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Three new compounds, namely, [Mn(hpcH)(H2O)2]·H2O (1), [Cd(hpcH)(DMF)(H2O)] (2), [Cu(hpcH2)2(H2O)2] (3), (hpcH3 = 5-hydroxy-1H-pyrazole-3-carboxylic acid) were solvothermally synthesized and characterized in detail. Compounds 1 and 2 are coordination polymers (CPs), exhibit two-dimensional (2D) layered structures and crystallize in monoclinic lattices with the C2/c and P21/c space groups, respectively. Compound 3 shows a 3D supramolecular structure constructed from six-coordinated mononuclear Cu2+ through hydrogen bonds and π–π stacking interactions. The hpcH3 ligand behaved in different coordinated modes in the three compounds. It lost two protons in compounds 1 and 2 and one proton in compounds 3. Furthermore, the photocatalytic degradation properties of compounds 1 and 2 were investigated. The results indicate that 1 and 2 show excellent photocatalytic activities for methylene blue (MB) under visible light. The photocatalytic degradation efficiency of 2 reached 96.7% in 90 minutes. The possible photocatalytic mechanisms displayed by CPs 1–2 for the photodegradation of MB have been addressed through the trapping experiment and theoretical calculations. [ABSTRACT FROM AUTHOR]

Two new iridium (III) complexes (Ir1‐Ir2) bearing different fluorinated 2‐(biphenyl‐4‐yl)‐2H‐indazole‐based compounds as cyclometalated ligands and Xantphos as an ancillary ligand were synthesized and fully characterized. The ultraviolet (UV)–vis absorption, photoluminescence, and electrochemistry properties were studied. The single crystal structures of Ir1‐Ir2 were determined by X‐ray diffraction, showing each adopts the distorted octahedral coordination geometry. To gain insights into the lowest energy electron transitions and the lowest triplet excited states, density functional theory calculations were used to further investigate the origination. Two complexes emit yellow photoluminescence with quantum yields of 49.7–72.5% in solution at room temperature. Their Commission Internationale de L'Eclairage color coordinates are (0.42, 0.53) and (0.39, 0.47), respectively. [ABSTRACT FROM AUTHOR]

Theoretical studies demonstrated that P350 is a promising extractant for separation of neptunium and plutonium. [Display omitted] • The complexation behaviors of Np(IV,V,VI) and Pu(IV) with three neutral phosphate ligands were explored by DFT. • These phosphate ligands have the ability to Pu(IV)/Np(IV) and Np(VI)/Np(V) separation. • The complexing ability of P350 is stronger than TBP and TiAP. • P350 is the more promising extractant for separation of Np and Pu in nitric acid solution. Effective treatment of the transuranic neptunium and plutonium from nuclear waste is of great importance and remains a challenge for developing advanced nuclear fuel cycles. Currently, novel ligands for efficient separation of actinides need to be designed urgently. Neutral extractants containing phosphorus have shown great potential for actinides separation. In this paper, we systematically explored the extraction and separation performances of neptunium(IV,V,VI) and plutonium(IV) by three phosphorus derivatives, di(1-methyl-heptyl) methyl phosphonate (P350), tri- iso -amyl phosphate (TiAP), and tributyl phosphate (TBP) by density functional theory (DFT). The outcomes showed that these neutral phosphorus reagents act as monodentate ligands through the P O group for all the extraction complexes. According to bonding nature analysis, the P350 ligand has the strongest complexing ability to the studied actinide cations. In addition, these ligands show a preference to coordination with Pu4+ and NpO 2 2+ over Np4+ and NpO 2 +, respectively. As expected, the thermodynamic analysis demonstrated the potential application of these neutral extractants in Np and Pu separation, among which the P350 ligand is more promising than TBP and TiAP in acid solution system. This work can help to further understand the separation mechanism of Np/Pu with neutral phosphorus reagents and provide insight into the development of highly efficient extractants in recovery of Np and Pu. [ABSTRACT FROM AUTHOR]

Abstraction of a chloride ligand from the dysprosium metallocene [(Cpttt)2DyCl] ( 1Dy Cpttt=1,2,4-tri( tert-butyl)cyclopentadienide) by the triethylsilylium cation produces the first base-free rare-earth metallocenium cation [(Cpttt)2Dy]+ ( 2Dy) as a salt of the non-coordinating [B(C6F5)4]− anion. Magnetic measurements reveal that [ 2Dy][B(C6F5)4] is an SMM with a record anisotropy barrier up to 1277 cm−1 (1837 K) in zero field and a record magnetic blocking temperature of 60 K, including hysteresis with coercivity. The exceptional magnetic axiality of 2Dy is further highlighted by computational studies, which reveal this system to be the first lanthanide SMM in which all low-lying Kramers doublets correspond to a well-defined MJ value, with no significant mixing even in the higher doublets. [ABSTRACT FROM AUTHOR]

We have reported two unprecedented single-ion magnets (SIMs) with the homoatomic LnN10 coordination geometry, where the central Ln (Ln = DyIII or ErIII) ion is interlocked by two pentadentate ligands (N5) affording a low symmetry polyhedron. Studies of dynamic magnetic behaviours show an effective energy of 79(4) K for [Dy(N5)2]3+ and 59(4) K for [Er(N5)2]3+, respectively. [ABSTRACT FROM AUTHOR]

Two three-dimensional (3-D) MOFs, [(C 2 H 5 ) 4 N)] 3 [H 3 O] 2 [Cd 6 Br(H 2 -DHBDC) 8 (DMF) 4 ] ( 1 ; H 4 -DHBDC=2,5-dihydroxy-1,4-benzenedicarboxylic acid, DMF=N,N-dimethylformamide) and [(CH 3 ) 2 NH 2 ] 2 [Cd 3 (H2-DHBDC) 4 (DMF) 2 ]·2DMF( 2 ), are prepared from the self-assembly reactions between Cd(CH 3 COO) 2 and H 4 -DHBDC, respectively. Both anionic frameworks consist of linear trinuclear Cd units (e.g., 1 : [Cd 3 BrO 2 (CO 2 ) 7 ] and [Cd 3 O 2 (CO 2 ) 8 ]; 2 : [Cd 3 O 2 (CO 2 ) 8 ]) linked by the H 2 -DHBDC ligands. The photoluminescent properties of compound 1 are tunable through cation-exchange with different metal ions. The results demonstrated an effective ion-exchange approach toward the functional modification of MOF materials. [ABSTRACT FROM AUTHOR]

A series of heterometallic 3d-Gd3+ complexes based on a lanthanide metalloligand, [M(H2O)6][Gd(oda)3] ⋅3 H2O [M=Cr3+ ( 1-Cr)] (H2oda=2,2′-oxydiacetic acid), [M(H2O)6][MGd(oda)3]2 ⋅3 H2O [M=Mn2+ ( 2-Mn), Fe2+ ( 2-Fe) and Co2+ ( 2-Co)], and [M3Gd2(oda)6(H2O)6] ⋅12 H2O [M=Ni2+ ( 3-Ni), Cu2+ ( 3-Cu), and Zn2+ ( 3-Zn)], are reported. Magnetic and heat-capacity studies revealed a significant impact on the magnetocaloric effect depending on the anisotropy of the 3d transition metal ions, as confirmed by comparison of the observed maximum values of −Δ Sm between complexes 2-Co and 1-Cr. In these two complexes, the 3d metal ions have the same spin ( S=3/2 for Co2+ and Cr3+ ions), and the theoretical calculation suggested a larger −Δ Sm value for 2-Co (47.8 J K−1 kg−1) than 1-Cr (37.5 J K−1 kg−1); however, the significant anisotropy of Co2+ ions in 2-Co, which can result in smaller effective spins, gives a smaller value of −Δ Sm for 2-Co (32.2 J K−1 kg−1) than for 1-Cr (35.4 J K−1 kg−1) at Δ H=9 T. [ABSTRACT FROM AUTHOR]

A series of unsymmetrical bis(imino)pyridylcobalt complexes was investigated by DFT–QEq method to correlate the net charges of cobalt center and their catalytic activities. The effective net charge values on cobalt atom, calculated by QEq method at doublet spin state, reflected the influences of substituents within their ligands. The catalytic activities of these cobalt complexes in ethylene polymerization continuously increase along with higher values of the effective net charges on cobalt atom. The energy differences at doublet and quartet states kept the constant tendency for the cobalt complexes without the steric influences of substituents within ligands. [ABSTRACT FROM AUTHOR]

The potential activities for two series of iron complex precatalysts on ethylene reactivity are evaluated by the density functional theory (DFT)-charge equilibration (DFT-QEq) method on the basis of the molecular mechanics (MM-QEq) method. All three spin states on the central iron atom are calculated through the two charge methods to obtain the effective net charge, in addition to the QEq method alone. The results show that reasonable charge values are obtained by the QEq method, well reflecting the influence of substituents and revealing correlations between the activity and the effective net charge. All these series of iron complex precatalysts present the same tendency: the potential activities are elevated along with a decreasing effective net charge on the iron atom. Relying on the electronic influence of substituents on the ligands, the variation trends are grouped into two classes, which present the same correlation. [ABSTRACT FROM AUTHOR]

A novelprocedure for the cascade reaction of the addition of aGrignard reagent to a nitrile with a copper-catalyzed C–N bondcoupling was developed, which afforded various polysubstituted phenanthridinesin moderate to good yields with tolerance for a wide variety of substrates.Experimental data demonstrated that the reaction proceeded more likelythrough a Cu(I/III) catalytic cycle. [ABSTRACT FROM AUTHOR]

Abstract: A new acentric heterometallic–organic framework, [CdMg (btec)(DMF)(H2O)3] (1) (H4btec=1,2,4,5-benzene tetracarboxylic acid), has been solvothermally synthesized. It features a 4-connected net with typical pts topology. To the best of our knowledge, compound 1 is the first example of Cd–Mg heterometallic organic framework based on the H4btec ligand. Compound 1 has potential unsaturated metal sites after the removal of coordination water molecules, so it shows good catalytic activity on the diethylzinc addition to benzaldehyde. The photoluminescent property of 1 is also investigated. [Copyright &y& Elsevier]

The TbIII compound [Tb(tci)(H2O)] n · n(DMF) ( 1) [H3tci = tri(2-carboxythyl)isocyanurate, DMF = N,N′-dimethylformamide] was synthesized by the reaction of terbium oxide, H3tci, and two drops of concentrated nitric acid in the presence of DMF and H2O. Single crystal X-ray analysis reveals that it features a three-dimensional (3D) framework based on infinite -Tb-COO-Tb- chains. The tci ligand in 1 links six different TbIII ions with its two carboxylate groups in μ2-κ1O;κ2O,O′ mode and the third in μ2-κ1O;κ1O′ mode. Thermal analysis reveals that it remains high thermal stability until 390 °C. Luminescence investigation shows that it emits characteristic green light of TbIII ions. [ABSTRACT FROM AUTHOR]

In this article, two different anionic ligands, 3,4-oxybis(benzoate) (bopH2) and sulfate, have been employed as co-ligands to perform a comparison on the structures of coordination polymers based on the Zn(II)–rigid 1,4-bis(imidazol-1-yl)benzene (bib) net. Two new coordination polymers, {Zn(bib)(bop)}∞ (1) and {Zn(bib)(SO4)}∞ (2), were synthesized from hydrothermal reactions and characterized by elemental analyses, IR and single-crystal X-ray diffraction. Complex 1 contains two unique 2-D layers, which are further interpenetrated to form a two-fold 2-D → 2-D framework. However, 2 consists of a 3-D structure with pcu topology constructed by sulfates as pillars. The structural difference of 1 and 2 indicates that size of the ancillary ligands play important roles in formation of such coordination architectures. Thermal and fluorescence properties of 1 and 2 are also investigated in the solid state. [ABSTRACT FROM AUTHOR]

Abstract: Under solvothermal conditions, one polynuclear FeIII complex of formula [Fe3{(py)C(ph)O}4Cl4][FeCl4] (1) was synthesized from reaction of phenyl-pyridine-2-yl-methanone oxime (py)C(ph)NOH with FeCl3, and one FeII/FeIII/FeII complex of composition [Fe3{(py)C(ph)NO}6][CH3COO] (2) was prepared from treatment of (py)C(ph)NOH with Fe(OAc)2. The most interesting synthetic feature of complex 1 is the in situ transformation of (py)C(ph)NOH into the (py)C(ph)O− ligand. Complexes 1 and 2 were characterized by X-ray single crystal diffraction, IR spectroscopy, and elemental analysis. X-ray analysis revealed that complex 1 contains a V-shaped FeIII core with two terminal FeIII atoms displaying distorted square-pyramidal geometries and one central FeIII ion exhibiting octahedron geometry. Complex 2 is a mixed-valence linear FeII/FeIII/FeII complex with all the three metal centers displaying distorted octahedron geometries. The low-temperature magnetic susceptibility measurement for the solid sample of 1 revealed the weak antiferromagnetic FeIII…FeIII interactions. Theoretical calculations based on density functional theory were performed using the crystal structure of complex 1. [Copyright &y& Elsevier]

Abstract: A novel organo-functionalized mesoporous MCM-41 type of hybrid materials MCM–Si–DPBB was synthesized by co-condensation of bidentate Si(OR)3 substituted N,N-2-diphenyloxyphosphine-4-bromomethyl-benzenamine (Si–DPBB) and tetraethoxysilane (TEOS) in the presence of the cetyltrimethylammonium bromide (CTAB) surfactant as template. Its ternary europium complex covalently bonded to the silica-based network MCM–Si–DPBB–Eu was also prepared by introduction the Eu(DBM)3(H2O)2 into the hybrid materials. The hybrid material MCM–Si–DPBB–Eu has strong luminescence, and when excited by the ligands absorption wavelength (386nm), it displays the emission of the Eu3+ 5D0-7F J (J =0, 1, 2, 3 and 4) transition lines due to the efficient energy transfer from the ligands to Eu3+. [Copyright &y& Elsevier]

Two cadmium(II) compounds, [Cd(nip)(phen)2]n (1) and [Cd2(nip)2(phen)2]n (2) [nip = 5-nitroisophthalate, phen = 1,10-phenanthroline], have been synthesized under hydro (or solvo) thermal conditions and characterized by single-crystal X-ray diffraction. Compound 1 exhibits a 1-D linear chain structure adopting the coordination mode in which one Cd is coordinated to two phen ligands. The formation of 1 was favored by selecting Cd(phen)2(NO3)2 as metal source in ethanol-water. Compound 2 displays a 1-D ladder-like chain structure featuring di-cadmium units. Both 1 and 2 are further assembled into 3-D supramolecular frameworks through interchain hydrogen bonding. [ABSTRACT FROM AUTHOR]

Abstract: Six new complexes constructed by 5-sulfosalicylic acid and bipyridyl-like ligands (2,2′-bipy and 1,10-phen), namely [Cu4(OH)2(ssal)2(phen)4 ·7H2O] (1), [Cu4(OH)2(ssal)2(bipy)4 ·2H2O] (2), [Cd(Hssal)(bipy)] (3), [Cd(HL)2(phen)2] (4), [Cr(ssal)(bipy)(H2O)2 ·2H2O] (5) and [Cr(ssal)(phen)2] (6) (H3ssal=5-sulfosalicylic acid, H2L= p-hydroxybenzenesulfonic acid, bipy=2,2′-bipy, phen=1,10-phen) were prepared under hydrothermal conditions and their structures were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are both tetranuclear copper complexes with a stepped topology. In complex 3, a new coordination mode of the Hssal2− group is reported in this work. During the synthetic process of complex 4, in situ decarboxylation of 5-sulfosalicylic acid into p-hydroxybenzenesulfonic acid is involved. Two chromium 5-sulfosalicylates (5 and 6) are reported for the first time. These new complexes display different supramolecular structures by O–H⋯O, C–H⋯O hydrogen bonds as well as π⋯π, C–H⋯π and O⋯π interactions. The results of magnetic determination show that ferromagnetic interactions exist in complex 1, however, antiferromagnetic interactions exist in 2. [Copyright &y& Elsevier]

The history for the development of chiral phosphorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent advances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced a renaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation. [ABSTRACT FROM AUTHOR]

Two unprecedented wheel-shaped nanoscale clusters {CoII16LnIII24} (Ln = Dy and Gd), with a diameter and a thickness of 3.0 nm and 2.0 nm, respectively, were obtained from the self-assembly of Co(NO3)2, Ln(NO3)3 and a pyridyl-functionalized β-diketone ligand. Notably, the gadolinium species exhibited a relatively large magnetocaloric effect. [ABSTRACT FROM AUTHOR]

Cationic cyclometalated Ir(III) complexes (Ir1 - Ir5) with fluorine-substituted 2-phenylpyridine (ppy) derivatives as C^N cyclometalating ligands and 2,2′-bipyridine (bpy) as the ancillary ligand, have been synthesized and fully characterized. The influences of the number and the position of fluorine atoms at the cyclometalating ligands on the photophysical, electrochemical and oxygen sensing properties of the Ir(III) complexes have been investigated systematically. The introduction of fluorine on the C^N cyclometalating ligands of the complexes results in blue-shifts of the maximum emission wavelengths, and increases in the photoluminescence quantum yields (Φ PL), phosphorescence lifetimes and energy gaps, compared to the non-fluorinated [Ir(ppy) 2 (bpy)]+PF 6 − (Ir0). Among them, 2-(2,4-difluorophenyl)pyridine-derived Ir4 shows the maximum blue-shift (514 nm vs. 575 nm for Ir0) and the highest Φ PL (50.8% vs. 6.5% for Ir0). The complex Ir3 with 2-(4-fluorophenyl)-5-fluoropyridine as C^N ligand exhibits the highest oxygen sensitivity and excellent operational stability in 10 cycles within 4000 s. Image 1 • The position and number of fluorine atoms affect properties of cationic Ir(III) complexes. • Fluorinated cationic Ir(III) complexes show increased photoluminescence quantum yields. • Fluorinated cationic Ir(III) complexes demonstrate excellent oxygen sensing stability. [ABSTRACT FROM AUTHOR]

Three complexes were synthesized based on two acylhydrazone ligands. Crystal structures disclose the coordination competition in the assembly of the ligands with metal ions. Gas adsorption measurements show that all the complexes exhibit good adsorption capacity toward CH 3 OH vapor over N 2 , H 2 , O 2 , and CO 2. [Display omitted] • Three complexes were synthesized and characterized based on two chain-like acylhydrazone ligands. • The crystal structures disclose the coordination competition occurs among the multiple coordination sites. • The three complexes exhibit good adsorption capacity toward CH 3 OH over N 2 , H 2 , O 2 , and CO 2. Two chain-like acylhydrazone ligands (L1 and L2) were synthesized from Schiff base condensation reaction of 3,3′-(1,4-piperazine-bis-(methylene)-bis-(2-hydroxy-5-methylbenzaldehyde)) (b) with isonicotinic hydrazide or nicotinic hydrazide, respectively. In the presence of Hg(II) or Cd(II) ions and in DMF/methanol solution, three complexes, formulated as {[Hg 3 L1 Br 6 ]·4DMF} n (1), {[Hg 2 L2 I 4 ]·2DMF} n (2), and [Cd 4 (L2) 2 I 8 (H 2 O) 2 ]·4DMF (3), were synthesized and further characterized via elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. Complex 1 exists as a 1D zag-zig chain polymer and complex 2 exists as a 1D looped chain polymer. Complex 3 exists as a rare tetranuclear structure. The structural differences of the three complexes and the coordination competition among the coordination sites were analyzed, and the results showed that the pyridyl nitrogen atoms have an obvious coordination ability prior to other sites. Furthermore, gas adsorption measurements were carried out, which show that the three complexes exhibit good adsorption capacity towards CH 3 OH over N 2 , H 2 , O 2 , and CO 2. [ABSTRACT FROM AUTHOR]

In the title cobaltocenium compound, [Co(C6H7)(C18H16P)]PF6, the CoIII atom is bound to methyl­cyclo­penta­dienenyl and η5-2-(diphenyl­phosphino)-1-methyl­cyclo­penta­dienyl ligands inclined to each other at 1.3 (2)°. [ABSTRACT FROM AUTHOR]

In this study we synthesized and characterized bis(3,5-dimethylpyrazolyl)dimethylsilane ( L1 ) and bis(3,5-dimethylpyrazolyl)phenylphosphine ( L2 ) and then prepared bidentate (NˆN) nickel complexes by reacting L1 or L2 with NiBr 2 (DME). In combination with methylaluminoxane, diethylchloroaluminum or ethyldichloroaluminum (EADC) as co-catalyst, L1 /Ni and L2 /Ni complexes exhibited moderate catalytic activities (240–1310 kg/mol Ni h) and high selectivities (up to 93.2%) for ethylene dimerization toward 1-butylene. The catalytic performance was substantially affected by the co-catalyst type and ligand environment, especially the bridge atom. [ABSTRACT FROM AUTHOR]

Abstract: Two isomorphous three-dimensional lanthanide metal-organic frameworks, K[Ln2(NTA)(ox)2(H2O)2]·3H2O (Ln = Pr (1) and Gd (2), NTA = nitrilotriacetate, ox = oxalate) have been synthesized under hydrothermal conditions and characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction, thermogravimetric analysis (TGA) and magnetic analyses. The 3D frameworks of compounds 1 and 2 possess three topologically nonequivalent 4-connected nodes synchronously and exhibit unprecedented (65∙8)(43∙63)(4∙65) topologies. Variable-temperature magnetic susceptibility measurements for complexes 1 and 2 indicate there exist antiferromagnetic interactions between magnetic centers. [ABSTRACT FROM AUTHOR]

Graphical abstract Three YbIII MOFs, showing a 3D (4,4,6)-connected {42.62.82}{43.63} 2 {48.67} 2 topology structure, a 3D (3,6)-connected {42.6} 2 {44.62.87.102} topology network, and a 2D 44 network, respectively, have been successfully obtained by ligands with different backbones. They all display highly sensitivity in the detection of acetone (ACE) as fluorescent sensors. Moreover, 2 exhibits a relatively good RhB photodegradation properties in aqueous solution under UV irradiation. The degradation ratio of RhB reaches 93.9% after 3 h. Abstract Three Yb(III)-based metal–organic frameworks (MOFs) with different bulky ligands, namely [Yb(L1) 1.5 (DMF)] n (1), [Yb(L2) 0.5 (NO 3)(DMF) 2 ] n (2) and [Yb(L3) 0.5 (L3) 0.5 (NO 3)(DMF)(H 2 O)] n (3) (H 2 L1 = terephthalic acid, H 4 L2 = 5,5′-(diazene-1,2-dily)diisophthalic acid, H 2 L3 = anthracene-9,10-dicarboxylic acid, and DMF = N,N -dimethylformamide), were solvothermally synthesized and structurally characterized by elemental analyses, IR spectra and X-ray diffraction (XRD) analyses. Single crystal XRD analyses indicate that the backbones of ligands play an important role in governing the formation of the final frameworks. When compound 1 and compound 2 assume 3D (4,4,6)-connected {42.62.82}{43.63} 2 {48.67} 2 and (3,6)-connected {42.6} 2 {44.62.87.102} topology structures, compound 3 displays a 2D 44 network. All the three compounds display high sensitivities in the detection of acetone (ACE) as fluorescent sensors. Moreover, 1 – 3 exhibit good photodegradation efficiencies towards rhodamine B (RhB) in aqueous solution under UV irradiation. [ABSTRACT FROM AUTHOR]

In this study, a regenerable magnetic ligand material (EDTA-mGO) was fabricated by binding chelating groups (EDTA) onto Fe 3 O 4 /graphene oxide and applied to remove U(VI) from aqueous solution. The sorption experiments were investigated under different experimental conditions, such as temperature, contact time and pH. EDTA-mGO showed fast removal capacity for U(VI) (<1.5 h) with high sorption ability (277.43 mg/g). The removal mechanisms mainly attributed to the metal-binding organic ligand (EDTA) and the electrostatic attractions between U(VI) and oxygenic functional groups. In addition, the as-prepared EDTA-mGO dispersed in water could be easily collected after the sorption by the external magnetic field within 10 s. The removal of U(VI) by EDTA-mGO followed the pseudo-second-order rate better than the pseudo-first-order. The thermodynamic data indicated the endothermic and the spontaneous nature of U(VI) sorption. Furthermore, the reproducibility studies suggested that EDTA-mGO has a good reusability and a high stability. [ABSTRACT FROM AUTHOR]

Environment-sensitive fluorescence ligands based on twisted intramolecular charge transfer (TICT) are often applied to target relevant biomacromolecules. In this work, several imidazole-based "D-π-A" fluorescent ligands with different amine side chains have been designed, which showed sensitivity toward solvent polarity and viscosity. The binding of obtained ligands with lipase led to enhancement of emission intensity. Results from binding parameters exhibited that the ligands bound with lipase in a 1:1 stoichiometry, and the flexible amine side chain appended ligand was more sensitive to lipase. The fluorescence quenching experiments of ligands with lipase suggested the involvement of a static quenching mechanism in the binding process. From the estimated thermodynamic parameters, complexation between the ligands and lipase was found to occur primarily via Van der Waals forces and hydrogen bonds formation. Observations from synchronous, 3D fluorescence and CD spectra pointed that the binding of ligands to lipase impacted the microenvironment around tyrosine and typtophan residues, but was not enough to change the secondary structure of lipase. Moreover, modeling calculation demonstrated that ligands were mainly located within the hydrophobic pockets of lipase. This study provides evidence for expanding the application of environment-sensitive fluorescent ligands for probes or drug candidates targeting lipase. • Three imidazole-based "D-π-A″ fluorescent ligands with different amine side chains were synthesized. • The photophysical properties in various solvents were systematically investigated. • A flexible amine side chain appended fluorescent ligand LA4 with excellent performance was more sensitive to lipase. • Expanding the use of environmentally sensitive fluorescent ligands for lipase-targeted probes or drug candidates. [ABSTRACT FROM AUTHOR]

Abstract: New two-dimensional metal–organic frameworks [Pb(Hbidc)] n (1) and [Cd(Hbidc)] n (2), constructed from multidentate ligand 1H-benzimidazole-5,6-dicarboxylic acid (Hbidc), have been synthesized under hydro/solvothermal conditions and fully characterized. Compound 1 is the first lead–organic framework based on Hbidc, and displays a 5-connected SnS network which contains 2D [Pb(CO2)] n layers. The Hbidc ligand exhibits a novel coordination mode (μ 5:η 2:η 2:η 2:η 1), which is reported for the first time in M-bidc frameworks. Compound 2 has a two-dimensional layer structure constructed of rod-shaped building blocks. Both the two 2D compounds are further assembled by hydrogen bonds and π–π stacking interactions into 3D supramolecular networks. Luminescent studies show that the title compounds exhibit different fluorescence emission activity at room temperature in the solid state. [Copyright &y& Elsevier]

Abstract: The synthesis of the anionic organolanthanide complexes supported by H2bppda (H2bppda= N,N′-bis(2-pyrrylmethylidene)-1,2-phenylenediamine) ligand via different synthetic strategies is reported. Treatment of 1:4 mixture of LnCl3(THF)3 and LiN(SiMe3)2 with 2 equivalents of H2bppda in THF gave complexes of the formula [Li(THF)4][Ln(bppda)2]·THF (Ln=Nd (1·THF), Sm (2·THF), Gd (3·THF), Dy (4·THF), Er (5·THF)) and [Li(THF)5][Yb(bppda)2] (6). Reaction of Nd(BH4)3(THF)3 with 2 equivalents of Na2bppda in THF generated [Na(THF)6][Nd(bppda)2] (7) in good yield. Treatment of 1·THF with 1 equivalent of CoCp2 in THF led to the isolation of [CoCp2][Nd(bppda)2] (8). All of the complexes have been characterized by single crystal X-ray diffraction and elemental analyses. Complexes 1·THF–5·THF are isomorphous and isostructural, and the geometry of the octa-coordinated Ln3+ ion in [Ln(bppda)2]− unit in these complexes is well described as either distorted dodecahedron or distorted bicapped trigonal prism. Lanthanide contraction was observed in 1·THF–5·THF and 6. The structures of complexes 1·THF, 7 and 8 are different from each other due to the variation of the cationic ions. The ring-opening polymerization reaction of ε-caprolactone initiated by 1·THF was conducted; it showed good activity. [Copyright &y& Elsevier]

Abstract: The tetranuclear cubane-like complex of the formula [Ni4(HL1)3(HL2)(H2O)(CH3OH)] [CH3COO]·2CH3OH·CH3CN (1) (H3L1=3-(2-hydroxybenzylideneamino)propane-1,2-diol; H2L2=3-aminoprppane-1,2-diol) has been prepared by a one-pot reaction of nickel(II) acetate, salicylaldehyde and 3-aminopropane-1,2-diol, where the H3L1 ligand was generated in situ via the condensation reaction between salicylaldehyde and 3-aminopropane-1,2-diol. The X-ray diffraction analysis of the complex showed a Ni4O4 cubane arrangement and the coordination environments of four Ni(II) ions are different from each other. Magnetic studies indicated ferromagnetic behavior for the complex. The magnetic data were fitted and the parameters were given as g =2.43, J 1 =15.96, and J 2 =4.116. [Copyright &y& Elsevier]

Abstract: Two new zinc(II)–triazole–aliphatic dicarboxylate coordination polymers, [Zn(trz)(Hsuc)] n (1), [Zn2(trz)2(tar)] n (2), have been hydrothermally synthesized by reaction of Zn salt, Htrz with H2suc and H2tar, respectively (Htrz=1,2,4-triazole, H2suc=succinic acid, H2tar=tartaric acid). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by X-ray powder diffraction, elemental analyses, IR spectra and TG analyses. Compound 1 displays a 2D layer structure containing {[Zn4(trz)4]4+} n layers decorated by the suc ligand. Compound 2 is in a 3D structure formed by the interconnection of 2D {[Zn4(trz)4]4+} n layers with tar ligand, resulting a 3,4-connected topological network. Due to the different coordination mode and conformation of aliphatic carboxylate ligand, the similar 2D {[Zn4(trz)4]4+} n layers stack in the –AAA– fashion in 1, while the {[Zn4(trz)4]4+} n layers hold together in the –ABAB– stacking sequence in 2. Additionally, the two compounds show strong fluorescence in the solid state at room temperature. [Copyright &y& Elsevier]

Abstract: Two new copper coordination polymers generated from mixed organic ligands 4,4′-bipydine and 1,2,4-benzenetricarboxylate [Cu3(1,2,4-BTC)2(4,4′-bipy)(H2O)4] 1 and [Cu(1,2,4-HBTC)(4,4′-bipy)] 2 (1,2,4-BTC=1,2,4-benzenetricarboxylate) have been prepared hydrothermally and characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the noncentrosymmetric space group , with , , , , and . Its structure contains two different one-dimensional (1-D) chains for the Cu ions, namely and ; the carboxylate of 1,2,4-BTC ligands links the two different 1-D chains into an interesting steplike neutral framework. Compound 2 crystallizes in the monoclinic space group , with , , , , , . Its structure contains novel paddle-wheel clusters Cu2(CO2)4(4,4′-bipy)2 as SBUs which are further linked by monoprotonated 1,2,4-BTC ligands into a 2-D neutral framework. The magnetic behaviors of both compounds have been studied. [Copyright &y& Elsevier]