Yaoting Fan

Cation Exchange Induced Tunable Properties of a Nanoporous Octanuclear Cu(II) Wheel with Double-Helical Structure

A double-helical octanuclear Cu(II) wheel 1 with 2.88 nm diameter was prepared through the reaction of a clinical medicine, telmisartan, with copper sulfate. Central copper ions can be partially replaced by bivalent zinc and cobalt ions and fully exchanged by trivalent iron ions. The properties of central metal ion-exchanged variants are much different from those of 1. Central metal ion exchange might be regarded as a powerful and effective method to modify properties from one crystalline material to another only by varying central metal ions under moderate conditions.

3D Coordination Framework with Uncommon Two‐Fold Interpenetrated {33⋅59⋅63}‐lcy Net and Coordinated Anion Exchange

Unusual {3(3)5(9)6(3)}-lcy topology has been found in an uncommon 3D six-connected, two-fold interpenetrated {3(3)5(9)6(3)}-lcy net (illustrated). The coordinated SO(4) (2-) anions in this framework can undergo a full exchange with Cl(-) anions, in the course of which the crystals change color as shown. The process has a solvent-mediated rather than a solid-state mechanism.Reaction of tetrazole-1-acetic acid with CuSO(4)5H(2)O produces two novel 3D coordination frameworks: ([Cu(3)(mu(3)-OH)(eta(1):eta(1):eta(1):mu(3)-SO(4))(tza)(3)]3 CH(3)OHH(2)O}(n) (1; Htza=tetrazole-1-acetic acid) and {[Cu(4)(mu(2)-OH)(eta(2):eta(2):mu(4)-SO(4))(tta)(5)]3 H(2)O}(n) (2; Htta=tetrazole). Framework 1 is constructed from a trinuclear copper cluster [Cu(3)(mu(3)-OH)(eta(1):eta(1):eta(1):mu(3)-SO(4))] and displays a six-connected framework with uncommon {3(3)5(9)6(3)}-lcy topology. Framework 2 presents a complicated five-nodal (3,4,6)-connected net with (4(2)6)(34(2)5(2)7)(4(3)6(2)8)(3(2)4(8)5(3)6(2))(4(6)8(6)10(3)) topology. The eta(2):eta(2):mu(4)-SO(4) bridging mode in 2 has not been found in the reported coordination polymers. The coordinated SO(4) (2-) anions in 1 can be replaced completely when the solid polymer is treated with an aqueous methanolic solution containing Cl(-) anions. Detailed atomic force microscopy studies indicate a solvent-mediated rather than a solid-state mechanism for the exchange process.

A linear piperazine-pyridine ligand and its Hg coordination polymer

Abstract Reaction of piperazine hexahydrate with 4-chloromethylpyridine hydrochloride affords a new piperazine–pyridine ligand: N,N′-bis(4-pyridylmethyl)piperazine (bpmp). X-ray structure analysis confirms an overall linear structure, in which the lone electron pairs of piperazine-N are in trans-position. Its zigzag polymer with Hg2+ was readily obtained in THF. Bpmp is held in the chair conformation in the polymer, and Hg2+ coordinates to two N atoms from different bpmp ligands and two I atoms.

A series of metal–organic polymers assembled from MCl2 (M = Zn, Cd, Co, Cu): structures, third-order nonlinear optical and fluorescent properties

In this paper four metal-organic polymers {[Zn(fcz)Cl2].CH3OH}n 1, {[Cd(fcz)2Cl2].CH3OH.2H2O}n 2, {[Co(fcz)2Cl2].2CH3OH}n 3 and {[Cu(fcz)2Cl2].2CH3OH}n 4 (fcz = fluconazole: alpha-(2,4-difluorophenyl)-alpha-(1H-1,2,4-triazol-l-ylmethyl)-1H-1,2,4-triazole-l-ethanol) were synthesized and characterized by X-ray single crystal diffraction. Polymer consists of 1-D infinite chains arranged along the b-axis. All of polymers 2-4 exhibit a 2-D rhombohedral grid structure. We study the third-order nonlinear optical properties of fcz and polymers 1-4 in DMF solution by using 8 ns laser pulses at 532 nm, and find that 1 and 4 exhibit different NLO properties from fcz and both 2 and 3 show similar NLO properties to fcz. 1 possesses strong NLO refractive effects and large NLO absorptive behaviors. 2, 3 and fcz exhibit strong refractive effects, but their NLO absorptive behaviors are weaker than that of 1. The NLO effects of 4 are very weak. The study of optical limiting (OL) effects by using 40 ps laser pulses at 532 nm shows that fcz and polymer 3 possess a strong OL effect. The optical limiting threshold values of 0.15 J cm(-2) for fcz and 0.16 J cm(-2) for are comparable to those of many heterothiometallate clusters. Polymers 1, 2 and 4 show a weak OL effect. The fluorescent spectra in DMF solution (concentration: 1 x 10(-4) mol dm(-3)) show that polymers 1-4 exhibit different luminescence properties from fcz. The maximum wavelength of polymers 1-3 are blue shifted gradually by 2-12 nm while polymer 4 exhibits a fluorescent self-quenching phenomenon. These results demonstrate that metal ions play an important part in the NLO and fluorescent properties of coordination polymers.

Structure extending and cation exchange of Cd(II) and Co(II) materials compounds inducing fluorescence signal mutation

Using 2D grids of [Cd(btx)2Cl2]n1 and [Co(btx)2Cl2]n2 (btx = 1,4-bis(triazol-1-ylmethyl)benzene) as parent complexes, with terminal dicarboxylic ions as anion substitutors and bridge ligands, we synthesized extended structures of 3D polymeric networks with {[Cd2(btx)2(tp)2]·H2O}n3 and [Co3(btx)4(tp)3(H2O)4]n4 (tp = terephthalic ion) with Schlafli symbols (423·65) and (44·62)(48·67), respectively. The complete cation exchanged products Cu2+-1, Cu2+-3 and Cd2+-4 were obtained by immersing 1, 3 and 4 into corresponding aqueous solutions of MCl2 (M = Cu2+ or Cd2+). Interestingly, fluorescence studies on the pre- and post-exchanged materials compounds indicate that central metal ions have great influence on the fluorescence signal of the materials compounds, and play more important roles than skeleton structures.

Coordination polymers based on a flexible bis(triazole) ligand and aromatic polycarboxylate anions: syntheses, topological structures and photoluminescent properties

Four new coordination polymers, namely, {[Cd(btmx)(BTEC)0.5(H2O)]·H2O}n (1), {[Cd(btmx)1.5(1,2,4-HBTC)]·(H2O)2}n (2), {[Co(btmx)(HBTC)]·2H2O}n (3) and [Co(btmx)(1,4-BDC)]n (4) (btmx = 1,4-bis(1,2,4-triazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene, H4BTEC = 1,2,4,5-benzenetetracarboxylic acid, 1,2,4-H3BTC = 1,2,4-benzenetricarboxylic acid, 1,3,5-H3BTC = 1,3,5-benzenetricarboxylic acid and 1,4-H2BDC = 1,4-benzenedicarboxylic acid) have been obtained under hydrothermal conditions and characterized structurally. Complex 1 is a 3D 3-fold interpenetrating (4,4)-connected net with (4·64·8)(42·62·82) topology. Complex 2 displays a 2D cabinet-like structure with infinite 1D double Cd–btmx chains. Complex 3 possesses a 3D 3-fold interpenetrating 4-connected framework with 66-dia topology. Complex 4 exhibits a (4,6)-connected 3D pillar-layered structure with point symbol of (44·62)(44·610·8). The structural differences of these complexes demonstrate that the flexible ligand btmx and aromatic polycarboxylate anions play critical roles in the formation of the resulting frameworks. Furthermore, the photoluminescent properties of 1 and 2 have been studied in the solid state at room temperature.

Novel coordination polymers of Zn(II) and Cd(II) tuned by different aromatic polycarboxylates: synthesis, structures and photocatalytic properties

Tuned by different aromatic polycarboxylates, six fascinating coordination polymers (CPs), namely, [Cd(pbmb)(p-bdc)]n (1), {[Zn3(pbmb)2(1,3,5-btc)2]·6H2O}n (2), {[Cd3(pbmb)3(1,3,5-btc)2(H2O)]·3H2O}n (3), {[Zn2(pbmb)(1,2,3-btc)(μ2-OH)]·H2O}n (4), [Cd(pbmb)(1,2,4,5-btec)0.5]n (5), and {[Cd(pbmb)(sdba)]·2H2O}n (6) (pbmb = 1,1′-(1,3-propane)bis-(2-methylbenzimidazole), p-H2bdc = 1,4-benzenedicarboxylic acid, 1,3,5-H3btc = 1,3,5-benzenetricarboxylic acid, 1,2,3-H3btc = 1,2,3 benzenetricarboxylic acid, 1,2,4,5-H4btec = 1,2,4,5-benzenetetracarboxylic acid, H2sdba = 4,4′-sulfonyldibenzoic acid), have been ideated and synthesized by hydrothermal reaction methods. Structural analyses reveal that complexes 1–3 feature three-dimensional (3D) structures (1: 4-connected 66 topology, 2: (3,4,6)-connected (65·7)(4·62)2(42·66·85·102) topology and 3: (2,3,4)-connected (65·8)2(63)2 topology), and the remaining CPs 4–6 exhibit 2D networks. The thermal stability and powder X-ray diffraction for 1–6 have been investigated as further properties. The optical band gaps are analyzed by diffuse-reflectance UV-vis spectra. Moreover, all of the materials manifest good photocatalytic activities for the degradation of methylene blue (MB) (1: 74%, 2: 41%, 3: 37%, 4: 76%, 5: 46%, 6: 75%, respectively) in water under the irradiation of a high-pressure mercury lamp.

Two novel two-dimensional double-sheet layered manganese(II) coordination polymers: synthesis, crystal structures and third-order nonlinear optical properties

Two novel Mn(II) coordination polymers [Mn(N3)2(bbp)2]n1 and {[Mn(NCS)2(bbp)2]·0.25H2O}n2 (bbp = 4,4′-trimethylenedipyridine) with 2D double-sheet layered structures were obtained by a normal synthesis method at room temperature. Interestingly, each layer contains two sheets; the double-sheet layer is formed around an octahedral coordination center, Mn(II), with bbp ligands knitted into each other. The structures both contain channels with dimensions of about 6.5 × 6.5 A for 1 and 6.7 × 6.0 A for 2. Both compounds have a similar construction, giving the same third-order nonlinear optical (NLO) behavior and weak antiferromagnetic properties. Their third-order NLO refractive indexes n2 are 1.21 × 10−18 m2 W−1 for 1 and 6.71 × 10−19 m2 W−1 for 2. The NLO susceptibilities χ(3) were calculated to be 4.78 × 10−12 esu and 2.40 × 10−12 esu, respectively.

Entangled Zn(II)/Cd(II) coordination complexes based on a flexible bis(methylbenzimidazole) ligand and different dicarboxylates

Eight entangled coordination complexes, formulated as [M(hbmb)0.5(o-phda)]n [M = Zn (1), Cd (2)], {[M(hbmb)(p-phda)]·H2O}n [M = Zn (3), Cd (4)], [M(hbmb)0.5(oba)]n [M = Zn (5), Cd (6)], {[M(hbmb)(sdba)]m}n [M = Zn, m = 2 (7); m = 1, Cd (8)] (H2phda = phenylenediacetic acid, H2oba = 4,4′-oxybis(benzoic acid), H2sdba = 4,4′-sulfonyldibenzoic acid), have been prepared by hydrothermal reactions of the flexible ligand 1,1′-(1,6-hexane)bis-(2-methylbenzimidazole)) (hbmb) with metal ions in the presence of various dicarboxylate coligands. Isostructural complexes 1 and 2 reveal 6-connected self-penetrating three-dimensional (3D) frameworks with (44·610·8)-roa topologies. 3 and 4 display 4-fold interpenetrating 3D frameworks with 66-dia topologies. 5 and 6 exhibit 3D 2-fold interpenetrating 6-connected frameworks with (412·63)-pcu topologies. Both 7 and 8 are 3D frameworks constructed through unusual 2D → 3D parallel interpenetration of corrugated 2D (4,4) nets, of which 7 shows a 4-connected (44·62)2 topology and 8 presents a 4-connected 44·62 topology. A systematic structural comparison of four pairs of complexes shows that the frameworks can be tuned by various dicarboxylate coligands and changeable conformations of the hbmb ligand. In addition, the chemical stability, thermal stability and photoluminescent properties of complexes 1–8 have also been investigated.

A series of novel metal-ferrocenedicarboxylate coordination polymers: crystal structures, magnetic and luminescence properties

Novel two-dimensional layered lanthanide(III)-ferrocenedicarboxylate coordination polymers {[M(η 2 -O 2 CFcCO 2 -η 2 )(μ 2 -η 2 -O 2 CFcCO 2 -η 2 -μ 2 ) 0.5 (H 2 O) 2 ]· m H 2 O} n (Fc=(η 5 -C 5 H 4 )Fe(η 5 -C 5 H 4 ), M=Tb 3+ , m =2, 1 ; M=Eu 3+ , m =2, 2 ; M=Y 3+ , m =1, 3 ) with trapezium-shaped units and one-dimensional wave-shaped Cd(II)-ferrocenedicarboxylate polymer {[Cd(η 2 -O 2 CFcCO 2 -η 2 )(H 2 O) 3 ]·4H 2 O} n ( 4 ) have been prepared and structurally characterized by single crystal diffraction. In polymers 1 – 3 , each central metal ion (Tb(III), or Eu(III) or Y(III)) is located in a pseudo-capped-tetragonal prism coordination geometry, and ferrocenedicarboxylate anion ligands have two coordination modes (bidentate-chelating mode and tridentate-bridging mode). The magnetic behaviors for 1 and 2 are studied in the temperature range of 5.0–300 K. The results show that the paramagnetic behavior of 2 is mainly due to the effective spin–orbital coupling between the ground and excited states through the Zeeman perturbation, and the weak magnetic interaction between Eu 3+ centers can be observed. In addition, compared with sodium ferrocenedicarboxylate, the fluorescent intensities of the polymers 1 – 4 are enhanced in the solid state.