Copper(II) and cadmium(II) complexes with an imide tethered imidazole and a copper(II) coordination polymer through ring opening reaction

The reactions of 2-(3-(1H-imidazol-1-yl)propyl)isoindoline-1,3-dione (L) with copper (II) chloride or copper(II) nitrate resulted in mononuclear complexes [CuL₄Cl₂]·12H₂O (1) or [CuL₄(H₂O)NO₃]NO₃·2H₂O (2) respectively; whereas the copper(II) acetate reacted with L to give a three dimensional coordination polymer {[Cu(L′)₂]·4H₂O}n (3), (where L′ = 2-(3-(1H-imidazol-1-yl)propylcarbamoyl)benzoate). The reaction of cadmium(II) acetate with L led to the formation of a seven-coordinated complex [CdL₃(O₂CCH₃)₂]·2H₂O (4).     

Synthesis,Characterization and Anti-Breast Cancer Activity of New 4-Aminoantipyrine-Based Heterocycles

4-Aminoantipyrine was utilized as key intermediate for the synthesis of pyrazolone derivatives bearing biologically active moieties. The newly synthesized compounds were characterized by IR, ¹H- and ¹³C-NMR spectral and microanalytical studies. The compounds were screened as anticancer agents against a human tumor breast cancer cell line MCF7, and the results showed that (Z)-4-((3-amino-5-imino-1-phenyl-1H-pyrazol-4(5H)-ylidene)methylamino)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 5, 3-(4-bromophenyl) -1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 13, 1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1-Hpyrazol- 4-yl)-3-(4-iodophenyl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 14, 3,3′-(4,4′-sulfonylbis(4,1-phenylene))bis(1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-yl)-4-oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile) 16, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-hydrazono-4-oxo-3-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbonitrile 17, (Z)-1-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-4-oxo-3-phenyl-2-(2-phenylhydrazono)-1,2,3,4-tetrahydro pyrimidine-5-carbonitrile 18, and (Z)-4-(3-amino-6-hydrazono-7-phenyl-6,7-dihydro pyrazolo[3,4-d]pyrimidin-5-yl)-1,5-dimethyl-2-phenyl-1,2-dihydropyrazol-3-one 19 were the most active compounds with IC₅₀ values ranging from 30.68 to 60.72 μM compared with Doxorubicin as positive control with the IC₅₀ value 71.8 μM.     

Synthesis,structure and properties of a novel 3D pentanuclear [Zn5(OH)2]8 + cluster-based (3,4,11)-connected coordination polymer

A novel coordination polymer based on the multidentate N-donor ligand 1-((1H-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, [Zn₅(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 [Zn₅(OH)₂]^8 + cluster. The optical band gap and photoluminescent property of compound 1 have been studied.     

Syntheses and optical,electrochemical, and photovoltaic properties of polymers with 6-(2-thienyl)-4H-thieno[2,3-b]indole with a variety of electron-deficient units

Conjugated polymers were synthesized and used for polymer solar cells with new electron-rich units, 6-(2-thienyl)-4H-thieno[2,3-b]indole (2-TTI). 2-TTI was coupled with electron-pulling units, including benzothiadiazole and benzimidazole derivatives, to provide push–pull types of conjugated polymers (poly(8-(heptadecan-9-yl)-6-(thiophen-2-yl)-8H-thieno[2,3-b]indole)-alt-(2-methyl-5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)-2-(trifluoromethyl)-2H-benzimidazole) (PTTIDOCF3), poly(8-(heptadecan-9-yl)-6-(thiophen-2-yl)-8H-thieno[2,3-b]indole)-alt-(5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)-2,1,3-benzothiadiazole) (PTTIDOBT), poly(8-(heptadecan-9-yl)-6-(thiophen-2-yl)-8H-thieno[2,3-b]indole)-alt-(2,2-dimethyl-4,7-di(thiophen-2-yl)-2H-benzimidazole) (PTTIMBI), and poly(8-(heptadecan-9-yl)-6-(thiophen-2-yl)-8H-thieno[2,3-b]indole)-alt-(2,2-dimethyl-5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)-2H-benzimidazole) (PTTIDOMBI)). The synthesized conjugated polymers provided deep highest occupied molecular orbital energy levels for higher open-circuit voltages (V_OC). The device composed of PTTIDOMBI and [6,6]-Phenyl C₇₁ butyric acid methyl ester PC₇₁BM (1:2) with chloronaphthalene additive showed a V_OC of 0.72 V, a short-circuit current (J_SC) of 9.16 mA/cm², and a fill factor of 0.43; this gave a power conversion efficiency (PCE) of 2.84%. The PTTIDOMBI provided better morphology for enhanced charge transport, and this led to the higher J_SC and PCE of the organic solar cells. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47624.     

A novel polyoxometalate-based metal-organic compound constructed from an unprecedented [Ag8(Hpyttz)4(H2pyttz)2] cluster and an in-situ [VW12O40]3 − anion

A novel polyoxometalate (POM)-based metal-organic compound constructed from a multinuclear Ag^I cluster and Keggin-type [VW₁₂O₄₀]^3 − anion, [Ag₄(Hpyttz)₂(H₂pyttz)][HVW₁₂O₄₀]·3H₂O (1) (H₂pyttz = 5′-(pyridin-4-yl)-1H,2′H-3,3′-bi(1,2,4-triazole), was hydrothermally synthesized and characterized by IR spectroscopy, TG analysis, powder and single-crystal X-ray diffraction. In compound 1, [VW₁₂O₄₀]^3 − (VW₁₂) was in-situ transformed from [SiW₁₂O₄₀]^4 − anion. Eight Ag^I ions were connected by six Hpyttz/H₂pyttz ligands with three coordination modes forming an unprecedented [Ag₈(Hpyttz)₄(H₂pyttz)₂] cluster, which connected with six VW₁₂ anions to construct a 2-D double-layer (3,6)-connected network with {4³}₂{4⁶.6⁶.8³} topology. Moreover, the photocatalytic activity of 1 has been investigated.     

Unsymmetrical 3- and 5-substituted bis(pyrazolyl)borate system

An unsymmetrical 3- and 5-substituted bis(azolyl)borate system, the sodium dihydrobis(3-trifluoromethyl-pyrazol-1-yl)(5-trifluoromethyl-pyrazol-1-yl)borate, Na[H₂B(3-(CF₃)pz)(5-(CF₃)pz)], has been synthesized by the reaction of 3-trifuoromethyl-pyrazole with Na[H₃B(5-(CF₃)pz)] in toluene solution. Na[H₂B(3-(CF₃)pz)(5-(CF₃)pz)] reacts with AgNO₃ in the presence of triphenylphosphine to afford the silver(I) bis(phosphane) adduct {[H₂B(3-(CF₃)pz)(5-(CF₃)pz)]Ag[P(C₆H₅)₃]₂}. These compounds have been characterized by elemental analyses, FT-IR, ESI-MS and multinuclear NMR spectroscopy. Solid state structure of {[H₂B(3-(CF₃)pz)(5-(CF₃)pz)]Ag[P(C₆H₅)₃]₂} is also reported. It features a κ²-N,N′ bonded bis(pyrazolyl)borate ligand and a pseudo-tetrahedral silver center.     

A rhenium(I) compound bearing a dimerized chromone NO bidentate chelator

Herein, we communicate the synthesis of a novel rhenium(I) complex, fac-[Re(CO)₃(chrpychr)Br] (1) from the equimolar reaction between 2-(4-oxo-4H-chromen-3-yl)-5H-chromeno[2,3-d]pyrimidin-5-one (chrpychr) and [Re(CO)₅Br]. The metal complex 1 was characterized via ¹H NMR-, IR- and UV–Vis spectroscopy and conductivity measurements. Single crystal X-ray analysis provides definitive confirmation in the structural elucidation of 1. DFT studies of 1 aided in the interpretation of its experimental IR spectrum.     

Synthesis and Crystal Structure of Two Coordination Polymers Assembled from a Versatile 4-(4-Hydroxypyridinium-1-yl)phthalic Acid

Two coordination polymers, namely, [Ni(L)(C₂H₃N)(H₂O)₅] _n (1), and [Mn(L)(H₂O)₂] _n (2) have been hydro(solvo)thermally synthesized through the reaction of 4-(4-hydroxypyridinium-1-yl)phthalic acid (H₂L) with divalent nickel and manganese salts. As a result of various coordination modes of the versatile 4-(4-hydroxypyridinium-1-yl)phthalic acid, these compounds exhibit structural diversity. Complex 1 exhibits a 3D coordination framework through the rich hydrogen bond. Complex 2 exhibits a 3D coordination network based on layers. These complexes have been characterized by powder X-ray diffractions (PXRD), IR spectroscopy, elemental analysis, thermogravimetry, single-crystal X-ray crystallography and solid UV spectroscopy.     

Construction of three Cd(II) coordination polymers based on extended pyridyl-tetrazolyl-bifunctional ligands: Structures and luminescent properties

Reactions of Cd(II) with three new pyridyl-tetrazole-bifunctional ligands, 3-(4-(1H-tetrazol-5-yl)phenyl)pyridine (HL¹), 4-(3-(1H-tetrazol-5-yl)phenyl)pyridine (HL²), and 3-(3-(1H-tetrazol-5-yl)phenyl)pyridine (HL³) resulted in three Cd(II) coordination polymers (CPs), namely, [CdL¹₂]_n (1), [CdL²₂]_n (2), and [CdL³₂(H₂O)]_n (3). Although the geometry of L¹ and L² is quite different, the coordination modes of Cd(II) ion and ligand, as well as the SBUs in compounds 1 and 2 are quite similar, thus give rise to 3D frameworks with same (3,6)-connected ant topology. Compound 3 is a 3D framework composed of 1D helical chains and features as (3,5)-connected tcj topology. The results showed that the topologies are largely dependent on the coordination angle between two coordination groups. The thermal stabilities and luminescent properties of compounds 1–3 have also been studied.     

Synthesis and structural characterization of isomeric monocarbon (η-dicyclopentenyl)-closo-rhodacarboranes stabilized by the agostic bonding interaction

The [7-Me₃N-nido-7-CB₁₀H₁₂] (1), after being treated with two molar equiv. of Proton Sponge, reacts with [(η⁴-C₁₀H₁₂)₂Rh₂(μ-Cl)₂] (2) in benzene–ethanol solution affording two isomeric monocarbon (η-dicyclopentenyl)-closo-rhodacarborane complexes, differing in hapticity of the carbocyclic ligand, viz. [2,2-{(2′,3′-η²):(5′-η¹)-C₁₀H₁₃}-1-(Me₃N)-2,1-closo-RhCB₁₀H₁₀] (3) and [2-{(1′-3′-η³)-C₁₀H₁₃}-1-(Me₃N)-2,1-closo-RhCB₁₀H₁₀] (4). Isomeric compounds 3 and 4 were characterized by analytical, multinuclear NMR spectroscopic data as well as by single-crystal X-ray diffraction study, which revealed the existence of an agostic C–H⋯Rh interaction in both the species.     

A 3-D silver(I) polymer with 5,6-dihydro-1,4-dithiin-2,3-dicarboxylate ligand,showing an unusual 6-connected (412.63)2(49.66) topology

The in situ reaction of AgClO₄·6H₂O with 5,6-dihydro-1,4-dithiin-2,3-dicarboxylic anhydride in the presence of lithium hydroxide afforded a photoluminescent three-dimensional (3-D) Ag^I coordination polymer, [Ag₂(L)]_∞ (1), which exhibited an unusual trinodal 6-connected (4¹².6³)₂(4⁹.6⁶) topological net (L = 5,6-dihydro-1,4-dithiin-2,3-dicarboxylate). Moreover, the luminescent/thermal properties of 1 have also been briefly investigated.     

A strategy for controlling charge and conformation in 2,2′-bipyridine complexes for use in photonic applications

The complex [ⁿBu₄N][Cu(H1)₂]·H₂O (H₂1 = 3,3′-dihydroxy-6,6′-dimethyl-2,2′-bipyridine) is readily formed from the reaction of H₂1 with [Cu(MeCN)₄][PF₆] in the presence of [ⁿBu₄N]Br; in the solid state the anion comprises a discrete dinuclear {[Cu(H1)₂](H₂O)₂[Cu(H1)₂]}^2– unit in which two oxygen atoms of each [H1]^– ligand and two water oxygens form a chair shaped hydrogen-bonded six-membered ring.     

Hydrothermal syntheses and characterization of a series of mixed-ligand luminescent CdII frameworks with novel 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl) acetate ligand and benzenedicarboxylate isomers

Under similar hydrothermal synthetic conditions using a novel flexible ligand 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl)acetonitrile (PPAN), benzenedicarboxylate isomers (H₂pa = phthalate, H₂ip = isophthalate, and H₂tp = terephthalate) and Cadmium(II) acetate, three novel mixed-ligand Cd(II) coordination polymers {[Cd₂(PPAA)₂(μ-pa)(H₂O)]·2H₂O}_n (1), {[Cd₄(PPAA)₄ (μ₄-ip)₂]·2H₂O}_n (2) and {[Cd₂(PPAA)₂(μ-tp)]·2H₂O}_n (3) (PPAA⁻ = 2-(3-(pyridin-2-yl)-1H-pyrazol-1-yl) acetate) have been isolated, in 1–3 PPAN, and are also hydrolyzed into a novel PPAA⁻ ligand. Complex 1 is a 1D coordination polymer in which the tetra-nuclear [Cd₄(PPAA)₄]^4 + structural units are extended by tri-dentate μ-pa^2 − ligands. Complex 2 contains binuclear [Cd₂(PPAA)₂]^4 + structural units, which are extended by four tetra-dentate μ₄-ip^2 − ligands to link eight neighboring binuclear [Cd₂(PPAA)₂]^4 + units ultimately forming a 2D layered framework, while complex 3 contains 1D double chain containing [Cd(PPAA)]_n cation structural units, which are further extended by tetradentate μ-tp^2 − ligands to form a new 2D layered framework. All the complexes have been investigated by elemental analysis, FT-IR, thermal analysis and fluorescence characterization. The flexible coordination modes of PPAA⁻ are also briefly analyzed. The flexible coordination modes of PPAA⁻ and benzenedicarboxylate isomers also reveal great potential in the construction of these novel mixed-ligand luminescent frameworks with diverse structural motifs and unique functional properties.     

Assembly of two Cu-based coordination polymers from 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylate ligand

Two novel Cu-based coordination polymers [Cu₅(HPyImDC)₄]·(NH₄)₃ (1) and [Cu₃(H₂O)₂(HPyImDC)₂(C₃N₂H₁₀)] (2) containing the 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylate (H₃PyImDC) ligand have been solvothermally synthesized. Single crystal X-ray diffraction analysis reveals that compound 1 exhibits a three dimensional framework with 1D rhombic channels, which can be simplified into a novel (3, 4)-connected network with Schläfli symbol of (6².14⁴)(6².8)₄. Compound 2 is one dimensional chain which packed with each other via π–π and hydrogen-bonding interactions to construct a three dimensional supramolecular structure. As the first example related to Cu (I) and Cu (I, II) coordination polymers based on H₃PyImDC ligands, compounds 1 and 2 are further studied by elemental analyses, IR spectroscopy and thermogravimetric analyses.     

In situ synthesis and dielectric properties of copper(II) and nickel(II) chiral Schiff base complexes

Two chiral Schiff base-containing complexes, [Cu(L¹)](ClO₄)₂·H₂O (1, L¹ = (S,S)-N1,N2-bis((1H-imidazol-4-yl)methylene)cyclohexane-1,2-diamine) and [Ni(L²)₂](ClO₄)₂ (2, L² = (S,S)-N1-((1H-imidazol-4-yl)methylene)cyclohexane-1,2-diamine) were synthesized from the reaction mixture of 1H-imidazole-4-carbaldehyde, (S,S)-1,2-diaminocyclohexane and Cu(ClO₄)₂·6H₂O or Ni(ClO₄)₂·6H₂O in methanol. Single-crystal X-ray diffraction analyses reveal that the in situ generated chiral Schiff base ligands L¹ and L² are bisubstituted and monosubstituted, respectively, corresponding to the different metal ions Cu^II and Ni^II. Variable-frequency and -temperature dielectric properties of 1 and 2 have been studied.     

Tuning the valence of 3,3-di(1H-tetrazol-5-yl)pentanedioic acid: Solvothermal synthesis of Eu(III) and bimetallic Eu(III)/Cu(II) compounds

3,3-Di(1H-tetrazol-5-yl)pentanedioic acid (H₄dtzpda) with four acidic hydrogen atoms can display different valence when reacted with different metal ions. Solvothermal reactions of H₄dtapda with Eu(NO₃)₃·6H₂O or Eu(NO₃)₃·6H₂O/Cu(NO₃)₂·6H₂O afford [Eu(Hdtzpda)(H₂O)₄]·4H₂O (1) and [Eu₂Cu(dtzpda)₂(H₂O)₁₀]·6H₂O (2), respectively, where only three acidic hydrogen atoms of H₄dtzpda are deprotonated in compound 1 while all the four acidic ones are deprotonated in compound 2. In compound 1, Hdtzpda^3 − acts as a pentadentate ligand to bridge Eu(III) centers via the oxygen atoms of the carboxylate group while in compound 2, dtzpda^4 − is a hepadentate one via not only the oxygen atoms of the carboxylate group but also the nitrogen atoms of the tetrazole rings. The luminescence properties of the two compounds in the solid state show both intraligand and characteristic peaks of Eu^3 + at room temperature.     

First use of the maleamate(−1) ligand in coordination chemistry: Dinuclear copper(II) complexes with N-donors and their interesting ‘organic’ chemistry

A systematic investigation of the reactions of 3d-metal ions with the maleamate(−1) ligand (HL⁻) in the presence of mono- , bi- or tridentate chelating N-donors has been initiated and the first results are described. Reaction schemes involving Cu(ClO₄)₂ · 6H₂O, HL⁻ and 1,10-phenanthroline or 2,6-bis(pyrazol-1-yl)pyridine (bppy) in MeCN gave complexes [Cu₂(HL)₃(phen)₂](ClO₄) (1) and [Cu₂(HL)₂(bppy)₂](ClO₄)₂ (3), respectively. The same reaction systems in MeOH afforded the new complexes [Cu₂L′₂(ClO₄)(phen)₂(MeOH)](ClO₄) (2b) and [Cu₂L′₂(bppy)₂](ClO₄)₂ (4) in which the maleamate(−1) ion has been transformed to the monomethyl maleate(−1) ligand L′⁻ via a novel, metal ion-assisted process. The reaction that leads to 2b takes place through the formation of the 1D coordination polymer [Cu(ClO₄)(phen)(MeOH)₂]_n(ClO₄)_n (2a), whose structure was assigned on the basis of its spectral similarity with the structurally characterized complex [Cu(ClO₄)(phen)(MeCN)₂]_n(ClO₄)_n (2c). Only the carboxylate oxygen atoms of HL⁻ and L′⁻ are coordinated to copper(II) in 1, 2b, 3 and 4.     

Synthesis and characterization of the dihydrosalpren ligand (H2L1) and of its trinuclear Ni(II) complex

The synthesis of the new unsymmetrical tetradendate Schiff ligand N-(2-hydroxybenzyl)-N′-(2-hydroxybenzylidene)-1,3-diaminopropane (H₂L¹) is reported. The ligand comprises two different coordination moieties: a rigid salicylaldimmine unit and a more flexible (2-hydroxybenzyl)-amino (hydrogenated salicylaldimmine) unit. The reaction of H₂L¹ with Ni(OAc)₂·4H₂O (1:1 molar ratio) leads to the spontaneous formation of a trinuclear complex with composition {[Ni(L¹)OH₂]₂(OAc)₂Ni}·2H₂O, characterized by X-ray crystallography, where two [Ni(L¹)] units act as O,O-bidentate chelate to a Ni(II) ion.     

Three 3D Cu(II) coordination polymers constructed from 1,2,4,5-benzenetetracarboxylate acid and three positional isomeric ligands

Based on 1,2,4,5-benzenetetracarboxylate acid (H₄btc), and mixed with three isomeric dipyridyl ligands, three novel 3D Cu(II) coordination polymers [Cu₂(btc)(4,4′-bpt)]·2H₂O (1) [4,4′-bpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole], [Cu(btc)_0.5(3,4′-bpt)]·0.5H₂O (2) [3,4′-bpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4- triazole] and [Cu(btc)_0.5(3,3′-bpt)]·2H₂O (3) [3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole] have been synthesized and characterized, respectively. 1 is a 3D pillared double-layer complex containing a novel bilayer unit; 2 is a 3D pillared-layer architecture with (4,4)-sql layer; 3 exhibits a 3D structure containing 3D [Cu(btc)]_∞ motif and 1D [Cu(bpt)]_∞ chain. The topological analysis shows that 1 can be simplified to a (4,6)-connected network with the Schläfli symbol of (4²·6⁴)₂(4⁸·6⁷), 2 a (4,6)-connected network with the symbol of (4⁴·6²)(4⁴·6¹⁰·8), and 3 a four-connected topology with the symbol of (3²·10³·11)₂(3²·10⁴).