Search

Two series of seven lanthanide metal coordination polymers (Ln–CPs) formulated as {[Ln(dttpa)1.5(H2O)2]·H2O}n [Ln = La3+ (1), Ce3+ (2), Nd3+ (3), Sm3+ (4) and Eu3+ (5)] and {[Ln (dttpa)1.5(H2O)]·xH2O}n [Ln = Tb3+ (6) and Er3+ (7), x = 0.75] have been successfully constructed using Ln3+ ions and 2,5-di(1H-1,2,4-triazol-1-yl)terephthalic acid (H2dttpa) via a hydrothermal method. Their 3D structures are fully characterised by Fourier transform infrared (FT-IR) spectroscopy, X-ray single-crystal analyses, powder diffraction analyses (PXRD), elemental analyses (EAs) and thermogravimetric analyses (TGAs). All Ln–CPs display the same topological property with the point symbol of {42·84}{44·62}2{49·66}2, and crystallize in the triclinic space group P1¯. Interestingly, Eu–CP (5) effectively sensitizes the visible emission of Tb3+ and shows high selectivity and stable response with the lowest detection limit of 9.88 nM. Furthermore, Tb–CP (6) acts as a good luminescence sensor to detect nitrobenzene (NB) with a detection limit of 12.5 nM. In addition, the magnetic susceptibility measurement for Er–CP (7) further shows that compounds constructed by dttpa2− are a kind of promising functional material. [ABSTRACT FROM AUTHOR]

A one-dimensional chiral gadolinium complex based on a tartaric acid derivative: crystal structure, thermal behavior and magnetic properties. Crystal structure of catena-poly[{ 2-3-carboxy-2,3-bis((4-methylbenzoyl)oxy)propanoato- 2O:O'}tris(methanol- 1O)lanthanum(III)], C63H63LaO27 Experimental details Single crystal X-ray diffraction data of the complex were collected on beam line 3W1A of the Beijing Synchrotron Radiation Facility (BSRF), using A MARCCD-165 detector ( I i = 0.71000 A) at a working voltage of 2.5 GeV, and the single crystals with regular shape, suitable size, and bright without cracks were selected under the polarization stereoscopic microscope. [Extracted from the article]

A one-dimensional chiral gadolinium complex based on a tartaric acid derivative: crystal structure, thermal behavior and magnetic properties. Crystal structure of catena-poly[{ 2-3-carboxy-2,3-bis((4-methylbenzoyl)oxy)propanoato- 2O:O'}tris(methanol- 1O)lanthanum(III)], C63H63LaO27 Experimental details Single crystal X-ray diffraction data of the complex were collected on beam line 3W1A of the Beijing Synchrotron Radiation Facility (BSRF), using A MARCCD-165 detector ( I i = 0.71000 A) at a working voltage of 2.5 GeV, and the single crystals with regular shape, suitable size, and bright without cracks were selected under the polarization stereoscopic microscope. [Extracted from the article]

Two three‐dimensional (3D) CdII coordination polymers, namely poly[[di‐μ‐aqua‐diaquabis{μ5‐4,4′,4′′‐[benzene‐1,3,5‐triyltris(oxy)]tribenzoato}tricadmium(II)] dihydrate], {[Cd3(C27H15O9)2(H2O)4]·2H2O}n, (I), and poly[[aqua{μ6‐4,4′,4′′‐[benzene‐1,3,5‐triyltris(oxy)]tribenzoato}(μ‐formato)[μ‐1,1′‐(1,4‐phenylene)bis(1H‐imidazole)]dicadmium(II)] dihydrate], {[Cd2(C27H15O9)(C12H10N4)(HCOO)(H2O)]·2H2O}n, (II), have been hydrothermally synthesized from the reaction system containing Cd(NO3)2·4H2O and the flexible tripodal ligand 1,3,5‐tris(4‐carboxyphenoxy)benzene (H3tcpb) via tuning of the auxiliary ligand. Both complexes have been characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR spectra, powder X‐ray diffraction and thermogravimetric analysis. Complex (I) is a 3D framework constructed from trinuclear structural units and tcpb3− ligands in a μ5‐coordination mode. The central CdII atom of the trinuclear unit is located on a crystallographic inversion centre and adopts an octahedral geometry. The metal atoms are bridged by four syn–syn carboxylate groups and two μ2‐water molecules to form trinuclear [Cd3(COO)4(μ2‐H2O)2] secondary building units (SBUs). These SBUs are incorporated into clusters by bridging carboxylate groups to produce pillars along the c axis. The one‐dimensional inorganic pillars are connected by tcpb3− linkers in a μ5‐coordination mode, thus forming a 3D network; its topology corresponds to the point symbol (42.62.82)(44.62)2(45.66.84)2. In contrast to (I), complex (II) is characterized by a 3D framework based on dinuclear cadmium SBUs, i.e. [Cd2(COO)3]. The two symmetry‐independent CdII ions display different coordinated geometries, namely octahedral [CdN2O4] and monocapped octahedral [CdO7]. The dinuclear SBUs are incorporated into clusters by bridging formate groups to produce pillars along the c axis. These pillars are further bridged either by tcpb3− ligands into sheets or by 1,4‐bis(imidazol‐1‐yl)benzene ligands into undulating layers, and finally these two‐dimensional surfaces interweave, forming a 3D structure with the point symbol (4.62)(47.614). Compound (II) exhibits reversible I2 uptake of 56.8 mg g−1 with apparent changes in the visible colour and the UV–Vis and fluorescence spectra, and therefore may be regarded as a potential reagent for the capture and release of I2. [ABSTRACT FROM AUTHOR]

Solvothermal reactions of Zn(ii) or Mn(ii) salts and 2-(4-carboxyphenoxy)terephthalic acid (H3cpota) in the presence of N-heterocyclic group ligands (1,10-phenanthroline (phen) or 1,4-di(1H-imidazol-1-yl)benzene (bib) or 4,4′-bipyridine (4,4′-bpy)) produced four multi-dimensional coordination polymers, namely, [Mn(μ3-Hcpota)(phen)]n·nH2O 1 (1D), [Mn2(μ4-Hcpota)(μ3-Hcpota)(μ2-bib)2(H2O)]n2 (3D), [Zn(μ3-Hcpota)(phen)]n·nH2O 3 (2D), and [Zn2(μ4-cpota)(μ2-4,4′-bpy)(μ3-OH)]n·nH2O 4 (3D). Complex 1 features a one-dimensional double ladder formed by syn–anti carboxylate-bridged dimeric Mn(ii) units with 8- and 26-membered rings in an alternating pattern sharing three atoms and gives a (42·6) topology. Complex 2 is formed by linear inorganic chains sharing Mn(ii) 8-membered rings in double syn–syn carboxylate bridges and H-bond R11(8) alternate modes, which are further connected to each other by two symmetry independent Hcpota2− ligands as well as coordinated bib bridges giving rise to a three-dimensional net with a novel (4·62)(4·68·8)(43·611·8)(43·63) topology. Complex 3 exhibits a two-dimensional layered structure containing 36-membered rings based on 8-membered dinuclear Zn(ii) units with (32·44)(34·46·64·7) fes-net topology. The phen and benzoic acid groups are like two kinds of blades in the two sides of the two-dimensional structure of 3. Complex 4 is an interesting three-dimensional (3,8)-connected network including tetranuclear tricyclic [Zn4(OH)2(COO)6] clusters with a new (4·5·6)2(42·56·616·72·82) topology. The semirigid tricarboxylate ligand (H3cpota) shows three geometric modes in the self-assembly of four coordination polymers: a) ‘L’ shape in 1, b) ‘I’ shape in 2 and 3, and c) ‘T’ shape in 4. Magnetization analyses disclose the antiferromagnetic behaviors of 1 and 2. Complexes 3 and 4 feature good solvent stability and can withstand ten common solvents. Luminescence investigations reveal that complex 3 has a highly sensitive, selective, low detection limit and well-recyclable properties in the detection of hexavalent chromium anions in aqueous solution. Quenching mechanisms are also studied in detail. [ABSTRACT FROM AUTHOR]

To evaluate magnetic properties of isostructural compounds, a series of 3D carboxylate coordination polymers [M(H2bpta)]n, (H4bpta = 2,2′,4,4′-biphenyltetracarboxylic acid, M = Fe(ii) (1), Ni(ii) (2), Cu(ii) (3) and Zn(ii) (4)), was synthesized in H2O–CH3CN or H2O solvents, respectively. Structurally, complexes 1–4 have isostructural features with (5,5)-connected 3D framework, wherein the M(ii) centre takes an octahedral coordination environment consisting of six oxygen atoms from carboxylates of ligands. The M(ii) sites are linked by syn–anti carboxylates to form chains with an M…M separation of 4.880(2) (M = Fe), 4.784(2) (M = Ni), 4.541(2) (M = Cu), and 4.607(2) Å (M = Zn), respectively. The shortest M…M distances between interchains locate 9.122(4), 9.077(3), 9.361(3), and 8.767(2) Å, respectively. Magnetically, the isostructural polymers show different magnetic behaviors due to different spins of central ions. Theoretical analysis indicates that couplings between magnetic ions obey uniform chain models. The magnetic susceptibility of 1 and 2 are perfectly fitted by the modified Fisher model to yield an effective intra-chain exchange coupling constant of −0.81(1) and 3.67(2) cm−1, respectively. For 3, a Heisenberg ferromagnetic S = 1/2 chain included the intra-chain magnetic exchange interaction (J = 9.28(1) cm−1, and zj′ = −0.068(3) cm−1), weak ferromagnetic interactions in intra-chains, and weak antiferromagnetic interactions between interchains. The phenomena of 1–3 accord with the common view that the exchange interaction between two magnetic M(ii) ions bridged by the syn–anti carboxylate bridge is dominantly weak ferro- or anti-ferromagnetic interactions. In addition, the M–O–C–O–M spin exchange interactions ☋J☋ of M2(CO2)2 (M = Mn(3d5)20, Fe(3d6), Co(3d7)20, Ni(3d8), Cu(3d9)) decrease in strength with Cu2(CO2)2 ＞ Ni2(CO2)2 ＞ Co2(CO2)2 ＞ Fe2(CO2)2 ＞ Mn2(CO2)2, consistent with orbit order. [ABSTRACT FROM AUTHOR]

One new polymer, [Ag 4 (C 5 O 5 ) 2 (H 2 O) 2 ] n (C 5 O 5 2− = croconate dianion), has been synthesized and characterized by element analysis, IR, Raman, single-crystal X-ray diffraction, PXRD, and luminescent analysis. X-ray structural analysis revealed that the ligand was de-protonized entirely and offered five oxygen donors taking part in the coordination, and the tetranuclear silver(I) ions showed 4 and 5 coordination geometries respectively. From the space perspective, the presence of 1D chains that are connected into 2D layers, which are further connected into 3D network can be found within the crystal structure by Ag O and weak Ag⋯Ag interactions. The thermal decomposition process consists of the loss of corresponding water molecules below 380 °C and follow-up decomposition of the main structure. Under the excitation of 380 nm light, the complex displayed green luminescent emission at room temperature. [ABSTRACT FROM AUTHOR]

Abstract In this work, four new complexes, [Mn(μ 3 -Hcpoia)(phen)(H 2 O)] n 1 , [Mn 2 (μ 4 -Hcpoia) 2 (μ 2 -bib)(H 2 O) 2 ] n 2 , [Zn(μ 2 -Hcpoia)(phen)(H 2 O)] n 3 , and [Zn 2 (μ 2 -Hcpoia) 2 (μ 2 –4,4′-bpy)(H 2 O) 2 ] n ·2nH 2 O 4 (H 3 cpoia = 4-(4-carboxyphenoxy)isophthalic acid, phen = phenanthroline, bib = 1,4-di(1H-imidazol-1-yl)benzene, 4,4′-bpy = 4,4′-bipyridine) have been synthesized by solvothermal reactions. Complexes 1 – 4 were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, powder and single-crystal X-ray diffraction. Complexes 1 and 2 present two-dimensional (2D) structures based on the dinuclear Mn(II) secondary building units with the vertex symbols of (4.82) and (32.44)(34.46.64.7), respectively. Complex 3 possesses one-dimensional (1D) structure and reveals a uninodal 2-connected chain with the 2C1 topology. Complex 4 exhibits a 1D ladder-like double chain, containing a 1D metal–organic chain interconnected by the 4,4′-bpy ligand with the vertex symbol of (42.6). Such a rich structural diversity of 1 – 4 is driven by various factors, including the type of the metal(II) ions and the ancillary ligands, as well as the coordination mode of ligand. Complexes 1 and 2 show antiferromagnetic interactions (J = −0.719 cm−1 for 1 , and J = −6.981 cm−1 for 2) in dimeric units with the Mn-Mn distances of 4.451(1) and 3.151(5) Å, respectively, that are related to double syn−anti carboxylate bridges and four bis-bidentate carboxylate groups with syn−syn and μ–oxo modes. The solid-state luminescent behaviors of 3 , 4 were also investigated systematically. Graphical abstract Two Mn(II)-CPs and two Zn(II)-CPs were constructed from metal salts, H 3 cpoia and N-heterocyclic group ligands. Their structures, magnetic properties and luminescence have been studied in detail. fx1 Highlights • Four Mn and Zn complexes based on an asymmetric semirigid tricarboxylate ligand, H 3 cpoia, are reported. • Structural diversity can be influenced by coordination mode of ligands, the nodes and the ancillary ligands. • The magnetic measurements of complexes 1 and 2 show antiferromagnetic interactions. • The luminescent properties of 3 and 4 are investigated systematically. [ABSTRACT FROM AUTHOR]

• Two new Zn-based coordination complexes were synthesized, and showed excellent fluorescence properties. • Complexes 1 and 2 exhibit high sensitivity and selectivity for Cu2+ sensing in aqueous solution. • Complexes 1 and 2 show different sensing mechanism to Cu2+. A great quantity of materials for the detection of Cu2+ have been reported, but the structural transformation of these materials is difficult to understand during the detection process and hence less reported. Here, two new Zn-based complexes, namely, [Zn 2 (L)(phen)(H 2 O) 3 ·2.4H 2 O] n (1) and {[Zn(2,2′-bpy)(H 2 O) 4 ][Zn(H 2 L) 2 (2,2′-bpy)(H 2 O) 2 ]·H 2 O} (2), have been successfully constructed under hydrothermal conditions by using the H 4 L linker (3,5-di(3,4-dicarboxylphenyl) pyridine), N-auxiliary ligands (phen = 1,10-phenanthroline and 2,2′-bpy = 2,2′-bipyridine), and Zn2+ with d 10 electron configuration. X-ray crystallographic analysis suggests that 1 features a 2D layer, which is further extend into a 3D supramolecular structure by hydrogen bonding interactions. 2 displays a 0D ionic structure, which can form 2D framework via hydrogen bonding. Notably, complexes 1 and 2 contain multiple O functional sites that can be used to detect guest metal ions. As expected, photoluminescence studies reveal that complexes 1 and 2 are promising luminescence sensors for selective detection of trace amounts Cu2+ ions in aqueous solutions by luminescence quenching mechanism, featuring high sensitivity, and low detection limits (74.6 nM and 301.7 nM). Complexes 1 and 2 have different sensing mechanisms for Cu2+. The quenching mechanism of complex 2 is rare, that is, the irreversible exchange of metal ions induces crystal structural transformation and the exchange process can be clearly monitored by visual color changes [Display omitted] [ABSTRACT FROM AUTHOR]

Luminescence sensors based on coordination complexes have attracted much attention due to their high sensitivity and low detection limit. In this work, three new Cd(II) coordination complexes (1 , 2 , 3) were synthesized under solvothermal conditions and characterized. Single crystal analyses show that complexes 1 – 3 present different framework structures due to the introduction of different organic linkers: 1 is a 0D structure, 2 and 3 being both 2D planar structures. Sensing studies reveal that complexes 1 – 3 exhibit excellent luminescence properties, and can act as dual-response luminescence sensors to detect trace amounts of Zn2+ and Tb3+ through luminescence turn-on, with high selectivity and sensitivity. This work opens a new way for designing and synthesizing multifunctional luminescence sensing materials as environmental monitors. [Display omitted] • Three excellent dual-function luminescence sensors based on Cd(II) complexes were synthesized. • They have high selectivity, sensitivity and anti-interference ability toward Zn2+ and Tb3+ in aqueous solution. • The detection limit for Zn2+ is as low as 20.08 nM. [ABSTRACT FROM AUTHOR]

The title coordination polymer, poly[aqua( μ 8 -1,1′-biphenyl-2,2′,4,4′-tetracarboxylate)lead(II)], [Pb 2 (C 16 H 6 O 8 )(H 2 O) 2 ] n , ( I ), was constructed by a multidentate ligand 1,1′-biphenyl-2,2′,4,4′-tetra- carboxylic acid (abbreviated as H 4 bpta) under hydrothermal condition. In the structure, two crystallographically independent Pb(II) cations exhibit different coordination geometries, wherein one of the Pb(II) ions is holodirected and coordinated by eight oxygen atoms [PbO 8 ] and another chelated by carboxylates, is slightly hemidirected and coordinated by seven oxygen atoms [PbO 7 ] [1]. The bpta 4− ligand connects eight Pb(II) atoms by adopting the μ 8 -bridging mode. The carboxylate groups (2,2′-COO − ) are in μ 4 - η 1 : η 2 : η 2 : η 2 -chelating/bridging, and the other two (4,4′-COO − ) are in μ 4 - η 1 : η 2 : η 1 : η 2 fashion. In addition, the structure of ( I ) consists of 1D chains built by carboxylate groups bridging a pair of quad-core cluster [Pb 4 O 4 ] units, which is further linked through bpta 4− to generate a unique 3D open framework. The coordination polymer is reinforced by intermolecular hydrogen bonding between oxygen atoms of the carboxylate groups, and coordination water molecules. The complex has also been characterized by PXRD, thermoanalysis, and luminescence. [ABSTRACT FROM AUTHOR]

Two new single-crystal structures involved 1-(3,5‐dicarboxylatobenzyl)‐1,2,4‐1- H ‐triazole‐3‐carboxylic acid ligand and their magnetic and luminescence properties. [Display omitted] • Two complexes containing Zn(Ⅱ) or Mn(Ⅱ) based on H 3 L ligand were synthesized and characterized. • The Zn(Ⅱ) complex exhibits good fluorescence property with the emission peak at 438 nm. • The luminescence mechanism of the Zn(II) complex has been elaborated by DFT and TDDFT analysis. • The Mn(Ⅱ) complex shows the weak ferromagnetic coupling in 1D manganese chain. Two new coordination complexes [Zn 2 (HL) 2 (phen) 2 ]·4H 2 O (1) and [Mn(HL)(H 2 O) 2 ] n (2) (H 3 L = 1-(3,5-dicarboxylatobenzyl)-1,2,4-1- H -triazole-3-carboxylic acid, phen = 1,10-phenanthroline) have been synthesized under solvothermal condition, and characterized by elemental analysis, and infrared spectroscopy, X-ray single-crystal and power diffraction analyses. Both crystal structures of complexes 1 and 2 belong to the monoclinic system with space group P 2 1 / c. In the two complexes, abundant weak intermolecular interactions (hydrogen bonds and π ··· π stacking) make their structure more stable. The thermal decomposition of the complexes was also studied by TGA techniques. Moreover, the solid-stated luminescent spectrum of complex 1 shows the obvious emission peak at 438 nm, and the intensity of the emission peak is stronger than those of free H 3 L and phen. DFT and TDDFT analyses explain that the fluorescence property of complex 1 derive from the π * - n transition from phen to the adjacent carbonyl of HL2-. Magnetic study reveals that complex 2 exists weak ferromagnetic coupling between manganese(II) centers from 2 K to 300 K. [ABSTRACT FROM AUTHOR]

Novel complexes of (half)-filled d-configurations, including [Zn(pdon)(SCN)(μ-Cl)(H2O)]n (1), [Cd2(pdon)2(μ1,3-SCN)4]n (2), [Hg(pdon)2Cl2] (3), and [Mn(pdon)2(SCN)2] (4) (pdon = 1,10-phenanthroline-5,6-dione), were synthesized and structurally characterized by single crystal X-ray diffraction. Self-assembly behaviors of these metal ions with anions are essentially different, although some of them are elements of the same group. Various supramolecular interactions of H-bonding, π···π stacking, and C−X···π (X = H, O, and S) are observed in the structures. In 1, central Zn2+ cations are connected to form an infinite one-dimensional (1D) zigzag chain by bridged Cl− and further extended to two-dimensional layers via weak interactions. Complex 2 consists of dinuclear units doubly bridged by two end-to-end (EE) SCN− anions and linked to 1D molecular helix along the b-axis with a long pitch of 13.077 Å. The helix displays racemic mixtures in the crystal. Complexes 3 and 4 are six-coordinated with distorted octahedron geometry. pdon serves as a terminal ligand in complexes. Spectroscopic and electrochemical properties of pdon and the complexes are studied in dimethyl sulfoxide (DMSO) solution at room temperature. Circular dichroism (CD) spectral results suggest that there is phenomenon of spontaneous resolution in the DMSO solution for the spiral structure 2. Novel complexes of (half)-filled d-configurations including [Zn(pdon)(SCN)(μ-Cl)(H2O)]n (1), [Cd2(pdon)2(μ1,3-SCN)4]n (2), [Hg(pdon)2Cl2] (3), and [Mn(pdon)2(SCN)2] (4) (pdon = 1,10-phenanthroline-5,6-dione) were synthesized and structurally characterized by single crystal X-ray diffraction. Self-assembly behaviors of these metal ions with anions are essentially different, although some of them are elements of the same group. [ABSTRACT FROM AUTHOR]