Search

With the introduction of 2,2′-bipyridine (2,2′-bipy) agent, two new zinc coordination polymers (CPs), {[Zn6(HL-H)4(2,2′-bipy)4]·¼H2O}n1 and {[Zn3(HL-H)2(H2O)4]·6H2O}n2, have been hydrothermally obtained derived from diphosphonic acid, 1-hydroxy-2-(3-pyridyl)ethylidene-1,1-diphosphonic acid (H5L = (H4C5N)CH2C(OH)(PO3H2)2, HL-H = (H4C5N–H)CH2C(OH)(PO3)2), and determined by single-crystal X-ray diffractions, elemental analysis, IR, powder X-ray diffractions (PXRD). The single-crystal X-ray diffractions reveal that compound 1 owns a novel 1-D fishbone-like inorganic chain structure built from binuclear building blocks [Zn2(O–P–O)2]n via [ZnO4]n tetrahedron linkers. It is the first example that N-heterlcyclic amine 2,2′-bipy is used as the second ligand to construct the compound 1 with the diphosphonic acid ligand H5L. Both hydrogen bonding and π–π stacking interactions further extend the 1-D chain to the 3-D supramolecular network. Compound 2 exhibits a 2-D reticulate layer structure containing 4-, 8- and 16-membered rings created from 1-D ladder-like inorganic chain, and the organic pyridine rings in the structure point to voids defined by the 16-membered rings. Moreover, the room-temperature fluorescence measurements show that both the compounds display two fluorescent emissions centered at 379, 424 nm for 1 and 380, 424 nm for 2, respectively, caused by intraligand π*–π emission state of organic pyridine ring (λex = 235 nm). With the introduction of 2,2′-bipyridine (2,2′-bipy) agent, two new Zn(II)-phosphonate CPs, 1-D {[Zn6(HL-H)4(2,2′-bipy)4]·¼H2O}n1 and 2-D {[Zn3(HL-H)2(H2O)4]·6H2O}n2 (H5L = (H4C5N)CH2C(OH)(PO3H2)2, HL-H = (H4C5N–H)CH2C(OH)(PO3)2), have been hydrothermally obtained and characterized. The thermal stabilities and fluorescent properties of them have been investigated. [ABSTRACT FROM AUTHOR]

A novel barium(II) coordination polymer (CP), [Ba3(L)2(H2O)4]n1, has been firstly isolated based on organic ligand 1‐[(2′‐carboxybiphenyl‐4‐yl)methyl]‐2‐propylimidazole‐4,5‐dicarboxylic acid (H3L=(HO2C)2(C3N2)(C3H7)CH2(C6H4)(C6H3)CO2H) by hydrothermal technique, and determined by single‐crystal X‐ray diffractions, elemental analysis, IR, powder X‐ray diffractions (PXRD). The Ba(II)‐CP 1 belongs to a novel 2‐D layer structure created from 1‐D serrated chain containing secondary building unit (SBU) [Ba(1)Ba(2)Ba(3)] via carboxylate group linkage. In 1, the ligand L3− gives a variety of coordinated styles, nonadentate: μ2:(η1η1), μ2:(η1η1), μ3:(η2η2) and decadentate: μ1:(η1η1), μ3:(η2η2), μ3:(η1η2), μ3:(η1η2), which is the first reported example. Moreover, the room‐temperature fluorescent measurements show that the Ba(II)‐CP 1 has specific ability to recognize copper(II) ion in aqueous solution by means of fluorescence quenching effect, corresponding obtained quenching constant Ksv=1.18×102 M−1 and the limit of detection LOD=0.274 μM. Fluorescence titration experiment reveals that there is a good linear relationship between copper ion concentration and fluorescence intensity in the concentration range of 2.0×10−6∼5.3×10−6 mol ⋅ L−1. The corresponding linear equation: y=402.41897–0.70486x, and linear correlation coefficient: R2=0.99866 (λex=310 nm and λem=412 nm). [ABSTRACT FROM AUTHOR]

Four Cd(II)- and Cu(II)-containing coordination polymers (CPs) based on a multidentate N-donor ligand and varied dicarboxylate anions, [Cd(3,3′-tmbpt)(p-bdc)]·2.5H2O (1), [Cd(3,3′-tmbpt)(m-bdc)]·2H2O (2), [Cu(3,3′-tmbpt)(m-bdc)]·H2O (3), and [Cu(3,3′-tmbpt)(p-bdc)]·2H2O (4), where 3,3′-tmbpt = 1 − ((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole,p-H2bdc = 1,4-benzenedicarboxylic acid, andm-H2bdc = 1,3-benzenedicarboxylic acid, have been prepared hydrothermally. The structures of the compounds were determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra and elemental analyses. Compound1exhibits a 3-D twofold interpenetrating framework with a 65·8 CdSO4topology. Compound2is a 2-D layer containing meso-helical chains with a 44·62sql topology. Compound3shows a 1-D → 3-D interdigitated architecture while4displays a 2-D → 3-D interdigitated architecture. The structural differences of the compounds indicate that the dicarboxylate anions and the central metal ions play important roles in the resulting structures of CPs. Optical band gaps and solid-state photoluminescent properties have also been studied. [ABSTRACT FROM PUBLISHER]

Two CdII-containing coordination polymers based on a multidentate N-donor ligand and two structure-related dicarboxylate ions, namely, [Cd2(3,4′-tmbpt)( o-bdc)2] ·2H2O ( 1) and [Cd2(3,4′-tmbpt)2( p-bdc)2] ·6.5H2O ( 2) [3,4′-tmbpt = 1-((1 H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(3-pyridyl)-1,2,4-triazole, o-H2bdc = 1,2-benzenedicarboxylic acid, and p-H2bdc = 1,4-benzenedicarboxylic acid], were prepared under hydrothermal conditions. The structures of the two compounds were determined by single-crystal X-ray diffraction analysis and further characterized by infrared spectra (IR) and elemental analysis. Compound 1 is a 3D framework containing infinite Cd-O chains. Compound 2 displays a 2D → 2D interdigitated architecture. The effect of the dicarboxylate ions on the structures of the compounds was discussed. Moreover, the optical bandgaps and photoluminescent properties of the compounds were investigated. [ABSTRACT FROM AUTHOR]

A novel coordination polymer based on the multidentate N-donor ligand 1-((1 H -1,2,4-triazol-1-yl)methyl)-3,5-bis(3-pyridyl)-1,2,4-triazole (3,3′-tmbpt) and 1,2,4,5-benzenetetracarboxylate anion (btec), namely, [Zn 5 (3,3′-tmbpt)(btec) 2 (OH) 2 ] ( 1 ), has been synthesized hydrothermally. Compound 1 displays a rare 3D (3,4,11)-connected framework based on a [Zn 5 (OH) 2 ] 8 + cluster. The optical band gap and photoluminescent property of compound 1 have been studied. [ABSTRACT FROM AUTHOR]

By introducing the second ligand 2,2'-bipy, a new copper(II) diphosphonate [Cu(HL)(2,2′-bipy)] 1 (HL = 1-hydroxyethylidenediphosphonate, 2,2′-bipy = 2,2′-bipyrimidine) has been hydrothermally synthesized and characterized by powder X-ray diffraction, elemental analysis, IR and TG-DTA. The single-crystal X-ray diffractions show that compound 1 possess a three-dimensional supramolecular structure, built from 1D chain via a single-bridge O-P-O in syn-anti fashion based on mononuclear unit [CuON]. UV-vis spectra and the nature of electron transfer of 1 are investigated, and the experimental results are in agreement with the quantum chemistry calculation using the B3LYP/6-31G* method. Fluorescent measurements reveal that two emission peaks of 1 centered at 382.5 and 424.5 nm are mainly caused by intraligand π*- π emission state of the second ligands (375, 429.5 nm, λ = 235 nm). Results of electrochemical studies (CV) indicate a higher donor ability of 1. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three MOFs based on diphosphonate coordination polymer are obtained. [•] The fluorescent measurements reveal all the three compounds display two fluorescent emission peaks. [•] Magnetism data indicate compound 1 is a canted antiferromagnet and compound 2 is a metamagnet. [ABSTRACT FROM AUTHOR]

Three new coordination polymers, namely {[Zn(5-OH-bdc)(2,4′-tmbpt)]·5H2O}n (1), [Ag3(L)(2,4′-tmbpt)2]n (2), and [Mn3(L)2(2,4′-tmbpt)2]n (3), have been prepared under hydrothermal condition (2,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3-(4-pyridyl)-5-(2-pyridyl)-1,2,4-triazole, 5-OH-H2bdc = 5-hydroxy-1,3-benzenedicarboxylic acid, and L = 5-(4-carboxybenzyloxy)isophthalic acid). The structures of compounds 1–3 have been determined by single-crystal X-ray diffraction analysis. The structures of 1 and 3 have been characterized by elemental analysis, infrared spectra, powder X-ray diffraction analysis and thermogravimetric analysis. Compound 1 displays a 2D 4-connected sql net with the Schläfli symbol of (44·62), which is further connected by the intermolecular hydrogen bonds to generate a 3D supramolecular architecture. Compound 2 is a 3D two fold interpenetrating framework with the Schläfli symbol of (3·6·7)(32·83·9)(3·64·72·8·9·10). Compound 3 is a 3D (3,6,6)-connected framework with the Schläfli symbol of (3·62)(34·66·85)(33·68·83·10). The pH-dependent photoluminescent spectra of compound 1 have been investigated, and the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra. Three compounds based on a multidentate N-donor ligand, Zn(II)/Ag(I)/Mn(II) ions and polycarboxylic acids have been synthesized under the hydrothermal conditions. The structures of these compounds have been characterized comprehensively. The pH-dependent photoluminescent spectra of compound 1 have been investigated. Moreover, the pH-dependent photoluminescent mechanism has been discussed and proved by UV–Vis absorption spectra. [ABSTRACT FROM AUTHOR]

Abstract Two 2-D diphosphonate coordination polymers (CPs), {[Co 3 (HL1-H) 2 (H 2 O) 4 ]·2H 2 O} n 1 and {[Fe 3 (HL2-H) 2 (H 2 O) 4 ]·6H 2 O} n 2 , (H 5 L1 = (1-hydroxy-2-(imidazo[1,2- a ]pyridin-3-yl)ethane-1,1-diyl)diphosphonic acid, H 5 L2 = 1-hydroxy-2-(3-pyridyl)ethylidene-1,1-diphosphonate acid), have been hydrothermally isolated and determined by single-crystal X-ray diffractions, elemental analysis, IR, powder X-ray diffractions (PXRD), TG-DSC. Both two compounds possess 2-D inorganic layer structures containing 1-D ladder-like inorganic chains with building blocks [M 2 O 2 ] n and [MO 6 ] n. Compound 1 is the first example of Co(II)-H 5 L1 diphosphonate. The photoluminescence studies show that both compounds display fluorescent emissions, 378.5, 431.5 nm for 1 and 321.5, 390 nm for 2 (λ ex = 235 nm), respectively. Magnetic results show that both 1 and 2 present ferro- (FM) and antiferro- (AFM) metamagnetic behavior aroused by spin canted antiferromagnetic coupling between metal(II) centers. Moreover, the studies on the zero-field alternating current (ac) magnetic susceptibility suggest that compound 2 displays slow magnetic relaxation property, being promising potential as magnetic materials. Graphical abstract Two 2-D Co(II)/Fe(II)-diphosphonate CPs have been hydrothermally isolated under the introduction of 4,4′-bipyridine template. Magnetism studies suggest that the compound 2 , {[Fe 3 (HL2-H) 2 (H 2 O) 4 ]·6H 2 O} n , displays AFM-FM metamagnetic property with an interesting slow magnetic relaxation behavior originated from spin-glass. fx1 [ABSTRACT FROM AUTHOR]