Cu(II) complexes of N-propyl-2-picolinamine N-oxide

Cu(II) complexes have been prepared with N-propyl-2-picolinamine N-oxide(PA) employing the perchlorate, tetrafluoroborate, nitrate, chloride and bromide salts. The following unique solids have been isolated and characterized: Cu(PA)₂X₂ (X = ClO₄^?, BF₄^? and NO₃^?) and Cu(PA)X₂ (X = Cl^?, Br^?). Characterization has been accomplished primarily by IR, electronic and ESR measurements of the solid state since considerable alteration of the complexes occurs on dissolution. PA bonds as a bidentate ligand via its N-oxide oxygen and amine nitrogen in all of the complexes. Anion coordination occurs in the halogen complexes and the nitrate ions appear to be bound to Cu(II) as monodentate ligands in Cu(PA)₂(NO₃)₂. In addition, there appears to be a rhombic distortion of the CuO₂N₂ chromophore of the perchlorate and tetrafluoroborate solids which is probably due to the steric requirements of the propyl substituents.     

Synthesis,characterization, antimicrobial,and nuclease activity studies of some metal Schiff-base complexes

A Schiff base (L) is prepared by condensation of cuminaldehyde and L-histidine, and characterized by elemental analysis, IR, UV-Vis, ¹H-NMR, ¹³C-NMR, and mass spectra. Co(II), Ni(II), Cu(II), and Zn(II) complexes of this Schiff-base ligand are synthesized and characterized by elemental analysis, molar conductance, mass, IR, electronic spectra, magnetic moment, electron spin resonance (ESR), CV, TG/DTA, powder XRD, and SEM. The conductance data indicate that all the complexes are 1 : 1 electrolytes. IR data reveal that the Schiff base is a tridentate monobasic donor, coordinating through azomethine nitrogen, imidazole nitrogen, and carboxylato oxygen. The electronic spectral data and magnetic measurements suggest that Co(II) and Ni(II) complexes are tetrahedral, while Cu(II) complex has distorted square planar geometry. XRD and SEM show that Co(II), Cu(II), and Zn(II) complexes have crystalline nature, while the Ni(II) complex is amorphous and the particles are in nanocrystalline phase. The in vitro biological activities of the synthesized compounds were tested against the bacterial species, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus; and fungal species, Aspergillus niger, Aspergillus flavus, and Candida albicans by the disc diffusion method. The biological study indicates that complexes exhibit more activity than the ligand. The nuclease activity of the ligand and its complexes are assayed on CT DNA using gel electrophoresis in the presence and the absence of H₂O₂. The Cu(II) complex shows increased nuclease activity in the presence of an oxidant when compared to the ligand, Co(II) and Ni(II) complexes.     

Structural and spectral studies of copper(II) and nickel(II) complexes of pyruvaldehyde mixed bis{N(4)-substituted thiosemicarbazones}

Pyruvaldehyde mixed bis(thiosemicarbazones) have been prepared in which the two thiosemicarbazone moieties have different N(4)-substituents. The mixed bis(thiosemicarbazones) and their copper(II) and nickel(II) complexes have been characterized with IR, electronic, mass, ¹H NMR (Ni) and EPR (Cu) spectra. Representative crystal structures have been solved of nickel(II) complexes with either a pyruvaldehyde mixed bis(thiosemicarbazone) or a bis(thiosemicarbazone) with identical N(4)-substituents acting as a tetradentate ligand. [Ni(Pu4M4DE)] has an N(4)-methylthiosemicarbazone substituent on the keto “arm” and N(4)-diethylthiosemicarbazone substituent on the aldehyde arm. [Ni(Pu4M)] contains two N(4)-methylthiosemicarbazone moieties. Both bis(thiosemicarbazones) form square-planar N₂S₂ complexes with nickel(II) and copper(II).     

Synthesis,characterization and biological studies of some Co(II), Ni(II) and Cu(II) complexes derived from indole-3-carboxaldehyde and glycylglycine as Schiff base ligand

The Schiff base ligand derived from indole-3-carboxaldehyde(indal) and glycylglycine(glygly) were synthesized and characterized by elemental analysis, IR, electronic spectrum, ¹H NMR and mass spectrum. Co(II), Ni(II) and Cu(II)–indal-glygly Schiff base complexes were synthesized and characterized by elemental analysis, molar conductance, IR, electronic spectra, magnetic measurements, ESR, electrochemical studies, TGA, DSC analysis, XRD and SEM. Conductance measurements indicate that the above complexes are 1:1 electrolytes. IR spectral data show that the ligand is tridentate and the binding sites are azomethine nitrogen, peptide nitrogen and carboxylato oxygen atoms. Electronic spectral measurements indicate tetrahedral geometry for Co(II) and Ni(II) complexes and square planar geometry for Cu(II) complex. Magnetic measurements show weak ferromagnetic behaviour for Co(II) and Ni(II) complexes and paramagnetic behaviour for Cu(II) complex. ESR spectral data shows the ionic link between metal and the Schiff base ligand. The metal complexes are found to be stabilized in the unusual oxidation states of the metal ion during electrolysis. Thermal analysis of the complex indicates that the decomposition takes place in three steps. IR and thermal studies indicate that the fourth position would be occupied by a water molecule in complexes. XRD shows that the complexes have the crystallite size of 31, 40 and 67 nm, respectively. The surface morphology of the complexes was studied by SEM. The antimicrobial activity of the ligand and its complexes were screened by Kirby Bayer Disc Diffusion method. DNA cleavage studies were performed for metal–Schiff base complexes in presence of hydrogen peroxide as oxidant.     

Copper(II) complexes of 2-aminoacetophenone N(4)-substituted thiosemicarbazones

Mononuclear copper(II) complexes with 2-aminoacetophenone thiosemicarbazone and three N(4)-substituted thiosemicarbazones have been prepared in ethanolic solution and characterized by physical and spectral methods. I.r., electronic and e.s.r. spectra of the complexes, as well as i.r., electronic, and ¹H- and ¹³C-n.m.r. spectra of the thiosemicarbazones, have been obtained. The 2-aminoacetophenone thiosemicarbazones coordinate as neutral ligands via the thiosemicarbazone moiety's azomethine nitrogen and thione sulfur, except for the piperidylthiosemicarbazone, which undergoes deprotonation and coordinates via the thiolato sulfur, as well as through the azomethine nitrogen. Complexes formed in the presence of triethylamine also form complexes with the anionic form of these thiosemicarbazones.     

Transition Metal Complexes of Dis(thiosemicarbazone): Synthesis and Spectral,and Antifungal Studies

Mn(II), Co(II), Ni(II), and Cu(II) complexes have been synthesized with benzil bis(thiosemicarbazone) (L) and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, thermogravimetric studies, infrared (IR), electronic, and electron paramagnetic resonance (eEPR) spectral studies. The molar conductance measurements of the complexes in DMF correspond to the non-electrolytic nature of the complexes. Thus these complexes may be formulated as [M(L)X₂] (where M = Mn(II), Co(II), Ni(II), Cu(II) and X = Cl^? and NO₃ ^?). On the basis of IR, electronic, and EPR spectral studies, an octahedral geometry has been assigned for Mn(II), Co(II), and Ni(II) complexes, whereas a tetragonal geometry for the Cu(II) complexes is presumed. The free ligand and its metal complexes were tested against the phytopathogenic fungi (i.e., Rhizoctonia baticola, Alternaria alternata) in vitro.     

Synthesis,Spectral, Characterization,and Anticancer Activity of Some Binary and Mixed Ligand Complexes of 4-Methyl-2-Pentanone Thiosemicarbazone and Some Amino Acids

The Schiff base ligand 4-methyl-2-pentanone thiosemicarbazone (MPTSC) (HL) has been synthesized by the interaction of 4-methyl-2-pentanone (MP) and thiosemicarbazone (TSC). The Ni(II), Cu(II), and Fe(III) binary complexes of this ligand have been prepared. The ternary complexes of VO(IV) and Mn(II) ions with HL and glutamine (Glu) as a secondary ligand, in addition to VO(IV), Mn(II), and La(III) with HL and glycine (Gly) as a secondary ligand, have also been synthesized. The binary and ternary complexes have been characterized based on elemental analysis, IR, UV-VIS, molar conductance, mass spectra, magnetic moment, and ESR measurements. The magnetic moment, UV, and ESR studies suggest that Ni(II) and Cu(II) complexes are square planar, whereas Fe(III), Mn(II), and La(III) complexes have octahedral geometry, but VO(IV) ternary complexes have square pyramidal geometry. The analytical data indicate that the metal-to-ligand ratio in binary complexes is 1:1, except HL-Cu(II) chloride complex where the metal-to-ligand to secondary ligand ratio in ternary complexes is 1:1:1. The anticancer studies showed that the anticancer activity is in the decreasing order: ternary complexes > binary complexes > free ligand (HL).

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis,spectral, thermal,and magnetic studies of cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II) complexes with N2O2 donor groups

A new Schiff base ligand was prepared by condensation of 2-hydroxy-4-methoxybenzaldehyde with 1,2-propanediamine. The ligand and its metal complexes were characterized by elemental analysis, FT-IR, ¹H and ¹³C NMR, magnetic moment, molar conductance, UV-Vis, SEM and thermal analysis (TGA). The molar conductance measurements indicated that all the metal complexes were non-electrolytes. IR spectra showed that ligand (L) behaves as a neutral tetradentate ligand and binds to the metal ions by the two azomethine nitrogen atoms and two phenolic oxygen atoms. The electronic absorption spectra and magnetic susceptibility measurements indicated square planar geometry for the Ni(II) and Cu(II) complexes while other metal complexes showed tetrahedral geometry. Also the surface morphology of the complexes was studied by SEM.     

Synthesis and characterization of the complexes of some transition metals with 2-acetyl pyridine (N-benzoyl) glycyl hydrazone

Complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with 2-acetyl pyridine (N-benzoyl) glycyl hydrazone(2-ApBzGH) have been synthesized and characterized by elemental analyses, molar conductances, magnetic susceptibility, IR, electronic, ESR,¹H,¹³C and¹¹³Cd NMR spectral and X-ray diffraction studies. IR and NMR data suggest the tridentate nature of the ligand coordinating as a neutral species in the addition complexes and as a uninegative species in the deprotonated complexes. The presence of more than one isomer of the ligand has been established by¹H NMR spectra of the ligand and complexes recorded over the 298–396 K range. The X-ray powder diffraction patterns of [Cd(2-ApBzGH)Cl]Cl and [Cu(2-ApBzGH)Cl(H₂O)₂]Cl are indexed for orthorhombic and tetragonal crystal systems respectively.     

Structural and Spectral Study of Copper(II) Complexes of Pyridil bis{3‐piperidyl‐, bis{hexamethyleneiminyl‐, bis{N(4)‐diethyl‐, and bis{N(4)‐dipropylthiosemicarbazones}

Pyridil bis(N(4)‐substituted thiosemicarbazones) have been prepared in which the substituents in place of the NH₂ group in the thiosemicarbazone moieties are piperidinyl (H₂Plpip), hexamethyleneiminyl (H₂Plhexim), diethylaminyl (H₂Pl4DE), and dipropylaminyl (H₂Pl4DP). IR, electronic, mass, and ESR spectra of their copper(II) complexes are reported. Crystal structure determinations of H₂Pl4DE and three of the copper(II) complexes of formula [Cu(Plpip)], [Cu(Plhexim)] and [Cu(Pl4DE)]₂ · 2[Cu(Pl4DE)], are included. H₂Pl4DE lacks hydrogen bonding between the thiosemicarbazone moieties, but each moiety is in the Z configuration form with hydrogen bonding from the thiosemicarbazone moieties to the pyridyl nitrogen atoms. The crystal used for the structure determination of [Cu(Plhexim)] was isolated from an electrochemical preparation. In all the new compounds the deprotonated ligands are N,N,S,S‐tetradentate, coordinating to the copper(II) centre through their azomethine nitrogen atoms and their thiocarbonyl sulfur atoms.     

Synthesis and magnetic,spectral and thermal eukaryotic DNA studies of some 2-acetylpyridine- [N-(3-hydroxy-2-naphthoyl)] hydrazone complexes

Complexes of Ni(II), Co(II), Cu(II), Zn(II), Cd(II), Hg(II) and U(VI)O₂ with 2-acetylpyridine-[N-(3-hydroxy-2-naphthoyl)] hydrazone (H₂APHNH) have been prepared and characterized by elemental analysis, molar conductance, thermal (TG, DTG), spectral (¹H NMR, IR, UV–Vis, ESR) and magnetic measurements. ¹H NMR spectrum of the ligand suggests the presence of intramolecular hydrogen bonding. IR spectra show that H₂APHNH is a bidentate, tridentate and/or tetradentate ligand. Thermal decomposition of some complexes ended with metal oxide as a final product. ESR spectra gave evidence for the proposed structure and the bonding for some Cu(II) complexes. Biological activity measurements were carried out.     

Synthesis,structural studies and bio-activity of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes with p -amino acetophenone salicyloyl hydrazone

Complexes of the type [M(pash)Cl] and [M(Hpash)(H₂O)SO₄] (M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); Hpash = p-amino acetophenone salicyloyl hydrazone) have been synthesized and characterized by elemental analyses, molar electrical conductance, magnetic moments, electronic, ESR and IR spectra, thermal studies and X-ray powder diffraction. All the complexes are insoluble in common organic solvents and are non-electrolytes. The magnetic moment values and electronic spectra indicate a square-planar geometry for Co(II), Ni(II) and Cu(II) chloride complexes and spin-free octahedral geometry for the sulfato complexes. The ligand coordinates through >C=N–,–NH₂ and a deprotonated enolate group in all the chloro complexes, and through >C=N–, >C=O and–NH₂ in the sulfato complexes. Thermal analyses (TGA and DTA) of [Cu(pash)Cl] show a multi-step exothermic decomposition pattern. ESR spectral parameters of Cu(II) complexes in solid state at room temperature suggest the presence of the unpaired electron in d _{x ² ? y ²} . X-ray powder diffraction parameters for [Cu(pash)Cl] and [Ni(Hpash)(H₂O)SO₄] correspond to tetragonal and orthorhombic crystal lattices, respectively. The complexes show a fair degree of antifungal activity against Aspergillus sp., Stemphylium sp. and Trichoderma sp. and moderate antibacterial activity against E. coli and Clostridium sp.     

Metal complexes of 4,5-dimethylpyrazole-3-carboxaldehyde phenylthiosemicarbazone

Several new transition metal complexes derived from 4,5-dimethyl-3-carboxaldehyde phenyl- thiosemicarbazone, LH, have been synthesized. The complexes are of stoichiometry, [CoL₂]X, X = Cl⁻, Br⁻, ClO⁻₄ or NO⁻₃, [MnL₂] and [CuX_nL_m], X = Cl⁻, Br⁻, NCS⁻ or N⁻₃; n = 1 or 0; m = 1 or 2 and L = the anion of LH. All complexes have been characterized by elemental analysis, spectral (i.r., electronic, NMR, ESR) and magnetic measurements. The ligand acts as tridentate monobasic co-ordinated to the metal ion via azomethine, pyrazole (N²) nitrogen atoms and the thiolo-sulphur. The ligand field and ESR parameters are used to interpret the nature of bonding of LH with the metal ion, ground state and the ligand field strength of LH and the various co-ordinated simple ions. The coupling constants of various co-ordinated nuclei with copper (II) are estimated from ESR spectra of copper (II) complexes.     

Transition metal ion complexes of a thiosemicarbazone derived from 6-methyl-2-acetylpyridine

Summary A series of metal ion complexes of the thiosemicarbazone, 3-azabicyclo[3.2.2]nonane-3-thiocarboxylic acid 2-[1-(6-methyl-2-pyridinyl)ethylidene]hydrazide (6 MLH) have been prepared and spectrally characterized. The ligand undergoes deprotonation to coordinatevia the thione sulphur, the imine nitrogen and the pyridyl nitrogen. A single anionic ligand such as Cl^–, Br^– and NO₃ ^– completes the bonding to the Cu^II and Ni^II centre. The compound derived from CoCl₂ contains two 6 MLH ligands bound to a Co^II centre and a CoCl ₄ ^2– counter ion. Complexes derived from perchlorate salts may feature 6 MLH, 6 ML, or both with the Co^II being oxidized to Co^III. The solids were characterized by i.r., electronic and e.s.r. spectroscopy. In addition, electronic and e.s.r. spectra of their chloroform solutions were recorded.NATO Fellow, on leave from Istanbul Medical Faculty, Istanbul University.     

Synthesis,spectroscopic and the biological activity studies of thiosemicarbazones containing ferrocene and their copper(II) complexes

Two Schiff bases, 1-acetylferrocene thiosemicarbazone (HL¹) and 1,1′-diacetyl-ferrocene dithiosemicarbazone (H₂L²) and their copper(II) complexes were prepared and characterized by elemental analysis, magnetic susceptibility, conductivity, and spectral (IR, UV–Vis, ESR) measurements The IR spectra showed that HL¹ acts as neutral or monobasic bidentate ligand, coordinating to copper(II) through either thiono- or thiolo-sulphur and azomethine-N atoms, whereas H₂L² is a neutral or dibasic mononucleating or binucleating quadridentate ligand coordinating through the same atoms. Other spectral measurements indicate that complexes [(L¹)₂Cu], [(L²)Cu] and [(HL¹)₂Cu]X₂, X?=?Cl, Br or ClO₄ have square-planar geometry around copper(II) while [(HL¹)CuX₂] and [(H₂L²)Cu₂X₄], X?=?Cl or Br, have distorted tetrahedral geometry. The biological activity studies of the complexes and the free ligands towards two gram positive and two gram negative bacteria and one fungal species have been studied and the potential is related to the nature and structure of the tested compounds.     

Synthesis,Spectral Studies and Bio‐activity of Some Ligand Bridged Polymeric Transition Metal Complexes of Acetone p‐Amino Acetophenone Isonicotinoyl Hydrazone

Ligand bridged polymeric complexes of the type [M(apainh)(H₂O)X] where, M=Mn(II), Co(II), Ni(II), Cu(II), and Zn(II); X=Cl₂ or SO₄; apainh=acetone p‐amino acetophenone isonicotinoyl hydrazone have been synthesized and characterized. The complexes are stable solids, insoluble in common organic solvents and are non‐electrolytes. Magnetic moments and electronic spectral studies suggest a spin‐free octahedral geometry for all Mn(II), Co(II), Ni(II), and Cu(II) complexes. IR spectra show tridentate nature of the ligand bonding through two >C?N and a >C?O groups. X‐ray powder diffraction parameters for some of the complexes correspond to orthorhombic and tetragonal crystal lattices. Thermal studies (TGA and DTA) of [Mn(apainh)(H₂O)SO₄] complex show multi‐step decomposition pattern of both an endothermic and exothermic nature. ESR data of Cu(II) chloride complex in solid state show an axial spectra, whereas, Cu(II) sulfate complex is isotropic in nature. The complexes show a significant antifungal activity against a number of pathogenic fungal species and antibacterial activity against Pseudomonas sp. and Clostridium sp. The metal complexes are more active than the ligand.     

Synthesis, spectroscopy, and magnetic characterization of copper(II) and cobalt(II) complexes with 2-amino-5-bromopyridine as ligand

The synthesis, spectroscopic, and magnetic characterization of two new copper(II) and cobalt(II) complexes are described. Both two compounds have the general formula [M(L)₂(Cl)₂] (M = Cu (I), Co (II); L = 2-amino-5-bromopyridine). These complexes were prepared in one-step synthesis and characterized by elemental analysis, FT-IR, UV-Vis, and EPR spectroscopy. Moreover, the single crystal structure of complex I was studied by the X-ray diffraction method. This compound consists of mononuclear units consisting of two ligands linked to metal via the nitrogen of pyridine ring. The UV-Vis spectra of copper(II) and cobalt(II) complexes show three and five absorption bands, respectively, attributed to the d-d transition of the metal ion, ligand → metal charge transfer and π → π* or n → π* transitions of the ligand. The FT-IR spectra show MN₂Cl₂ vibrations at 500–300 cm^?1. The complexes show room temperature magnetic moments of 1.78 and 4.12 μ_B for Cu(II) and Co(II), respectively. The X-band electron spin resonance (ESR) spectra of Cu(II) complex in DMF or DMSO frozen at liquid nitrogen temperature show the typical ΔM_S = ±1 transition.     

Synthesis, spectral and thermal studies of new copper (II) complexes with 1,2-di(imino-2-aminomethylpyridil)ethane

New copper (II) complexes of Schiff bases with 1,2-di(imino-2-aminomethylpyridil)ethane with the general composition CuLX _m (H₂O) _x , [L = Schiff base, X = Cl^?, Br^?, NO₃ ^?, ClO₄ ^?, CH₃COO^?, m = 2; X = SO₄ ^2?, m = 1] were prepared by template synthesis. The complexes were characterized by elemental analysis, conductivity measurements, magnetic moments, IR, UV–VIS and EPR spectra. The thermal behavior of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Infrared spectra of all complexes are in good agreement with the coordination of a neutral tetradentate N₄ ligand to the cooper (II) through azomethinic and pyridinic nitrogen. Magnetic, EPR and electronic spectral studies show a monomeric distorted octahedral geometry for all Cu(II) complexes. Conductance measurements suggest the non-electrolytic nature of the compounds, except for copper (II) nitrate and perchlorate complexes which are 1:2 electrolytes. Heats of decomposition, ΔH, associated with the exothermal effects were also determined.     

Synthesis,Spectroscopic and Magnetic Studies on Metal Complexes of 5-Methyl-3-(2-Hydroxyphenyl)Pyrazole

A tridentate ONN donor ligand, 5-methyl-3-(2-hydroxyphenyl)pyrazole; H₂L, was synthesized by reaction of 2-(3-ketobutanoyl)phenol with hydrazine hydrate. The ligand was characterized by IR, ¹H NMR and mass spectra. ¹H NMR spectra indicated the presence of the phenolic OH group and the imine NH group of the heterocyclic moiety. Different types of mononuclear metal complexes of the following formulae [(HL)₂M][sdot]xH₂O (M=VO, Co, Ni, Cu, Zn and Cd), [(HL)₂M(H₂O)₂] (M=Mn and UO₂) and [(HL)LFe(H₂O)₂] were obtained. The Fe(III) complex, [(HL)LFe(H₂O)₂] undergoes solvatochromism. Elemental analyses, IR, electronic and ESR spectra as well as thermal, conductivity and magnetic susceptibility measurements were used to elucidate the structures of the newly prepared metal complexes. A square-pyramidal geometry is suggested for the VO(IV) complex, square-planar for the Cu(II), Co(II) and Ni(II) complexes, octahedral for the Fe(III) and Mn(II) complexes and tetrahedral for the Zn(II) and Cd(II) complexes, while the UO₂(VI) complex is eight-coordinate. Transmetallation of the UO₂(VI) ion in its mononuclear complex by Fe(III), Ni(II) or Cu(II) ions occurred and mononuclear Fe(III), Ni(II) and Cu(II) complexes were obtained. IR spectra of the products did not have the characteristic UO₂ absorption band and the electronic spectra showed absorption bands similar to those obtained for the corresponding mononuclear complexes. Also, transmetallation of the Ni(II) ion in its mononuclear complex by Fe(III) has occurred. The antifungal activity of the ligand and the mononuclear complexes were investigated.     

Synthesis,spectral, and antifungal studies of transition metal complexes with sixteen-membered hexadentate macrocylic ligand

A novel hexadentate nitrogen donor [N₆] macrocyclic ligand viz, 1,5,11,15,21,22-hexaaza-2,14-dimethyl-l4,12-diphenyltricyclo[15.3.1.I(7–11)]docosane[1,4,6,8,10(22)-11,14,16,18,20(21)]decaene (L), has been synthesised. The Co (II), Ni (II), and Cu (II) complexes with this ligand have been prepared and subjected to elemental analysis, molar conductance, magnetic susceptibility measurements, mass, ¹H NMR (ligand), IR, electronic, and ESR spectral studies and electrochemical investigation. On the basis of molar conductance the complexes can be formulated as [M(L)]X₂ (where M = Co (II), Ni (II), Cu (II) and X = Cl⁻ and NO₃⁻) due to their 1: 2 electrolytic nature in DMSO. All the complexes are of the high-spin type and are six-coordinated. On the basis of IR, electronic, and ESR spectral studies, an octahedral geometry has been assigned for the Co(II) and Ni(II) complexes, whereas a tetragonal geometry for the Cu(II) complexes was found. Antimicrobial activity of L and its complexes as growth inhibiting agents have been screened in vitro against two species (F. moniliformae and R. solani) of plant pathogenic fungi. The text was submitted by the authors in English.