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Five new silver(I) coordination polymers of types [Ag2L1(NO3)2]n(1), [Ag2L2(NO3)2]n(2), [Ag2L3(NO3)2]n(3), [Ag2L4(NO3)2]n(4), and [AgL5(NO3)]n(5) have been synthesized, where L1–L5are the Schiff base ligands formed from 2:1 condensation of acetylacetone with the symmetrical diamines H2N(CH2)nNH2, with n= 2 and 6 to give L1and L2, 1,2-bis(2-aminophenoxy)ethane to give L3, 1,4-bis(2-aminophenoxy)butane to give L4, and 1,6-bis(4-aminophenoxy)butane to give L5. The single crystal X-ray structures of the Ag(I) complexes 1–5have been determined. Both 1and 2adopt three-dimensional polymeric network structures, while 3–5adopt two-dimensional-layered framework structures. In 1and 2, the terminal O and γ-C atoms of two acacH-imine domains of the same ligand bind to different silver ions, while in each of 3–5a γ-C from one or both acacH-imine domains binds to a silver ion, with the remaining coordination sites occupied by bridging monodentate or bidentate nitrato groups and/or a Schiff base ligand oxygen donor. [ABSTRACT FROM AUTHOR]

Abstract: The 1:1 interaction of the diastereopure Schiff bases (1S,2S)-bis(acetylacetone)-cyclohexanediimine (L 1 ) and (1R,2R)-bis(acetylacetone)cyclohexanediimine (L 2 ) with CdI2 yields the new helical metal coordination polymers [CdL 1 I2] n (1) and [CdL 2 I2] n (2). The respective X-ray structures, as expected, confirmed 1 and 2 to be enantiomeric, existing as right-handed (P) and left-handed (M) helical chains in which both L 1 and L 2 are formally present in their (unusual) uncharged ketoamine form, with the (protonated) amine nitrogens not coordinated. The Cd(II) centres in 1 and 2 display distorted tetrahedral coordination geometries being bound to two iodo ligands and two oxygen donor atoms from individual ketoamine domains belonging to different Schiff base ligands. [Copyright &y& Elsevier]

The interaction of the diastereopure N,N'-bis(acetylacetone)cyclohexanediimine ligands, L[sup1](1R,2R), L[sup2] (1S,2S), and their 1:1 mixture, with Zn(lI) chloride has been investigated. Four new coordination polymers, [ZnL[sup1]CI[sub2] ̇ H[sub2]O][subn](1), [ZnL[sup2]CI[sub2]̇ H[sub2]O][subn] (2), [ZnL[sub2]Cl[sub2]][subn] (3), and [Zn[sub6](L[sub2])[sub6]Cl[sub12]̇2H[sub2]O][subn] (4), each consisting of an infinite single helical chain displaying different pitches and/or handedness have been isolated. The complexed Schiff base ligands are present in their deprotonated enol forms, and the nitrogen atoms, which do not coordinate, are protonated because of proton transfer from the adjacent enol oxygen (coupled with concomitant N-H⋯O bond formation); each bound ligand is thus pseudo-zwitterionic. The respective zinc centers are bound to two chioro ligands and two oxygen donors from acacH-imine units belonging to different N,N'-bis(acetylacetone)cyclohexanediimine ligands such that the coordination at each zinc is distorted tetrahedral. Compounds 1 and 2, prepared from enantiopure L[sup1] and L[sup2], respectively, are enantiomers with similar structures, with the helical pitch in each being 17.0 Å. Overall, the structure Of 3 may be described as a one-dimensional helical chain with a pitch of 17.3 Å, with each period corresponding to two L[sup2] ligands and two metal centers. The structure of [(Zn[sub6]L[sup2][sub6]CI[sub12])̇2H[sub2]O][subn] (4) contains six Zn(Il) centers connected via six L[sup2] ligands to form a "bowed" helical repeat unit, with the pitch of the helix corresponding to 43.5 Å. Supramolecular (intra- and intermolecular) aspects of all these unusual polymeric structures are discussed. Finally, the synthesis and characterization of an unprecedented six zinc-node discrete supramolecular assembly, [Zn[sub6](L[sup1])[sub3](L[sup2])[sub3]Cl[sub12]] (5), incorporating a 78-membered metallacycle, is also reported. [ABSTRACT FROM AUTHOR]

The solid micro/nanospheres of uniform size precipitated from the Schiff base condensation reaction showed good adsorption capacity towards Zn2+, and displayed satisfactory adsorption capacities and good reusabilities towards the dyes CV, MB, and NR. [Display omitted] • Macrocycle M exhibited AIEE characteristics in DMF/water and displayed a highly selective recognition of Zn2+ in DMF. • The micro/nanospheres of M showed an adsorption capacity of 121 mg·g−1 towards Zn2+. • The micro/nanospheres displayed satisfactory adsorption capacities and good reusabilities towards the dyes CV, MB, and NR. A Schiff base macrocycle (M) containing both isophthalamide and bissalicylaldehyde scaffolds was successfully designed and synthesized. M exhibited typical aggregation-induced enhanced emission characteristics in a mixed solvent of DMF/water, and showed high selectivity for the recognition of Zn(II) over other metal ions. The binding process, binding ratio, and association constant of M with Zn(II) were estimated through UV–vis and fluorescence spectra titrations, isothermal titration calorimetry, and 1H NMR titration experiments, and the detection limit towards Zn(II) was calculated as 1.03 × 10−7 mol·L−1. Interestingly, a large amount of micro/nanospheres of M with remarkable size uniformity were obtained from the reaction medium with sulfuric acid as a catalyst. On the basis of exploring the formation process of the micro/nanospheres and the key factors affecting their morphology and size, the Zn(II) and dye adsorption experiments were carried out. The results indicated that the micro/nanospheres of M can be applied to Zn(II) and dye adsorption with satisfactory removal rates. [ABSTRACT FROM AUTHOR]

• Two Schiff base macrocycle complexes with different structures were synthesized. • The two complexes exhibit satisfactory adsorption capacities toward methanol and ethanol vapor. • The two complexes exhibit different photocatalytic degradation activities toward three dyes. A Schiff base macrocycle (H 2 L) containing both pyridine-2,6-dicarboxamide and bissalicylaldehyde skeletons was designed and synthesized. In the presence of Zn(Ac) 2 or Cu(Ac) 2 salts, two complexes, formulated as [Zn 4 (L 2–) 2 (Ac–) 2 (OH–) 2 ]·2DMSO (1) and [Cu 2 (L 2–) 2 ]·4DMSO (2), were synthesized and further characterized via elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 exists as a centrosymmetric tetranuclear dimer with a 1:2 molar ratio of H 2 L and Zn2+ ions, while complex 2 exists as a binuclear dimer with a 1:1 molar ratio of H 2 L and Cu2+ ions. The structural difference between the two complexes reveals that metal ions are the key factors determining the coordination structures. Moreover, the gas/vapor adsorption and photocatalytic degradation experiments were carried out, which show that both complexes exhibit good adsorption capacities for methanol and ethanol vapor, and complex 2 possesses a better photocatalytic activity than 1 toward organic dyes RhB, MB, and MO under UV light irradiation. Two complexes were synthesized from a Schiff base macrocycle with Zn(II) or Cu(II). Complex 2 exhibits a better photocatalytic degradation activity than 1 toward RhB, MB, and MO under UV irradiation, and it is of potential use as a photocatalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Two helical Schiff base probes containing a triphenylamine or tetraphenylethylene scaffold were synthesized. • Both H 4 TPA and H 4 TPE exhibit typical AIE characteristics in the mixed solvent of THF/H 2 O. • H 4 TPA and H 4 TPE display high selectivity and sensitivity for the recognition of Cu2+ in THF/HEPES. Two helical Schiff base compounds (H 4 TPA and H 4 TPE) containing a triphenylamine (TPA) or tetraphenylethylene (TPE) scaffold were successfully synthesized and characterized. Both H 4 TPA and H 4 TPE exhibited typical aggregation-induced emission characteristics in the mixed solvent of THF/H 2 O. The two compounds also showed high selectivity and sensitivity for the recognition of Cu2+ over other ions in THF/HEPES (1:4, V / V , pH = 7.4, 2.0 × 10–5 M), and could be used as turn-off fluorescent probes for Cu2+. The stoichiometric ratios and association constants were estimated via Job's plots and UV–vis spectra titration, and the detection limits of H 4 TPA and H 4 TPE toward Cu2+ were calculated to be 2.41 × 10–7 M and 1.38 × 10–7 M, respectively. Besides, the crystal structure of the complex obtained from the interaction of H 4 TPA with Cu2+ well illustrated the binding modes, which helped us understand the Cu2+ recognition mechanism of H 4 TPA and H 4 TPE. Moreover, the detection of Cu2+ and spiked recovery experiments were carried out, which indicated that the two probes can be applied to Cu2+ detection in real samples with satisfactory recoveries. [ABSTRACT FROM AUTHOR]

[Display omitted] • Template-free synthesis of a tetrastyrene [2 + 2] Schiff base macrocycle with AIE properties and a twisted mesomer crystal structure. • The macrocyclic molecule has high affinity for Cu2+, a low detection limit and a high anti-interference ability. • During the synthetic process, uniform microspheres with particle size varying with water content can be obtained by adding different ratios of water to the reaction solvent. Despite positive progress on the study of the supramolecular self-assembly of 2,6-diimidopyridine-containing macrocycles with interpenetrating or interlocking structures via anionic recognition and hydrogen bonding interactions between the pyridine imide group and the axial ligand, there are few studies on the assembly of micro-nanomaterials formed by non-covalent interactions between such molecules. Schiff base compounds containing 2,6-diacyliminopyridine units are also an excellent class of metal ion acceptor, and their structures can be easily modified and modulated to be widely used in metal ion probes. Based on previous studies, we obtained an AIE [2 + 2] Schiff base macrocyclic LCX containing 2,6-diimidopyridine units by a one-step condensation reaction. LCX has excellent AIE fluorescence properties, high affinity for Cu2+, and its binding to Cu2+ is not interfered by pH changes or co-existing metal ions. The detection limit is low at 242.00 nM. Electron microscopy experiments showed that the self-assemblies formed by LCX and Cu2+ were core–shell nano-microspheres with spiked surfaces. In addition, during the synthetic process, different nanosized nanospheres of uniform size were obtained by simply adjusting the ratio of water, thereby providing a new method for the synthesis of uniformly sized nanorods. [ABSTRACT FROM AUTHOR]

A racemic salicylaldehyde Schiff base (L) containing a pyridine-2,6-dicarboxamide scaffold was successfully synthesized and characterized. L exhibited a typical aggregation-induced emission (AIE) characteristic in the mixed solvent of THF/H 2 O. The UV–Vis absorption spectra and fluorescence emission spectra showed a high selectivity and sensitivity of L for the recognition of Cu2+ over other ions in the solution of THF/H 2 O (2:3), and indicated L can be used as a turn-off fluorescent probe for Cu2+. The stoichiometric ratio, association constant, and the detection limit of probe L toward Cu2+ were estimated using Job's plot method, UV–Vis spectra titration, and fluorescence spectra titration. More importantly, a Cu(II) complex was synthesized from the coordination interaction of probe L with Cu2+ and characterized by X-ray crystal diffraction technique. The crystal structure well illustrated the binding mode of L with Cu2+, contributing to the further understanding of the coordination mechanism. [Display omitted] • The fluorescence spectra showed an AIE characteristic of L in THF/H 2 O. • L displayed a selective recognition and acted as a turn-off fluorescent probe for Cu2+ in THF/H 2 O (2:3). • The structure of the Cu(II) complex provided a good interpretation for the Cu2+ recognition mechanism of probe L. [ABSTRACT FROM AUTHOR]

Four complexes were synthesized based on a salen-type Schiff base ligand. The structural differences of complexes 1 – 4 disclose both metal ions and coordination sites influence the structures. Gas adsorption measurements show that all the complexes exhibit good adsorption capacity toward methanol vapor. [Display omitted] • Four complexes with 2D sheet, 1D zig-zag, or centrosymmetric trinuclear structures were synthesized and characterized. • The structures of the complexes indicated both the metal ions and coordination sites affect the final structures. • All the complexes displayed a relatively good adsorption performance toward methanol vapor. A salen-type Schiff base ligand (H 4 L) was designed and synthesized from the condensation reaction. Four complexes, formulated as {[Cd(H 5 L+)Cl 2 (μ 2 − Cl)]·2CH 3 OH} n (1), {[Cd(H 4 L)Br 2 ]·H 2 O} n (2), {[Cd 2 (H 4 L) 2 I 4 ]·CH 3 OH} n (3), and [Cu 3 (L 4-)(μ 3 − Ac) 2 ]·CH 3 OH·H 2 O (4) were synthesized and characterized by single-crystal X-ray diffraction. Complex 1 exists as a 2D sheet structure and each Cd(II) ion in the complex is six-coordinated with an octahedral geometry. Both complexes 2 and 3 exist as 1D zig-zag structures and each Cd(II) ion in the two complexes is five-coordinated with a trigonal bipyramidal geometry. Complex 4 exists as a centrosymmetric trinuclear structure, in which two Cu(II) ions are five-coordinated with a square pyramidal geometry and the other Cu(II) ion is six-coordinated with an octahedral geometry. The structural differences are attributed to coordination ability of the coordination sites and coordination configurations of the metal ions. Furthermore, alcohol vapor adsorption measurements showed that all the synthesized complexes exhibited good adsorption capacities toward methanol vapor. [ABSTRACT FROM AUTHOR]

Two racemic Schiff bases (H 4 L 1 and H 4 L 2) were synthesized and characterized, and the crystal structures indicated their helical configurations with equal amounts of P - and M -helicity. The aggregation-induced emission (AIE) and selective ion recognition properties of H 4 L 1 and H 4 L 2 were investigated using UV–vis absorption and fluorescence spectra. The results showed that both H 4 L 1 and H 4 L 2 exhibited obvious "AIE + ESIPT" characteristics in THF/H 2 O solution upon increasing the water fraction. Both H 4 L 1 and H 4 L 2 displayed an obvious turn-off fluorescence response to Cu2+ and F−, and a slight turn-off response to Fe3+ in DMSO, while they displayed an efficient selective ion recognition of Cu2+ in THF/H 2 O (1: 1, V / V). The corresponding stoichiometry ratio, association constant, Stern-Volmer quenching constant, and the detection limits were determined via Job's plots, UV–vis spectra titration as well as fluorescence spectra titration experiments. The crystal structures of the complexes obtained from the interactions of H 4 L 1 with Cu2+ and Fe3+ illustrated their binding modes and binding differences, which helped us interpret the ion recognition mechanism of H 4 L 1 and H 4 L 2. In addition, the application of H 4 L 2 on test strips was performed, indicating that H 4 L 2 can be used for the rapid detection of Cu2+ and F− in THF. The acid-responsive fluorescence behavior of H 4 L 2 showed that the white light emission can be obtained upon the addition of hydrochloric acid or aldehyde c into H 4 L 2. [Display omitted] • Two helical Schiff base probes were synthesized and structurally characterized. • Both H 4 L 1 and H 4 L 2 exhibit obvious "AIE + ESIPT" characteristics in THF/H 2 O solution. • H 4 L 1 and H 4 L 2 display an efficient selective ion recognition of Cu2+ in THF/H 2 O (1: 1, V / V). [ABSTRACT FROM AUTHOR]

• Four 1D coordination polymers have been synthesized and characterized. • The ligands show different coordination sites in coordination polymers. • Methanol vapor adsorption for the four complexes was measured. Four coordination polymers, [Hg L1 Br 2 ] n (1), {[Cd(L1) 2 Cl 2 ]·2CH 3 OH} n (2), [Hg L2 Cl 2 ] n (3) and [Cd(L2) 2 Cl 2 ] n (4), have been synthesized and characterized from two hydrazone Schiff base ligands (L1 and L2) with mercury(II) or cadmium(II) halide, respectively. In complexes 1 and 3 , each mercury(II) center is five-coordinated with distorted square pyramidal geometry in 1D coordination polymers. In complexes 2 and 4 , each cadmium(II) center is six-coordinated with slightly distorted octahedral geometry in 1D looped-chain structures. Interestingly, the ligands show different coordination sites in the formation of coordination polymers. In complexes 2 , 3 and 4 , the ligands coordinate to the metal centers by pyridine nitrogen atoms and amino nitrogen atoms, whereas in complex 1 it coordinates by pyridine nitrogen atoms and carbonyl oxygen atoms instead of amino nitrogen atoms. [ABSTRACT FROM AUTHOR]

• Five complexes were synthesized based on two reduced Schiff base ligands. • The structural differences of the five complexes were discussed in detail. • Antifungal activities of the ligands and complexes were investigated. Two reduced Schiff base ligands (L1 and L2) were synthesized from two Schiff base compounds containing pyridine-2,6-dicarboxamide skeletons. In the presence of Zn(II) or Ag(I) ions, five complexes, formulated as [Zn L1 Cl 2 ] (1), [Ag L1 NO 3 ]·4CH 3 CN (2), {[Ag L1 ]·NO 3 ·DMSO} n (3), {[Zn L2 Cl 2 ]·2DMF·H 2 O} n (4), and [Ag 2 (L2) 2 (CH 3 CN) 2 ]·2NO 3 ·2CH 3 CN (5), were synthesized and further characterized via elemental analysis, FT-IR spectra and single-crystal X-ray diffraction. Complexes 1 and 2 exist as similar mononuclear [1+1] metallomacrocycles. Complexes 3 and 4 exist as 1D zig-zag chain polymers. Complex 5 exists as a centrosymmetric [2+2] metallamacrocycle. The structural differences of the complexes reveal two different configurations of the ligands in coordination with metal ions. Furthermore, antifungal measurements show that all of the three Ag(I) complexes exhibit good inhibiting effects against M. grisea and S. sclerotiorum. [Display omitted] [ABSTRACT FROM AUTHOR]

Two coordination polymers based on a bisacylhydrazone ligand were synthesized and characterized. Their structures disclosed the ligand can adopt three types of sites to coordinate with metal ions. The antibacterial test showed CP 1 exhibited good antibacterial activity against multidrug-resistant Escherichia coli. [Display omitted] • Two coordination polymers were synthesized and characterized based on a bisacylhydrazone ligand. • Crystal structures of the two polymers disclosed three types of sites in the ligand • CP 1 exhibited one-electron redox process and remarkable antibacterial activity against MDREC. A flexible bisacylhydrazone ligand (H 4 L) was designed and synthesized from the condensation reaction of dialdehyde 3,3′-thiobis(methyiene)-bis-(5-methyl-salicylaldehyde) (b) with isonicotinic hydrazide. In the DMSO/methanol solution, two coordination polymers (CPs), formulated as {[Ag(H 4 L)NO 3 ]·DMSO·2H 2 O} n (CP 1) and {[Zn 2 (H 2 L 2-) 2 ]·3DMSO·3H 2 O} n (CP 2), were synthesized from H 4 L with Ag(I) or Zn(II) ions, respectively. These two CPs were characterized via elemental analysis, FT-IR spectra, and single crystal X-ray determination. The results show that CP 1 exists as a 1D looped-chain polymer, while CP 2 exists as a 2D sheet polymer. The coordination configurations of the two CPs were analyzed and compared in detail, which disclose the terminal pyridyl nitrogen atoms exhibit obviously stronger coordination ability compared to other sites. In addition, photophysical, electrochemical and antibacterial properties of H 4 L and the two CPs were investigated. [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]

A tetraphenylethylene-based acylhydrazone macrocycle (H 8 L) was designed and synthesized via Schiff base condensation reaction. The [2 + 2] molecular structure of H 8 L was determined via 1H NMR, 13C NMR, elemental analysis, ESI-MS, and single crystal X-ray diffraction. The "ESIPT + AIE" and selective recognition properties of macrocycle H 8 L were investigated via UV–vis absorption spectra and fluorescence emission spectra. The results showed that macrocycle H 8 L exhibited an obvious AIE characteristic in THF/H 2 O solution with varying water fraction, and displayed a selective "turn-on" response to Al3+ ions in the solution of THF/H 2 O (V : V = 4: 1). In addition, the visualization of latent fingerprints and the application of H 8 L on test strips were performed as well. A tetraphenylethylene-based Schiff base macrocycle (H 8 L) has been synthesized and characterized. The luminescence spectra disclosed that H 8 L displayed a selective recognition and acted as a "turn-on" fluorescent sensor to Al3+ ions in THF/H 2 O solution. The application of H 8 L on latent fingerprints and test strips indicated that H 8 L can be used as a promising fluorescent material. [Display omitted] • The luminescence spectra showed an ESIPT and AIE characteristic of macrocycle H 8 L in the THF/H 2 O solution with different water fraction. • H 8 L displayed a selective recognition and acted as a "turn-on" fluorescent sensor for Al3+ ions in the THF/H 2 O solution. • The application of H 8 L on latent fingerprints and test strips indicated that it can be used as a promising fluorescent material. [ABSTRACT FROM AUTHOR]

• A polydentate Schiff base ligand was synthesized and characterized. • The coordination reactions of the ligand with copper(II) acetate were investigated under different molar ratios, and characterized by single-crystal X-ray diffraction. • Hirshfeld surface analysis, DFT, electrochemical and magnetic properties of the two complexes were investigated. The Schiff base condensation reaction of N,N′ -bis(2-amiophenyl)-pyridine-2,6-dicarboxamide and 2-hydroxy-3-methoxybenzaldehyde yielded a polydentate ligand (H 4 L). The coordination reactions of the ligand with copper(II) acetate were investigated under different molar ratios, and the reaction products were characterized by infrared spectroscopy, element analysis, single-crystal X-ray diffraction and powder X-ray diffraction. In the case of a 1:1 molar ratio of ligand H 4 L and copper(II) acetate, a mononuclear complex [Cu(H 2 L 2−)] (1) was obtained. By contrast, the treatment of ligand H 4 L with twice copper(II) acetate afforded a dinuclear complex [Cu 2 (L 4−)(CH 3 OH)(H 2 O)]‧H 2 O (2). The different coordination configurations in the two complexes reveal that the ratio of organic ligand and metal ion has remarkable influences on the structural topologies. Furthermore, Hirshfeld surface analysis, DFT, electrochemical and magnetic properties of the two complexes were investigated as well. Two Cu(II) complexes were synthesized in the case of different molar ratios of a Schiff base ligand with copper(II) acetate. A view of the different geometries discloses that the ligand can participate in the coordination reactions through two different deprotonated forms. [Display omitted] [ABSTRACT FROM AUTHOR]

Four complexes were synthesized and characterized from two helical pyridylamide ligands. A view of the geometry of these complexes discloses the self-discriminating and self-recognition process in the coordination-driven chiral assembly. [Display omitted] • Four new complexes derived from two helical pyridylamide ligands have been synthesized and characterized. • The crystal structures of the four complexes reveal the chiral self-assembly process in the coordination reaction. • Cyclic voltammetric measurements and methanol vapor adsorptions for the complexes are investigated. Two helical pyridylamide ligands N2,N6-bis(2-(nicotinamido)phenyl)pyridine-2,6-dicarboxamide (L1) and N2,N6-bis(2-(isonicotinamido)phenyl)pyridine-2,6-dicarboxamide (L2) have been designed and synthesized. Four complexes, namely, {[Zn(L1)I 2 ]‧2CH 3 OH‧H 2 O} n (1), [Ag 2 (L1) 2 ]‧(NO 3) 2 (2), {[Ag(L2)NO 3 ]‧H 2 O} n (3), and {[Ag(L2) 2 ]‧2H 2 O} n (4) were obtained via the solvent evaporation method from the reaction of the ligands with Zn(II) or Ag(I) ions respectively. The two ligands together with four complexes were structurally determined by single-crystal X-ray diffraction and additionally characterized by infrared spectroscopy, element analysis and powder X-ray diffraction. The crystal structures reveal different chiral self-assembly processes in the reaction of the helical liands with Zn(II) or Ag(I) ions. Complexes 1 , 2 and 4 exhibit as a heterochiral coordination polymer or binuclear metallamacrocycle, while complex 3 exists as a homochiral coordination polymer. Besides, the structural differences between complexes 3 and 4 show that the reaction ratio of the ligand with metal ions has obvious influences on the coordination configuration. Furthermore, thermogravimetric analysis and methanol vapor adsorption properties of the synthesized complexes have been investigated, and cyclic voltammetric measurements of complexes 2 – 4 were carried out as well. [ABSTRACT FROM AUTHOR]

Four complexes were synthesized and characterized from a new 2, 2′-bipyridyl hydrazone Schiff base ligand. The diverse architectures of the complexes show that the 2, 2′-bipyridyl ligand and metal ions have significant impacts on the coordination configurations. [Display omitted] A new 2, 2′-bipyridyl hydrazone Schiff base ligand (H 2 L) was synthesized, and four novel complexes, namely, [Ni 2 (L 2−) 2 ]‧3CH 3 OH (1), [Zn 2 (L 2−) 2 ]‧DMF‧3H 2 O (2), [Cd 3 (H 2 L) 2 Cl 6 (H 2 O) 2 ]‧2H 2 O (3), and {[Zn 2 (L 2−)Cl 2 ]‧CH 3 OH} n (4), were obtained via the solvent evaporation method. The four complexes were structurally investigated by single-crystal X-ray diffraction and additionally characterized by powder X-ray diffraction, infrared spectroscopy and element analysis. X-ray analytical results show that complexes 1 and 2 exhibit dinuclear double helicates with similar structures. Complex 3 exists as a trinuclear structure with two different configurations in the cadmium ions. Complex 4 exists as a one-dimensional coordination polymer with two different configurations in the zinc ions. The diverse architectures of the complexes show that the spacer 2, 2′-bipyridyl ligands and metal ions have significant impacts on the structures and the coordination modes. Furthermore, thermogravimetric analysis, DFT and luminescence properties of the complexes have been investigated, and electrochemical studies for complex 1 were carried out as well. [ABSTRACT FROM AUTHOR]

Abstract: A new category of dinucleating macrocyclic Schiff base ligands with ring sizes from 34- to 52-membered have been synthesised employing metal template procedures involving the reaction of o-phenylenediamine with a series of α,ω-bis(3′-hydroxy-4′-formylphenyloxy)alkanes in the presence of calcium(II), barium(II) or manganese(II). The latter cations act as ‘transient’ templates for formation of the corresponding metal-free Schiff base macrocyclic ligands, H4L n (where n signifies the number of carbons in each linking bis-alkoxy chain); the macrocycles corresponding to n =4, 6 and 8 were isolated and characterised while, for n =1, in which single methylene groups acts as the bridges between salicyl moieties, the cyclic product was used directly for preparation of its dinuclear complex, [Zn2L1], without prior isolation. Evidence for the templating role of barium in the preparation of H4L6 and H4L8 was obtained by isolation of the corresponding species of type H4L n ·2Ba(ClO4)2 (n =6 or 8) as ‘intermediates’ before generation of the respective metal-free macrocycles. Reaction of zinc(II) acetate with the free macrocycles in methanol yielded complexes of type [Zn2L n ] in all cases. A related non-cyclic ligand, H2L0 and its corresponding mononuclear complex, [ZnL0]·H2O, were also synthesised and its spectral properties compared with those of the macrocyclic derivatives. The elemental analyses, 1H NMR, IR, UV–Vis and MS spectra of the respective zinc complexes in each case were in accord with the formation of the expected 2:2 condensation product. The results of DFT calculations to probe aspects of the electronic and structural natures of both H2L1 and H4L4 are briefly presented. [Copyright &y& Elsevier]