Search

The target for the self-assembly of functional microporous metal-organic frameworks (MOFs) could be realized by employing ligand-directed and/or template-induced strategies, which prompted us to explore the synthetic technique of d10 secondary-building-unit-based nanoporous frameworks. Here, the exquisite combination of a paddle-wheel [Mn2(CO2)6(OH2)2] cluster and a TDP6- ligand contributes one robust honeycomb framework of {(Me2NH2)2[Mn2(TDP)(H2O)2]·3H2O·3DMF}n (NUC-31; DMF = N,N-dimethylformamide), whose activated state with the removal of associated aqueous molecules characterizes the outstanding physicochemical properties of nanochannels, penta- and tetracoordinated Mn2+ serving as highly open metal sites, rich Lewis base sites (rows of C═O groups and Npyridine atoms), and excellent thermal stability. Moreover, it is worth mentioning that Lewis acid-base sites on the inner surface of the channels in activated NUC-31 successfully form one unprecedented canal-shaped acid-base confined space with evenly distributed open metal sites of Mn2+ and Npyridine atoms as the canal bottom as well as two rows of C═O groups serving as dyke dams. Catalytic experiments displayed that activated NUC-31 could serve as an efficient heterogeneous catalyst for the chemical fixation of CO2 with epoxides into cyclic carbonates under mild conditions. Furthermore, NUC-31 could effectively catalyze the reaction Knoevenagel condensation, which should be ascribed to the synergistic polarization effect aroused from its plentiful Lewis base sites in the confined channel space. Hence, these results demonstrate that the employment of ligand-directed and template-dependent strategies could overcome the self-assembled barriers of functional microporous MOFs and achieve unexpected frameworks.

The exquisite combination of Ba2+ and Zn2+ with the aid of 2,4,6-tri(2,4-dicarboxyphenyl)pyridine (H6TDP) under the condition of solvothermal self-assembly generates one highly robust [Ba3Zn4(CO2)12(HCO2)2(OH2)2]-organic framework of {[Ba3Zn4(TDP)2(HCO2)2(OH2)2]·7DMF·4H2O}n (NUC-27), in which adjacent 2D layers are interlaced via hydrogen-bonding interactions to form a 3D skeleton with peapod-like channels and nano-caged voids. It is worth emphasizing that both Ba2+ and Zn2+ ions in NUC-27 display the extremely low coordination modes: hexa-coordinated [Ba(1)] and tetra-coordinated [Ba(2), Zn(1), and Zn(2)]. Furthermore, to the best our knowledge, NUC-27 is one scarcely reported 2D-based nanomaterial with an unprecedented Z-shaped hepta-nuclear heterometallic cluster of [Ba3Zn4(CO2)12(HCO2)2(OH2)2] as SBUs, which not only has plentiful low-coordinated open metal sites but also has the excellent physicochemical properties including omni-directional opening pores, ultrahigh porosity, larger specific surface area, and the coexistence of Lewis acid-base sites. Just as expected, thanks to its rich active metal sites and pyridine groups as strong Lewis acid-base roles, completely activated NUC-27 displays high catalytic efficiency on the chemical transformation of epoxides with CO2 into cyclic carbonates under mild conditions and effectively accelerates the reaction process of Knoevenagel condensation.

Guided by mixed ligands strategy, a novel binuclear cadmium(II) coordination polymer, {[Cd2(HDDB)(m-bib)(H2O)2]·1.5H2O·DMF}n (1) [H5DDB = 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid, m-bib = 1,3-bis(imidazol-1-yl)benzene], was constructed under solvothermal condition and then was further characterized by X-ray crystallography, IR, EA, TG, and PXRD. Structure analysis shows 1 displaying a new (3,4)-c {6.82}4{62.84} sheet when HDDB4− ligands and the [Cd2(COO)2] SBUs were simplified into 3-connected and 4-connected nodes. And further fluorescence analysis revealed that 1 showing outstanding performances as efficient chemo-sensor in the detection of NFT antibiotic in aqueous solution with low LOD, high selectivity, high sensitivity, and strong anti-interference. Besides, the mechanisms of luminescence quenching were explored from the viewpoints of inner filter effects (IFE) and the photo-induced electron transfer (PET), implied by the optical spectroscopy and quantum chemical calculation. Based on the mixed ligands strategy, a 2D binuclear Cd(II)CP was constructed and can be act as efficient chemo-sensor in the detection of NFT antibiotic in aqueous solution.

In terms of documented references, multifunctional MOFs with high catalytic performance could be constructed from the combination of metal cations and polycarboxyl-pyridine ligands, which could eff...

In terms of ligand-directed synthetic strategy, multifunctional metal–organic frameworks (MOFs) could be assembled by employing organic ligands with nitrogen-containing heterocycles, which could se...

With the aim of exploring and enriching nanocaged functional platforms of lanthanide–organic frameworks, the subtle combination of [Ln2(CO2)8] secondary building units and [Ln(CO2)4] units by emplo...

The exquisite combination of independent 3p [In(CO2)4] units and 4f [Tb2(CO2)8] clusters in the presence of the designed hexatopic 2,4,6-tri(2,4-dicarboxyphenyl)pyridine ligand engenders one peculi...

A novel 1D cadmium-based luminescent metal-organic complex {[Cd(CIP)2(H2O)2]n·2.5H2O} (1) (HCIP=4-(4-carboxylphenyl)− 2,6-di(4-imidazol-1-yl)phenyl)pyridine), has been synthesized through a solvothermal method. The single-crystal X-ray diffraction analysis shows that complex 1 exhibits a 1D chain structure that is further extended to a 3D supramolecular framework by H-bonds and and π-stacking interaction. Luminescence tests suggest that complex 1 displays excellent sensitivity and selectivity to detect Fe3+, CrO42-/Cr2O72-, and a wide range of nitroaromatic explosives. It is the first example of a Cd-based LMOC as luminescent probe to detect Fe3+, CrO42-/Cr2O72- in aqueous solution and nitroaromatic explosives in both liquid and vapor phases.

Two porous isomorphic 3D Eu(III)/Nd(III) lanthanide metal–organic frameworks (Ln-MOFs), formulated as {[Eu(BCPB)(H2O)(DMF)]·H2O·1.5CH3OH}n (1) and {[Nd(BCPB)(H2O)(DMF)]·2H2O}n (2), have been designed and synthesized by using the tripodal ligand of 3,5-bis(2-carboxy-phenoxy)-benzoic acid (H3BCPB) under solvothermal condition. Complexes 1 and 2 display 3D (3,6)-c net with the point symbol of {4·62}2{42·610·83}. Furthermore, fluorescent measurements showed 1 has highly selective detection for Fe3+ and CrO42− ions in aqueous solution, which shows that it acts as a chemical sensor for detecting Fe3+/CrO42− in aqueous solution. Meanwhile, gas adsorption properties of 1 and 2 have also been studied at different temperatures for N2, CH4 and CO2.

The triboelectric nanogenerator (TENG), based on the triboelectrification coupled with electrostatic induction, can directly convert ambient mechanical energy into electric energy. However, the output performance of TENG is still low and demands further improvement to speed up the commercial application. In this work, we demonstrate a TENG based on a flexible and transparent composite film made of PDMS and ZIF-8. When the amount of the ZIF-8 is 4 wt%, the generated output current and voltage of the TENG are gradually increased up to 16.3 μA and 176 V, which are 210% and 230% higher than that of TENG without ZIF-8, respectively. Impregnated ZIF-8 which exhibits a positive polarity lowers the effective work function of the PDMS and enhance the surface charge density, verified by Kelvin probe force microscope measurement.

Four coo;rdination polymers (CPs), namely, [Ni(HDNA)(bibp)(H2O)]n (1), [Co(HDNA)(bibp)]n (2), {[Co(HDNA)(bibp)]·H2O}n (3) and {[Zn(HDNA)(bibp)]·H2O}n (4), have been synthesized from the mixed-ligand strategy of 6-(3,5-dicarboxylphenyl)nicotinic acid (H3DNA) and 4,4′-bis(benzimidazo-1-ly)benzene (bibp). Structural analyses revealed that four CPs all feature 2D sheets with diverse nets from {44.62}-sql net (1), {Co2(COO)2} SBUs based {44.62}-sql net (2), to 4-connected {65.8} sheet (3&4). Besides, the temperature-dependent magnetic susceptibilities of CPs 1-3 were investigated. And the luminescent sensing indicated CP 4 is a good bifunctional sensor for Fe3+ and Cr2O72- ions.

Two new metal−organic frameworks (MOFs), formulated as {[Ni3(TCPB)2(bibp)2]·4dioxane·DMF·H2O}n (1), {[Mn3(TCPB)2(bimp)(DMF)]}n (2) have been constructed from polycarboxylate ligand as well as bis(imidazole) ligands under hydrothermal method (H3TCPB=1,3,5-tris(4-carbonylphenyloxy)benzene, bibp = 4,4'-bis(imidazol-1-yl)biphenyl, bimb= 1,4-bis(imidazol-1-ylmethyl)benene). Structural analysis reveals that both 1 and 2 are two-fold interpenetrated 3D frameworks. Complex 1 is a novel 2-nodal (3,10)-{3.42}2 {34.410.514.614.72.8}-3,10T3 net, the structure of 2 is a (3,8)-connected {43}2{46.618.84}–tfz–d net. Furthermore, sorption behaviors of 1 for gases (N2, H2, CH4, and CO2) and organic dyes (MB, RhB, MO) showed that 1 has high selectivity for the adsorption of CO2 over CH4 and MB over other dye molecules (RhB and MO), respectively. In addition, the magnetic properties measurements indicated that both 1 and 2 display antiferromagnetic interactions between trinuclear {M3(COO)6} SBUs.

Two novel metal–organic frameworks, formulated as [Mn(CIP−)2] (1) and [Ag(CIP−)] (2) (HCIP = 4-(4-carboxylphenyl)-2,6-di(4-imidazol-1-yl)phenyl)pyridine), were solvothermally synthesized based on a pyridyl-imidazole-carboxyl multifunctional ligand. The single-crystal X-ray diffraction analysis shows that complex 1 is a 3D microporous framework with uncoordinated imidazole groups, and complex 2 is a 2D + 2D → 2D 3-fold parallel interpenetrated network. Complex 1 exhibited excellent CO2 selective absorption over N2 and CH4. IAST calculations revealed that the selectivities of 1 for the CO2/CH4 (50 : 50) and CO2/N2 (15 : 85) mixtures were 8.0 and 117 at 273 K under 1 bar, respectively. Moreover, the luminescence investigations displayed that complex 2 is an excellent MOF-based multiresponsive fluorescent probe for Fe3+, CrO42−/Cr2O72− and the pesticide 2,6-Dich-4-nitroaniline, with high selectivity and sensitivity. Notably, complex 2 exhibited a highly sensitive sensing ability (5.2 × 104 M−1) and a low detection limit (1.7 × 10−7 M) for 2,6-Dich-4-nitroaniline. To the best of our knowledge, this is the first Ag-MOF-based fluorescent sensor that can simultaneously detect metal ions, inorganic anions and pesticides.

Based on the mixed ligands p-terphenyl-2,2′′,5′′,5′′′-tetracarboxylate acid (H4tptc) and 1,10-phenanthroline (phen), four novel coordination polymers, [Cu(tptc)0.5(phen)]n (1), [Cd(tptc)0.5(phen)]n (2), [Mn(tptc)0.5(phen)]n (3), and [Mn(H2tptc)(phen)]n (4), were constructed under solvothermal conditions and further characterized. Structure analyses reveal that CPs 1–4 are two-dimensional sheets with different binuclear SBUs. Moreover, electrochemical studies show that CP 1 is an electrochemically active material with good electrochemical reversibility. Luminescence sensing investigations indicate that CP 2 is a bifunctional sensor in terms of detecting Cr(VI) anions in aqueous media and 2,6-dichloro-4-nitroaniline (DCN) in DMF solution. Besides, the study on the magnetic properties of CP 3 and 4 reveals both of them have antiferromagnetic interactions between the adjacent MnII ions.

Two Cd(II) coordination polymers (CPs) were assembled from the mixed ligand strategy of π-conjugated aromatic polycarboxylates and bis(imidazole) linkers, with the structures being a 2-fold interpenetrating 3D bbf net for 1 and a 2D hxl sheet for 2. The fluorescence measurements revealed that both Cd(II) CPs were promising luminescent sensors for the detection of nitrofuran/nitroimidazole antibiotics (ABXs) with low detection limits. Besides, the luminescence quenching of the two Cd(II) CPs toward ABXs was investigated by using DFT calculations and spectral overlap experiments.

On the basis of the bifunctional 1,4-bis(imidazol-1-yl)terephthalic acid (H2BTA), four three-dimensional (3D) Pb(II)/Zn(II) coordination polymers (CPs), {[Zn(BTA)]·1.5(DOA)}n (1), [Zn(BTA)]n (2), [Pb(BTA)]n (3), and [Pb(BTA)]n (4), have been synthesized (DOA = dioxane). Structural analyses reveal that two Zn(II)-based complexes are 3D (4,4)-c pts pseudo-supramolecular isomers for 1 and 2, and two Pb(II)-based complexes are supramolecular isomers with a 3D (4,5,6)-c net for 3 and a 3D 6-c pcu net for 4, respectively. Furthermore, the gas adsorption behaviors of complexes 1 and 2 for N2, CO2, and CH4 have been studied in detail at varying temperatures, and the results showed that the adsorption capacities to CO2 at 273 K and 1 bar are stronger than those of other gases. Meanwhile, the selectivity of 1 and 2 for CO2/CH4 was evaluated by the usage of the ideal adsorbed solution theory, whose selectivity exceeded those of reported MOFs under similar conditions. In addition, the fluorescent measurements showed ...

Three 3D Cd(II) complexes, namely, {[Cd4(L)2(dioxane)3(H2O)3]·DMA·5H2O}n (1), {[Cd2(L)(phen)(H2O)3.5]·4H2O}n (2) and {[Cd2(L)(phen)(H2O)4]·3H2O·DMA}n (3) have been synthesized from the ligand of 3,5-di(2′,5-dicarboxylphenyl)pyridine (H4L) with or without the assistance of phen auxiliary linker (phen = 1,10-phenanthroline). Complex 1 displays a 3D (4,4,9)-connected net with the point symbol of {3.45}{32.414.55.611.72.82}{45.6}. Complex 2 shows a 3D (4,8)-connected net with the point symbol of {43. 63}2{46.619.83}. Complex 3 presents a 3D 4-connected net with the point symbol of {43.62.8}. The fluorescence measurements showed 1–3 exhibit sensitive detection of Fe(III) and Cr(VI) ions with a low detection limit. In addition, the gas sorption isotherms of complex 3 for N2, H2, CO2 and CH4 were investigated, and the corresponding uptakes are 239.8 cm3 g−1 for N2 and 93.9 cm3 g−1 for H2 at 77 K, 50.5 cm3 g−1 for CO2 and 17.0 cm3 g−1 for CH4 at 298 K, 54.8 cm3 g−1 for CO2 and 24.2 cm3 g−1 for CH4 at 273 K, respectively. Based on the N2 isotherm, the Brunauer−Emmett−Teller (BET) and Langmuir surface area of 3 were calculated to be 610.1 and 710.5 m2 g−1, respectively. Moreover, the two binary gas mixtures adsorption was also studied, indicating that the adsorption of 3 for CO2 is better than that of CH4, which was verified by ideal adsorbed solution theory (IAST) with the adsorption selectivity being 8.5 (landfill gas, CO2/CH4 = 0.5/0.5) and 7.2 (natural gas, CO2/CH4 = 0.05/0.95).

Based on the hydrolysates of N,N′-bis(3,5-dicarboxylatophenyl)pyromelliticdi-imide) (H4L) and 1,3-bis(imidazol-1-ylmethyl)benzene (bimb), three coordination polymers, namely, {[Zn(BTC)0.5(bimb)]·4H2O}n (1), [Cu(BTC)0.5(bimb)]n (2), and {[Cd(AIP)(H2O)]·H2O}n (3), have been obtained under solvothermal conditions. The possible hydrolysis mechanism of H4L was investigated here. Structural analyses reveal that complex 1 is a 3D (4,4)-c {64.82}{66}2-bbf net. Complex 2 displays a 2D 4-c {32.62.72}-kgm sheet. While complex 3 exhibits a 3D (3,6)-c {4.62}2{42.610.83}-rtl net based on binuclear {Cd2(COO)4} SBUs. Besides, luminescent sensing investigation indicated that 1 and 3 exhibit highly sensitive and selective sensing of chromate anions in aqueous solution.

Two lanthanide metal-organic frameworks (LOFs), namely, {[Tb(L3−) (H2O)]·3CH3CN}n (1) and {(Me2NH2+)0.5·[Gd(L3−)(HCOO−)0.5 H2O]·DMF·4EtOH·H2O}n (2) have been constructed by tris(4-carboxyphenyl)phosphane oxide (H3L) under solvothermal conditions. Structural analyses indicate that complex 1 appears a 3D 6-connected {412∙63} net based on the binuclear {Tb2(COO)2} clusters. Complex 2 is also a 3D framework. Furthermore, the photoluminescence of 1 in the solid state and different solvent emulsions were studied, the results indicate that 1 shows characteristic green emission of Tb3+ ion and has better fluorescent recognition for sorts of organic solvent molecules and Fe3+ ion. Finally, the result of the variable-temperature magnetic susceptibilities suggests that complex 2 have antiferromagnetic behavior between Gd(III) ions.

Based on the mixed ligands of aromatic pentacarboxylate of 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid (H5L) and 1,4-bis(imidazol-1-yl) benzene (bib), two novel coordination polymers, namely, [Ni1.5(H2L)(bib)1.5(H2O)2]n (1), and {[Pb2(HL)(bib)1.5(H2O)]·H2O}n (2) have been synthesized and characterized by EA, IR, TG, PXRD. Structure analyses reveal that complexes 1 and 2 are both (3,4,4)-connected structures with the same stoichiometry of (3-c)2(4-c)2(4-c), the 2D {63}2{64.8.10}{64.82}2 trilayer for 1, and 3D {6.82}2{64.82}2{8.104.12} network for 2. Complexes 1 and 2 exhibit excellent recyclable, selective, and sensitive detection of Cr(VI) anions in aqueous solution. The possible mechanism for selective luminescence quenching responses toward Cr(VI) anions is also discussed in detail.

Three novel coordination polymers (CPs), formulated as [Co2(TZI)(OH)(H2O)2]n (1), {[Co(H2TZI)2(BIB)(H2O)2]·(H2O)2}n (2), and [Ni(HTZI)(BPB)(H2O)]n (3) (H3TZI = 5-(1H-tetrazol-5-yl)isophthalic acid, BIB = 1,4-bi(1-imidazolyl)benzene, and BPB = 1,4-bi(1- pyridyl)benzene), have been synthesized under hydrothermal methods, using 5-(1H-tetrazol-5-yl)isophthalic acid ligand (H3TZI) and two different N-donating ancillary ligands. Their structures have been determined by single-crystal X-ray diffraction analysis, elemental analysis (EA), IR spectra (IR), powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). X-ray single-crystal diffraction analyses reveal that complex 1 possesses a 2D bilayer structure, complex 2 displays a 3D supermolecular structure with a Co(H2TZI)2 SBU by H-bond interactions between neighbouring 1D chains, and complex 3 presents a 2D framework with a dinuclear [Ni2N4]2+ SBU. Furthermore, the magnetic properties of 1–3 have been investigated, the results show there are antiferromagnetic interactions between the Co ions in 1 and 2, and the ferromagnetic interactions between Ni ions in 3.

Two novel coordination polymers, {[Cd(TZMB)(1,4-bib)0.5]·(H2O)1.5} (1) and {[Zn(TZMB)(1,4-bib)0.5]}n (2), have been synthesized under solvothermal conditions. Complex 1 displays a 3D structure with the (47.84)(4.72.83) topology and Complex 2 is a 3D structure with the point symbol of {4.82}{4.85}. And complex 1 shows good luminescent quenching effect for organic solvent molecules (actone and p-nitrophenol) and Fe3+.

Two 3D modular designed coordination polymers, namely, {[H2N(CH3)2]2[Mn(TPT)]}n (1), and {[Cd(TPT)0.5(bib)]·0.5H2O}n (2) (H4TPT = p-terphenyl-2,2″,5″,5‴-tetracarboxylate acid, and bib = 1,3-bis((imidazol-1-yl) benzene) have been synthesized and structural characterized by EA, IR, TG, PXRD. Single-crystal X-ray diffraction analyses reveal that complex 1 is a 3D 4-connected {42.63.8}–sra net with the tiling modular being [42.62.82] = [4a.4b.62.8a.8b] (transitivity is 2451). While complex 2 is a 3D (4,4)-connected {64.82}{66}2–bbf net with tiling modular is [6.82]+[63.8] = [6 c.8a.8b]+[6a.6b.6 c.8a] (transitivity is 2352). The variable-temperature susceptibility of 1 has been investigated. Besides, complex 2 exhibits highly sensitive sensing of FeIII ions in DMF solution.

Based on the mixed ligands synthesis strategy, a 3D cobalt (II) coordination polymer, [Co(tptc)0.5(bib)]n (1), has been assembled from p-terphenyl-2,2″,5″,5″'-tetracarboxylate acid (H4tptc) and 1,3-bis((imidazol-1-yl) benzene (bib). Structural analysis revealed that complex 1 is a 3D framework, which can be simplified into a (4,4)-connected {64.82}{66}2 bbf net. And the modular analysis reveals the tiling of 1 is [6.82] + [63.8] = [6c.8a.8b] + [6a.6b.6c.8a] with the transitivity is 2352. And the luminescent sensing investigation indicating complex 1 exhibits highly sensitive sensing of CrO42−/Cr2O72− anions in aqueous solution through strong luminescence quenching effects.

Four coordination complexes, namely, [Cu(HBCB)]n (1), {[Cu(HBCB)(o-bimb)]·H2O} (2), {[Cu1.5(BCB)(m-bimb)1.5]·DMF}n (3), and [Co1.5(BCB)(bpy)1.5(H2O)]n (4), have been assembled from the semirigid tripodal 3,5-bis(2-carboxylphenoxy)benzoic acid (H3BCB) in the presence or absence of the N-donors (o-bimb = 1,2-bis(imidazol-1-ylmethyl)benzene, m-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, bpy = 4,4′-bipyridine). Structural analyses revealed that complex 1 features a {Cu2(COO)4} SBUs based 3D (3,6)-connected {4·62}2{42·610·83}-rtl net. Complex 2 displays an interesting coordination molecule cage structure. Complex 3 exhibits a 2D (3,4,4)-connected {4·62}2{4·64·8}2{64·82} sheet. And complex 4 shows a 3D (3,4,6)-connected {5·62}2{56·64·7·82·92}{64·8·9} net based on the binuclear {Co2(COO)2} SBUs and Co2 ions. The temperature-dependent magnetic susceptibilities indicated there are gradual spin transition behavior in 1, and antiferromagnetic interactions in 4.

Two new coordination polymers, namely [Zn(TZMB)]n (1) and {[Zn(TZMB)](H2TZMB)]·(C2H5OH)0.5(H2O)2.5}n (2), (H2TZMB = 4,4′-(1H-1,2,4-triazol-1-yl)methylene-bis(benzonic acid), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction analysis, elemental analysis (EA), IR spectrum analysis (IR), powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Single X-ray diffraction analysis reveals that complex 1 is a 3D 3,6-connected net with the point symbol of (6110.84)(63)2 and complex 2 is a 2D 3-connected net with the point symbol of (63). Furthermore, luminescent properties of complexes 1 and 2 were also investigated in detail.

Based on 5,5 ′ -(1,3,6,8-tetraoxobenzo[ lmn ][3,8] phenanthrolin-2-7-diyl)bis-1,3- benzenedicarboxylic acid (H 4 BIPA-TC), two novel 2D coordination polymers, formulated as {[Cd(BIPA-TC) 0.5 (1,4-bib)(H 2 O)]·(H 2 O) 3.5 } n ( 1 ) and {[Cd 2 (BIPA-TC)(4,4 ′ -bibp)(H 2 O)]·(H 2 O)} n ( 2 ) have been solvothermally synthesized with the help of two bis(imidazole) linkers, 1,4-bib and 4,4 ′ -bibp(1,4-bib = 1,4-bis(benzimidazo-1-ly)benzene and 4,4 ′ -bibp = 4,4′-bis(imidazolyl)biphenyl). Single-crystal X-ray diffraction analysis shows that complex 1 is a (4,4)-connected bilayer network structure with the point symbol of (4 6 ·4 8 ) 2 (4 2 ·6 4 ), which further expand into an interestingly 2D + 2D → 3D interweaved framework. Complex 2 possesses a (4,6)-connected network with two kinds of {Cd 2 (COO) 2 } SBUs with the point symbol of (3 2 ·4 2 ·5 2 )(3 4 ·4 4 ·5 4 ·6 3 ), which further pack into a 3D supramolecular architecture through hydrogen bonds. Furthermore, the luminescent recognition properties of 1 and 2 for small organic molecules, nitroaromatic compounds, and metal cations have been explored systematically.

Based on the designed π-conjugated aromatic pentacarboxylate of 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid (H5DDB) and bis(imidazole) ancillary linkers (bib = 1,4-bis(imidazol-1-yl)benzene, m-bimb = 1,3-bis(imidazol-1-ylmethyl)benzene, p-bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), five 3D coordination polymers, namely, {Co2(HDDB)(bib)1.5(H2O)2]·H2O}n (1), {[Mn2.5(H2DDB)(HDDB)(bib)0.5(μ2-H2O)(H2O)1.5]·(Hbib)·0.5(H2bib)·0.5H2O}n (2), {[Cd2(HDDB)(bib)1.5(H2O)]·2.5H2O}n (3), {[Cd2(HDDB)(m-bimb)]·H2O}n (4), and {[Cd2(DDB)(p-bimb)]·2.5H2O·0.5(p-H2bimb)}n (5), have been obtained and characterized. Complex 1 is a 3D 3-fold interpenetrating (3,4)-c {83}2{85·9}-vtx net. Based on the binuclear {Mn2(COO)2} SBUs, as well as the trinuclear {Mn3(COO)4(μ2-H2O)2} SBUs, complex 2 shows a 3D 3,4,6-c 3,4,6T10 net with a point symbol of {3·72}2{32·73·8}{32·76·86·10}. Complex 3 displays an unprecedented 3D (3,4,4)-c net with a point symbol of {6·82}2{64·82}2{8·104·12} based on the binuclear {Cd2(COO)4} SBUs. Complex 4 shows an interesting 3D (3,10)-c {410·632·83}{43}2 net based on the quadrilateral tetranuclear {Cd4(COO)8} SBUs. Complex 5 exhibits a linear tetranuclear {Cd4(COO)4} SBU-based 3D (4,10)-c deh1 net with a point symbol of {3·45}2{34·412·510·614·73·82}. A variable temperature magnetic susceptibility investigation indicated that antiferromagnetic interactions exist between the neighbouring metal ions in 1 and 2. Fluorescence measurements showed that 3–5 are promising luminescence sensors for the detection of Cr(VI) anions (CrO42− and Cr2O72− anions) in aqueous solution.

Four 3D novel coordination polymers (CPs), formulated as {[Co3(TCPB)2(bibp)2(dioxane)2.5(H2O)2]·(DMF)}n (1), {[Cd6(TCPB)4(bibp)4(dioxane)(H2O)2]·(dioxane)3·DMF·(H2O)0.5}n (2), {[Co1.5(TCPB)(bimb)0.5(DMF)(dioxane)]}n (3), and {[Zn1.5(TCPB)2(bimb)(DMF)(dioxane)2]·dioxane}n (4) (H3TCPB = 1,3,5-tris(4-carbonylphenyloxy)benzene, bibp = 4,4′-bis(imidazol-1-yl)biphenyl, and bimb = 1,4-bis(imidazol-1-ylmethyl)benzene), have been synthesized under solvothermal conditions and characterized by elemental analyses (EA), single-crystal X-ray diffraction analyses, X-ray powder diffraction analyses (PXRD), IR spectra, and thermogravimetric analyses (TGA). The structural analyses reveal that complex 1 can be simplified as a new 2-nodal (3,10)-{3·42}2 {34·410·514·614·72·8}-3,10T3 net, complex 2 has a 3D 2-nodal (3,8)-c network with the point symbols of {42·5}2{44·59·68·73·83·9}, complex 3 exhibits a novel 3D framework with the point symbol of {410·632·7·82}{43}2, and the structure of 4 is a (3,8)-connected {43}2{46·618·84}-tfz-d net. Furthermore, gas sorption behaviors of complex 1 for N2, H2, CH4, and CO2 have been comprehensively studied at varying temperatures: the results reveal that the adsorption capacity of 1 to N2 is stronger than those of other gases. Meanwhile, IAST calculations reveal that 1 exhibits excellent selective separation for CO2/CH4. Magnetic measurements indicate that both 1 and 3 have antiferromagnetic interactions within the trinuclear clusters. In addition, the fluorescent measurements showed that 2 and 4 exhibit highly selective and sensitive detection of Fe3+ and Cr3+ ions.

Two lanthanide metal–organic frameworks (LOFs), namely, {[Eu(L3−)(H2O)]·5H2O}n (1) and {[Dy(L3−) (H2O)]·2CH3CN}n (2), have been synthesized based on tris(4-carboxyphenyl)phosphane oxide (H3L) and further characterized by powder X-ray diffraction (PXRD), IR spectroscopy, elemental analyses and thermogravimetric (TG) analyses. X-ray diffraction analyses showed that complexes 1 and 2 are isostructural, and thus the structure and gas adsorption properties of complex 1 and the magnetic properties of 2 were described as a representative in detail. Complex 1 appears to have a 3D 6-connected {412·63} net based on binuclear {Eu2(COO)2} SBUs. Furthermore, the adsorption properties of 1 have been investigated using N2, H2, CO2 and CH4 gases. 1 has high CO2 uptake and exhibits highly selective adsorption of CO2 over CH4 at room temperature, which allows 1 to have a potential application in gas separation and purification. Finally, its full magnetic properties revealed that complex 2 displays antiferromagnetic coupling between DyIII ions and single-molecule magnet (SMM) behavior. According to the Arrhenius law, the anisotropy barrier (Ueff) and pre-exponential factor (τ0) were extracted by fitting of the alternating current data, giving the values of 53.5 K and 3.1 × 10−7 s, respectively. The afforded α parameter is less than 0.10, suggesting a single relaxation process.

Two novel coordination polymers, formulated as {[Zn(HTPO)(bib)]·4H 2 O} n ( 1 ), {[Cu 3 (TPO) 2 (bib) 3 ]·2DMF·0.5EtOH·0.5H 2 O} n ( 2 ) (H 3 TPO = tris(4-carboxylphenyl)phosphine oxide; bib = 1,4-bis(1H-imidazol-4-yl) benzene), have been synthesized under solvothermal method and characterized by single-crystal X-ray diffraction, elemental analysis (EA), IR spectra, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD). Structural analysis reveals that complex 1 is a 2D 4-connected sheet with an intriguing 2D + 2D→2D network. Complex 2 displays a 3D 3,4-connected net with the point symbol of {10 3 } 2 {10 6 } 3 . Furthermore, the photoluminescence properties of 1 and 2 were investigated in the solid state and various solvent emulsions, the results show that 1 and 2 have better fluorescent recognition for organic molecules, Fe 3+ and Hg 2+ ions.

Two manganese (II) coordination polymers, namely, [Mn1.5(BCB)(bpy)1.5(H2O)]n (1), and [Mn(HBCB)(bibp)2(H2O)] (2), have been assembled from the mixed ligands of the flexible tripodal ligand of 3,5-bis(2-carboxylphenoxy)benzoic acid (H3BCB) and two rigid N-donors (bpy = 4,4'-bipyridine, and bibp = 4,4'-bis(imidazolyl)biphenyl). Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Structural analysis reveals that complex 1 is a 3D (3,4,6)-connected {5*62}2{56*64*7*82*92}{64*8*9} net based on two kinds of inorganic nodes of binuclear {Mn2(COO)2} SBUs and Mn(2) ions. While complex 2 is a hydrogen bonds based 3D supramolecule with 6-connected {412*63}-pcu net. Besides, the variable-temperature susceptibilities of 1 and 2 have been investigated.

Three novel coordination polymers, formulated as {[M(Htcpb)(4,4′-bpy)·(DMF)·(Dioxane)0.5·(H2O)2]}n (M = Co (1), Cd (2)), {[Zn2(Htcpb)(Hbim)](DMF)3·(Dioxane)2·(H2O)3}n (3) (H3tcpb = 1,3,5-tris(4-carbonylphenyloxy) benzene, 4,4′-bpy = 4,4-bipyridine and Hbim = benzimidazole), have been synthesized. Their structures have been determined by single-crystal X-ray diffraction analysis, elemental analysis (EA), IR spectra (IR), powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). Complexes 1 and 2 are isomorphic and feature 2-fold interpenetrating 2D sheets, which are further expanded into a 3D supramolecular structure through hydrogen bonds. Complex 3 shows a 2-fold interpenetrating 3D (4,6)-c net with the point symbol of (43·612)·(43·63)2. Furthermore, the magnetic property of 1, as well as the luminescence sensing of complexes 2 and 3 for small organic molecules, nitrobenzene derivatives (NDVs) and metal ions have been investigated.

Four three-dimensional (3D) Cd(II)/Mn(II) coordination polymers, namely, {[Mn1.5(TCPB)(H2O)(μ2-OH2)]·H2O}n (1), {[Cd3.5(TCPB)2(H2O)3(μ2-OH2)(μ3-OH)]·H2O}n (2), [Mn1.5(TCPB)(bib)0.5(DMF)]n (3), and {[Cd2(TCPB)(HCOO)(bib)(H2O)]·0.5dioxane}n (4), have been constructed from the flexible tripodal ligand of 1,3,5-tris(4-carbonylphenyloxy)benzene (H3TCPB) with or without the help of bib auxiliary linker (bib = 1,4-bis(imidazol-1-yl)benzene). On the basis of the one-dimensional (1D) rod-like {Mn3(COO)8(μ2-H2O)2}n secondary building units (SBUs), complex 1 displays a 3D (4,8)-connected flu net with the point symbol of {412.612.84}{46}2. Complex 2 shows a novel 3D 12-connected {312.440.512.62} net based on the 1D {Cd6(COO)12(μ3-OH)2(μ2-OH2)2}n SBUs. When the bib bridging ancillary linker was introduced, a trinuclear {Mn3(COO)6} SBU based 2-fold interpenetrated 3D (3,8)-connected {43}2{46.618.84}-tfz-d net for 3, and a binuclear {Cd2(COO)3} SBU based 3D (3,7)-connected {4.62}{47.614} net with interesting self-penetr...

Seven inorganic-organic hybrid complexes, based on 3,5-dimethyl-2,6-bis(3-(pyrid-2-yl)-1,2,4-triazolyl) pyridine (H 2 DBPP), have been obtained under the solvothermal reactions, namely, [M 2 (HDBPP) 2 (ox)] (M = Co for 1 , Zn for 2 , and Ni for 3 ), [Zn 2 (H 2 DBPP) 2 (ox)]·[Mo 6 O 19 ]·4H 2 O ( 4 ), [M 2 (H 2 DBPP) 2 (ox)]·[β-H 2 Mo 8 O 26 ]·2H 2 O (M = Co for 5 , and Ni for 6 ), and [Ni 2 (H 2 DBPP) 3 ]·[β-H 2 Mo 8 O 26 ]·5H 2 O ( 7 ). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Crystal structural analysis revealed that these complexes composed of [M 2 (H 2 DBPP) 2 (ox)] or [Ni 2 (H 2 DBPP) 3 ] cations and polyoxometallates interacted by electrostatic interactions and hydrogen bonds. Interestingly, the anions of these complexes took on [Mo 6 O 19 ] 2− cluster, single [β-H 2 Mo 8 O 26 ] 2− cluster, and twin [β-H 2 Mo 8 O 26 ] 2− clusters by changing the metal ions, and solvents. Besides, the magnetic property of complexes 1 , 3 , 5 – 7 , the solid state luminescence properties of complexes 2 , 4 and the photocatalytic activities of complexes 4 , 7 have been investigated.

Two ternary cadmium(II) coordination polymers, with the formulas being {[Cd(tptc)0.5(bpz)(H2O)]·0.5H2O}n (CP 1), and [Cd(tptc)0.5(bpy)]n (CP 2), were designed through mixed ligands strategy. Benefiting from the excellent chemical stability and luminescent property, two Cd(II) CPs possessing efficient multi-functional fluorescent responses toward Cr(VI) anions, 2,6-dichloro-4-nitroaniline pesticide, and nitrofuran antibiotic in aqueous media with high sensitivity, selectivity, and excellent recyclable behaviors with the detection limits (LODs) are 235 ppb for CrO42− anion, 343 ppb for Cr2O72− anion, 112 ppb for DCN pesticide, 62 ppb for NFT antibiotic for CP 1, and 173 ppb for CrO42− anion, 270 ppb for Cr2O72− anion, 638 ppb for DCN pesticide, 184 ppb for NFT antibiotic for CP 2, respectively. Besides, the mechanisms of luminescence quenching were revealed from the viewpoint of internal filter effect (IFE) and photoinduced electron transfer (PET).

A stable Cd(II) based luminescence coordination polymer, {[Cd(tib)2](NO2)2·0.5DMA·H2O}n (CdCP, tib ​= ​1,3,5-tris(1-imidazolyl)benzene), containing the 2D {4^3}2{4^6.6^6.8^3}-kgd cationic sheet, has been successfully obtained and applied as an efficient and versatile chemical sensor. Fluorescence sensing experiments revealed that CdCP displays high sensitivity and selectivity for detecting inorganic Cr(VI) anions and nitrofuran/nitroimidazole antibiotics (ABXs) in aqueous solutions via luminescence quenching effects. In addition, the mechanisms of fluorescent quenching were discussed based on optical spectroscopy and quantum chemical calculation, which indicated that the quenching mechanisms involving internal filter effect (IFE) and photo-induced electron transfer (PET). This work provides a meaningful strategy for design multi-responsive cationic MOFs/CPs as chemical sensor in the detection of pollutants in water.

Two coordination polymers (CPs), namely, [Cd1/2(L)1/3(bib)1/2(H2O)]n (1) and {[Cd2(HL)2(bibp)2]·3H2O}n (2), have been assembled from the tripodal ligand tris(p-carboxyphenyl)phosphane oxide (H3L) with the help of 1,4-bis(imidazol-1-yl)benzene (bib) or 4,4′-bis(imidazol-1-yl)biphenyl (bibp). Structural analyses revealed that complex 1 is an unprecedented (3,4)-connected {103}2{106}3 net with 2D [Cd3(L)2]n sheets arranged in an ABCA′B′C′A′′B′′C′′ fashion. Complex 2 exhibits 3-fold interpenetrated sheets with a 4-connected {44·62}-sql sheet. Structural comparison reveals that the length of bis(imidazole) ancillary linkers plays a critical role in determining the structures and topologies. To our delight, fluorescence measurements show that the two Cd(II) CPs can selectively and sensitively detect Hg2+ cations and nitrobenzene derivatives (nitrobenzene, p-nitrotoluene, p-nitroaniline, and p-nitrophenol), which suggests that the two Cd(II) CPs are promising bifunctional luminescence sensor materials that could sense metal ions and small organic molecules.

Based on the tripodal 1,3,5-tris(imidazol-1-yl)benzene (tib) ligand, four transition metal coordination polymers, namely, {[Ni3(tib)2(H2O)12]·(SO4)3}n (1), {[Co1/6(tib)1/3]·(O)1/3}n (2), and [M(tib)(hip)]n (M = Mn for 3, and M = Co for 4) (hip = 5-hydroxyisophthalic acid), were synthesized through solvothermal method. Their structures were defined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric analyses (TGA). Complex 1 displays a 2D 3-connected (63) hcb net. Complex 2 is a 2D (3,6)-connected (43)2(46.66.83) kgm net. Complex 3 and 4 present similar 2D 4-connected (44.62) sql net. Moreover, the solid state luminescence properties of complexes 1 and 3 were investigated.

A coordination unsaturated copper (II) coordination polymer, [Cu(tptc)0.5(bpy)(H2O)]n (1), was constructed from the mixed ligands of p-terphenyl-2,2'',5'',5'''-tetracarboxylate acid (H4tptc) and 1,3-bis(imidazol-1-ylmethyl)benzene (bimb) under hydrothermal condition. Structural analysis revealed that CP 1 is a 2D 4-connected {32∙62∙72} kgm polymeric sheet, which can be further expanded into 3D supramolecular through hydrogen bonds. The coordination unsaturated central Cu(II) ions endow the CP 1 open metal sites, displaying good electrochemical reversibility as well as high efficiency in photocatalytic degradation of methylene blue (MB) under UV irradiation.

Two copper (II) coordination polymers, namely, [Cu(tptc)0.5(bpy)(H2O)]n (1), [Cu(H2tptc)0.5(bpz)]n (2), have been assembled from the mixed ligands of p-terphenyl-2,2′',5′',5′''-tetracarboxylate acid (H4tptc) and chelating N donors of 2,2′-bipyridine (bpy) or 2-(1H-pyrazol-3-yl)pyridine (Hbpz). Structural analysis revealed that two CPs are both 1D polymeric chains, which can be further expanded into 3D supramolecular through hydrogen bonding and π∙∙∙π packing interactions. And the electrochemical studies show that both two Cu(II) CPs are electrochemically active materials with good electrochemical reversibility.

Three 5-hydroxy isophthalic acid (H2OIP) based coordination polymers, namely, {[Cu(OIP)(bimb)]·H2O}n (1), {[Co2(OIP)2(bimb)2]·H2O}n (2), and [Zn(OIP)(bimb)]n (3) were synthesized under hydrothermal conditions in the presence of bis(imidazole) bridging linkers (bimb = 1,3-bis(1H-imidazol-4-yl)benzene (bimb)). Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analysis. Complex 1 displays a 3D ABAB packing supramolecular structure with 4-connected 2D wave sql sheet. Complex 2 possesses a 3D 5-connected bnn net based on [Co2(COO)2] secondary building unit (SBU) with a Schlafli symbol of (46·64). Complex 3 features a 2D flat sql net with Zn ions as 4-connected nodes. Moreover, the magnetic property of complex 2 and the solid state luminescence of complex 3 have been investigated.

A series of trinuclear coordination polymers (CPs), {[Ln1.5(DDB)(FA)0.5(H2O)2.5]·6H2O}n (Ln = Sm for 1, Eu for 2, Tb for 3, Dy for 4), have been constructed from Ln cations and 1,3-di(2,4-dicarboxyphenyl)benzene (H4DDB) with the help of in situ generation of formate anions under solvothermal reactions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD), and thermogravimetric (TG) analyses. Complexes of 1–4 exhibit the unprecedented (3,8)-connected 3D architectures with the Schlafli Symbol of (4.52)2(42.512.66.75.83), based on the trinuclear [Ln3(COO)6] SBUs. Besides, luminescence investigations indicated that 1 and 4 show ligand-based fluorescence, while 2 and 3 show typical red or green emission with 4f–4f transitions for Ln ions. White light emission can be achieved by doping Dy ions into the Eu complex.

Six coordination polymers (CPs), {[M(ITA)]·0.5H2O}n (M = Zn 1, M = Mn 2), {[Zn(ITA)(bib)0.5]·1.5H2O}n (3), {[Ni(ITA)(bib)0.5(H2O)3]·H2O}n (4), {[Zn(ITA)(bimb)0.5]·0.5H2O}n (5) and [Cd(ITA)(bimb)0.5(H2O)2]n (6), have been derived from the designed bifunctional 2-(imidazol-1-yl)terephthalic acid (H2ITA) with or without bis(imidazole) linkers (bib = 1,4-bis(imidazol-1-yl)benzene, bimb = 1,4-bis(imidazol-1-ylmethyl)benzene). X-Ray single-crystal diffraction analysis reveals that complexes 1 and 2 are isomorphic with the same 3D (4)-connected {4·63·82} net. Complex 3 features a 3D 2-fold interpenetrated (3,4)-connected fsc net with point symbol of {4·82·103}{4·82}. Complex 4 displays a 2D 3-connected {63)-hcb sheet, which can be further expanded into a 3D supramolecular network through hydrogen bonding interactions. Complex 5 exhibits an unprecedented 3D 2-fold interpenetrated (3,4)-connected dmc net with point symbol of {4·82}{4·85}. Complex 6 shows a 3D (3,4)-connected {4·82·103}{4·82}-fsc net. Structural comparison reveals that not only the coordination preferences of metal ions but also the auxiliary bis(imidazole) linkers play crucial roles in the control of the final structures. Besides, the photoluminescence properties as well as the photocatalytic activities for the degradation of methylene blue (MB) under UV-vis light of 1, 3, 5 and 6 have been investigated.

Two isostructural Zn (II) luminescent coordination polymers (CPs), namely, [Zn(tptc)0.5(bpy)]n (1) and [Zn(tptc)0.5(pyp)]n (2) {H4tptc ​= ​p-terphenyl-2,2″,5″,5‴-tetracarboxylic acid, bpy ​= ​2,2′-bipyridine, pyp ​= ​3-(pyrid-2-yl) pyrazole} were synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction, elemental analysis, Infrared spectra, powder X-ray diffraction, thermogravimetric analysis. The structural analysis of Zn-CPs shows that they are isostructural and present 2D sheet structures with 4-connected {44.62}-sql topology, which are further expanded into 3D supermolecular structures by H-bonding interaction. Furthermore, the luminescent experiments revealed that CPs 1 and 2 show highly sensitive and selective sensing for CrO42−/Cr2O72− anions and nitrofurantoin in aqueous medium.

Based on the mixed ligands strategy of p -terphenyl-2,2″,5″,5‴-tetracarboxylate acid (H 4 tptc) and 1,10-phenanthroline (phen), a novel Zinc(II) coordination polymer, {[Zn(tptc) 0.5 (phen)]·dioxane} n ( 1 ), has been constructed. Structural analysis revealed that complex 1 is a 1D polymeric chains based architecture, with the porosity is 25.3% after remove the solvents. The gas adsorptions reveal that complex 1 displaying high CO 2 selective absorption over N 2 and CH 4 . Besides, the luminescent sensing investigation indicating complex 1 exhibiting highly luminescent sensitive sensing of Cr(VI) anions in aqueous solution.