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Two Ni(II) carboxyphosphonates, namely [Ni(H4L)2] (1) and [Ni(H3L)(H2O)]·2H2O (2) (H5L=HOOCC6H4CH2N(CH2PO3H2)2), have been hydrothermally synthesized. Structural analyses reveal that 1 shows a two-dimensional (2D) inorganic layer structure, and the layers are further packed into a three-dimensional (3D) supramolecular structure through the interlayer hydrogen-bonding interactions. In 2, two adjacent {NiO5N} polyhedra are connected to form a {Ni2O8N2} dimer, and these dimers are further linked by {CPO3} tetrahedra to form a one-dimensional (1D) chain. Consecutive chains are further connected by the intermolecular hydrogen-bonding interactions, resulting in a 2D supramolecular layer structure. Magnetic analyses exhibited that 1 shows major antiferromagnetic behavior, whereas 2 displays ferromagnetic interactions at low temperatures. Meanwhile, the magnetic properties of 1 and 2 have also been quantified using the Curie–Weiss law and the PHI program package, respectively. Two nickel(II) carboxyphosphonates with different structures showed different magnetic behaviors. Meanwhile, the magnetic properties of 1 and 2 have also been quantified using the Curie–Weiss law and the PHI program package.

Construction and investigation of dual-functional metal-organic frameworks (MOFs) with luminescent sensing and proton conduction provide widespread applications in clean energy and environmental monitoring fields. By selecting a phosphonic acid ligand 4-pyridyl-CH

It remains a challenge to exploit dual-functional metal-organic frameworks (MOFs) for applications, including luminescence detection and proton conduction. With the deliberate selection of the bifunctional organic ligand 5-sulfoisophthalic acid monosodium salt (NaH2bts), and the phosphonic acid ligand N,N'-piperazine (bismethylenephosphonic acid; H4L), a robust three-dimensional (3D) noninterpenetrating dual-functional MOF, [Tb(H2L)(H2bts)(H2O)]·H2O (1), has been synthesized hydrothermally. On the basis of the excellent thermal and chemical as well as superior luminescence stabilities in water and solutions with different pHs, 1 can serve as the simple, rapid, and highly selective and sensitive luminescence detection of the carcinoid biomarkers 5-hydroxytryptamine (HT) and its metabolite 5-hydroxyindole-3-acetic acid (HIAA) with detection limits of nanomolar magnitude in water and in simulated blood plasma and urine systems. Due to the change in the signals that could be readily differentiated by the naked eye under a UV lamp, a portable test paper has been developed. The probable quenching mechanisms are discussed in detail. In addition, a great number of hydrogen-bonding networks are formed among the uncoordinated carboxylic oxygen atoms, sulfonate oxygen atoms, protonated nitrogen atoms, and water molecules, which provide potential proton-hopping sites for proton conduction, leading to a maximum proton conductivity of 2.3 × 10-4 S cm-1 at 368 K and 95% relative humidity. The above results suggest that rationally designed dual-functional MOFs can open an avenue for the development of occupational diagnostic tools and alternative energy technology.

Two types of lanthanide(III) oxalatophosphonates, namely, [Ln(H2L)(C2O4)]·H2O [Ln = La (1), Ce (2), Pr (3)] and [Ln2(H3L)(C2O4)3(H2O)4]·2H2O [Ln = Eu (4) and Dy (5)] have been hydrothermally obtained by using (4-carboxypiperidyl)-N-methylenephosphonic acid (H3L) as the phosphonate ligand and oxalate as the second ligand. These five compounds have the same precursor, but they exhibit two different 2D layered structures. Compounds 1–3 are isostructural and exhibit a 2D layered structure in which {Ln(1)O9}, {Ln(2)O9} and {CPO3} polyhedra via corner-sharing and edge-sharing are interconnected into a 1D chain. These chains are further cross-linked by oxalate anions into a 2D layered structure, and the uncoordinated carboxylate groups are oriented toward the interlayer space. Compounds 4 and 5 are isostructural and also show a 2D layered structure. Lanthanide ions are interconnected by oxalate anions forming a 2D layered structure, and the carboxyl groups of H3L are grafted on the two sides of the layer. The structure variations are attributed to the effect of lanthanide contraction. In addition, the luminescence properties of compounds 4 and 5, and the magnetic properties of compound 5 have been studied.

Two metal phosphonates with or without the free Lewis basic pyridyl sites, namely, [Zn1.5(HL)]·2H2O (1) and [Cd0.5(H3L1)]·H2O (2) have been hydrothermally obtained from 4–pyridyl–CH2N(CH2PO3H2)2 (H4L) and 3–pyridyl–CH2N(CH2PO3H2)2 (H4L1). The pyridyl N atom of 1 is uncoordinated with Zn(II) ion, whereas the pyridyl N atom of 2 is coordinated with Cd(II) ion, which leads to the different luminescent sensing abilities for Cu2+ ion. Compound 1 shows a highly selective and sensitive luminescent sensor for sensing Cu2+ with a low detection limit of 2.7 nM in aqueous solution. However, 2 can not be used as a luminescent sensor for metal ions. The result indicates that the presence of the free Lewis basic pyridyl sites in the framework plays an important role in the recognition of metal cations. Meanwhile, the quenching mechanism for 1 is also investigated, which can be attributed to the weak interaction between the free Lewis basic sites from the HL3– ligands and Cu2+ ions.

Two novel zinc(II) phosphonates, [Zn(H4L)]·2H2O (1) and [Zn(H4L)(2,2′-biim)] (2) (2,2′-biim = 2,2′-biimidazole), were synthesized based on (2,4,6-trimethylbenzene-1,3,5-triyl) tris(methylene) triphosphonic acid (H6L), via hydrothermal techniques. Structural characterization was conducted using single-crystal X-ray diffraction analyses, X-ray powder diffraction analyses (PXRD), FT–IR spectroscopy, thermogravimetric analyses (TGA) and elemental analyses (EA). Compound 1 was a 2D layered structure that exhibited high selectivity and sensitivity as a luminescent probe for the detection of polychlorinated benzene, with a very low detection limit of 8.20 × 10−7 M. Compound 2 possessed a one-dimensional chain structure that transformed into a 2D supramolecular structure through hydrogen bonding interactions. The excellent Lewis base recognition sites in 2 facilitated high sensitivity toward Hg2+ ions, with a low detection limit of 5.30 × 10−7 M. The test paper experiment showed that 2 could be made into the test paper to quickly detect Hg2+ by naked eye. Meanwhile, the probable sensing mechanisms were also discussed in this paper.

Five chiral and achiral copper(II) carboxyphosphonates, namely, [Cu(4-cppH)(2,2′-bipy)(H2O)] (1: R-1 and S-1), [Cu9(4-cpp)6(2,2′-bipy)6] (2), [Cu3(4-cpp)2(2,2′-bipy)2] (3), [Cu3(4-cpp)2(1,10-phen)2]·4H2O (4), and [Cu(4-cppH)(1,10-phen)]·H2O (5), had been hydrothermally synthesized. Among them, 1 showed an unexpected 1D chiral helical chain from achiral carboxyphosphonate ligand by spontaneous resolution. In 2, the interconnection of {CuN2O3}, {CuO4}, and {CPO3} polyhedra formed a 1D chain. Such chains were further connected to a 2D layer through the carboxyphosphonates ligands. Compounds 3 and 4 were isostructural and exhibited a 2D layer, which was constructed from {CuO3N2}/{CuO4} polyhedra and the carboxyphosphonate ligands. In 5, the interconnection of neighboring {CuN2O3} polyhedra formed a dimer. These dimers were connected with the carboxyphosphonate ligands to form a chain. Interestingly, the homochiral copper(II) phosphonate (R-1 or S-1) could be obtained by utilizing the (+)-cinchonine or (−)-cin...

Four new transition metal phosphonates with 2D and 3D supramolecular structures, namely [Cu2(1,10-phen)2(HL)2(L)]·H2L (1), [Zn(1,10-phen)(HL)2] (2), [M(1,10-phen)(HL)2(H2L)] (M = Mn (3), and Cd (4)) (H2L = phenylphosphonic acid, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. In compound 1, two {CuN2O3} square pyramids and three {CPO3} tetrahedra are interconnected through phosphonate oxygen atoms to form a cluster unit via edge- and corner-sharing. Neighboring units are further assembled into a 3D supramolecular structure through π–π stacking and hydrogen bonding interactions. For compound 2, two {ZnO3N2} square pyramids and four {CPO3} tetrahedra are interconnected by phosphonate oxygen atoms to a cluster unit via corner-sharing. Then the adjacent clusters are further assembled into a 3D supramolecular structure through π–π stacking interactions. Compounds 3 and 4 are isomorphous and adopt a 2D supramolecular structure. The interconnection of {MO4N2} and {CPO3} polyhedra leads to a cluster unit through corner-sharing, and such units are further assembled into a 2D supramolecular structure by π–π stacking and hydrogen bonding interactions. The surface photovoltage properties of compounds 1 and 3 and luminescence properties of compounds 2 and 4 have been studied. The surface photovoltage spectra (SPS) and field-induced surface photovoltage spectra (FISPS) of compounds 1 and 3 indicate that they all possess certain photo-electric conversion properties and show p-type semiconductor characteristics. Luminescence properties of compounds 2 and 4 indicate that they may be candidates for potential luminescent materials.

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−.

Three novel cadmium(II) carboxyphosphonates with three-dimensional (3D) frameworks and supramolecular structures, namely, Cd3[(L)2(1,10-phen)1.5]·H2O (1), Cd[(L′)(H2biim)] (2), and Cd[(L′)(H2biim)(H2O)]·H2O (3) (L = OOC–C6H4–CH2PO3, L′ = OOC–C6H4–CH2PO2(OC2H5), 1,10-phen = 1,10-phenanthroline, H2biim = 2,2′-biimidazole), were synthesized under hydrothermal conditions and were structurally characterized. For compound 1, the Cd(1)O6, Cd(2)O4N2, Cd(3)O2N2, Cd(4)O4 and CPO3 polyhedra were interconnected in a one-dimensional (1D) chain along the b-axis via corner- and edge-sharing. The adjacent chains were connected with each other by sharing the L3− anions, giving rise to a 3D framework structure. Compound 2 adopted a 3D supramolecular structure. The interconnection of two Cd(1)O4N2 polyhedra and two CPO3 tetrahedra via corner-sharing formed a structure unit, with such units further connected in the bc-plane by sharing the L′2− anions to exhibit a 2D layer, and then the neighboring layers were further assembled into a 3D supramolecular structure by π–π stacking interactions. In compound 3, the Cd(1)O4N2 and CPO3 polyhedra were interconnected to form a unit, and then the interconnection of multi-units were assembled into two kinds of 1D chains, whereby chains and other chains are further connected by π–π stacking interactions to present a 3D supramolecular structure. The luminescence properties of compounds 1–3 were investigated. Meanwhile, the excellent abilities of compounds 2 and 3 for the selective recognition of tryptophan (Trp) were demonstrated.

Two new metal carboxyphosphonates with 2D supramolecular and layered structures based on 4-HOOCC6H4CH2PO(OH) (OC2H5) (H2L′), namely, [Cd(H2L)2(H2O)2] (1) and [Ag(H2L)] (2) [H3L = 4-HOOCC6H4CH2PO(OH)2], have been synthesized under hydrothermal conditions. For compound 1, {CdO6} octahedra and {CPO3} tetrahedra are interconnected into a 1D chain via corner–sharing along the a–axis. Then the adjacent chains are further connected through hydrogen bonds of the carboxyl acid groups of ligands into a 2D supramolecular structure in the ac plane. Compound 2 features a 2D layered structure. Every two {AgO3} polyhedra and two {CPO3} tetrahedra are interconnected into a unit via corner–sharing. Such untis are further connected through carboxyphosphonate ligands to form a 2D layered structure. There is a 40–atom window in compound 2. The luminescent properties of compounds 1 and 2 have also been studied.

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.

Three new alkaline earth metal carboxyphosphonates with a 3D supramolecular structure, namely, Ca[(H3L)(H2O)] (1), Sr[(H3L)(H2O)2] (2) and Ba[(H3L)(H2O)] (3) (H5L = 4-{[bis(phosphonomethyl)amino]methyl}benzoic acid), have been synthesized under hydrothermal conditions. For compound 1, {CaO6} and {CPO3} polyhedra are interconnected into a 1D double-chain via corner-sharing. Adjacent chains are further cross-linked via the organic backbone {–C6H4CH2N(CH2)2–} of the carboxyphosphonate ligands, generating a 2D layer. These neighboring 2D metal phosphonate layers are connected through hydrogen bonding interactions to form a 3D supramolecular structure. In compound 2, two edge-sharing {SrO7} polyhedra form centrosymmetric {Sr2O12} units. Then, these {Sr2O12} units are connected by phosphonate groups to form a 1D chain, which is further cross-linked by N atoms from carboxyphosphonate ligands to form a 2D inorganic layer. These 2D inorganic layers interdigitate through hydrogen bonding interactions to generate a 3D supramolecular structure. In compound 3, the connections of {BaO10} and {CPO3} polyhedra form a 2D layer via corner-sharing and edge-sharing. Then adjacent layers are further assembled into a 3D supramolecular structure through hydrogen bonding interactions. The thermal stabilities and luminescence properties of compounds 1–3 were investigated. Interestingly, compounds 1–3 are selective and reversible for sensing of 1-butanol, 1-propanol and ethanol, respectively.

Two new metal carboxyphosphonates with 3D framework structures, [Sn2(HL)·2H2O] (1) and [Pb2Cl(H2L)] (2) (H5L = 4-HOOCC6H4CH2N(CH2PO3H2)2), have been synthesized under hydrothermal conditions. For compound 1, every two Sn(1)O3 and Sn(2)O3 polyhedra are linked by CPO3 tetrahedra to form a 2D inorganic layer via corner-sharing in the bc-plane. Then the adjacent layers are further assembled into a 3D supramolecular structure through π–π stacking interactions. Compound 2 features a 3D open-framework structure. The Pb(1)O5Cl, Pb(2)O5 polyhedra and CPO3 tetrahedra are interconnected into a 2D inorganic layer via corner-sharing in the ac-plane. Such layers are further connected through carboxyphosphonate ligands to form a 3D open-framework structure. The luminescent properties of compounds 1 and 2 have also been studied.

Three novel metal carboxyphosphonates with a 3D pillared-layered structure, namely, [Mn(HL)] (1), [Co(HL)]·H2O (2), and [Cd3(L2)(H2O)3] (3), (H3L = 4-HOOCC6H4CH2NHCH2PO3H2), have been hydrothermall...

Two new cobalt phosphonates, [enH 2 ] 0.5 [Co(HL)(H 2 O)] · H 2 O (1) and [Co 2 (HL)(H 2 L) 2 ] · 2NH(CH 3 ) 2 · 3H 2 O (2) (H 3 L = 2-hydroxyphosphonoacetic acid; en = ethylenediamine), 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. For compound 1 , Co(II) atoms are octahedrally coordinated. The CoO 6 octahedra and CPO 3 tetrahedra are linked by HL 2 − into a 2D layered structure in the bc -plane. The ethylenediamine molecules and solvate water molecules are located between two adjacent layers. The structure of compound 2 composed of Co1O 6 and Co2O 6 octahedra via bridging phosphonate ligands leads to a 2D layered structure with one-dimensional channel system along c -axis direction. The dimethylamine molecules and solvate water molecules are located between two adjacent layers. The surface photovoltage properties of compounds 1 and 2 have also been studied.

By the introduction of oxalate as the second ligand, five new lanthanide oxalatophosphonate hybrids with a 2D layered structure, namely, [Ln(H2L)(C2O4)(H2O)]·2H2O [Ln = Nd (1), Sm (2), Eu (3), Tb (4), Dy (5), H3L = H2O3PCH2NCH2(CH2CH2OPO2H)], have been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1-5 are isostructural and exhibit a 2D layer formed by the interconnection of a 1D zigzag chain of {Ln(C2O4)}(+) with the phosphonate ligands. The effect of lanthanide contraction induces the decrease of the lattice parameters and crystal size from Nd to Dy. The luminescence properties of compounds 2-5 have been studied.

By introduction of 4,4′-bipyridine (4,4′-bipy) as a second organic ligand, two new nickel(II) carboxyphosphonates with a 3D framework structure, namely, [Ni3(H2L)2(4,4′-bipy)(H2O)4] (1) and [Ni3(H2L′)2(4,4′-bipy)2(H2O)2]·4H2O (2) (H5L = 4-{[bis(phosphonomethyl)amino]methyl}benzoic acid; H5L′ = N,N-bis(phosphonomethyl)aminoacetic acid) have been synthesized under hydrothermal conditions. Compounds 1 and 2 both feature three-dimensional (3D) framework structures with two-dimensional (2D) layers pillared by 4,4′-bipy. For compound 1, {Ni(1)O4N2}, {Ni(2)O6} and {CPO3} polyhedra form a 2D inorganic layer in the bc-plane via corner-sharing. Then adjacent layers are further pillared by 4,4′-bipy ligands into a 3D pillar-layered structure. In compound 2, {Ni(1)O4N2}, {Ni(2)O4N2} and {CPO3} polyhedra are interconnected by carboxyphosphonate ligands to a 2D layer in the ab-plane. Neighboring layers are further cross-linked via 4,4′-bipy ligands, generating a 3D framework structure. Whereas the carboxylate oxygen atoms of carboxyphosphonate ligands are coordinated to Ni(II) atoms in compound 2 but not in compound 1. The surface photovoltage and luminescence properties of compounds 1 and 2 have been investigated at the same time.

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.

Two novel organic–inorganic hybrid materials of oxovanadium–organophosphonate with a 3D supramolecular structure, [{M(1,10-phen)}(VO)(OH)(hedp)]·H2O (M = Cu (1), Zn (2); hedpH4 = 1-hydroxyethylidenediphosphonate, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. Compounds 1 and 2 are isomorphous and adopt a three-dimensional supramolecular network structure. The interconnection of {(VO4)(OH)}, {MN2O3} and {CPO3} polyhedra leads to a 2D layer through corner-sharing, and such layers are further assembled into a 3D supramolecular structure by π–π stacking interactions. Surface photovoltage and luminescent properties of the two compounds have also been studied.

Two novel divalent metal carboxyphosphonates with a 3D pillared-layered structure, [Zn(HL)] (1) and [CdCl(H2L)] (2) (H3L = 4-HOOCC6H4CH2NHCH2PO3H2), have been synthesized under hydrothermal conditions. Compounds 1 and 2 both feature three-dimensional (3D) framework structures with two-dimensional (2D) inorganic layers pillared by H3L. In compound 1, each {ZnO4} tetrahedron is linked via corner-sharing by three {CPO3} tetrahedra to form a two-dimensional (2D) inorganic layer in the ac-plane. The adjacent layers are further pillared by the organic backbone {–C6H4CH2NHCH2–} of the carboxyphosphonate ligand, generating a 3D pillared-layered structure. For compound 2, each Cd(II) cation is six-coordinated, and the interconnection of two {CdCl2O4} octahedra forms a dimer via edge-sharing. The dimers are interconnected by {CPO3} tetrahedra via corner-sharing to form a 2D inorganic layer in the ab-plane. Such neighboring 2D inorganic layers are further cross-linked through the organic pillars of the carboxyphosphonate ligand, thus resulting in a 3D pillared-layered structure. An interesting feature of compounds 1 and 2 is the presence of alternate left- and right-handed helical chains in their structures. It is of note that two title compounds are both stable up to high temperature. The luminescent properties of compounds 1 and 2 have also been studied.

Four novel organic–inorganic hybrid materials of the copper(II)–molybdophosphonate family, [Cu(1,10-phen)Mo2O5(H2O)(hedp)] (1), [{Cu(1,10-phen)}{Cu(1,10-phen)(H2O)}MoO2(hedpH)2]·H2O (2), [Cu(1,10-phen)Mo0.5O(hedpH)] (3), and [{Cu(2,2′-bipy)(H2O)}MoO2(hedp)]·2H2O (4) (hedpH4 = 1-hydroxyethylidenediphosphonate, 2,2′-bipy = 2,2′-bipyridine, 1,10-phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions. In compound 1, the interconnection of {MoO6}, {CuN2O2}, and {CPO3} polyhedra leads to a 2D layer through edge-sharing and corner-sharing, and such layers are further assembled into a 3D supramolecular structure by π–π stacking interactions. Compound 2 contains a 1D chain built up from {MoO6}, {CuN2O3}, and {CPO3} polyhedra, and then these 1D chains are further extended into 2D supramolecular layer by hydrogen bonding interactions. Such neighboring layers are further assembled into a 3D supramolecular structure via the π–π stacking interactions. For compound 3, the [{Cu(1,10-phen)}2MoO2(...

Hydrothermal reactions of lanthanide(III) chlorides and H2O3PCH2NCH2(CH2CH2OPO2H) (H3L) with oxalate anion lead to six novel lanthanide oxalatophosphonates with a three-dimensional (3D) framework structure, namely, {[Ln(H2L)(C2O4)(H2O)]·nH2O}∞ [n = 3 (compounds 1–3), 2 (compounds 4–6); Ln = Ce (1), Pr (2), Nd (3), Sm (4), Eu (5), and Tb(6)]. Compounds 1–6 are isostructural and feature a complex 3D network built from 1D chains of lanthanide oxalate and {Ln(H2L)}2+ chains. These lanthanide oxalatophosphonates possess two types of channels with dimensions of 11.6 A × 4.4 A and 13.8 A × 8.9 A along the a- and b-axis, respectively, and these channels incorporate some crystalline water molecules therein by hydrogen-bonding interactions. They show an unusual noninterpenetrated (3,5)-connected topology. The title compounds were characterized by X-ray single-crystal diffraction and X-ray powder diffraction (XRD) as well as with infrared spectroscopy and elemental and thermogravimetric analysis. Furthermore, the te...

Three new divalent metal(II) diphosphonates with layered structure, [Cd 2.5 (L)(H 2 O) 2 F]·H 2 O ( 1 ), [Cd 3.5 (HL)(L)] ( 2 ) and [ Sn 3 O(L)] ( 3 ) (H 4 L = C 6 H 11 N(CH 2 PO 3 H 2 ) 2 ), have been hydrothermally synthesized and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction as well as with infrared spectroscopy, elemental and thermogravimetric analysis. For compound 1 , each Cd(II) atoms are octahedrally coordinated [Cd(1)O 4 NF, Cd(2)O 5 F, Cd(3)O 6 ]. These cadmium octahedra form a 1D chain along the b -axis through edge- and corner-sharing, and such chains are further interlinked by CPO 3 tetrahedra via corner-sharing to form a 2D layer. In compound 2 , the interconnection of Cd(1)O 6 , Cd(2)O 5 N(1), Cd(3)O 6 and Cd(4)O 5 N(2) polyhedra via bridging diphosphonate ligands leads to a 2D Cd(II) phosphonate layer, which is analogous to that of compound 1 . The structure of compound 3 shows a novel layered structure, in which the interconnection of three SnO 3 trigonal pyramids via the bridging oxygen atom forms a trimer, the so-built trimers are bridged by the diphosphonate ligands into a 2D Sn(II) phosphonate layer. In all three compounds, the organic groups of the ligands are oriented toward the interlayer space. Luminescence properties of compounds 1 and 2 have also been studied.

Using the heptadentate ligand hedpH4 (1-hydroxyethylidenediphosphonic acid) and lanthanide chloride, two isomorphous series of coordination frameworks of the general formula [NH4][Ln(hedp)(H2O)]·H2O (series 1, orthorhombic P212121, Ln = La (1), Ce (2), Pr (3), Nd (4)) and [NH4][Ln(hedp)(H2O)] (series 2, orthorhombic Pnma, Ln = Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Y (10), Er (11)) have been assembled and characterized with IR, elemental analysis, thermogravimetric analysis, and single-crystal and powder X-ray diffraction methods. In both series, each inorganic chain based on LnO8 and CPO3 polyhedra are interconnected through phosphonate ligands to form chiral and achiral 3D open-framework structures with left- and right-handed helical chains. Meanwhile, the two series also exhibit two types of 3D framework structures with similar network topologies. The crystal water molecule plays an important role to induce chiral structure and affects the crystal packing of the molecules with extensive hydrogen bondi...

Five new lanthanide(III) diphosphonates, namely, Ln[(HL)(H2O)]·H2O [Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5); H4L = C6H11N(CH2PO3H2)2] were synthesized under hydrothermal reaction conditions at 140 °C and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, IR spectroscopy, elemental, and thermogravimetric analysis. Compounds 1–5 are isostructural and exhibit a 2D framework structure. The LnO8 polyhedra form 1D zigzag chains along the c axis by edge-sharing, which are further interconnected by CPO3 tetrahedra through edge- and corner-sharing to form a 2D layer in the ac plane. The cyclohexyl groups of the ligands are orientated toward the interlayer space.

Two new zinc phosphonates with 2-hydroxyphosphonoacetic acid (HPAA) and 1-hydroxyethylidenediphosphonic acid (hedpH 4 ), [Zn 2 {HO 3 PCH(OH)CO 2 } 3 ]·2NH 2 (CH 3 ) 2 ·3H 2 O ( 1 ) and [Zn 3 {CH 3 C(OH)(PO 3 ) 2 } 2 ]·2NH 2 (CH 3 ) 2 ·H 2 O ( 2 ) have been synthesized under mixed-solvothermal conditions at 160 °C and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy and elemental analysis. The structure of compound 1 comprises Zn1O 6 and Zn2O 6 octahedra connected by [HO 3 PCH(OH)CO 2 ] 2− to form a 2D layered structure with one-dimensional channel system along c -axis direction, and the protonated dimethylamine cations are being located between two adjacent layers. Interestingly the layers of 1 arranged in an alternative sequence (ABAB). Compound 2 features a 3D framework structure with channels along the b - and c -axis, respectively. The charge-compensating protonated Hdma + cations and solvate water molecules are located inside the channels along the c -axis. A notable feature for compound 2 is the presence of the alternate left- and right-handed helical chains in the structure. The luminescence properties of compounds 1 and 2 have also been studied.

A new functionalized polyoxomolybdate [(HOOCC5H9NCH2PO3)2Mo5O15]4– (1) was synthesized by solvothermal reaction at 120 °C and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction as well as with infrared spectroscopy, elemental analysis, and thermogravimetric analysis. The title polyoxoanion consists of a ring of five distorted MoO6 octahedra linked through four edge-sharing and one corner-sharing junctions. Two pending carboxyphosphonate ligands are attached on opposite sides of the ring by the two PO3 groups. As a result the two dangling arms with their terminal carboxylate groups protrude away from the {Mo5O15} framework in diametrically opposed directions. Each Mo5-ring is further connected to adjacent Mo5-ring through hydrogen bonds, which consist in the protonated nitrogen atoms, the carboxyl oxygen atoms from L3– ligands and oxygen atoms from {Mo5O15} cluster to form a 2D framework structure.

By introduction of oxalate as the second ligand, 12 novel lanthanide oxalatophosphonates with two types of three-dimensional (3D) framework structures, namely, [Ln2(H4L)(C2O4)3(H2O)]·3H2O (Ln = La ...

By using the N-morpholinomethylphosphonic acid as the phosphonate ligand and oxalate as the second metal linker, seven novel lanthanide(III) oxalatophosphonates with two types of 3D framework structures, namely, [Ln3(HL)(C2O4)4(H2O)4]·2H2O (Ln = Pr (1), Nd (2), Sm (3), H2L = O(CH2CH2)2NCH2PO3H2) and [Ln2(H2L)(C2O4)3(H2O)3]·H2O (Ln = Eu (4), Gd (5), Tb (6), Dy (7)), have been synthesized under hydrothermal conditions. Compounds 1−3 are isostructural and feature a complex 3D framework structure formed by the interconnection of 3D network of {Ln3(C2O4)4}+ with 1D chains of {Ln3(HL)}8+. Compounds 4−7 are isostructural and possess a 3D framework structure different from that in compounds 1−3. The interconnection of Ln(III) ions by chelating oxalate ligands lead to a lanthanide oxalate layer down the c-axis. These layers are linked by H2L ligands to form a 3D framework type with channel system down the a-axis. Luminescence properties of compounds 3, 4, 6 and 7 have also been studied.

A novel 3D cadmium carboxyphosphonate containing left-hand helical chains, Cd 3 Cl 2 [(O 3 PCH 2 –N(H)C 5 H 9 –COO) 2 (H 2 O) 2 ] · 4H 2 O 1 has been synthesized by hydrothermal reaction at 120 °C and structurally characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. In compound 1 , the hexanuclear clusters based on Cd(1)O 4 Cl 2 , Cd(2)O 4 Cl 2 , Cd(3)O 6 and CPO 3 polyhedra are interconnected through carboxyphosphonate ligands to form a 3D open-framework structure with channel system. The result of connections in this manner is the formation of 20- and 30-atom rings that are parallel to one another and run in the a -axis direction. It is interesting that a type of left-hand helical chain is formed by HL 2− ligands bridging Cd 3 ions running along the b -axis.

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.

Two new manganese(II) phosphonates, (NH4)Mn2.5[(O3PCH(OH)CO2)2(H2O)] (1) and [NH3(CH2)4NH3]0.5Mn2.5[(O3PCH(OH)CO2)2(H2O)] (2) have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The two isomorphous compounds feature a 3D framework structure. The Mn(1)O6 and Mn(3)O5 polyhedra are bridged by the CPO3 tetraheda into a MnII phosphonate layer in ac-plane. Mn(2)O6 polyhedra are linked to each other by CPO3 tetraheda to form infinite chains, which are connected to layers by carboxylate groups to form a 3D framework structure with channels along the a- and c-axis, respectively. The NH4+ ions or protonated 1, 4-butylenediamine cations are located inside the channels along the a axis.

Three lanthanide diphosphonates, [NH3(CH2)4NH3]Ln[hedpH][hedpH2] (Ln = Sm (1), Gd (2), Dy (3); hedp = 1-hydroxyethylidenediphosphonate), have been synthesized by hydrothermal reaction with 1,4-diaminobutane as the template and characterized by single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. The vertex-sharing connections of the LnO7 polyhedra and CPO3 tetrahedra result in an infinite chain along the b axis. The chains are cross-linked by hydrogen bonds to form a three-dimensional network with channels containing the [NH3(CH2)4NH3]2+ cations.

Two new metal phosphonates with a 3D pillared layered framework based on N,N′-piperazinebis(methylenephosphonic acid), H2O3PCH2NC4H8NCH2PO3H2 (H4L), Sn[O3PCH2NHC4H8NHCH2PO3] (1) and Pb3(OH)2[O3PCH2NC4H8NCH2PO3] (2), have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1, each ψ-square pyramidal SnO4 unit is in turn corner-shared by four CPO3 tetrahedral from four different phosphonate ligands to form two-dimensional inorganic puckered layers in ab planes. In compound 2, the complicated inorganic layer (bc planes) is built up of ψ-PbO4N, PbO6 and CPO3 polyhedra. The overall structure for two compounds may be described in terms of alternating inorganic infinite layers and organic pillars {CH2N(C2H4)2NCH2}, to form a 3D pillared layered structure.

Two new divalent metal aminodiphosphonates with a layered structure, Mn2[(HL)(H2O)F]·H2O (1) and Cd3.5[(HL)L] (2) (H4L = CH3CH2CH2N(CH2PO3H2)2), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. In 1, two MnO4F2 and two MnO5F polyhedra are interconnected via edge-sharing into a tetramer, and such tetramers are bridged by the diphosphonate ligands into a Mn(II) phosphonate layer in the ab-plane. The structure of 2 also features a 2D layered structure, in which the CdO5N and CdO6 polyhedra are interconnected into a 1D chain. The chains are then cross-linked via phosphonate oxygen atoms to form Cd(II) phosphonate layers in the ab-plane.

A new Anderson-type heteropolyanion-supported nickel imidazole complex, [Himi]2[Ni(imi)3(H2O){Ni(OH)6Mo6O18}]·2H2O (imi = imidazole) (1) has been prepared by conventional aqueous solution synthesis and structurally characterized by single-crystal X-ray diffraction as well as by infrared spectroscopy, elemental and thermogravimetric analysis. Compound 1 possesses a one-dimensional (1D) wave-like infinite chain structure composed of Anderson-type heteropolyanion [Ni(OH)6Mo6O18]4− covalently linked by [Ni(imi)3(H2O)]2+ unit. Furthermore, the chains are extended into a 2D supramolecular framework in the ac plane via hydrogen-bonding interactions.