) in the presence of 1,4-benzenedicarboxylic acid (H2-BDC) or 1,3,5-benzenetricarboxylic acid (H-BTC) in DMF/H2O solvent afforded two compounds, namely, [Cd(QLC)(BDC)1/2(H2O)]n (1) and [Cd(QLC)(BTC)1/3]n (2). Both compounds are two-dimensional (2D) frameworks but feature different cadmium-carboxylate clusters as a result of the presence of the polycarboxylate ligands with different geometries and coordination preference. The dinuclear Cd2(QLC)2 units in 1 are bridged by the pairs of bridging water ligands to give a one-dimensional (1D) chain, which is further linked by the second ligand of BDC2– to form a 2D structure. Compound 2 is constructed from unique hexanuclear macrometallacyclic Cd6(QLC)6 clusters, which are linked by the surrounding BTC3– ligands to generate a 2D structure. Photoluminescence studies showed both compounds exhibit ligand-centered luminescent emissions with emission maxima at 405 and 401 nm, respectively.

Reactions of DyCl3·6H2O or Dy2O3 with 2-quinolinecarboxylic acid (H-QLC) yielded two compounds, namely, [Dy4(QLC)12(H2O)6]·4H2O (1) and [Dy(QLC)3(H2O)2]n (2). Compound 1 is a linear tetranuclear structure with one central [Dy2(QLC)4(H2O)4] subunit and two terminal [Dy(QLC)3(H2O)] subunits linked by bridging QLC− ligands. Compound 2 has a one-dimensional (1D) chain wherein the [Dy(QLC)2] unit formed by two QLC− ligands chelating a Dy(III) ion is connected by the bridging QLC− ligands. Compounds 1 and 2 exhibit slow magnetic relaxation behaviour in the absence of a static magnetic field, which is rarely observed in lanthanide-carboxylate compounds. During the structural evolution from a linear Dy4 cluster of 1 into a 1D chain of 2, the anisotropy energy barrier (Ueff) is enhanced from 45.4(2) to 144.2(1) K. Though the Dy(III) centers in 1 and 2 all are eight-coordinated with square antiprismatic coordination environments, the higher energy barrier observed for 2 could be the result of a more favorable crystal field for the Dy(III) ions in 2.

A novel sulfonate-carboxylate ligand of biphenyl-3,3'-disulfonyl-4,4'-dicarboxylic acid (H4-BPDSDC) and its lanthanide-organic frameworks {[LnK(BPDSDC)(DMF)(H2O)]·x(solvent)}n (JXNU-2, where JXNU denotes Jiangxi Normal University, DMF indicates dimethylformamide, and Ln = Sm(3+), Eu(3+), and Pr(3+)) were synthesized and structurally characterized. The three isomorphous lanthanide compounds feature three-dimensional frameworks constructed from one-dimensional (1D) rod-shaped heterometallic Ln-K secondary building units and are an illustration of a Kagome-like lattice with large 1D hexagonal channels and small 1D trigonal channels. The porous material of the representive JXNU-2(Sm) has an affinity to quadrupolar molecules such as CO2 and C2H2. In addition, the JXNU-2(Sm) compound exhibits humidity- and temperature-dependent proton conductivity with a large value of 1.11 × 10(-3) S cm(-1) at 80 °C and 98% relative humidity. The hydrophilic sulfonate group on the surface of channels facilitates enrichment of the solvate water molecules in the channels, which enhances the proton conductivity of this material. Moreover, the JXNU-2(Eu) material with the characteristic bright red color shows the potential for recognition of K(+) and Fe(3+) ions. The enhancing Eu(3+) luminescence with the K(+) ion and quenching Eu(3+) luminescence with the Fe(3+) ion can be associated with the functional groups of the organic ligand.

A series of dinuclear Dy(III) compounds with the general formula [Dy2(μ2-anthc)4(anthc)2(L)2] (anthc(-) = 9-anthracenecarboxylate, L = 2,2'-bipyridyl (1), 1,10-phenanthroline (2), and 4,7-dimethyl-1,10-phenanthroline (3)) were synthesized and magnetically characterized. These compounds exhibit single-molecule magnet (SMM) behavior in the absence of the direct-current field, which is rarely observed for carboxylate-bridged dinuclear Dy2 system. With the first coordination sphere of Dy(III) centers being fixed, the energy barrier was modulated by sequentially modifying the terminal neutral L ligands in this Dy2 system. Theoretical calculations revealed that the symmetry of the charge distribution surrounding the Dy(III) centers in 1-3 is the decisive factor to determine the relaxation of the SMMs. The combination of the larger charge distribution along the magnetic axis and lower charge distribution in the equatorial plane (hard plane) formed by five coplanar coordination atoms including two N atoms provided by an L ligand led to a strong easy-axis ligand field in these compounds. This work presents a rational method to modulate the dynamic magnetic relaxation of the lanthanide SMMs through fine-tuning electrostatic potential of the atoms on the hard plane.

Coordination polymers constructed from metal ions and organic ligands have attracted considerable attention owing to their diverse structural topologies and potential applications. Ligands containing carboxylate groups are among the most extensively studied because of their versatile coordination modes. Reactions of benzene-1,4-dicarboxylic acid (H2BDC) and pyridine (py) with ZnIIor CoIIyielded two new coordination polymers, namely, poly[(μ4-benzene-1,4-dicarboxylato-κ4O:O′:O′′:O′′′)(pyridine-κN)zinc(II)], [Zn(C8H4O2)(C5H5N)]n, (I), andcatena-poly[aqua(μ3-benzene-1,4-dicarboxylato-κ3O:O′:O′′)bis(pyridine-κN)cobalt(II)], [Co(C8H4O2)(C5H5N)2(H2O)]n, (II). In compound (I), the ZnIIcation is five-coordinated by four carboxylate O atoms from four BDC2−ligands and one pyridine N atom in a distorted square-pyramidal coordination geometry. Four carboxylate groups bridge two ZnIIions to form centrosymmetric paddle-wheel-like Zn2(μ2-COO)4units, which are linked by the benzene rings of the BDC2−ligands to generate a two-dimensional layered structure. The two-dimensional layer is extended into a three-dimensional supramolecular structure with the help of π–π stacking interactions between the aromatic rings. Compound (II) has a one-dimensional double-chain structure based on Co2(μ2-COO)2units. The CoIIcations are bridged by BDC2−ligands and are octahedrally coordinated by three carboxylate O atoms from three BDC2−ligands, one water O atom and two pyridine N atoms. Interchain O—H...O hydrogen-bonding interactions link these chains to form a three-dimensional supramolecular architecture.

A coordination polymer [Zn(H-ntb)]n (1) based on the tritopic carboxylate linker of 4,4′,4′'-nitrilotribenzoate (H3-ntb) was reported here. Compound 1 crystallizes in a polar space group of Pca21 and contains two-dimensional layers formed from the left- and right-handed helical chains pillared by the benzoate moieties to give a three-dimensional structure. The present compound 1 features a noncentrosymmetric structure and displays a strong phase-matchable second-harmonic-generation (SHG) response of 1.2 times that of potassium dihydrogen phosphate (KDP). The inherent polarity of the 4,4′,4′'-nitrilotribenzoate and distortive [ZnO4] tetrahedrons as well as the asymmetric arrangement of the building blocks are responsible for the SHG activity for 1.

The benzophenone-3,3′-disulfonyl-4,4′-dicarboxylic acid (H4–BODSDC) ligand and compounds, {(H3O)[Ln(BODSDC)(H2O)2]}n (Ln = Tb(1), Eu(2), and Gd(3)), were synthesized and structurally characterized. The lanthanide centers are bridged by the carboxylate groups of BODSDC4– ligands to give a one-dimensional (1D) chain. The 1D chains are connected by the BODSDC4– ligands to yield a three-dimensional (3D) structure featuring 1D channels. The lanthanide ions are efficiently sensitized by the BODSDC4– ligand with an appropriate triplet excited state to generate characteristic Tb(III) and Eu(III) emissions in Tb(1) and Eu(2), respectively. Thus the binary compound, {(H3O)[Tb0.93Eu0.07(BODSDC)(H2O)2]}n (abbreviated as Tb0.93Eu0.07-BODSDC), was achieved for use as a ratiometric temperature sensor. The ratio values of Tb(III) emission at 544 nm (ITb) and Eu(III) emission at 616 nm (IEu) for Tb0.93Eu0.07-BODSDC linearly vary with temperature over a wide range, which indicates that the Tb0.93Eu0.07-BODSDC is a thermome...

A new compound, {[Co(bmzbc)(2)]center dot 2DMF}(n) (JXNU-1, JXNU denotes Jiangxi Normal University), based on the 4-(benzimidazole-1-yl)benzoate (bmzbc(-)) ligand has been synthesized and structurally characterized. The Co(II) ions are bridged by the rod-like bmzbc(-) ligands to give a two-dimensional (2D) sheet wherein the Co(II) ions are spatially separated from each other by the long bmzbc- rods. The 2D sheets are further stacked into a 3D framework with ID channels occluding the guest DMF molecules. Detailed magnetic studies show that the individual octahedral Co(II) ions in JXNU-1 exhibit field-induced slow magnetic relaxation, which is characteristic behavior of single-ion magnets (SIMs). The rarely observed positive value of zero-field splitting (ZFS) parameter D for the Co(II) ion in JXNU-1 demonstrates that JXNU-1 is a unique example of Co(II)-based SIMs with easy-plane anisotropy, which is also confirmed by the calculations. The microporous nature of JXNU-1 was established by measuring CO2 sorption isotherms. The abrupt changes observed in the C3H8 and C2H6 adsorption isotherms indicate that a structural transformation occurred in the gas-loading process. The long connection between the magnetic metal centers in JXNU-1 meets the requirements for construction of porosity and SIM in a well-defined network, harmoniously providing a good candidate of functional molecular materials exhibiting SIM and porosity.

2-Fold interpenetrating chiral quartz nets with opposite handedness have been observed in a centrosymmetric coordination polymer {[Zn3(bmzbc)6]·11.5DMF}n (Hbmzbc = 4-(benzimidazole-1-yl)benzoic acid), which is a unique example of an interpenetrating enantiomorphic pair of quartz nets that have never been realized before.

The highly odd-numbered 15-connected nonanuclear [Ln9(μ3-O)2(μ3-OH)12(O2C−)12(HCO2)3] and 9-connected trinuclear [Ln3(μ3-O)(O2C−)6(HCO2)3] lanthanide-carboxylate clusters with triangular and linear carboxylate bridging ligands were synergistically combined into Ln-MOFs, [(CH3)2NH2]3{[Ln9(μ3-O)2(μ3-OH)12(H2O)6][Ln3(μ3-O)(H2O)3](HCO2)3(BTB)6}·(solvent)x (abbreviated as JXNU-3, Ln = Gd, Tb, Er; BTB3– = benzene-1,3,5-tris(4-benzoate)), displaying a (3,9,15)-connected topological net. The JXNU-3(Tb) exhibits highly selective CO2 adsorption capacity over CH4 that resulted from the high localized charge density induced by the presence of the nonanuclear and trinuclear cluster units. In addition, JXNU-3(Tb) with high chemical stability and characteristic bright green color exhibits fluorescent pH sensing, which is pertinent to the different protonation levels of the carboxylate groups of the benzene-1,3,5-tris(4-benzoate) ligand with varying pH.

A dysprosium-carboxylate coordination polymer, {[Dy2(2,2′-bpdc)3(e-urea)(H2O)](e-urea)}n (1) (2,2′-bpdc2 − = 2,2′-biphenyldicarboxylate and e-urea = ethyleneurea), has been synthesized using a deep-eutectic solvent of choline chloride/e-urea. Four Dy3 + ions are linked by the carboxylate oxygen atoms of the 2,2′-bpdc2 − ligands to form a linear Dy4 unit, which is further linked by the carboxylate groups of the 2,2′-bpdc2 − ligands to give a rare example of one-dimensional chain based on the linear Dy4 secondary building units. Detailed static and dynamic magnetic analysis of 1 revealed that 1 exhibits a slow magnetic relaxation behavior.

Two cadmium(II) coordination polymers, namely, [Cd-3(m-phth)(2)(atz)(2)](n) (1) (m-phth = m-phthalate and atz = 3-amino-1,2,4-triazolate) and [Cd(atphth)(H2O)](n) (2) (atphth = 2-aminoterephthalate), were synthesized and structurally characterized. Compound 1 features a three-dimensional (3D) pillared framework based on two-dimensional (2D) cadmium-benzenedicarboxylate ladders pillared by the triazolate ligands. Compound 2 has a 3D framework constructed from 2D cadmium-benzenedicarboxylate layers, which are further linked by Cd-N bonds between the cadmium ions and amino groups of the atphth(2-) ligands of the adjacent layers to form the final 3D structure. Compounds 1 and 2 exhibit solid-state photoluminescence with emission maxima at 448 and 470 nm, respectively.

Two new cadmium(II) coordination compounds, [Cd4(SBTC)2(2,2′-bpy)6(H2O)4](2,2′-bpy) (1) (2,2′-bpy = 2,2′-bipyridyl) and {[K2Cd(SBTC)(H2O)4](H2O)2}n (2), were synthesized using a novel ligand of 5-sulfonyl-1,2,4-bezenetricarboxylic acid (H4-SBTC) featuring three carboxylate groups and one sulfonate group stationed on a phenyl central motif. Compound 1 is a discrete tetranuclear [Cd4(SBTC)2(2,2′-bpy)6(H2O)4] structure with a solvated 2,2′-bpy molecule, wherein the four cadmium ions are bridged by two μ3-SBTC4– ligands. The discrete tetranuclear [Cd4(SBTC)2(2,2′-bpy)6(H2O)4] motif is extended into a three-dimensional (3D) supramolecular framework through hydrogen bonds and π–π interactions. In compound 2 the cadmium ions and potassium ions are interconnected by the SBTC4– ligands and bridging water molecules to give a complex 3D structure. The 3D structure is constructed by a rare 3D inorganic cadmium-potassium-oxide framework, in which the cadmium and potassium ions are bridged by the sulfonate groups and bridging water molecules. In the solid state, compounds 1 and 2 exhibit photoluminescence with emission maximum at 380 and 445 nm, respectively.

Two mononuclear compounds Ln(e-urea)8(NO3)3 (Ln = Dy(1) and Tb(2)) have been urothermally synthesized by using the ethyleneurea (e-urea) as an organic ligand and a solvent. The e-urea ligand with a single donor atom is a unique ligand for coordinating to lanthanide ions, which is very different from those commonly observed polytopic ligands with suitable coordination pockets to encapsulate lanthanide(III) ions or chelating organic ligands. The lanthanide center surrounded by eight e-urea ligands is in a square antiprismatic environment with an approximate D4d local symmetry. Magnetic properties of both compounds have been investigated in detail using direct-current and alternating-current susceptibility measurements. The Dy(1) analogue displays slow magnetic relaxation behavior with an effective energy barrier of the magnetic relaxation of 37.68 K and the pre-exponential factor τ0 of 1.47 × 10−9 s in the presence of direct-current field of 2 kOe.

Two coordination compounds with novel sulfonate–carboxylate ligand of 2,5-disulfonylterephthalate acid (H 4 DSBDC), namely, [Ni(2,2′-bpy)(H 2 O) 4 ](DSBDC) 0.5 ( 1 ) and [Mn(DSBDC) 0.5 (2,2′-bpy)(H 2 O) 2 ] n ( 2 ) (2,2′-bpy = 2,2′-bipyridyl), have been synthesized. In situ formation of H 4 DSBDC ligand derived from 5-sulfonyl-1,2,4-benzenetricarboxylic acid is unprecedented and involves a fundamentally new substitution of sulfonate for carboxylate to in situ ligand synthesis reaction. Compound 1 has a mononuclear nickel [Ni(2,2′-bpy)(H 2 O) 4 ] 2+ motif charged with tetraanionic DSBDC 4− ion. The [Ni(2,2′-bpy)(H 2 O) 4 ] cations and DSBDC 4− anions are linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure. Compound 2 is a one-dimensional polymeric chain based on the dinuclear Mn 2 units. The one-dimensional chains are linked by hydrogen bonds and π–π interactions to form a three-dimensional supramolecular structure. The temperature-dependent magnetic susceptibility data of 1 and 2 have been investigated. The Curie constant C and Weiss constant θ are 1.29 cm 3 K mol −1 and −1.61 K for compound 1 , respectively, revealing antiferromagnetic interactions between the Ni(II) ions. The magnetic data of 2 are fitted with the dinuclear Mn 2 model giving the best fitting results of g = 2.04, J = −0.68, and zj ′ = −0.016 cm −1 , which indicate the antiferromagnetic interactions are present in 2 .

[Yb2(SBTC)(ox)(H2O)5] n (1) (H4-SBTC = 5-sulfonyl-1,2,4-benzenetricarboxylic acid and ox = oxalate) has been hydrothermally synthesized by reaction of 5-sulfonyl-1,2,4-benzenetricarboxylic acid with Yb(NO3)3∙5H2O. In situ formation of oxalate derived from H4-SBTC is unprecedented and adds a new oxalate formation reaction to in situ ligand syntheses. Compound 1 features a 2-D bilayered coordination network, which is further extended into a 3-D supramolecular framework through interlayered hydrogen bonds. Magnetic measurements on 1 indicate that there is an antiferromagnetic interaction between Yb(III) ions.

Organizing magnetically isolated 3d transition metal ions, which behave as single-ion magnet (SIM) units, in a coordination network is a promising approach to design novel single-molecule magnets (SMMs). Herein 3D chiral and 2D achiral cobalt(ii) coordination compounds based on single metal nodes with a 4-(benzimidazole-1-yl)benzoic acid (Hbmzbc) ligand, namely, [Co(bmzbc)2(1,2-etdio)]n () (1,2-etdio = 1,2-ethanediol) and [Co(bmzbc)2(Hbmzbc)]n (), have been synthesized and structurally characterized. The 3D chiral structure with 2-fold interpenetrating qtz topological nets consisting of totally achiral components was obtained via spontaneous resolution, while the achiral structure is a 2D (4,4) net. In both structures, individual cobalt(ii) ions are spatially well separated by the long organic ligands in the well-defined networks. Magnetic measurements on and showed field-induced slow magnetic relaxation resulting from single-ion anisotropy of the individual Co(ii) ions. Analysis of the dynamic ac susceptibilities with the Arrhenius law afforded an anisotropy energy barrier of 16.8(3) and 31.3(2) K under a 2 kOe static magnetic field for and , respectively. The distinct coordination environments of the Co(ii) ions in and lead to the different anisotropic energy barriers.

An organic ligand 4-(1,2,4-triazol-1-yl) benzoic acid (Htzbc) with a nonlinear optical (NLO) chromophore has been synthesized. Reaction of Zn(NO3)2 with Htzbc ligand in 1-n-butyl-3-methylimidazolium tetrafluoroborate ionic liquid afforded compound Zn(tzbc)2 (1). The Htzbc organic solid and 1 crystallize in the acentric Pn and Cc space groups, respectively. The tetrahedral Zn2+ center in 1 coordinates to two triazole nitrogen atoms and two carboxylate oxygen atoms from four tzbc– ligands, leading to a noncentrosymmetric 5-fold interpenetrating diamondoid network. Second-harmonic generation (SHG) measurements revealed the Htzbc solid and 1 have SHG activities. The Htzbc compound has a large SHG effect, which is approximately 3 times that of KDP and is type-I phase matchable, while 1 also belongs to phase-matchable class with a SHG response of about 1.2 times that of KDP. The SHG active of the organic solid can be derived from the inherently dipolar Htzbc molecule as well as the optimal relative orientation ...

The title compound, [CuNa(C4H3O7S)(C10H8N2)(H2O)3]n, consists of one CuIIcation, one NaIcation, one 2-sulfonatobutanedioate trianion (SSC3−), one 2,2′-bipyridyl (bpy) ligand and three coordinated water molecules as the building unit. The coordination of the CuIIcation is composed of two pyridyl N atoms, one water O atom and two carboxylate O atoms in a distorted square-pyramidal coordination geometry with an axial elongation. The NaIcation is six-coordinated by three water molecules and three carboxylate O atoms from three SSC3−ligands in a distorted octahedral geometry. Two SSC3−ligands link two CuIIcations to form a Cu2(SSC)2(bpy)2macrocyclic unit lying across an inversion centre, which is further linked by NaIcationsviaNa—O bonds to give a one-dimensional chain. Interchain hydrogen bonds link these chains to form a two-dimensional layer, which is further extended into a three-dimensional supramolecular framework through π–π stacking interactions. The thermal stability of the title compound has also been investigated.

A multifunctional ligand of 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid (H4-DSNDA) and its Eu(III) coordination polymer {(H-dpp)[Eu(DSNDA)(H2O)4](H2O)4}n (dpp = 1,3-di(4-pyridyl)propane) (1) have been synthesized. Compound 1 is a 2D anionic network based on the paddle-wheel Eu2(CO2)4 building blocks charge-balanced by the monoprotonated H-dpp molecules. Compound 1 shows intense red characteristic europium(III)-centered emission. The Eu(III) emissive state exhibits a single-exponential decay with a lifetime of 0.212 ms as measured at 613 nm after excitation at 346 nm. No observable emission peak arising from the DSNDA4− ligand (λem = 408 nm) is observed in the emission spectrum of compound 1, indicating an efficient energy transfer occurs from DSNDA4− organic ligand to Eu(III) ions. The results reveal the large π-rich aromatic organic ligand is a suitable chromophoric moiety for sensitization of Eu(III) luminescence.

A sulfonate-carboxylate ligand, 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid (H(4)-DSNDA), and eight new lanthanide coordination polymers {[Pr(4)(OH)(4)(DSNDA)(2)(H(2)O)(12)](H(2)O)(10)}(n) (1), [Ln(H(2)-DSNDA)(0.5)(DSNDA)(0.5)(H(2)O)(5)](n) (Ln = La(2), Nd(3), Sm(4), Eu(5), Gd(6), and Dy(7)), and {[Er(H-DSNDA)(H(2)O)(4)](H(2)O)}(n) (8) have been synthesized. Detailed crystal structures of these compounds have been investigated. Compound 1 has a 3D framework featuring the unique cubane-shaped [Pr(4)(μ(3)-OH)(4)] clusters and is a binodal 4,8-connected network with (4(16)·6(12))(4(4)·6(2))(2) topology. Compounds 2-7 are isostructural and have 2D layered structures. Compound 8 is also a 2D layer but belongs to different structural types. The luminescence behavior of compound Eu(5) shows that the π-rich aromatic organic ligands efficiently transfer the absorbed light energy to the Eu(III) ions, thus enhancing the overall luminescent properties of compound Eu(5). The magnetic properties of all compounds except for the diamagnetic La(2) compound have been investigated. In addition, elemental analysis, IR spectra, and thermogravimetric analysis of these compounds are also described.

Three new hybrid mercury halides compounds with 1,4-diazabicyclo[2.2.2]octan (DABCO) ligand, namely, Hg 2 (μ 2 -I) 2 I 3 (H-DABCO) ( 1 ), {[Hg 5 (μ 2 -I) 6 I 4 (μ 2 -DABCO) 2 ][Hg 2 I 4 (μ 2 -DABCO)]} n ( 2 ) and {[Hg 2 (μ 2 -Br) 2 Br 2 (μ 2 -DABCO)]·2(HgBr 2 )} n ( 3 ), have been synthesized. Compound 1 crystallizes in a P 2 1 chiral space group and is a discrete dinuclear mercury(II) compound with inorganic Hg 2 (μ 2 -I) 2 I 3 unit. Compound 2 consists of 1D neutral [Hg 5 (μ 2 -I) 6 I 4 (μ 2 -DABCO) 2 ] n broad polymeric array containing uncommon inorganic decanuclear [Hg 10 (μ 2 -I) 12 I 8 ] n clusters, and neutral guest Hg 2 (μ 2 -DABCO)I 4 molecules. Compound 3 is composed of a neutral [Hg 2 (μ 2 -Br) 2 Br 2 (μ 2 -DABCO)] n polymeric chain and guest inorganic HgBr 2 molecules. In all cases, the halide ions participate in the framework connectivity as bridging ligands. A variety of coordination geometries displayed by the metal sites such as linear, trigonal and tetrahedral are observed in these compounds. Of the three compounds, only compound 3 displays photoluminescence with a emission maximum at 528 nm upon excitation at 468 nm. In addition, these compounds are characterized by IR, elemental analysis, and thermogravimetric analysis.

Two isomorphous compounds [Eu(2,2′-bpdc)(NO3)(e-urea)3]n (1) and [Tb(2,2′-bpdc)(NO3)(e-urea)3]n (2) (2,2′-bpdc2 − = 2,2′-biphenyldicarboxylate and e-urea = ethyleneurea) have been synthesized using a deep-eutectic solvent of choline chloride/e-urea. The lanthanide ions are linked by the 2,2′-bpdc2 − ligands to form one-dimensional helical chains in these compounds. Of special interest is the presence of parallel left- and right-handed single helices with the ratio of 1:1 in both compounds. Detailed photoluminescence studies show that both compounds exhibit typical lanthanide luminescent emissions and the excitation energy has been efficiently transferred to the lanthanide ions from the organic ligands.

Solvo(hydro)thermal reactions of CuX (X = Cl, Br, I) with 4-methyl-1,2,4-triazole-3-thiol (Hmptrz) ligand afforded four new copper(I) coordination polymers, namely, [Cu(μ4-mptrz)]n (1), [Cu(μ2-Hmptrz)(μ2-I)]n (2), [Cu12(μ4-mptrz)4(μ4-I)3(μ3-I)4(μ2-I)]n (3), and [Cu(μ2-Hmptrz)(μ2-DmptrzSS)I]n (4) (DmptrzSS = 4,4′-dimethyl-3,3′-dithiodi-1,2,4-triazole), respectively. Single-crystal X-ray diffraction revealed that compound 1 has a two-dimensional (2D) layered structure with (44·62) topology and contains meso-helical (CuS)n chains. Compound 2 features a one-dimensional (1D) chain structure constructed from an unusual inorganic [Cu(μ2-S)2Cu(μ2-I)2Cu]n chain formed from two types of four-membered Cu2(μ2-S)2 and Cu2(μ2-I)2 rings. Compound 3 is a two-dimensional (2D) structure constructed from rugby-shaped Cu6I5 and planar Cu4I3 cluster units, and two types of Cu(mptrz)2 units. The I− ion in structure 3 displays its coordination versatility with μ4-, μ3-, and μ2- bridging coordination modes. Compound 4 has a doub...

Three new coordination compounds with 4-sulfophthalic acid (H3SPA) ligand, namely {[Pb3(4-SPA)2(H2O)](H2O)}n (1), [Mn(4,4′-bpy)2(H2O)4][Mn2(4-SPA)2-(4,4′-bpy)4(H2O)4]·7.5(H2O) (2) and Cu2(4-HSPA)2(2,2′-bpy)2(H2O)2 (3) (4,4′-bpy = 4,4′-bipyridine and 2,2′-bpy = 2,2′-bipyridine), have been synthesized. The structures exhibit different dimensionality depending on the nature of the metal ions and/or the ancillary ligands. Compound 1 has a 2D layered architecture constructed from one-dimensional inorganic lead(II) oxygen chains containing tetranuclear [Pb4(μ2-O)4] cluster. Compound 2 has a dinuclear manganese [Mn2(4-SPA)2(4,4′-bpy)4(H2O)4] motif charged with mononuclear [Mn(4,4′-bpy)2(H2O)4]2+ cation. Compound 3 is a discrete dinuclear copper(II) structure that linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure. In the solid state, compound 1 exhibits blue photoluminescence with the maximum at 432 nm upon excitation at 350 nm. The temperature-dependent magnetic susceptibility data of 2 have been investigated. The Curie constant C and Weiss constant θ are 3.14 emu K mol−1 and −2.09 K, respectively, revealing antiferromagnetically magnetic interactions between the Mn2+ ions. In addition, these compounds are characterized by powder X-ray diffraction, IR, elemental analysis, and thermogravimetric analysis.

Reactions of Zn(NO3)2·6H2O with 1,2,4-triazole (Htrz) and 1,3,5-benzenetricarboxylic acid (H3BTC) or 5-sulfoisophthalic acid (5-H3SIP) afforded two coordination polymers, {[Zn5(μ3-OH)2(trz)2(BTC)2(DMF)2]·x(solvent)}n (1) and {[Zn7(trz)8(5-SIP)2(H2O)4]·4(H2O)}n (2). Compound 1 has pentanuclear [Zn5(μ3-OH)2] clusters, which are linked by the triazolate ligands to give a 2D layer. The 2D layer is further bridged by BTC3− ligands to form a 3D framework. The 3D framework of 1 has 1D channels filled by solvent molecules. Desolvated 1 shows a moderate CO2 uptake and high CO2/CH4 and CO2/N2 adsorption selectivities due to its carboxylate oxygen decorated pore environment. Compound 2 contains a rare 3D zinc-triazolate framework constructed from a pentanuclear [Zn5(trz)8] cluster wherein the five zinc atoms are arranged linearly. The 3D zinc-triazolate substructure has 1D open channels filled by 5-SIP3− ligands, which interact with the zinc-triazolate framework through Zn–O bonds, leading to a non-porous 3D structure of 2. Introduction of BTC3− into the zinc-triazolate system gave the porous structure of 1. While a variation of BTC3−, 5-SIP3− was introduced into the zinc-triazolate system yielding a non-porous structure of 2, demonstrating that the secondary ligands play an important role in the formation of the final structures.

Self-assembly of Cd(NO3)2 with o -phthalic acid monopotassium salt (KHphth) in the presence of ethylenediamine (en) produced a new heterometallic coordination polymer [CdK2(phth)2(en)0.5(H2O)]n (1). Single-crystal X-ray analyses reveal that it crystallizes in a monoclinic space group P 21/c. a = 11.6707(6) A, b = 8.1019(4) A, c = 20.9503(11) A, β = 94.6640(10)o. The complex displays an en-pillared 3D framework, which is constructed from 2D [CdK2(phth)2(H2O)]n layers featuring uncommon inorganic cadmium-potassium-oxide layers containing potassium-oxide layers. In the solid state, complex 1 shows photoluminescence with the maximum emission intensities at 355 nm upon excitation at 312 nm. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Three inorganic–organic supramolecular networks based on 2-[(4,6-dimethylpyrimidinyl)-2-thio] acetic acid (HL) and Zn(II), Ag(I) and Cu(II) salts have been prepared and structurally characterized by single-crystal X-ray diffractions. Mononuclear complex [ZnL 2 (1,2-DAP)]·2H 2 O ( 1 ) (1,2-DAP = 1,2-diaminopropane) exhibits a three-dimensional cavity architecture through hydrogen bonds and π–π interaction. The crystal structure of (AgL) n ( 2 ) consists of two-dimensional brick-wall framework. [Cu 2 L 4 (CH 3 OH) 2 ]·3CH 3 OH ( 3 ) contains dinuclear copper units, which are bridged by four acetate groups. Electrochemical behaviors have been systematically investigated by different electrochemical methods. Complex 3 shows a pair of quasi-reversible redox peaks. The electrode process is controlled by diffusion. The diffusion coefficient ( D ) for 3 is about 10 −6 cm 2 s −1 . The electron transfer number ( n ) and the transfer coefficient ( α ) are 2 and 0.33, respectively.

The compounds [Cu2(SIP-O)(bpy)2(H2O)2]·7H2O (1) and [Mn(HSIP)(bpy)]n (2) were synthesized by the hydrothermal reactions of Cu(OH)2 or MnCl2, 5-sulfoisophthalic acid monosodium salt (NaH2SIP), and 2,2′-bipyridine (bpy). Single-crystal X-ray diffraction reveals that the unprecedented hydroxylation of SIP3– catalyzed by Cu2+ occurs and produces the discrete SIP-O4–-bridged dicopper(II) compound 1. The hydrogen-bonding association of the seven lattice water molecules of 1 leads to the formation of an unusual 2D-layered water consisting of fused four- and sixteen-membered water rings and a discrete water octamer consisting of a cyclic tetramer and four dangling water molecules. Compound 2 is a 3D coordination polymer and has two kinds of topologically equivalent 4-connected nodes based on Mn2+ and HSIP2– with a rare (4.65) topology.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

The crystal structure of the title compound, {[Tm(C(8)H(3)O(7)S)(H(2)O)(5)] x 1.5C(10)H(8)N(2) x 0.5H(2)O}(n), is built up from two [Tm(SIP)(H(2)O)(5)] molecules (SIP(3-) is 5-sulfonatobenzene-1,3-dicarboxylate), three 4,4'-bipyridyl (bpy) molecules and one solvent water molecule. One of the bpy molecules and the solvent water molecule are located on an inversion centre and a twofold rotation axis, respectively. The Tm(III) ion coordination is composed of four carboxylate O atoms from two trianionic SIP(3-) ligands and five coordinated water molecules. The Tm(3+) ions are linked by the SIP(3-) ligands to form a one-dimensional zigzag chain propagating along the c axis. The chains are linked by interchain O-H...O hydrogen bonds to generate a two-dimensional layered structure. The bpy molecules are not involved in coordination but are linked by O-H...N hydrogen bonds to form two-dimensional layers. The two-dimensional layers are further bridged by the bpy molecules as pillars and the solvent water molecules through hydrogen bonds, giving a three-dimensional supramolecular structure. pi-pi stacking interactions between the parallel aromatic rings, arranged in an offset fashion with a face-to-face distance of 3.566 (1) Angstrom, are observed in the crystal packing.

A novel 3D coordination polymer [Mn(tzda)(4,4′‐bipy)(H2O)] n (1) of mixed ligands, (1,3,4‐thiadiazole‐2,5‐diyldithio)diacetic acid (H2tzda) and 4,4′‐bipyridine, has been hydrothermally synthesized and characterized by single‐crystal X‐ray diffraction and IR spectra. Complex 1 crystallizes in the orthorhombic space group Pbca with a=18.1657(9)A, b=9.0882(5)A, c=22.9333(12)A. In the structure, each Mn(II) ion is in a distorted octahedral coordination geometry, three among four coordination sites of the equatorial plane are occupied by the carboxylate oxygen atoms and the remaining site is occupied by the water molecule while the apical positions are occupied by two nitrogen atoms from two bipy molecules. The six‐coordinated Mn ions are interlinked by flexible tzda ligands to form layers, which are sustained by rigid 4,4′‐bipy ligands into a 3D open framework. The magnetic property of 1 was also investigated and the magnetic susceptibility data were rationally fitted with J=−0.103 cm−1, g=2.09, zJ′=−0.02 cm−...

The atomic bonding of the segregated cell of Al-Li alloy in earlier ageing condition was calculated according to the empirical electron theory (EET) in solid. The results showed that the strongest covalent bond was the Al-Al bond in the segregated cell without vacancy, while the strongest covalent bond was the Al-Li bond in the cell containing vacancy. Since the difference of electronagativity between the Al and Li atoms was obvious, it was inclined to form the Al-Li segregated cell of short range order structure in the condition of vacancy joining. The short range order structure with vacancy was probably the embryo or precursor structure of the metastable phase ' δ (Al3Li). As the ' δ (Al3Li) was coherence with matrix, the bond net strength was enhanced by the precipitation of ' δ (Al3Li) and hence the alloy was strengthened.

A new coordination compound, [Pb(phen)(NO3)3(H2O)]n(1), has been synthesized by the reaction of Pb(NO3)2 with phenanthroline (phen) in water. The complex was crystallized using the solution diffusion method and structurally characterized by X‐ray single crystal diffraction. The compound 1 crystallizes in the monoclinic space group P21/c. In the structure unit of the compound 1, the central Pb(II) ion is six‐coordinated with two nitrogen atoms from the phen, three oxygen atoms from three nitrate groups and one oxygen atom from a water molecule. The [Pb(phen)(NO3)2(H2O)] units are linked together by O1, N3, and O3 bridge from nitrate groups, resulting in the formation of one‐dimensional chain structures. It is further connected by hydrogen bonds and π‐π interactions formed a complicated supramolecular compound. In addition, the spectral properties and TG analyses for the compound 1 are also discussed The IR, UV‐Vis spectra of the title compound as well as its thermodecomposition behavior were also discussed...

A novel 3D coordination polymer [Gd2(tzda)3(H2O)5] n (1) has been synthesized by hydrothermal reaction of Gd(NO3)3 with a flexible building unit—(1,3,4‐thiadiazole‐2,5‐diyldithio)diacetic acid (H2tzda). X‐ray single crystal diffraction analysis reveals that 1 belongs to triclinic system, P1¯ space group. The crystallographic data are: a=9.6769(7)A, b=13.4539(9) A, c=14.9369 (10)A, α=65.9050(10)°, β=82.1290(10)°, γ=80.1210(10)°. In the structure, two Gd(III) ions are both nine‐coordinated and in different coordination environments while the tzda2‐ anions display three different coordination modes to link Gd(III) ions and then form a complicate three‐dimensional network structure.

Hydrothermal reactions of Cd(NO 3 ) 2 and NaH 2 SIP (5-sulfoisophthalic acid monosodium salt) at pH = 2 and 7 produce [Cd 2 (μ 2 -OH 2 ) 2 (HSIP) 2 (H 2 O) 6 ] (1) and [Cd 5 (μ 2 -OH) 2 (μ 3 -OH) 2 (SIP) 2 (H 2 O) 5 ] n (2), respectively. A similar hydrothermal reaction in the presence of dpp [1,3-bis(4-pyridyl)propane] yields ([Cd 3 (SIP) 2 (dpp) 6 ]·4(H 2 O)} n (3). Single-crystal X-ray diffraction reveals that compound 1 has a discrete dinuclear structure with the [Cd 2 (μ 2 -OH 2 ) 2 ] unit. Polymer 2 features an inorganic layer, which has centrosymmetric 12- and 24-membered rings composed of chair-shaped [Cd 4 (μ 3 -OH) 2 ] units and Cd(μ 2 -OH) 2 (CO 2 ) units, and is interconnected by SIP into a 3D framework. Complex 3 contains a 1D ladder-like [Cd 4 (SIP) 4 ] n unit with four cadmium atoms co-planar, which is interconnected by dpp into a 2D nanosized layered structure. In the solid state, compounds 1 and 3 exhibit blue-violet photoluminescence with maxima at 436 and 409 nm upon excitation at 342 and 350 nm, respectively. However, compound 2 shows photoluminescence with the maximum at 306 nm upon excitation at 270 nm.

A coordination polymer [Co4(μ2-H2O)2(1,4-ndc)4(dpp)2]n (1) with the 1,4-naphthalenedicarboxylic acid (1,4-H2ndc) and 1,3-di(4-pyridyl)propane (dpp) mixed ligands has been synthesized and structurally and magnetically characterized. Compound 1 features a 3D framework based on the tetranuclear [Co4(μ2-H2O)2(COO)6] secondary building units (SBUs) where the four cobalt ions are coplanar. The 3D coordination network of 1 is a rare 10-connected network of (36·434·53·62) topology based on the tetranuclear cobalt cluster nodes. Magnetic measurements on compound 1 indicate that there is a net antiferromagnetic coupling among the Co(II) ions.

In the title compound, [Ag2(C10H6NO2)2(C2H8N2)]·4H2O, each AgI atom is three-coordinated by one N atom and one O atom from one quinoline-2-carboxyl­ate anion, and by one N atom from one ethyl­enediamine ligand. The dinuclear mol­ecule is centrosymmetric. A three-dimensional supra­molecular structure is formed through hydrogen-bonding and π–π inter­actions.

The title compounds, 6-bromo-1,4-dihydro-1,4-di(otolyl)-1,2,4,5-tetrazin-3(2H)-one, C 16 H 15 BrN 4 O, and 3,6-dibromo-1,4-dihydro-1,4-bis(p-methoxyphenyl)1,2,4,5-tetrazine, C 16 H 14 Br 2 N 4 O 2 , were prepared from 4-bromo-3-(o-tolyl)sydnone and 4-bromo-3-(pmethoxyphenyl)sydnone, respectively, in thf under ultrasonic irradiation, and identified with IR, 1 H NMR, mass spectrum and elemental analyses. The heterocyclic rings of both title compounds appear to lack aromatic character, as judged from the bond lengths