Polymeric Coordination Complexes Research Articles

Scalable novel lanthanide-ligand complex for robust flexible micro-supercapacitors

Herein we report on the excellent, supercapacitor performance and flexible device application of a robust, new polymeric metal-ligand complex, which is readily synthesized at room temperature via a straightforward, one-step protocol using the N4 donor, namely 3,3′-diaminobenzidine (DAB) and gadolinium(III) nitrate. Thus, the coordination polymer (Gd-DAB) complex synthesized in a facile and economically feasible synthesis route paves the way for realizing a new class of affordable, durable energy devices for storage applications. The results of complementary characterization techniques not only corroborated the proposed structure but also revealed a potential two-dimensional (2D)/sheet-like organization similar to the coordination polymer (COP). The electrochemical tests performed on the as-prepared sample, in the form of an electrode active component, showed brilliant supercapacitive characteristics with the capacitive retention exceeding over 100% even after 5000 cycles. The complex has been used as an active media for the fabrication of an interdigitated flexible and symmetric supercapacitor. The electrochemical storage device evaluation, under different bending angles (up to 180o) and twisting conditions at the current density of 10 μA/cm2 for 5000 cycles, revealed the capacitive retention of ∼50% after 5000 cycles.

Syntheses, Characterization, and X-ray Crystal Structure of Mn(III) Coordination Polymer of 2-((2-Hydroxyethylimino) Methyl)-6-Methoxyphenol

The present investigation describes the synthesis of the ligand 2-((2-hydroxyethylimino)methyl)-6-methoxyphenol (H2L) and its complex of Mn(III) cation. The structure of the compound was elucidated by spectroscopic study and X-ray diffraction for the complex formulated as [{Mn(μ–HL)2}(C2N3)]n. The complex crystallizes in the monoclinic space group P21/n with the following unit cell parameters: a = 5.8172 (3) Å, b = 11.8695 (7) Å, c = 17.2616 (11) Å, b = 96.565 (6)°, V = 1178.57 (12) Å3, Z = 2, R1 = 0.0603 and wR2 = 0.1516. For this compound, the structure reveals that two monodeprotonated ligand interact with one Mn(III) in bidentate fashion while the third coordination site of the ligand interact with another Mn(III) of a neighboring unit. Thus, a polymeric coordination complex is obtained. The Mn(III) is hexacoordinated and the coordination environment can be described as slightly distorted octahedral geometry. Numerous hydrogen bonds link the molecules into three-dimensional network.

Polymeric coordination complex of lithium(I) with aqua and cyanurate ligands.

The polymeric title complex, poly[hexa-μ-aqua-diaquatetra-μ-cyanurato-tetralithium] [Li4(C3H2N3O3)4(H2O)7] n , synthesized at room temperature from an aqueous solution of lithium hydroxide and cyanuric chloride, crystallizes in the triclinic space group P . There are two distinct Li+ cations in the asymmetric unit, one of which, Li1, has distorted trigonal-bipyramidal geometry and is coordinated via oxygen to two cyanurate anions occupying equatorial positions, and three water mol-ecules, two in the axial positions and the third in an equatorial position. One of the axial water ligands and the equatorial water ligand are involved in bridging to a crystallographically equivalent Li1 cation. A centre of inversion lies between the two Li1 cations and the Li1⋯Li1 distance is 3.037 (5) Å. The remaining axial water ligand bridges to the second Li cation, Li2, which is disordered over two crystallographic sites with approximately equal occupancy, and has an Li1⋯Li2 distance of 3.438 (7) Å. The terminal Li2 cation is coordinated to three water mol-ecules and an oxygen atom from a cyanuric anion and has a distorted tetra-hedral geometry. A three-dimensional network of inter-molecular hydrogen bonds involving N-H⋯O, O-H⋯O and O-H⋯N inter-actions serves to hold the structure together. The title compound was further characterized using IR and UV-vis spectroscopy and TG-DTA analysis.

Cross‐linked poly(N‐vinylpyrrolidone)‐titanium tetrachloride complex: A novel stable solid TiCl4 equivalent as a recyclable polymeric Lewis acid catalyst for regioselective ring‐opening alcoholysis of epoxides

AbstractCross‐linked poly(N‐vinylpyrrolidone) resin beads were prepared as macromolecular ligand precursors by suspension copolymerization of N‐vinyl‐2‐pyrrolidone and N,N′‐methylenebisacrylamide (MBA) as a crosslinking agent in water. Subsequently, the resulting polymer carrier precursor was readily combined with titanium tetrachloride to form a stable polymeric coordination complex (PNVP/TiCl4), and this novel stable TiCl4 equivalent evaluated as a heterogeneous and reusable solid Lewis acid catalyst for the regio‐and stereoselective nucleophilic ring opening of various epoxides with various alcohols to prepare β‐alkoxy alcohols in excellent yields without generating any waste. The MBA‐cross‐linked PNVP and resultant catalyst were characterized by Fourier transform infrared spectroscopy (FT–IR), field‐emission scanning electron microscope (FE–SEM), energy dispersive X‐ray (EDX), inductively coupled plasma (ICP), and thermogravimetric analysis (TGA) techniques. Moreover, the catalyst is very stable, easily separated, and reused at least five times without significant loss of activity. In terms of scope, yields, the amount of catalyst used, and reaction time, the PNVP‐TiCl4 complex catalyst is an improvement over previously reported heterogeneous catalysts for ring opening of epoxides methods. Further, the experimental outcome revealed that using the copolymer beads as carriers with a high percentage of crosslinking and the high mesh size leads had an adverse effect on the reaction rate.

Synthesis, characterization and fluorescence properties of mixed-ligand cobalt(II), copper(II), zinc(II) and cadmium(II) coordination polymer complexes involving 4,4’-bipyridine and 2,5-pyridinedicarboxylic acid

Four mixed-ligand coordination polymer complexes of cobalt(II), copper(II), zinc(II), and cadmium(II) were synthesized by solvothermal method in 1:1:1 metal: 4,4’-bipy: 2,5-pdc molar ratio using 2,5-pyridinedicarboxylic acid (2,5-pdc) and 4,4’-bipyridine (4,4’-bipy). These complexes are viz; 1. [Co2(4,4'-bipy)(2,5-pdc)2(H2O)4]n 2. [Cu2(4,4'-bipy) (2,5-pdc)2]n 3. [Zn2(4,4'-bipy)(2,5-pdc)2(H2O)4]n and 4. [Cd3(4,4'-bipy)(2,5-pdc)2(OOCCH3)2(H2O)4]n.. All these complexes (1-4) have been characterized by elemental analyses (C,H,N), FT-IR-spectra, thermal analyses (TGA/DTA/DTG), fluorescence spectra and powder X-ray diffraction (PXRD) analyses to arrive at conclusion regarding their geometrical structure.

Base-catalyzed oxidation of poly (ethylene glycol) by alkaline permanganate: Part II. Kinetics and mechanistic of decomposition of coordination intermediate complex

The kinetics of decomposition of coordination polymer poly (ethylene glycol) intermediate complex [PEG-MnVIO42-] which was formed during the progression of the relatively fast first stage for the oxidation of poly (ethylene glycol) (PEG) by alkaline permanganate have been investigated by conventional spectrophotometer. Pseudo first -order condition in the presence of [PEG] substrate as a synthetic polymer in large excess over [MnO4-] was showed first-order overall reaction kinetics. The influence of the alkali concentration on the decomposition rate constants indicated that the oxidation rates were increased with increasing the alkali concentration, therefore, the decomposition process was considered of base-catalyzed nature. The rate constant of decomposition was found to be 2.3 x10-4 s−1, whereas the deprotonation constant was 2.88 dm3 mol−1 at 45 °C. The activation parameters have been calculated and found to be ΔH≠ = 34.93 kJmol−1; ΔS≠ = −176.2 Jmol-K−1 and ΔG≠ = 90.96 kJmol−1. The chemical structure of such synthesized acid-derivative of PEG was elucidated by elemental analysis and spectral data. The negative results of 2,4-dinitrophenyl hydrazine and hydroxylamine identified investigations along with (FTIR) spectra results indicated that the oxidation product is the acid derivative of poly (ethylene glycol) (ADPEG). The synthesis procedure of the acid-derivative of PEG (ADPEG) as the final oxidation product was described in detail. The product yield was found to be ~ 98%. It is found that the oxidation product (ADPEG) has a high tendency for chelation with most polyvalent metal ions in particularly the divalent metal ions forming their corresponding coordination polymer complexes. Therefore, this distinct property of the product renders it to be used as a chelating agent of high performance, non-toxicity and low cost compared with the chelating agents available in the markets. A suitable reaction mechanism for the decomposition in terms of electron-transfer nature was suggested and discussed.

Pressure-driven structural and spin-state transition in a Hofmann clathrate coordination polymer

Hofmann-type organometallic frameworks are well known for their porous crystal structure, exhibiting interesting electronic, optical, and magnetic properties, and are therefore considered as promising materials for various technological applications. Here, using density functional theory+U (DFT+U) calculations, we investigate the spin-state transition in a newly synthesized Hofmann clathrate, namely the Fe{OS(CH3)2}2{Ag(CN)2}2 complex, by applying hydrostatic pressure as an external perturbation. Our study reveals that under a relatively low isotropic hydrostatic pressure, the complex exhibits a reversible spin switching, whereas it undergoes a structural phase transition when the pressure is larger and anisotropic. The spin state of the Fe atom in the Hofmann clathrate complex transforms from high spin to intermediate spin state under anisotropic compression of the lattice parameters. The coordination polymer complex remains a magnetic semiconductor after the pressure-driven structural transformation.

Cu(II) coordination polymer bearing diazenyl-benzoic ligand: Synthesis, physico-chemical and XRD/HSA-interactions

New binuclear copper(II) complex [Cu2L2] zig-zag coordination polymer (CCP) have been synthesized via one-pot copper(II) acetate/(E)-2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoic dye through an in situ aqua doubly deprotonated ligand substitution reaction. The coordination polymer complex was characterized by spectroscopic and CHN-elemental analysis. The crystal structure has been specified by the XRD-method exhibiting that the Cu(II) center geometry is with five-coordinated distorted tetragonal pyramidal. The desired CCP structure chains are connected into a 2D-Supramolecular assembly via one C-H…O H-bond and enhanced by a π–π stacking interactions. These interconnections strengthened the lattice of CCP that originated the formation of super thermal CCP complexes. The fundamental vibrational wavenumbers and electron transfer in the free ligand are combined with the complex before and after coordination to demonstrate the spectral behavior of L−2 in the desired zig-zag CCP. The 2D-fingerprint (2D-FP) and Hirshfeld surface analysis (HSA) computations were served to prove the 2D-network packed crystal lattice interactions.

Synthesis, characterization, reactivity, and catalytic studies of heterobimetallic vanadium(V) complexes containing hydrazone ligands

Six heterobimetallic alkali metal dioxidovanadium(V) coordination polymer complexes {[M6{VO(μ-O)}2(μ-OH)4(μ4-slox/nph)].n DMF}∞ where M = Na, K, and Cs; n = 1 for (1), 0 for (2)-(6) of two dihydrazone ligands, disalicylaldehydeoxaloyldihydrazone (H4slox) and bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (H4nph) are reported. All the complexes have been characterized by various physicochemical techniques such as elemental analyses, molar conductance, IR, NMR, UV–vis, and cyclic voltammetry. The IR, 1HNMR, and 13CNMR spectral data suggest that the dihydrazones are coordinated through phenolate/naphtholate oxygen, enolate oxygen, and azine nitrogen atoms to the metal centres. The structure of complex {[Na6{VO(μ-O)}2(μ-OH)4(μ4-slox)].DMF}∞ (1) is also determined by single-crystal X-ray data, which revealed that the H4slox coordinated via all possible dative sites to metal centres as tetrabasic octadentate ligand. The vanadium metal centres adopted distorted square-pyramidal coordination geometries, and the sodium atoms are also in five coordination atmospheres. The electronic spectra of the complexes showed LMCT bands in addition to intra-ligand π → π* and n → π* transitions. As evident from the cyclic voltammetry, the complexes showed two metal-centred electron transfer reactions {[(VVVV(slox)2−/VVVIV(slox)3−] and [(VVVIV(slox)3−/VVVIV(slox)4−]}, in addition to the ligand centred electron transfer reactions. Further, bovine serum albumin (BSA interaction studies of the complexes {[Na6{VO(μ-O)}2(μ-OH)4(μ4-slox)].DMF}∞ (1) and [Na6{VO(μ-O)}2(μ-OH)4(μ4-nph)]∞ (4) revealed strong binding affinity. Moreover, the catalytic studies of the complexes (1) and (4) were found to be effective for the oxidation of alcohols into their corresponding aldehydes and ketones and bromination of some organic substrates in the presence of H2O2 as an oxidizing agent.

Electrocrystallization, structural and physicochemical characterization of a novel copper(II) dinuclear paddle-wheel complex with sulindac, [Cu2(Suln)4]∙3H2O

The electrocrystallization, structural and magnetic characterization of a copper(II) complex with the anti-inflammatory drug sulindac [HSuln = 2-[(3Z)-6-fluoro-2-methyl-3-[(4-methylsulfanylphenyl)methylidene]inden-1-yl]acetic acid], with formula [Cu2(C20H16FO3S)4]∙3H2O, is reported. Single crystals were grown directly on the surface of a sacrificial copper wire and were suitable for X-ray diffraction analysis. The complex is a 1D polymeric coordination complex consisting of paddlewheel moieties, formed by four sulindacate units bridging two copper(II) ions, and three disordered water molecules occupying the voids in the unit cell, with axially connected units through the neighboring sulfinyl oxygen atom located in the phenyl moiety. The complex presents a strong antiferromagnetic exchange interaction. Variable temperature magnetic susceptibility displays an unusual increase in the magnetic moment with decreasing temperature from 60 to 30 K, which may be indicative of the presence of a small amount of a monomeric Cu(II) species or traces of molecular oxygen. The product was additionally characterized by FTIR, UV–Vis spectroscopy, and TGA/DTA-DSC.

Similarities of Coordination Polymer and Dimeric Complex of Europium(III) with Joint and Separate Terpyridine and Benzoate

A dimeric complex of trivalent europium [Eu2Cl4(bc)2(ptpy)2] (1), containing the separate ligands 4'‐phenyl‐2,2':6',2''‐terpyridine (ptpy) and benzoate (bc–) and a one‐dimensional double strand coordination polymer of the composition 1∞[EuCl2(cptpy)] (2) with 4‐[2,2':6',2''‐terpyridin]‐4'‐yl‐benzoate (cptpy–) were obtained. The products exhibit structural similarities despite the character of joint and separate functionality of the ligands. The dimer 1 shows photoluminescence with high quantum yield [61(2) %]. Eu3+ emission lifetime is 1.493(1) ms at room temperature and rises to 1.649(1) ms upon cooling to 77 K.

Synthesis, characterization, crystal structure, Hirshfeld surface analysis and spectroscopic properties of bis(5-aminoisophthalato)bispicolinecopper (II)

The 2D coordination polymer of Cu(II), [Cu(5-aip) (3-pic)2]n (5-aip = 5-aminoisophthalato, 3-pic = 3-picoline) was characterized by elemental analysis, FT-IR and UV–Vis spectroscopy and single crystal XRD techniques. The X-ray single crystal data revealed that the polymeric coordination complex crystallizes in the monoclinic system with P21/n space group and Cu(II) ion has five (square pyramidal) coordination number. X-ray diffraction analysis show that Cu(II) has a distorted square pyramidal geometry with τ = (175.75–160.0)/60) = 0.2625. Hirshfeld surface analysis was carried out, which reveals the nature of intermolecular contacts, the fingerprint plots and molecular surface contours (dnorm, di and de) provide the information about the percentage contributions [H⋯H (40.5%), C⋯H (29.2%), Cu⋯O (4.7%), N⋯H (4.9%), N⋯O (1.5%) and O⋯H (17.4%)] and revealed them major and minor contributions of the bond interactions for [Cu(5-aip) (3-pic)2]n complex. According to UV–Vis spectrum, d-d transition observed at 712 nm (ε = 65 dm3mol−1cm−1) which is assigned to the dz2 (a1)→dx2-y2 (b1) transition. Thermogravimetric analysis was carried out to fallow the thermal stability of the complex.

Photoluminescence studies of copolymer metal complexes with 8-hydroxyquinoline, hexamethylenediamine and formaldehyde

This current research article provides the information on the synthesis of 8-HQHMDAF resinous copolymer and co-polymeric metal complexes prepared from it. 8-HQHMDAF resinous copolymer was incorporated withformaldehydethroughrefluxed-condensationof8-hydroxyquinolineand1, 6-diamino hexane in fixed molar ratio for 5 hrs using two molar acidic catalyst that is hydrochloride. Reaction maintained at 124 ± 2 0C constant temperatures. The newly developed copolymer 8-HQHMDAF resin functioned as ligands to form co-ordination polymer complex in a molar ratio of 2:1 with three transition metal ions Cu2+, Ni2+ and Zn2+. The reaction conducted for 3hrs with an efficient reflux maintained at 60 °C temp. Elemental composition of 8-HQHMDAF-M copolymeric metal complexes was analyzed by elemental analysis method. FT-IR and 1H NMR Spectroscopic technique describe the structure of 8-HQHMDAF-M complex. The photoluminescence properties of newly synthesized copolymer metal complex samples were recorded on RF-501 (PC) S CE (LVD) MODEL PL spectrometer is used to records the photoluminescence spectra of synthesized copolymer metal complexes of three transition metal ion. Aim of the whole current study is the development new polymeric metal complexes to investigate its photo luminescent property and significant contributions from active researchers in the field.

1-D copper(I) coordination polymer based on bidentate 1,3-dithioether ligand: Novel catalyst for azide-alkyne-cycloaddition (AAC) reaction

A novel 1,3-bis(4-fluorophenylthio)-propane ligand based CuI 1-D polymeric coordination complex having formula ([(CuI)2{ArS(CH2)3SAr}2]n, Ar = 4-F-C6H4) has been synthesized and characterized by 1H NMR, 13C NMR and single crystal XRD techniques. This complex has been employed for the first time as suitable catalyst for base-free one-pot three-component regioselective azide-alkyne cycloaddition (AAC) reaction. A novel 1,2,3-triazole compound with sulfur functionalized pendant arms has also been prepared using our catalytic system in a multicomponent manner via one-pot two-step reaction.

Synthesis, characterization and H2 adsorption performances of polymeric Co(II) and Ni(II) complexes of pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole

We studied the synthesis and characterization of polymeric coordination complexes of Co(II) and Ni(II) ions with pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole. The e lemental analysis, infrared spectroscopy, powder X-ray diffraction, magnetic susceptibility, thermal analysis and X-ray single crystal techniques were used in the characterization. The X-ray single crystal analysis suggests that the pyrazine-2,3-dicarboxylato ligand acts as a bridging ligand through the oxygen atoms of the carboxylate groups and the nitrogen atoms on the pyrazine ring. The 1-vinylimidazole ligand behaves as a monodentate ligand via the ring nitrogen atom. Further, the H2 adsorption studies were carried out at 75 K for various increasing pressures and the highest H2 adsorption performances for Co(II) and Ni(II) complexes were estimated as 2.66 and 2.99 wt% at 87 bar. The theoretical calculations using the crystal data were also performed to determine the voids in the structure of Co(II) complex.

A novel zinc(II) complex containing square pyramidal, octahedral and tetrahedral geometries on the same polymeric chain constructed from pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole

In this study, a novel Zn(II) complex of pyrazine-2,3-dicarboxylic acid and 1-vinylimidazole was synthesized and fully characterized by elemental analysis, IR spectroscopy, thermal analysis, X-ray powder diffraction, and X-ray single crystal techniques. The X-ray single crystal data revealed that the polymeric coordination complex crystallizes in the monoclinic system with C2 space group and shows a peculiar feature as having the Zn(II) ions with four (tetrahedral), five (square pyramidal) and six (octahedral) coordination numbers on the same polymeric chain. In the complex, the pyrazine-2,3-dicarboxylato ligand acts as a bridging ligand via the ring nitrogen atoms and the carboxyl oxygen atoms while the 1-vinylimidazole ligand coordinates to the metal ion as monodentate via the ring nitrogen atom. In addition, the surface area and hydrogen adsorption studies were carried out and it was found that the complex has a small BET surface area but it can adsorb considerable amount of hydrogen gas at different pressures. Further, the accessible surface area and free volume of the Zn(II) complex were calculated at a Connolly diameter of 0.8 Å by the Grand Canonical Monte Carlo simulation. Synopsis A novel Zn(II) complex including square pyramidal, octahedral and tetrahedral geometries on the same polymeric chain was synthesized using pyrazine-2,3-dicarboxylic acid as a bridging ligand and 1-vinylimidazole as a second ligand, structurally characterized by spectroscopy, thermal analysis and crystallography studies, and investigated for hydrogen adsorption performance.

Sonochemical synthesis of two novel Pb(II) 2D metal coordination polymer complexes: New precursor for facile fabrication of lead(II) oxide/bromide micro-nanostructures

Two new lead(II) coordination polymer complexes (CSCs) (2D), [Pb2(L)2(Br)2]n·H2O (1), [Pb2(HL/)(L/)(H2O)2]n·H2O (2), where L = C6H5NO2 (2-pyridinecarboxylic acid) and L/ = C9H6O6 (1,3,5-tricarboxylic acid), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or microsized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on complexes 1 and 2 shows that Pb2+ ions are 8-coordinated, 7 and 9-coordinated, respectively. Topological analysis shows that the compound 1 and 2 are 4,6L26 and bnn net, respectively. However, neither the shape nor the morphology is maintained, showing the role of sonochemistry to modulate both morphology and dimensions of the resulting crystalline material, independently of whether we have a 2D coordination polymer (CP). Finally, micro structuration of lead(II) bromide oxide and lead(II) oxide have been prepared by calcination of two different lead (II) CPs at 700 °C that were characterized by SEM and XRD.

Synthesis, characterization, and hydrogen storage capacities of polymeric squaric acid complexes containing 1-vinylimidazole

In this work, three new polymeric coordination complexes were synthesized using squaric acid and 1-vinylimidazole. The structures of the coordination polymers, formed with Co(II), Zn(II), and Cd(II) ions, were characterized by elemental analysis, infrared spectroscopy (IR), thermal analysis (Thermogravimetry, TG; Derivative Thermogravimetry, DTG; Differential Scanning Calorimetry, DSC), magnetic susceptibility, X-ray powder diffraction, and X-ray single crystal techniques. The X-ray single crystal method showed that the squarato ligand behaves as bis(monodentate) via the oxygen atoms in μ1,3-mode and 1-vinylimidazole coordinates to the metal ion via the ring nitrogen atom as monodentate in the complexes. The central ions in the complexes obtained as single crystal exhibited slightly distorted octahedral geometries. The surface areas and hydrogen storage capacities of the synthesized complexes were also examined.

The development of a promising photosensitive Schottky barrier diode using a novel Cd(ii) based coordination polymer.

A novel 1D Cd(ii) based coordination polymer (complex 1) has been synthesized involving an 8-aminoquinoline based Schiff base ligand and cyanate ion. It has been characterized by elemental analysis, different spectroscopy methods and X-ray single crystal diffraction technique. Most interestingly it exhibits unique properties like electrical conductivity and photosensitivity which shows its potential in optoelectronic device application. We prove both experimentally and theoretically that electrical conduction under irradiation of visible light increases many fold in comparison with that under dark condition. Our synthesized material based device shows some paramount behaviour under irradiance of light which is obvious in light sensing Schottky devices. The rectification ratio of our complex based device was found to be 12.44 and 27.74 under dark and photoirradiation conditions respectively. The discovery of such type of coordination polymer advances the area of optoelectronic devices.

Synthesis, crystal structure, stability studies, DNA/albumin interactions, and antimicrobial activities of two Cu(II) complexes with amino acids and 5-nitro-1,10-phenanthroline

One-dimensional (1-D) coordination polymer and mononuclear copper(II) complexes, ([Cu(nphen)(asn)]ClO4)n (1) and [Cu(nphen)(gln)(H2O)]ClO4·H2O (2) (nphen = 5-nitro-110-phenanthroline, asn = asparagine, gln = glutamine), have been synthesized and characterized by IR spectroscopy, ESI-MS, CHN analysis, and single-crystal X-ray diffraction. These binary and ternary complexes of copper(II) with nphen, asn, and gln have been investigated using potentiometric methods in 0.1 M KCl aqueous ionic media at 298.2 K. The protonation constants of the ligands and the stability constants of 1 and 2 have been calculated from the potentiometric data using the “BEST” software package. The potentiometric results have been analyzed using the “SPE” software package, and the distribution curves for the copper-containing species have been determined for the ternary systems. The CT-DNA-binding properties of these complexes have been investigated by thermal denaturation measurements and both absorption and emission spectroscopy. Further, the interaction of these complexes with bovine serum albumin (BSA) and human serum albumin (HSA) has been investigated using absorption and emission spectroscopy. The thermodynamic parameters, free energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS) were calculated by the van’t Hoff equation and discussed. The distances between the serum albumins and 1 and 2 have been obtained according to fluorescence resonance energy transfer (FRET). Conformational changes of serum albumins have been observed from synchronous fluorescence technique. The antimicrobial activity of the complexes has also been tested on some bacteria. The effect of different amino acids on the copper(II) complexes are discussed.