Yan-Yu Zhu

Synthesis, crystal structures and luminescence properties of lanthanide oxalatophosphonates with a three-dimensional framework structure

Six new three-dimensional (3D) lanthanide oxalatophosphonates, [Ln(HL)(C2O4)0.5(H2O)2]·H2O (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6); H3L = H2O3PCH(OH)CO2H), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction as well as by infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1–6 are isomorphous and they exhibit a complex three-dimensional (3D) open-framework structure with a one-dimensional channel system along the c-axis. The interconnection of the lanthanide(III) ions by phosphonate ligands results in a lanthanide phosphonate layer, and these layers are further bridged by oxalate anions to form a 3D open-framework. Compound 6 shows strong red luminescence in the solid state at room temperature.

Synthesis, structure, surface photovoltage and magnetic properties of a novel 3D homochiral manganese phosphonate with right-handed helical chains

A novel 3D homochiral manganese phosphonate with right-handed helical chains, [enH2]0.5Mn2[(HL)(L)] (1) (H3L = 2-hydroxyphosphonoacetic acid; en = ethylenediamine) has been synthesized by hydrothermal techniques. X-Ray diffraction analysis indicates that compound 1 consists of A channels with right-handed single helical chains, B channels with right-handed double helical chains and C channels with achiral channels that are connected through manganese centers and L3− ligands to form a homochiral coordination polymer. Surface photovoltage spectroscopy (SPS) of compound 1 indicates that it possesses positive SPV response in the range of 300–600 nm and shows p-type semiconductor characteristic. Magnetic susceptibility studies of compounds 1 reveal that there exist weak antiferromagnetic interactions between the manganese centers.

Synthesis, crystal structures, and surface photovoltage properties of four new metal diphosphonates based on the mixed ligands

By introduction of 2,2′-bipy or 1,10-phen as a second organic ligand, four new metal diphosphonates with mixed ligands, namely, [M(2,2′-bipy)(hedpH3)2]·H2O (M = Co (1), Ni (2)), [M(1,10-phen)(hedpH3)2]·H2O (M = Co (3), Ni (4)) (hedpH4 = 1-hydroxyethylidenediphosphonic acid, 2,2′-bipy = 2,2′-bipyridine, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. Compounds 1 and 2 are isostructural and adopt a 2D supramolecular network. Each {MN2O4} octahedron and four {CPO3} tetrahedra are interconnected into a {M(2,2′-bipy)(hedpH3)2} (M = Co (1), Ni (2)) unit via corner-sharing. These isolated units are interlinked through hydrogen bonding interactions to form 1D infinite chains, which are further assembled into a 2D supramolecular network through π–π stacking interactions. Compounds 3 and 4 are also isostructural and show a 1D double chain structure constructed from {M(1,10-phen)(hedpH3)2} (M = Co (3), Ni (4)) units. In compounds 3 and 4, the {M(1,10-phen)(hedpH3)2} units are linked to each other through hydrogen bonds to form a 1D infinite chain and then these 1D chains are further extended into 1D double chains by π–π stacking interactions. The surface photovoltage properties of compounds 1–4 have been investigated.

Syntheses, structures, luminescence and molecular recognition properties of four new cadmium carboxyphosphonates with 2D layered and 3D supramolecular structures

Four new cadmium carboxyphosphonates with 2D layered and 3D supramolecular structures, namely, Cd3[(4-cppH)2(4-cppH2)2] (1), Cd[(2,2′-bipy)(4-cppH)] (2), [Cd3(1,10-phen)3(4-cpp)2]·6H2O (3) and [Cd(4,4′-bipy)(4-cppH)(H2O)2]·2H2O (4) (4-cppH3 = 4-carboxyphenylphosphonic acid, 2,2′-bipy = 2,2′-bipyridine, 1,10-phen = 1,10-phenanthroline and 4,4′-bipy = 4,4′-bipyridine), were synthesized under hydrothermal conditions. In compound 1, {Cd(1)O6}, {Cd(2)O6}, {Cd(3)O6} and {CPO3} polyhedra form a layer in the ab plane via edge- and corner-sharing. Neighboring layers assemble into a 3D supramolecular network by hydrogen bonding interactions. The structure of compound 2 shows a new layered structure, in which the interconnection of two {Cd(1)O4N2} and two {CPO3} polyhedra via corner-sharing forms a tetranuclear cluster, and the so-built tetranuclear clusters are bridged by phosphonate ligands into a 2D layer. For compound 3, {Cd(1)O4N2}, {Cd(2)O4N2}, {Cd(3)O3N2} and {CPO3} polyhedra are interconnected by carboxyphosphonate ligands to a 2D layer in the ac plane. Then the adjacent layers are further assembled into a 3D supramolecular structure through π–π stacking interactions. Cd(II) ions in compound 4 are bridged by 4,4′-bipy molecules into layers in the ab plane. These layers are held together by hydrogen bonds into a 3D supramolecular structure. The thermal stabilities and luminescence properties of compounds 1–4 were investigated. Interestingly, compound 1 is selective and reversible for sensing of DMF and acetone.

Mixed-solvothermal synthesis, structures, luminescent and surface photovoltage properties of four new transition metal diphosphonates with a 3D supramolecular structure

Four new transition metal(II) diphosphonates with a 3D supramolecular structure, M(hedpH2)3·3NH2(CH3)2NH(CH3)3·3H2O (M = Mn (1), Co (2), Ni (3), Zn (4); hedpH4 = 1-hydroxyethylidenediphosphonate acid) have been synthesized under mixed-solvothermal conditions and structurally characterized. Compounds 1–4 are isomorphous and adopt a three-dimensional supramolecular network structure containing {M(hedpH2)3}4− cluster units. The interconnection of {MO6} and {CPO3} polyhedra via corner-sharing forms a {M(hedpH2)3}4− cluster, and these isolated clusters are extended by hydrogen bonds to form a two-dimensional layer structure, which are further connected through hydrogen bonding interactions to give rise to a 3D supramolecular structure. Surface photovoltage spectroscopy (SPS) of compounds 1–4 indicates that it possesses positive SPV response in the range of 300–600 nm and shows p-type semiconductor characteristic. Luminescence properties of the four compounds have also been studied.

Synthesis, crystal structure and luminescence properties of eight new lanthanide carboxyphosphonates with a 3D framework structure

By using the carboxyphosphonic acid as the ligand, eight new three-dimensional (3D) lanthanide carboxyphosphonates, namely Ln[L(H2O)2]·2H2O (Ln = Ce (1), Pr (2), Nd (3), Sm (4), Eu (5), Gd (6), Y (7), Tb (8); H3L = H2O3PCH2–NC5H9–COOH) have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. The eight isomorphous compounds feature a 3D framework structure. In these compounds, the inorganic chains based on LnO8 and CPO3 polyhedra are interconnected through carboxyphosphonate ligands to form a 3D framework structure with a channel system. The result of connections in this manner is the formation of 40- and 24-atom rings that run in the a- and b-axis directions. The luminescence properties of compounds 5 and 8 have also been studied.

Two fluorescent lead phosphonates for highly selective sensing of nitroaromatics (NACs), Fe3+ and MnO4− ions

Two novel lead(II) phosphonates with a 2D double-layer and a 3D framework structure, namely, [Pb(BPDP)] (1) and [Pb3(BPDP)1.5(OOCC6H4COOH)3] (2) (H2BPDP = 4,4′-biphenyldiphosphonate(monoethyl ester), H2bdc = HOOCC6H4COOH), have been synthesized under hydrothermal conditions. Compounds 1 and 2 are stable in air and insoluble in water. Thermogravimetric analyses reveal that compounds 1 and 2 remain unchanged up to about 233 °C and 212 °C, respectively. Luminescence explorations demonstrated that compounds 1 and 2 exhibit highly selective and sensitive sensing for nitroaromatics (NACs). In ion recognition, the choice of solvent for compounds 1 and 2 has a different effect. Experiments proved that the identification of compounds 1 and 2 in aqueous solution is superior to that in ethanol solution. Moreover, compounds 1 and 2 also exhibit highly selective and sensitive sensing for Fe3+ and MnO4−. These results reveal that compounds 1 and 2 may be excellent fluorescent sensors for p-NP, Fe3+, and MnO4−.

Syntheses, crystal structures, surface photovoltage, luminescence and molecular recognition properties of zinc(II) and iron(II) carboxyphosphonates with 2D and 3D supramolecular structures

Four new transition metal carboxyphosphonates with 2D and 3D supramolecular structures, namely, Fe2[(HL)(H2O)] (1), Fe(H4L)2 (2), Zn(H3L) (3) and Zn2(HL) (4) (H5L = 4-HO2C–C6H4–CH2N(CH2PO3H2)2), have been synthesized under hydrothermal conditions. For compound 1, {FeO5N} and {CPO3} polyhedra are interconnected into a 2D layer in the bc-plane via corner-sharing. Then the adjacent layers are further assembled into a 3D supramolecular structure through π–π stacking interactions. Compound 2 shows a 3D supramolecular structure. {FeO6} and {CPO3} polyhedra are interconnected into a 2D layer in the bc-plane via corner-sharing, which is further linked through π–π stacking interactions to form a 3D supramolecular structure. The overall structure of compound 3 can be described as a 2D supramolecular structure. The {ZnO4} polyhedra are interconnected by {CPO3} tetrahedra via corner-sharing to form a 1D chain. These neighboring metal phosphonate chains are connected through hydrogen bonding interactions to give rise to a 2D supramolecular structure in the ac-plane. In compound 4, {ZnO3N} and {ZnO4} polyhedra are interconnected by {CPO3} tetrahedra via corner-sharing and edge-sharing to form a 2D inorganic layer in the bc-plane, which is further linked through π–π stacking interactions to form a 3D supramolecular structure. The surface photovoltage properties of compounds 1–2 and luminescence properties of compounds 3–4 have been investigated. More interestingly, compound 4 is selective for sensing DMF and acetone.

Mixed-solvothermal synthesis, structures, surface photovoltage, luminescence and molecular recognition properties of three new transition metal phosphonates with 3D framework and supramolecular structures

Three new transition metal(II) phosphonates with 3D framework and supramolecular structures, namely, [M1.5(L)(H2O)]·NH2(CH3)2·H2O (M = Ni (1), Co (2)) and [Zn2(H2L)(HL)]·NH2(CH3)2·3H2O (3) (H4L = C5H4NCH2C(OH)(PO3H2)2), have been synthesized under mixed-solvothermal conditions and structurally characterized. Compounds 1 and 2 are isostructural and adopt a 3D framework structure. The {M(1)O5N} octahedra and {CPO3} tetrahedra are interconnected into a 1D chain via corner-sharing, which is further linked to adjacent chains through pyridyl rings to form a 2D layer structure. Neighboring layers are bridged through {M(2)O6}, leading to a 3D framework structure with a 1D channel system along the b-axis. For compound 3, the {Zn(1)O4} and {Zn(2)O4} polyhedra are interconnected by phosphonate groups into a 1D double chain, and the double chain is further connected to adjacent chains through hydrogen bonds to form a 2D supramolecular network. Then these neighboring layers are further connected through hydrogen bonding interactions to give rise to a 3D supramolecular structure. Surface photovoltage spectroscopy (SPS) and field-induced surface photovoltage spectroscopy (FISPS) of compounds 1 and 2 indicate that they possess a positive SPV response in the range of 300–800 nm and show p-type semiconductor characteristics. Compound 3 has been realized for the sensitive sensing of N,N-dimethylformamide (DMF) by a luminescent method.

Two novel cadmium(II) carboxyphosphonates with 3D framework structure: synthesis, crystal structures, luminescence and molecular recognition properties

Two novel cadmium(II) carboxyphosphonates with 3D framework structure, namely, [Cd3(L)2(H2O)2] (1) and [Cd3Cl2(HL)2(H2O)2] (2) (H3L = H2O3PCH2–NC5H9–COOH) have been synthesized under hydrothermal conditions and structurally characterized. For compound 1, the interconnection of Cd(1)O5N, Cd(2)O6, and CPO3 polyhedra via edge- and corner-sharing forms a 1D chain. The adjacent chains connect with each other by sharing the carboxyphosphonate ligands, thereby generating a 2D layered structure. Neighboring layers are composed in a 3D pillared-layered structure by carboxyphosphonate ligands. Compound 2 exhibits a 3D framework structure. The Cd(1)O4Cl, Cd(2)O4Cl2, and CPO3 polyhedra are interconnected into a 2D layered structure in the bc-plane via corner-sharing, which is further linked to adjacent layers through carboxyphosphonate ligands to form a 3D framework structure. The luminescence properties of compounds 1 and 2 have been investigated. An interesting feature of compound 2 is that it is selective and reversible for sensing of acetone.