Ternary and binary copper(II) complexes: synthesis,characterization, ROS-inductive,proteasome inhibitory,and anticancer properties

Three ternary copper(II) complexes, [Cu(phen)(L-phe)Cl]·2H₂O, [Cu(phen)(L-leu)Cl]·4½H₂O, and [Cu(phen)(L-tyr)Cl]·3H₂O, and four binary copper(II) complexes, [Cu(phen)Cl₂]_, Cu(L-phe)₂·½H₂O, Cu(L-leu)₂·½H₂O, and Cu(L-tyr)₂·H₂O (where phen = 110-phenanthroline, L-phe = L-phenylalanine, L-tyr = L-tyrosine, L-leu = L-leucine and Cl^- = chloride), were synthesized and characterized by elemental analysis, spectroscopic techniques (FTIR, UV–visible, fluorescence spectroscopy), magnetic susceptibility, molar conductivity, and lipophilicity measurement. X-ray diffraction determination of a single crystal of [Cu(phen)(L-tyr)Cl] showed two independent molecules in the asymmetric unit, each with the same distorted square pyramidal geometry about copper(II). p-Nitrosodimethylaniline assay revealed that the three ternary complexes were better inducers of reactive oxygen species over time than binary complexes, CuCl₂, and free ligands. All the copper(II) complexes in this series inhibited the three proteolytic activities in the order Trypsin-like > Caspase-like > Chymotrypsin-like. In terms of anticancer properties, the copper(II)-phen complexes had GI50 values of less than 4 μM against MCF-7, HepG2, CNE1 and A549 cancer cell lines, more potent than cisplatin.     

Synthesis,crystal structures,and characterization of copper(II) carboxylate complexes incorporating 1,10-phenanthroline and bipyridine

A series of Cu(II) carboxylate complexes (carboxylate?=?2-fluorobenzoic acid (2-HFBA) or 4-fluorobenzoic acid (4-HFBA)) containing either one chelating 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) have been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, and thermal analyses. In [Cu(bipy)(H₂O)(2-FBA)₂] (1), [Cu(bipy)(H₂O)(4-FBA)₂] (3), and [Cu(phen)(H₂O)(2-FBA)₂] (4), Cu is five-coordinate in a square pyramidal geometry and four-coordinate in [Cu(phen)(2-FBA)₂] (2). The four complexes are extended into 1-D chains through hydrogen-bonding and π?···?π interactions in 1 and 4, only hydrogen-bonding in 2, and π?···?π interactions in 3. These contacts lead to aggregation and supramolecular self-assembly.     

Syntheses,characterizations and SOD-like activities of ternary copper(II) complexes with 1,10-phenanthroline and L- α -amino acids

Three new complexes, [Cu(phen)(L-argH⁺)Cl]Cl?·?2.5H₂O (1), [Cu(phen)(L-leu)(H₂O)]Cl?·2.5H₂O (2) and [Cu(phen)(L-met)(H₂O)]Cl?·?2H₂O (3), where phen?=?1,10-phenanthroline, L-arg?=?L-argininate, L-leu?=?L-leucinate, and L-met?=?L-methioninate, were synthesized and characterized by elemental analysis, molar conductivity, IR and UV-Vis spectroscopies. Complex 1 was structurally characterized by single-crystal X-ray diffraction. The superoxide dismutase (SOD)-like activities of the three complexes were determined by the improved NBT method. The results show that the complexes have high superoxide dismutase-like activities and may act as good mimics for superoxide dismutases.     

Novel Copper(II) Thiodibenzoic Acid Coordination Polymers by in situ Extrusion of Sulfur from 2,2′‐Dithiodibenzoic Acid and the Unique Oxidation of Disulfide to Sulfate

Slow diffusion reaction of 2,2′‐dithiodibenzoic acid (dtdb) with CuCl₂ in the presence of N‐donor ligands results in the formation of different coordination polymers where both S–S and C–S scission and oxidation of S is observed. X‐ray diffraction analysis of [Cu(tdb)(phen)(H₂O)]₂ · 2H₂O.2DMF] ( 1 ), [Cu(tdb)(py)₂(H₂O)]₂ ( 3 ), and [Cu(tdb)(bipy)(H₂O)]₂ · 0.5H₂O ( 4 ) (tdb = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = 2,2′‐bipyridine) show that the metal ions are coordinated to the carboxylate oxygen atoms of the in situ generated tdb ligand in a monodenate fashion. In [Cu(phen)(SO₄)₂(H₂O)₂]_n ( 2 ) and [Cu(bipy)(SO₄)₂(H₂O)₂]_n ( 5 ), the sulfur is oxidized to sulfate ions prior to coordination with the metal. Complex 1 has a dimeric structure with π–π interactions between the phen ligands, whereas 3 and 4 form 1D polymeric chains.     

Mono-, di-, and trinuclear phosphonate oxygen-bridged copper(II) complexes: syntheses,structures, and properties

Reactions of copper salts, zoledronic acid, and 2,2′-bipyridine/1,10-phenanthroline in aqueous ethanolic solutions afforded four phosphonate oxygen-bridged copper complexes, Cu(bipy)(H₄zdn)(HSO₄) (1), [Cu₂(bipy)₂(H₂zdn)(H₂O)(Cl)]·4H₂O (2), [Cu₂(phen)₂(H₂zdn)(H₂O)(Cl)]·2.5H₂O (3), and [Cu₃(bipy)₃(H₄zdn)(H₂zdn)(SO₄)]·5H₂O (4) (H₅zdn = zoledronic acid, bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline). The copper centers of 1–4 have square pyramidal coordination geometries. The Cu(II) ions are coordinated to bipy/phen, zoledronate, and HSO₄^?/Cl^? forming mononuclear units for 1, dinuclear for 2 and 3, and trinuclear for 4. These building units are further extended into 3-D supramolecular networks via multiple hydrogen bond interactions. Temperature-dependent magnetic properties of 2 and 4 suggest weak antiferromagnetic coupling (J = ?4.53(8) cm^?1 for 2, J = ?1.69(4) cm^?1 for 4). The antitumor activity of 2 was evaluated against the human lung cancer cell line and indicates effective time- and dose-dependent cytotoxic effects.     

Ru-catalyzed highly enantioselective hydrogenation of α-keto Weinreb amides

Asymmetric hydrogenation of α-keto Weinreb amides has been realized with [Ru((S)-Sunphos)(benzene)Cl]Cl as the catalyst and CeCl 3·7H2O as the additive.A series of enantiopure α-hydroxy Weinreb amides(up to 97% ee) have been obtained.Catalytic amount of CeCl3·7H2O is essential for the high reactivity and enantioselectivity and the ratio of CeCl3·7H2O to [Ru((S)-Sunphos)(benzene)Cl]Cl plays an important role in the hydrogenation reaction.     

Three new binuclear copper(II) complexes with isonicotinic acid N-oxide: syntheses,crystal structures and properties

Three new copper(II) complexes with isonicotinic acid N-oxide (HL) and 1,10-phenanthroline (phen) as ligands, [Cu(L)(phen)(H₂O)]₂(NO₃)₂···2H₂O (1), [Cu(L)(phen)(H₂O)]₂(ClO₄)₂···2H₂O (2), and [Cu(L)(phen)Br]₂- [Cu(L)(phen)(H₂O)]₂Br₂···6H₂O (3) have been synthesized and structurally characterized. The structures of all three complexes feature a Cu₂ dimer formed by two Cu(II) ions interconnected by two bridging ligands. Each copper(II) ion has a distorted square pyramidal coordination geometry with elongated axial coordination by an aqua ligand or halogen anion. The isonicotinic acid N-oxide anion is bidentate, being coordinated to two Cu(II) ions through its N-O oxygen and one of its carboxylate oxygen atoms. Magnetic susceptibility measurements show a Curie–Weiss paramagnetic behavior characteristic of one unpaired electron for a copper(II) ion for all three complexes.     

Synthesis and application of a new copper(II) complex containing oflx and leof

Two new copper(II) complexes of [Cu(Ofloxacin)(phen)(H₂O)] · (NO₃) · 2H₂O and [Cu(Levofloxacin)(phen)(H₂O)] · (NO₃) · 2H₂O were obtained and their structures were studies. Both ligands and complexes were assayed against gram-positive and gram-negative bacteria by the in vitro doubling dilutions method. The inhibitory effect of the ligands and complexes on the leukemia HL-60 cell line were measured with the MTT assay method and the liver cancer HePG-2 cell line measured by the SRB method. The results indicated that the complexes have stronger inhibitory effect on HL-60 than on HePG-2. The complex [Cu(Levofloxacin)(phen)(H₂O)] · (NO₃) · 2H₂O (I) has stronger effect on HL-60 than the complex (Cu(Ofloxacin)(phen)(H₂O)] · (NO₃) · 2H₂O (II). The text was submitted by the authors in English.     

Synthesis,crystal structures,and fluorescence properties of (RS)-2-methylglutarato Zn(II), Cd(II) complexes

Reactions of fresh M(OH)₂ (M = Zn²⁺, Cd²⁺) precipitate and (RS)-2-methylglutaric acid (H₂MGL), 2,2′-bipyridine (bipy), or 1,10-phenanthroline (phen) in aqueous solution at 50°C afforded four new metal–organic complexes [Zn₂(bipy)₂(H₂O)₂(MGL)₂] (1), [Zn₂(phen)₂(H₂O)(MGL)₂] (2), [Cd(bipy)(H₂O)(MGL)] · 3H₂O (3), and [Cd(phen)(H₂O)(MGL)] · 2H₂O (4), which were characterized by single crystal X-ray diffraction, IR spectra, TG/DTA analysis as well as fluorescence spectra. In 1, the [Zn(bipy)(H₂O)]²⁺ moieties are linked by R- and S-2-methylglutarate anions to build up the centrosymmetric dinuclear [Zn₂(bipy)₂(H₂O)₂(MGL)₂] molecules. In 2, the 1-D ribbon-like chains [Zn₂(phen)₂(H₂O)(MGL)₂] _n can be visualized as from centrosymmetric dinuclear [Zn₂(phen)₂(H₂O)₂(MGL)₂] units sharing common aqua ligands. Both 3 and 4 exhibit 1-D chains resulting from [Cd(bipy)(H₂O)]²⁺ and [Cd(phen)(H₂O)]²⁺, respectively, bridged alternately by R- and S-2-methylglutarate anions in bis-chelating fashion. The intermolecular and interchain π···π stacking interactions form supramolecular assemblies in 1 and 1-D chains in 2–4 into 2-D layers. The hydrogen bonded lattice H₂O molecules are sandwiched between 2-D layers in 3 and 4. Fluorescence spectra of 1–4 exhibit LLCT π → π* transitions.     

Synthesis,characterization, and cytotoxicity of platinum(II)/palladium(II) complexes with 4-toluenesulfonyl-L-amino acid dianion and diimine/diamine

Eight new platinum(II)/palladium(II) complexes with 4-toluenesulfonyl-L-amino acid dianion and diimine/diamine ligands, [Pd(en)(Tsile)]·H₂O (1), [Pd(bipy)(Tsile)] (2), [Pd(bipy)(Tsthr)]·0.5H₂O (3), [Pd(phen)(Tsile)]·0.5H₂O (4), [Pd(phen)(Tsthr)]·H₂O (5), [Pd(bqu)(Tsthr)]·1.5H₂O (6), [Pt(en)(Tsser)] (7), and [Pt(en)(Tsphe)]·H₂O (8), have been synthesized and characterized by elemental analyses, ¹H NMR and mass spectrometry. The crystal structure of 7 has been determined by X-ray diffraction. Cytotoxicities were tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and sulforhodamine B assays. The complexes exert cytotoxicity against HL-60, Bel-7402, BGC-823, and KB cell lines with 4 having the best cytotoxicity against HL-60, Bel-7402, and BGC-823 cell lines; the compounds are less cytotoxic than cisplatin.     

Thermal investigation of some heterocyclic ligand complexes of tin(IV) in the solid state

1,10-phenanthroline (phen), 2,2′-bipyridyl (bipy), pyridine (py) and 4-picoline (4-pic) complexes of dibutyltindichloride (Bu₂SnCl₂) and dimethyltindichloride (Me₂SnCl₂) were synthesized. The complexes were characterized with the help of elemental analyses, IR spectra and thermal analyses. The complexes were found to have the compositions [Bu₂SnCl₂·phen], [Bu₂SnCl₂·bipy], [Me₂SnCl₂·phen], [Me₂SnCl₂·bipy], [Me₂SnCl₂·2py] and [Me₂SnCl₂·2(4-pic)]·H₂O. All these complex compounds appeared to posses octahedral structures. Thermodynamic parameters, such as activation energyE _a ^* enthalpy change ΔH and entropy change ΔS, for the dehydration and sublimation of the complexes were evaluated using some standard methods.     

Direct electrochemical synthesis and characterization of cobalt and nickel complexes with 2-pyridinone and 2-pyridinemethanethiol-1-oxide

Summary The electrochemical oxidation of anodic metals (nickel and cobalt) in MeCN solutions of 2-pyridinone (HOpy) or 2-pyridine methanethiol-1-oxide (HPMTO) or its dimer, 2,2′-dithiodimethyldipyridine-1,1′-dioxide (DPMTO), gives the simple complexes [Ni(Opy)₂]·2H₂O, [Co(Opy)₂]·2H₂O, [Ni(PMTO)₂]·2H₂O and [Co(PMTO)₂]·3H₂O. When 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) was added to the electrolytic phase, only three mixed complexes were obtained: [Ni(Opy)₂bipy]·H₂O, [Co·(Opy)₂phen]·H₂O and [Ni(Opy)₂phen]·5H₂O. The complexes were characterized by their elemental analyses, i.r. spectra and magnetic properties.     

Synthesis,characterization and crystal structures of Ni(II), Cd(II) complexes with N -(2-propionic acid)-salicyloyl hydrazone and bipy/phen

The ligand N-(2-propionic acid)-salicyloyl hydrazone(H₃L, 1) and its new transition metal(II) complexes [NiHL(bipy)H₂O] (2), [CdHL(bipy)(H₂O)₂]₂·2H₂O (3) and [NiHL(phen)H₂O]·H₂O (4) (HL is a dianion, bipy?=?2,2′-bipyridine and phen?=?1,10-phenanthroline) were synthesized and characterized on the basis of elemental analyses, IR, ¹H NMR, molar conductivity and thermal analysis. Single crystal X-ray diffraction showed that 1 is in keto form and connected by hydrogen bonds to form a two-dimensional supermolecular compound. Complexes 2 and 4 have the same structure with distorted meridional octahedral geometry with 1 as a tridentate ligand with keto-form coordination by azomethine, carboxyl O and acyl O. In 3, ligand 1 bridges two Cd(II) atoms by μ ₂-O of carboxyl. H-bonding is an important weak interaction for constructing supermolecular frameworks. There are π–π interactions between bipy or phen rings in 3 or 4, respectively.     

Anthraquinone‐2,6‐disulfonate as Versatile Ligand for the Synthesis of Hydrogen‐Bonded Supramolecules

The reactions of anthraquinone‐2,6‐disulfonic acid disodium salt (Na₂a‐2,6‐dad) with Cu^II, Mn^II, and Zn^II with 1,10‐phenanthroline (phen) or 2,2′‐dipyridyl (bipy) under hydrothermal conditions formed two or three‐dimensional supramolecules of stoichiometries [Cu(a‐2,6‐dad)(phen)(H₂O)₃](H₂O)₄ ( 1 ), [Mn(a‐2,6‐dad)(bipy)₂(H₂O)](H₂O)₂ ( 2 ), and [Zn(a‐2,6‐dad)(bipy)₂(H₂O)](H₂O)₂ ( 3 ), which were synthesized and characterized. The arrangement around each metal atom is distorted octahedral. The ligands in all the compounds are engaged in intermolecular hydrogen bonding leading to the formation of hydrogen‐bonded networks, the compounds show novel π–π stacking interactions. Photoluminescence measurements indicate that the compound [Zn(a‐2,6‐dad)(bipy)₂(H₂O)](H₂O)₂ ( 3 ) shows strong blue luminescence in the solid state at room temperature.     

Hydrothermal syntheses and characterization of cobalt(II) and nickel(II) complexes of 1,3-adamantanedicarboxylic acid and 1,10-phenanthroline

Two coordination complexes, namely [Co(phen)(H₂O)L]·H₂O and [Ni₂(phen)₂(H₂O)₂L₂]·4H₂O (phen = 1,10-phenanthroline, H₂L = 1,3-adamantanedicarboxylic acid) have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. [Co(phen)(H₂O)L]·H₂O consists of 1D chains of the complex plus lattice H₂O molecules. Interchain hydrogen bonds and π–π stacking interactions assemble the 1D chains into 2D layers. [Ni₂(phen)₂(H₂O)₂L₂]·4H₂O is a binuclear complex which is assembled into a 3D supramolecular structure by strong hydrogen bonds and π–π stacking interactions. Both complexes were characterized by physico-chemical and spectroscopic methods.     

Cucurbit[8]uril-based inclusion compounds containing iron(II), cobalt(III), and nickel(II) complexes with cyclam and cyclen as guest molecules: Synthesis and crystal structures

New inclusion compounds containing iron(II), cobalt(III), and nickel(II) complexes with the cyclic polyamine ligands cyclam and cyclen in the macrocyclic cavitand cucurbit[8]uril (CB[8]) were obtained: {trans-[Fe(Cyclam)(CO)(OCHO)]@CB[8]}Cl · 15H₂O, {cis-[Co(Cyclen)(H₂O)Cl]@CB[8]}Cl₂ · 20H₂O, and {cis-[Ni(Cyclen)(H₂O)Cl]@CB[8]}Cl · 12H₂O. According to X-ray diffraction data, the complexes are in the cavity of each CB[8] molecule. The complexes of the above molecular formulas were isolated in the solid state as supramolecular compounds with CB[8] and structurally characterized for the first time.     

Solvothermal Synthesis of New Luminescent Zinc(II) Coordination Polymers with One‐Dimensional Homochiral Structures

By using a dual‐ligand approach, two new homochiral zinc(II) coordination polymers, Zn₂(phen)₂(H₂O)₂(cam)₂ · ethanol ( 1 ) and Zn(bipy)(cam) ( 2 ) [phen = 1,10‐phenanthroline, bipy = 2,2′‐bipyridine, H₂cam = (1R,3S)‐(+)‐camphoric acid] have been synthesized under solvothermal conditions. Compound 1 has a zigzag chain‐like structure and compound 2 has a linear chain‐like structure. The two compounds exhibit intense photoluminescence upon photoexcitation at 280 and 290 nm, respectively.     

Positional isomeric and N-donor auxiliary chelating ligand effect on engineering crystalline architectures of four lead(II) complexes with diverse fluorescent properties

This work presents an investigation on the positions of the substituent and N-donor auxiliary chelating ligand (bipy/phen) effect on engineering of crystalline architectures of four Pb(II) complexes with a pair of methyl-substituted 3-sulfobenzoic isomers: [Pb(4-msba)(phen)(H₂O)] (1), [Pb(4-msba)(bipy)(H₂O)]·H₂O (2), [Pb(5-msba)(phen)₂]·9H₂O (3), and [Pb₂(5-msba)₂(bipy)₂(H₂O)₂] (4) (4/5-msba?=?4/5-methyl-3-sulfobenzoate, phen?=?1,10-phenanthroline and bipy?=?2,2′-bipyridine). The lead(II) ions exhibit hemidirected geometry in 1–4. The positions of the methyl as well as the auxiliary chelating ligands influence coordination modes of the sulfonates and thus determine the architectures. As the position of methyl in aromatic ring changes from 4 to 5, the structures change from 2-D sheet-like compounds for 1 and 2 to 0-D dimeric species for 3 and 4. A water cluster (H₂O)₁₈ exists in 3, which further assembles into a water tape with a new pattern T4(3)4(3)10(3)A4. Complex 3 loses crystallinity rapidly in the open air and turns into [Pb(5-msba)(phen)₂]·2H₂O (3A). Thermal stabilities and solid state fluorescent properties of 1, 2, 3A, and 4 have been studied.     

Tetranuclear and One‐dimensional Cobalt Complexes with 5‐tert‐Butyl Isophthalic Acid and Chelating Neutral Ligands

Two new Co^II coordination polymers [Co₄(tbip)₄(bipy)₄(H₂O)₄] ( 1 ) and [Co(tbip)(phen)(H₂O)] · H₂O ( 2 ) (H₂tbip = 5‐tert‐butyl isophthalic acid, bipy = 2,2′‐bipyridine, phen = 1,10‐phenanthroline) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 is a tbip‐bridged tetranuclear cobalt(II) complex, which is further linked by hydrogen bonds to form a supramolecular network. Compound 2 shows a tbip‐bridged linear chain structure, which is extended by hydrogen bonds to generate a double chain. Magnetic measurements show that there are weak ferromagnetic interactions between the adjacent Co^II ions in 1 .     

Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5-Chloro-1-phenyl-1H-pyrazole-3,4-dicarboxylic Acid

Five new transition metal complexes [Cu(HL)₂(H₂O)₂] ( 1 ), [Cu(HL)₂(phen)] ( 2 ), [Cu(HL)₂(H₂O)]₂(4,4′‐bipy) ( 3 ), [Zn(HL)₂(H₂O)₂]·(4,4′‐bipy) ( 4 ), [Ag(HL)(4,4′‐bipy)]_n ( 5 ), (H₂L=5‐chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid, phen=1,10‐phenanthroline; 4,4′‐bipy=4,4′‐bipyridine) have been synthesized and characterized. Complexes 1 , 2 and 4 exhibit monomeric structures, 3 shows a dinuclear structure, 5 displays 1D chain structure, and all extend to 3D supramolecular network via rich hydrogen bonds. Complexes 1 , 2 , 3 , 5 comprise single helical chains, while complex 4 generates quadruple‐stranded helical chains. Furthermore, the antibacterial activities of the titled complexes against bacterial species, three Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis and Candida albicans) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were studied and compared to the activities of free ligands by using the microdilution method.