Wei-Wei Zhou

A direct white-light-emitting metal-organic framework with tunable yellow-to-white photoluminescence by variation of excitation light.

A direct white-light metal-organic framework (MOF), [AgL](n) x nH(2)O (1, L = 4-cyanobenzoate), obtained by the reaction of deprotonated 4-cyanobenzoic acid and AgNO(3) in water, was found to exhibit tunable yellow-to-white photoluminescence by variation of excitation light. Interestingly, the close pure white emission of 1 has CIE-1931 chromaticity coordinates of (0.33, 0.34) when excited by 349-nm UV light, which is compatible to the light output of the deep UV LED.

Nonlinear optical and ferroelectric properties of a 3-D Cd(II) triazolate complex with a novel (63)2(610·85) topology

A novel 3-D (3,6)-connected topological architecture, obtained by reacting Cd(ClO4)2 x 6H2O with Htrtr (Htrtr = 3-(1,2,4-triazole-4-yl)-1H-1,2,4-triazole) under solvothermal conditions, presents a non-centrosymmetric polar packing arrangement, resulting in a strong second harmonic generation (SHG) response and ferroelectric property.

A ferroelectric inorganic–organic hybrid based on NLO-phore stilbazolium

A ferroelectric inorganic–organic hybrid based on in situ substituted stilbazolium cation (TAMS2+ = trimethylamino-N-methyl stilbazolium) has been obtained. Single-crystal X-ray structure analysis demonstrates that the NLO-phore organic component of the complex is embedded into the inorganic polymeric [Bi2Cl8]2− framework and shows a polar arrangement with the cooperation of the nonsymmetric inorganic component. The measurement of ferroelectric and nonlinear optical properties show typical ferroelectricity and second harmonic generation (SHG) responses as well as a significant improvement of the laser damage threshold and thermal stability of relative organic material.

Novel 3-D PtS-like tetrazolate-bridged manganese(II) complex exhibiting spin-canted antiferromagnetism and field-induced spin-flop transition

Two novel manganese(II) tetrazolate coordination polymers, Mn 3(Hbta) 4(mu 2 -OH) 2(H 2O).2H 2O ( 1) and Mn(bta)(H 2O) ( 2), were obtained by the hydrothermal reaction of MnCl 2.4H 2O with N, N-bis[1(2) H-tetrazol-5-yl]amine (H 2bta) in different pH values. Compound 1 exhibits a 2-D (4,4) layer structure, which is built from binuclear Mn 2(mu 2-OH) 2 subunits and mu 3-bridging Hbta (-) linkers. Compound 2 is a helical framework, and its 3-D PtS-like net is constructed by Mn 2(bta) 2 dimers and mu 5-bridging bta (2-) linkers. Magnetic measurements reveal that compound 1 displays an antiferromagnetic ordering, while compound 2 exhibits the coexistence of a spin-canted antiferromagnetic coupling and a field-induced spin-flop transition.

Hydrothermal syntheses, crystal structures and luminescent properties of zinc(II) coordination polymers constructed by bifunctional tetrazolate-5-carboxylate ligands

Two bifunctional 1H-tetrazolate-5-carboxylate ligands with different flexibilities, H2tza (1H-tetrazolate-5-acetic acid) and H2tzf (1H-tetrazolate-5-formic acid), were employed in the construction of zinc(II) complexes in the presence/absence of secondary ligands such as 2,2′-bipy and 4,4′-bipy. Three tza coordination polymers and two tzf dinuclear complexes, namely [Zn(tza)(H2O)]n (1), [Zn3(tza)2Cl2(2,2′-bipy)2(H2O)2]n (2), [Zn2(tza)2(4,4′-bipy)]n (3), [Zn(tzf)(H2O)3]2·2H2O (4) and [Zn(tzf)(2,2′-bipy)(H2O)]2·H2O (5), were hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Polymer 1 is a 3-D two-fold interpenetrating diamond-like network with tetranuclear [Zn(COO)]4 clusters as tertiary building units (TBUs) and µ3-κN3:κO2:κO1,N1 bridging tza as linkers. Polymer 2 presents a 2-D structure formed by the linkage of 1-D Zn-carboxylate [Zn(COO)]n helical chains and µ3-κN4:κO2:κO1,N1 bridging tza. In 3, 2-D (4,4) nets are built up with dinuclear [Zn(COO)]2 clusters and µ3-κN4:κO2:κO1,N1 bridging tza, which are pillared through 4,4′-bipy to gain a 3-D self-penetrating LB-1 (446108) topology. In dinuclear complexes 4 and 5, two Zn(II) atoms are bridged by a tzf ligand in a µ2-κN2:κO1,N1 fashion. The results denote that tetrazolate-5-carboxylate ligands can adopt variable coordination modes in the formation of the complexes, and different Zn-carboxylate aggregates can serve as tertiary building units (TBUs). The effects of the nature of tetrazolate-5-carboxylate ligands and secondary ligands, and hydrothermal reaction conditions on the structural topologies of the obtained complexes have been investigated. The photoluminescent properties and thermal stabilities of 1–5 have also been discussed.

A novel heterometal-organic coordination polymer with chelidamic acid: nonlinear optical and magnetic properties

A novel 2-D heterometal-organic coordination polymer [AgCu2(C7H2NO5)(C7H3NO5)]n·2nH2O, obtained by a hydrothermal reaction, exhibits a (44) topology and good third-order nonlinear optical and magnetic properties, which may be a good candidate for NLO and magnetic multifunctional materials.

Topological derivation from centrosymmetry to noncentrosymmetry in a three-dimensional polar framework material

Strong second harmonic generation (SHG) response was presented by a three-dimensional polar framework material [Cu2(L)Br]n (1; L = 5-(4-pyridyl)tetrazole), which was obtained by reacting CuBr with HL under solvothermal conditions and displayed an noncentrosymmetric (3,4)-connected topology derived from the centrosymmetric CdSO4 net.