Metal chelates of heterocyclic nitrogen-containing ketones,Part XXII. Spectroscopic studies on rhodium(III) complexes of phenyl-2-picolylketone-2-pyridyl hydrazone

Summary Mono, bis and tris complexes of rhodium(III) with phenyl-2-picolylketone-2-pyridyl hydrazone (PPKPyH) have been characterized. In every case, the imino-proton of PPKPyH shows marked acidity associated with the coordination to rhodium(III). Electronic spectra show that all complexes are octahedral. The B-values suggest a strong covalency in the metal-ligand -bond and the Dq-values indicate a medium-strong ligand field. The magnetic susceptibility indicates that PPKPyH forms low-spin complexes with rhodium(III).¹H n.m.r. spectra show that the tris(ligand) complexes arecis isomers. I.r. spectra show that the ligand is neutral or monobasic tridentate or bidentate. Far i.r. studies show that [Rh(PPKPyH)X₃] · 2 H₂O (X = Cl, Br or I) aremer isomers. The effect of pH variation on the rection products is also discussed.     

Synthesis,molecular modeling,TD-DFT,antimicrobial, and in vitro therapeutic activity of new spherical nano-sized sulfonamide imine ligands and their zinc (II) and copper (II) complexes

A series of nanometer-sized spherical sulfonamide imine ligands HL ¹ -HL ⁵ and their copper and zinc complexes were synthesized and fully characterized based on elemental analyses, spectroscopic (UV/vis, FT-IR, NMR, EPR, SEM) studies, molar conductance and thermal analyses. Furthermore, computational studies of HL ¹ -HL ⁵ were carried out by the DFT/B3LYP method. TD-DFT, HOMO and LUMO energy values, chemical hardness, electronegativity, electrophilic index, softness, and other parameters were calculated. Screening against several pathogenic microorganisms indicated that HL ¹ exhibited high activity against the tested Gram-negative bacteria relative to other analogues and the inhibition activity is greater than the standard Gentamicin. Analogously, HL ² exhibited high potent activity against the tested Gram-positive bacteria. Copper complexes exhibited a higher potent activity than zinc analogues. Noteworthy, inhibition activity of [Cu ( L ³ )(OAc)] complex is higher than that of the standard Ampicillin. [Cu ( L ² )(OAc)] complex displayed a similar activity of the standard bactericides and fungicides in use. The complexes showed appreciated values of MIC against bacterial strains: B. subtilis (MIC = 0.4 μg / mL), E. coli and S. pneumonia (MIC = 1.95 μg / mL) and P. aeruginosa (MIC = 7.81 μg / mL). in vitro cytotoxic activities study proved that [Cu ( L ³ )(OAc)] complex exhibited appreciable activity versus (HEPG-2); IC₅₀ = 4.8 μg/ml, while [Cu( L ² )(OAc)] complex showed a high activity against (MCF-7); IC₅₀ = 6.2 μg/ml. These results could be considered as new findings of promising antitumor candidates for experimental chemotherapy.     

Structural and models of dioxouranium(VI) with rhodanine azodyes--V.

The synthesis of several new coordination compounds of dioxouranium(VI) heterochelates with bidentate rhodanineazol compounds derived from rhodanine are described. The ligands and uranyl complexes have been charcaterized by various physico-chemical techniques. The bond lengths and the force constants have been calculated from asymmetric stretching frequency of O-U-O group. The infrared spectral studies showed a monobasic bidentate behaviour with the oxygen and azonitrogen donor system. The ligands contain intramolecular hydrogen bonds.     

Cobalt(II), nickel(II) and copper(II) complexes of syn-2-picolyl phenyl and syn-2-quinaldyl phenyl ketoximes

Summary The syn-2-picolyl phenyl ketoxime (HL₁) and the syn-2-quinaldyl phenyl ketoxime (HL₂) give [M(HL)LX], [M(HL)₂X₂] and [ML] solid complexes (M=Co, Ni and Cu; X=Cl^–, Br^– and NO ₃ ^– which have been characterized by elemental analysis, room temperature magnetic moments and electronic and i.r. spectral measurements.     

Synthesis and characterization of some octahedral transition metal complexes with phenyl-2-picolylketone thiosemicarbazone

Summary A series of transition metal complexes with phenyl-2-picolylketone-thiosemicarbazone, LH, of the general formula [ML₂]Cl_nmH₂O, (M=Cr³⁺, Mn²⁺, Fe²⁺, Rh³⁺, Ir³⁺ or Ru³⁺; n=0 or 1 and m=1,2 or 3) have been prepared and characterized. Magnetic and spectral (electronic and vibrational) data are commensurate with an octahedral ligand field for all complexes. The variable temperature magnetic moment shows that the iron(II) complex exists in a temperature-dependent high-spinlow-spin equilibrium. The far i.r. spectra show that the strength of the M–S bond follows the order: Mn²⁺ 2+3+3+3+3+. The various ligand field parameters, Dq, B' and are calculated.     

Effect of temperature and absorbed ionizing radiation doses on the electric and electronic properties of copper(II) complexes

A large number of copper(II) complexes derived from their related pyridine derivatives were prepared, crystallized and their characteristics established. The temperature dependence of d.c. electronic (electrical) conductivity and the electronic absorption properties of the materials under investigation were studied before and after exposure to various absorbed gamma does up to 10⁷ rads using a ⁶⁰Co gamma cell. The effect of gamma absorbed doses on the d.c. electrical conductivity and electronic absorption spectra of γ-irradiated samples are discussed on the basis of the effect of ionizing radiation firstly on metal—oxygen, and secondly on CC bonds regarding the substituent effect on their electronic delocalization and their geometrical structures.     

Metal chelates of heterocyclic nitrogen-containing ketones,X. Synthesis and characterization of platinum(II) complexes of syn-2-picolyl phenyl andsyn-2-picolyl methyl ketoximes. The phenomena of isomerism

Summary Platinum(II) complexes derived from syn-2-picolyl phenyl and syn-2-picolyl methyl ketoximes, LH and LH, respectively, were synthesised and characterised by elemental analyses, magnetic and molar conductivity measurements and by electronic and vibrational spectroscopic studies. The mode of bonding in these complexes is discussed and their isomerization have been investigated.     

Synthesis and ligating behaviour of 5-heteroaryl-1-phenylpent-1-yne-3,5-diones

Summary Ethyl phenylpropiolate reacts with -acetylfuran and -acetylpyridine in the presence of NaOEt to yield the respective acetylenic -diketones as well as 2-heteroaryl-6-phenyl-4H-pyran-4-ones as minor products. Copper(II), nickel(II) and cobalt(II) complexes of the title compounds were prepared and characterized by elemental analysis, i.r., u.v.-vis., e.s.r. spectra, electrical conductivity and magnetic measurements. The data suggest square-planar and octahedral structures for the copper(II) and cobalt(II) complexes, respectively. The nickel(II) complexes appeared to be either square-planar or octahedral depending upon the nature of the ligand.     

Metal chelates of heterocyclic Nitrogen containing ketones. XV. Five-coordinate nickel(II) and copper(II) complexes with a sulphur-nitrogen tridentate schiff base

Summary Complexes of the Schiff base, 2-picolylphenylketone-hydrazine-S-benzyl dithiocarbazate, PPKBzTE, with nickel(II) and copper(II) halides have been prepared and characterized using spectral (¹H n.m.r., i.r., uv-visible and e.s.r.) and magnetic measurements. A square pyramidal geometry is assumed for [Ni(PPKBzTE-H)X]₂(X=Cl or. Br) and a square planar structure for [Ni(PPKBzTE-H)I]. The spectral studies in inert solvents show the presence of temperature dependent equilibria between tetrahedral and five-coordinate species in the chloro-and bromo-complexes. The interaction of nickel(II) complexes with various heterocyclic nitrogen Lewis bases yielded distorted octahedral 12 adducts. Copper(II) complexes, [Cu₃(PPKBzTE)(PPKBzTE-H)Cl₅] and [Cu(PPKBzTE-H)Br]₂ were separated and associated with a five-coordinate structure. Variable temperature magnetic susceptibility and the spectral studies showed that they are trimeric and dimeric, respectively.Abstracted from his Ph.D. Thesis.     

Metal chelates of heterocyclic nitrogen containing ketones,Part IX. Magnetic and spectral studies of the dimeric copper(II) complex of 2-picolyl methyl ketone semicarbazone and its ligation by solvent molecules

Summary The preparation and characterization of [(PMKSC-H)Cu]₂Cl₂ by i.r. electronic and e.s.r. spectra as well as variable temperature magnetic susceptibility are described and a square planar geometry is assumed for the isolated complex. The magnetic susceptibility data indicates overall antiferromagnetic spin coupling. The variable temperature magnetic susceptibility in conjunction with the best fitting procedure yielded: 2J=–46cm^–1, g=2.15 and 6=–5 K. E.s.r. data confirm the existence of spin-spin coupling with D=0.0398 cm^–1. The g-values obtained from the e.s.r. studies were g₁₁=2.24, g=2.08 and g_av.=2.13. The results were used to estimate the Cu-Cu separation in the dimer. The problem of ligation of the dimeric copper(II) complex by various organic solvents was investigated. E.s.r., i.r. and electronic spectra together with the magnetic susceptibiliy studies indicate that [(PMKSC-H)Cu]₂Cl₂ dissociated in polar solvents to give the adducts [(PMKSC-H)CuL_s]Cl which were isolated and characterized.