Mixed-ligand Copper Complexes Research Articles

Synthesis, Characterization, DFT calculations and molecular Docking study of Novel Copper mixed ligands complex on Drosophila melanogaster for insecticidal properties

In this study, the novel mixed ligand complex of copper is prepared from (Z)-N’-((E)-2-hydroxy-3,5-diiodobenzylidene)-N,N-dimethylcarbamohydrazono-thioic acid schiff base(H2L)and 2,2’-bypyridine. The characterization has been done by NMR, elemental analysis, IR and HRMS. Computation calculations based on DFT showed that the HOMO-LUMO energy gap is -5.81 eV for ligand and -5.53 eV for the Cu(II) complex and the [Cu(L)(bipy)] is having square pyramidal geometry. The binding energy values obtained from the molecular docking with acetylcholinesterase enzymes of Drosophila melanogaster for ligand (H2L) and [Cu(L)(bipy)] are -6.8 and -7.4 (kcal/mol) respectively. These values showed that the ligand (H2L) and [Cu(L)(bipy)] are having affinity for the target enzyme.

Synthesis of Cu(II)-Caffeine Complex as potential therapeutic Agent: Studies on Antioxidant, anticancer and pharmacological activities

In this present article, we have synthesized a new mono-nuclear mixed-ligand complex of copper(II) with bypyridine (byp, ligand1), caffeine (caf, ligand2) and thiocyanate (thcy, ligand3). This mixed-ligand complex with caf as the secondary ligand has the ratio of metal: ligand1: ligand2: ligand3 is 1:1:2:2 and has the formula [Cu(byp)(Caf)2(SCN)2] (denoted as Complex A). Structure of Complex A was established from the UV spectra, FTIR, mass and the thermal analysis data. The donor sites of the ligands were ascertained from the changes in the values of ν(SCN) of thiocyanate, ν(C − N1) of bypyridine, ν(C − O) of carboxylic and ν(C − N9) of caffeine. Complex A has shown potential SOD-like activity as a good antioxidant agent and with that it shows in-vitro antibacterial efficiency and anti-cancer activity against colorectal adenocarcinoma (Caco-2) and breast cancer (Mcf-7) cell lines. The present study confirms that Complex A has immense potential as an effective cytotoxic agent against human colorectal adenocarcinoma and breast cancer diseases.

Mixed-ligand complexes of copper(II) with 1, 10’-Phenanthroline and amino acids

ABSTRACT The speciation of the ternary systems formed by copper(II), 1,10’-Phenanthroline (Phen) and the amino acids: Histidine (HHis, HL), Arginine (HArg, HL), Lysine (HLys, HL), Aspartic acid (H2Asp, H2L), Glutamic acid (H2Glu, H2L) and Tyrosine (H2Tyr, H2L) was studied by means of emf(H) electromotive force measurements in aqueous solution at 25°C using 1.0 mol.dm−3 KNO3 as the ionic medium. The data obtained through potentiometric measurements were analysed using the computer program generalised least-squares LETAGROP. The species distribution diagrams as a function of pH were briefly discussed. The stability of the ternary complexes was compared with the corresponding one of the binary complexes in terms of ∆log K and % R.S. Spectrophotometric studies, UV-vis absorption and circular dichroism (CD), were employed to analyse the coordination modes of the ligands, the adopted geometry, and the stability of the major ternary complexes present in solution

Copper(II) complexes as novel anticancer drug: Synthesis, spectral studies, crystal structures, in silico molecular docking and cytotoxicity

Three novel mixed ligand complexes of copper, derived from the parent cyclohexylthiosemicarbazones were synthesized along with the secondary ligands such as 2-picoline and 5,5’-dimethylbipyridine. They are characterised by elemental analysis, spectroscopic techniques (IR, UV-vis) and X-ray crystallography. The single crystal X-ray structure showed that the complex 1 is having distorted square pyramidal geometry and complex 2 is having distorted square planar geometry. The complex 3 is a 1D polymer. The interaction of complexes with CT-DNA was studied by absorption spectral titration and fluorescent measurements. The observed data shows that the complexes bind with CT-DNA via an intercalative mode of binding. Efficient PTZ57R (bp: 2886) cleavage ability of the synthesized compounds were explored by gel electrophoresis. Molecular docking studies of the Cu(II) complexes with corresponding DNA protein were carried out. An in vitro cytotoxicity study of the complex was carried out against MDA-MB-231 breast cancer cell line.

Mixed-ligand complexes of copper(ii) with thienoyltrifluoroacetonate and nitrogen containing ligands: synthesis, structures, antimicrobial activity, cytotoxicity, Hirshfeld surface analysis and DFT studies.

Mixed-ligand complexes of copper(ii) with thienoyltrifluoroacetonate (TTA-H), 2,2′-bipyridine (bipy), 1,10-phenanthroline (phen), and tetramethylethylenediamine (tmen), associated with counter ions such as Cl−, and NO3− have been synthesized and characterized by molar conductance measurements, elemental analysis, mass spectrometry, IR and UV-Vis spectroscopy, antimicrobial activity, cytotoxicity assay studies, and single-crystal X-ray diffraction. The UV-Vis spectra and crystal structures are consistent with the adoption of square pyramidal geometry for all of the complexes except [Cu(TTA)tmen]NO3 and [Cu(TTA)2tmen] which have square planar and octahedral geometries, respectively. Conductance measurements of the mixed-ligand complexes indicated that they were all non-electrolytes, with the ligands and anions being coordinated to Cu except [Cu(TTA)tmen]NO3 which is a 1 : 1 electrolyte. All of the complexes were moderately active on all the fungi tested (Candida albicans, Aspergillus niger, Penicillium notatum, Rhizopus stolonifer) except [Cu(TTA)bipyCl] which showed increased activity in Candida albicans and Aspergillus niger. All of the compounds tested showed LC50 values greater than 100 with [Cu(TTA)(phen)NO3] being the least toxic of the compounds. Molecular geometries of the complexes were optimized at the PBE1PBE/def2SVP and PBE1PBE/6-311g(d,p) level of theory and the results were compared with the single-crystal X-ray diffraction data. Electronic properties such as HOMO, LUMO, HOMO–LUMO gaps and global reactivity descriptors are reported at the PBE1PBE/6-311g(d,p) level of theory. Hirshfeld surface analysis was carried out to investigate the cooperative non-covalent supramolecular interactions within the various complexes.

Synthesis and Characterization of Mixed Ligand Complexes of Copper(II) with Adenine and Dicarboxylic Acids

Three mixed ligand complexes of copper(II) with adenine and dicarboxylic acids have been synthesized. The resulting complexes were characterized by their melting point, solubility, metal content analysis, FT-IR and UV-visible spectroscopy, magnetic measurement, thermal analysis, cyclic voltammetric measurement and X-ray powder diffraction study. The products are microcrystalline powder, slightly soluble in water and decompose at high temperature. Under experimental condition, the ligands adenine (Ade) behaves as a neutral ligand, whereas oxalic acid (OxH2), succinic acid (SucH2) and tartaric acid (TarH2) are doubly deprotonated to form dianionic ligands that are coordinated to the Cu(II) ion. The Cu(II) content analysis of the complexes confine to their stoichiometry [Cu(Ade)(L)(H2O)] (L = Ox, Suc, or Tar dianion). Electrochemical redox behavior of the complexes in their reaction medium was also examined. They exhibit quasi-reversible one-electron transfer processes. Dhaka Univ. J. Sci. 69(2): 76-81, 2021 (July)

Mixed ligand complexes of copper(II) with benzoyltrifluoroacetone, 1,10-phenanthroline and 2,2′-bipyridine: Structure, spectroscopic and antimicrobial properties

Mixed ligand copper(II) complexes of Benzoyltrifluoroacetone (BTAH) with 1,10-phenanthroline (Phen) and 2,2′-bipyridine (Bipy) were synthesized and characterized. These complexes, namely [Cu(BTA)(Phen)(NO3)] (1), [Cu(BTA)(Phen)Cl] (2), [Cu(BTA)(Bipy)(NO3)] (3), [Cu(BTA)(Bipy)Cl] (4), and [Cu(BTA)(Phen)Br]•H2O (5), were characterized by elemental analysis; spectral; magnetic and molar conductance measurements; mass spectrometry; thermal analysis and antimicrobial susceptibility testing. The structures of 1 and 4 contained square pyramidal copper(II) environments. The microbiostatic activity revealed that the copper complexes showed pronounced activity in all the tested bacteria, except in Klebsiella pneumonia, Escherichia coli and Salmonella enterica in which some of the complexes were moderately active on the bacterial strains.

Potentiometric, thermodynamics and coordination properties for binary and mixed ligand complexes of copper(II) with cephradine antibiotic and some N- and O-bound amino acids (α-alanine and β-alanine)

As a model for forecasting the ligand properties of antibiotics in living organisms, formation equilibria of binary and ternary Cu(II) complex with Cephradine (Cep) antibiotic in presence of α-alanine (α-Ala) and β-alanine (β-Ala) amino acids have been studied using the potentiometric titrations. Many factors were investigated like the formation constant, protonation constant, composition and stabilities of the species formed with copper(II) ions in water and water-ethanol solutions of different compositions. The thermodynamics were calculated and the data clarified. The pH-titrations of the reaction mixtures have been revealed 1:1:1 (Cu:Cep:amino acid (AA)) ternary complex formation. By aid of Δ log10K, Δ log10β and log10X parameters, quantitative matching of the stability of mixed-ligand complexes and the stability of the binary complexes was done. Investigations of the stability of the ternary complexes relative to their corresponding binary complexes indicated that formation of ternary complexes is more preferable than binary metal complexes. The obtained data from protonation of the investigated cephradine antibiotic and β-Ala/α-Ala amino acids and their complex formation equilibria will be a significant contribution to workers carrying out mechanistic studies in biological media.

Identification of cytotoxic copper(II) complexes with phenanthroline and quinoline, quinoxaline or quinazoline-derived mixed ligands

A series of mixed ligand copper(II) complexes, formulated as [Cu(L1-L5)(phen)(H2O)](ClO4)2 (1–5), where phen = 1,10-phenanthroline, L1 = 2-pyridin-2-yl-quinoline, L2 = 2-pyridin-2-yl-quinoxaline, L3 = 6,7-dimethyl-2-pyridin-2-yl-quinoxaline, L4 = 4-phenyl-2-pyridin-2-yl-quinoline, and L5 = 4-phenyl-2-pyridin-2-yl-quinazoline, were synthesized and characterized. The molecular structure of 3, which alone formed into appreciable crystals, was determined by single-crystal X-ray studies, and the coordination geometry around Cu(II) was nearly square pyramidal (τ, 0.092). DNA and protein binding, DNA cleavage and in vitro cytotoxicity of the mixed ligand complexes 1–5 were investigated and compared with their analogue bis-complexes [Cu(L1-L5)2H2O](ClO4)26–10. All five mixed ligand complexes exhibited efficient DNA and protein binding, wherein 5 was the most potent. DNA cleavage studies revealed that all mixed ligand complexes engage in self-activated DNA cleavage, with 2 producing full conversion of supercoiled DNA to nicked circular form. Complex 5, with the highest DNA- and protein-binding efficiencies, demonstrated the highest cytotoxicity to A549 non-small human lung carcinoma cell (IC50 = 3.85 μM), three times more potent than cisplatin. Metal-assisted reactive oxygen species (ROS) were found to be responsible for cytotoxicity of the complexes. Fluorescent staining assays showed that all complexes induce apoptotic cell death along with some degree of necrosis. Western blot analysis of caspase-3 expression of cells exposed to Cu(II) complexes 1 and 5 revealed that both promote apoptosis, with 5 demonstrating more potency. Thus, the mixed ligand copper complexes demonstrated efficient biological activity compared to bis-complexes, with 5 holding promise for future investigation towards development as a cancer therapeutic.

Synthesis of the Three Mixed-ligand Metal Complexes and One Organic Salt of 3,5-Dinitrobenzoic Acid for Biopharmaceutical Optimization Through Monoethanolamine: Structures and DFT Studies of Complexes

The simplest derivatives of benzoic acid show a wide spectrum of the biological action mostly being poor water soluble. In order to demonstrate on example of 3,5-dinitrobenzoic acid (DNBA) a possibility of the simultaneous enhancement of water solubility and antimicrobial activity the complexation (salt formation and metal coordination) approach has been examined. Monoethanolamine (MEA) is selected as the complexing agent. Three isomorphic mixed-ligand complexes of Cu, Ni, Co with DNBA and MEA as well one organic salt in the polymorphic form have been synthesized and their structures are characterized by the element analysis, FTIR and X-ray crystallography. Measurements of water solubility and determination of the antimicrobial activity attest that a solubility of the copper mixed-ligand complex and organic salt is increased about four and eight times with simultaneous enhancement of the bioactivity. The DFT studies by B3LYP/def2-TZVP and B3LYP/6-311G (d,p) showed that Cu, Ni, and Co complexes with DNBA and MEA have high-spin ground electronic states as a doublet, triplet and quartet, respectively. Calculated bond lengths and bond angles of all metal complexes in higher-spin ground electronic states are in good agreement (about R2 = 0.97) with X-ray data. Additionally, the energies of the frontier MOs and frontier electron densities and also electrostatic potential of isostructural complexes have been analyzed by the DFT/6-311G(d,p) method. The water solubility and bioactivity of poorly soluble 3,5-dinitrobenzoic acid are enhanced by a preparation of three isostructural metal complexes and one polymorphic organic salt with participation of monoethanolamine and DFT study of metal complexes has been carried out.

The Digestibility of feed and productivity of young fattening pigs when using mixed-ligand complexes of copper

The balancing research has shown that there are certain changes in the body of young pigs for fattening under the infl uence of consumed feed and feed additives. During the balance experiment on pigs for fattening, the protein, fat and carbohydrate digestibility ratios and the nitrogen balance were studied. The digestibility and absorption of nutrients of the feed are infl uenced by many factors such as animal species, age, physiological state, feed type, method of retention, ratio and size of components, individual characteristics and others. The relationship between digestion and nutrient uptake in young pigs for fattening under the infl uence of Copper sulphate and the mixed-ligand complex of Copper added to the compound feed in diff erent quantities was investigated. The optimal dose of Copper in the compound feed for pig fattening pigs was established for feeding diff erent levels and sources of Copper. According to the results of the balance experiment, the best indices of the digestibility of nutrients were found in animals, the dose of the mixed-ligand complex of Copper in the compound feed was 21.2 g/t. With this dose of Copper chelate, the rate of digestibility of organic substances was 85.4 %, crude protein – 79.3 %, crude fat – 68.1 %, crude fi ber– 41.8 % and nitrogen-free extractives – 90.5 %, which exceeded control analogues, respectively, by 1.5%, 3.4; 2,7; 9.7 and 1.1 %. It was also found that the highest levels of Nitrogen uptake were observed in the animals of the experimental groups fed the Copper chelate in the amounts of 21.2 and 15.4 g/t respectively – 54.4 % and 54.3 %, respectively, by 9.9 % (p≤0.05) and 9.7 % higher compared to control animals. The impact of diff erent doses of mixed-ligand complex of Copper had an eff ect on the growth rates of animals, as evidenced by the results of live weight of pigs. The animals of the 4th and 5th experimental groups had the highest live weight, which fed the Copper bathrobe in the amount of 21.2 and 15.4 g/t of compound feed, which covered the Copper defi cit in the diet by 55 % and 40 %. Animals of these groups at the age of 150 days had a live weight of 2.3 % and 1.9 % more, respectively, compared to the same indicator in the control group. And at the age of 180 days pigs of the 4th experimental group were dominated by analogues of control by 3.8 %, and by 5th – by 3.3 %. Therefore, the results of the studies indicate a positive eff ect of the addition of organic-mineral origin of the mixed-ligand complex of Copper on the growth and development of young pigs on fattening. Key words: live weight, digestibility coeffi cient, pigs, fattening, organic substances, protein, fat, fi ber, Copper.

Physicochemical and non-linear optical studies of mixed ligand Cu(I), Fe(II) and Ru(II) complexes containing triphenylphosphine and a Schiff base derived from furfural and hydrazine hydrate

Abstract Mixed ligand complexes of Copper, Iron and Ruthenium containing triphenylphosphine and a simple Schiff base made up of furfural and hydrazine hydrate have been synthesized and characterized by their UV, IR, NMR, elemental analysis and magnetic susceptibility measurements. The characterization techniques suggest that the copper complex exhibits four coordinated square planar geometry, the iron complex exhibits a five coordinated square pyramidal geometry and the ruthenium complex exhibits a six coordinated octahedral geometry. The monomeric nature of the complex is assessed from their magnetic susceptibility values. The third-order nonlinear optical parameters of the complex were investigated by Z-scan technique. Nonlinear transmission measurements carried out using nanosecond laser pulses at 532 nm show that the complexes can be used as potential optical limiters.

Thermodynamics of Mixed Ligand Complex Formation of Copper(II) and Nickel Ions with Glycine and Histidine in Solution

Mixed ligand complexes of copper(II) and nickel(II) with glycine (Gly) and histidine (His) have been studied in aqueous solution using calorimetric, potentiometric and spectrophotometric data at 298.15 K and the ionic strength of I = 0.5 mol·L–1 (KNO3). The thermodynamic parameters of formation of various mixed complexes have been determined. The probable coordination modes of amino acid residues in mixed ligand complexes is discussed.

Mixed-ligand copper complexes with unsymmetrical tridentate Schiff base ligands and 2,2′-bipyridine: Synthesis, x-ray crystallography and antibacterial properties

Three new mixed-ligand Cu(II) complexes with general formula [CuLx(2,2′-bipyridine)]ClO4 (x = 1–3) where synthesized and characterized by x-ray crystallography, elemental analyses, and spectroscopic techniques such as FTIR and UV–Vis spectroscopy. The complexes contain an unsymmetrical Schiff base ligand (Lx) and one 2,2′-bipyridine co-ligand. The Schiff base ligands are NN’O type unsymmetrical ligands which are the mono-condensed form of the reactions between meso-1,2-diphenyl-1,2-ethylenediamine with salicylaldehyde (1), 5-bromosalicylaldehyde (2) or 3-methoxysalicylaldehyde (3). Antibacterial activity of the new complexes along with their parent complexes, i.e. [CuLx(pyridine)]ClO4(1a-3a) were studied against 2 g negative bacteria (E. Coli and K. Pneumonia) and 2 g positive bacteria (S. aureus and B. Subtilis). The complexes were almost inactive against the studied gram negative bacteria but showed very good activity against the studied gram positive ones.

Solvatochromism of Copper(II) Complexes Derived from Trifluoroacetylacetone and Dinitrogen Ligands

Mixed ligand copper(II) complexes of the empirical formula [Cu (L)(TFAA)]X, where L represents 2,2´-bipyridine (Bipy), 1,10´-phenanthroline (Phen), or 4,7-diphenyl-1,10´- phenanthroline (Dphen), TFAA is 1,1,1-Trifluoro-2,4-pentanedione, and X is the counter ion (BF4- or ClO4-), were synthesized and characterized by spectroscopic, magnetic, molar conductance, elemental, and thermal analysis. Solvatochromic studies revealed that all the complexes showed bathochromic shifts. A square planar geometric structure is proposed for the perchlorate and tetrafluoroborate complexes. Spectral properties supported a square planar structure provided by the N2O2 chromophores. The mixed ligand copper complexes exhibited promising catalytic activity in the decomposition of hydrogen peroxide via the first-order reaction; the catalytic efficiency of perchlorate complexes was greater than that of tetrafluoroborate complexes. Potentiometric analyses of the aqueous mixed ligand copper complexes were carried out. The protonation constants of the free ligands and the stability constants of the complexes were determined using pH titration. The sequence of the stability of ternary complexes with respect to their ligands decreased in the order: Bipy˃ Phen˃ Dphen. The kinetic and thermodynamic parameters were calculated using the Coat-Redfern equation. The stability of the complexes was observed to be in line with the results obtained from the potentiometric analyses. The synthesized complexes were examined for their antimicrobial activity against two pathogenic bacteria (Staphylococcus aureus)as Gram-positive bacteria and (Pseudomonas fluorescens) as Gram-negative bacteria and one type of fungus (Fusarium oxysporum). The results indicated that the complexes exhibited higher antimicrobial activity than the ligands. It was also observed that perchlorate complexes had higher activity than tetrafluoroborate, and the growth of inhibitory activity of the complexes followed the order Bipy˃ Phen˃ Dphen.

Experimental and computational characterization of structural and spectroscopic features of mixed ligand copper complexes-prototypes for square-pyramidal stereochemistry

Two new mixed ligand copper complexes with 1,10-phenanthroline and monodentate pyrazoles (3,5-dimethyl-4-R-pyrazole, where R = nitro or iodo), stand as case-studies for a revisited view on Ligand-Field (LF) qualitative and semi-quantitative issues, brought in conjunction with the rich information offered by the state-of-the art computational methods. The combined analysis of the first TD-DFT energies and density difference maps enables a scheme of the LF split in the complexes with a specific variety of square-pyramidal coordination geometry, namely the case when the π-type anisotropy due to the two types of aromatic amine ligands shows different orientation with respect of the averaged basal plane. The density difference maps were used as ancillary tools for checking the coordination process and observing the nephelauxetic effect. Clear correlations are drawn between computed and experimental UV–Vis and EPR spectra, rationalizing the Landé factors in terms of Ligand Field states.

Cyclic voltammetric behavior of binary and mixed ligand copper complexes with picolinic acid, nicotinic acid and diethyldithiocarbamate in acetone medium

Cyclic voltammetric behavior of binary and mixed ligand copper complexes with picolinic acid, nicotinic acid and diethyldithiocarbamate in acetone medium

SYNTHESIS OF NEW BORON COMPOUNDS WITH AMOXICILLIN AND SOME OF ITS METAL COMPLEXES WITH USE THEM IN ANTIBACTERIAL, ASSESSMENT OF HEPATOPROTICTIVE AND KIDNEYACTIVITY, ANTICANCER AND ANTIOXIDANT APPLICATIONS

Objective: New ligand ({7-[2-amino-2-(4-hydroxyphenyl)-acetamido-3,3-dimethyl-6-oxo-2-thia-5-aza bicyclo[3,2,0]heptane-4-carboxylic boric anhydride}) with its Co (II), Ni (II) and Cu (II) complexes. And new mixed ligand copper complex was synthesized.
 Methods: The ligand was synthesized by the reaction of boric acid with amoxicillin (1:1) and the mixed ligand complex has been synthesized by the reaction of the ligand, 4-aminoantipyrine and Cu (II) ion (1:1:1).
 Results: All studied compounds were characterized by the spectral method: Fourier transform infrared, ultraviolet-visible, thermal analysis (TG and DTG), flame atomic absorption and nuclear magnetic resonance. Also CHNS, melting point, magnetic susceptibility and molar conductivity.
 Conclusion: According to the obtained data, all complexes were non electrolyte and the geometry was octahedral for all complexes. All synthesized compounds were tested as antibacterial agents against Escherichia Coli, Pseudomonas auroginosa as Gram-negative bacteria (G-) and Staphylococcus aureus epidermis as Gram-positive bacteria (G+). The results showed that copper complexes were more active in (10-2M) than the other compounds. The medicinal applications (hepatoprotective and kidney in serum of mice, histopathological of liver and kidney, anticancer and antioxidant in human cell were studied of the synthesized compounds and gave a good results in all tested.

Synthesis, Characterization and Antimicrobial Activities of New Mixed Ligand Complexes of Copper(II) with 1,10-Phenanthroline and Thymine

A novel mixed ligand complexes having the formulae [Cu(L1)2(H2O)2]Cl2 and [Cu(L1)2L2H2O]Cl (L1 = 1,10-phenanthroline, L2 = thymine) have been prepared and characterized by various physicochemical studies such as elemental analysis, molar conductance in nonaqueous solvent, infrared and electronic spectra. Both the ligands as well as the metal complexes were used further to investigate the biological activities (antibacterial) against Staphylococcus aureus (SA) (ATCC 25923), Streptococcus pneumonia (SP) (clinical isolate), methicillin-resistant Staphylococcus aureus (MRSA) (clinical isolate), Klebsiella pneumoniae (KP) (clinical isolate), Escherichia coli (EC) (clinical isolate), and Shigella boydii (SBD) (ATCC 12022). On comparing the biological activities, the complexes showed enhanced antimicrobial activity compared to the free metal salt with thymine being lower than that of 1,10-phenanthroline.

1,10-Phenanthroline-copper mediated ligand transformations: Synthesis and characterization of unusual mixed ligand complexes of copper (II)

Abstract The present work describes the results of treatment of two pentacoordinated copper(II) complexes with 1,10-Phenanthroline (PHEN). During the course of the reaction, in situ generated PHEN-Cu complex has mediated the ligand transformations. In spite of the structural similarities of the precursor complexes used, structurally distinct unusual mixed ligand complexes viz. dichlorido (3-methyl [1,2,4] triazolo[3,4-b] [1,3] benzothiazole) 1,10-phenanthroline copper(II) and dichlorido-µ-N,N-benzimidazolato dibenzimidazole di-1,10-phenanthroline dicopper (II) chloride are formed. These complexes are characterized by IR, ESI-MS, EPR and UV–Vis spectral studies. X-ray crystal structures of both the complexes are described. Further, the observed results have inspired the synthesis of 3-methyl [1,2,4] triazolo[3,4-b] [1,3] benzothiazole, by a new synthetic approach.