AN INVESTIGATION OF THE Cu(II) COMPLEXES OF CERTAIN CEPHALOSPORIN ANTIBIOTICS: SPECTRAL, THERMAL, AND PHOTOCHEMICAL STUDIES

Osman, Ahmed H.; Aly, Aref A. M.; El‐Maali, Nagwa Abo; Al‐Hazmi, Gamil A.A.

doi:10.1081/sim-120014306

Cited by 17 publications

(15 citation statements)

References 12 publications

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“…The square-pyramidal structure (Figure 2) is also proposed for [Cu 2 (H 2 MBT)(OAc) 2 (C 2 H 5 OH) 2 ]. This is based on the appearance of a distinguished band at 17,200 cm )1 , which may be assigned to the 2 B 1 fi 2 E g transition [25]. Also, the magnetic moment values (1.99 and 1.80 B.M.)…”

Section: Electronic Spectra and Magnetic Studiesmentioning

confidence: 99%

Spectral, Magnetic, Electrical and Thermal Studies on Malonyl bis(thiosemicarbazide) Complexes

El-Metwally

Gabr

El‐Asmy

et al. 2006

Transition Met Chem

106

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Mono-and binuclear complexes of malonyl bis(thiosemicarbazide), H 4 MBT, with VO 2+ , Co 2+ , Ni 2+ , Cu 2+ , Cd 2+ and Pt 4+ have been isolated. The elemental analyses, magnetic moments, spectra [u.v.-vis., i.r., e.s.r. (for Cu 2+ ; VO 2+ ) and mass], thermal and voltammetric measurements [for Co 2+ and Ni 2+ ] have been used to characterize the isolated complexes. The ligand behaves as binegative quadridentate with Cu 2+ , Co 2+ and VO 2+ ions, binegative pentadentate with Pt 4+ and hexadentate, either as trinegative in [Cd 2 (HMBT)(OC 2 H 5 )(C 2 H 5 OH)]H 2 O or mononegative in [Ni 2 (H 3 MBT)(OAc) 3 (C 2 H 5 OH)]. The lack of thiol and/or enol hydrogen during the complex formation was confirmed pH-metrically. The pK's (10.70, 8.50 and 8.15) of H 4 MBT reveal the removal of CSNH protons in one step and CONH in two steps. Also, the stability constants reveal a higher value for the Cu 2+ complex and a lower one for VO 2+ . The TG analyses suggest high stability for most complexes followed by thermal decomposition in different steps. The kinetic and thermodynamic parameters for some decomposition steps in VO 2+ and Pt 4+ thermograms have been calculated.

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Section: Electronic Spectra and Magnetic Studiesmentioning

confidence: 99%

Spectral, Magnetic, Electrical and Thermal Studies on Malonyl bis(thiosemicarbazide) Complexes

El-Metwally

Gabr

El‐Asmy

et al. 2006

Transition Met Chem

106

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“…These bonding sites are suggested based on the following evidence: i) the disappearance of ν (N 2 H); ii) the shift of ν (C=N) to a lower frequency by 41 cm -1 ; iii) the appearance of a new band at 443 cm -1 , assignable to ν (Cu-N) [38,39]; iv) the disappearance of the thioamide band, ν (C=S), with the simultaneous appearance of new bands at 607 and 352, ascribed to ν (C-S) and ν (Cu-S) cm -1 vibrations, respectively [40]. The coordinated water gives absorption frequency at 3455, 850, and 550 cm -1 due to ν (OH), rocking and wagging, respectively [41]. Also, the appearance of a new band at 292 cm -1 , due to (Cu-Cl) vibration [40], is good evidence for the existence of chloride inside the coordination sphere.…”

Section: Flotation Mechanismmentioning

confidence: 99%

“…Also, the appearance of a new band at 292 cm -1 , due to (Cu-Cl) vibration [40], is good evidence for the existence of chloride inside the coordination sphere. Moreover, the electronic spectra of the complexes (as has been presented elsewhere) [42] exhibits one broad band more or less centered at 16600 cm -1 which is assigned to a combination of the transitions 2 B 1g → 2 E 1g and 2 B 1g → 2 A 1g , associated with a square planar configuration around the Cu(II) ion [41]. In addition to the d-d transition, the band observed at 2197 cm -1 is attributed to intraligand charge transfer [41].…”

Section: Flotation Mechanismmentioning

confidence: 99%

“…Moreover, the electronic spectra of the complexes (as has been presented elsewhere) [42] exhibits one broad band more or less centered at 16600 cm -1 which is assigned to a combination of the transitions 2 B 1g → 2 E 1g and 2 B 1g → 2 A 1g , associated with a square planar configuration around the Cu(II) ion [41]. In addition to the d-d transition, the band observed at 2197 cm -1 is attributed to intraligand charge transfer [41]. All the above observations suggest a square planar structure for the complex [Cu(A-p-ClPT)(Cl)(H 2 O)] as shown in Chart 2.…”

Section: Flotation Mechanismmentioning

confidence: 99%

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Spectrophotometric determination of copper(II) in natural waters, vitamins and certified steel scrap samples using acetophenone-p-chlorophenylthiosemicarbazone

Ghazi

El-Shazly

G.A.A.

et al. 2006

JICS

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A very simple, highly sensitive and selective spectrophotometric procedure was developed for the determination of copper(II). It is based on the reaction at pH 4-9 between the synthesized acetophenone-p-chlorophenylthiosemicarbazone (A-p-ClPT) and Cu(II) forming a green complex, Cu(II):A-p-ClPT (1:2), that floats quantitatively with oleic acid (HOL) surfactant. It exhibits a constant and maximum absorbance at 600 nm in both aqueous and surfactant layers. Beer ' s law is obeyed over the concentration range 0.25-6.35 mg l -1 with a detection limit of 0.021 mg l -1 for a standard aqueous solution of Cu(II) with a concentration of 3.82 mg l -1 (calculated on the basis of 3σ) and molar absorptivities of 5.5 × 10 3 and 1.3 × 10 4 mol l -1 cm -1 in aqueous and surfactant layers, respectively. Sandell's sensitivity was calculated to be 0.244 μg cm -2 and the relative standard deviation (n = 9) was 0.19%. The different analytical parameters affecting the flotation and determination processes were examined. The proposed procedure has been successfully applied to the analysis of Cu(II) in natural waters, certified scrap steel samples and vitamin samples. The results obtained agree well with those samples analyzed by atomic absorption spectrometry (AAS). Moreover, the flotation mechanism is suggested based on some physical and chemical studies on the solid complexes isolated from aqueous and surfactant layers.

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“…Synthesis of new Schiff bases and their metal complexes still the aim of many recent investigations [4][5][6]. Therefore, and in continuation of our previous studies on characterization of transition metal complexes [7][8][9], the present investigation deals with the synthesis, characterization and photochemical studies of cobalt(II) and nickel(II) complexes of Schiff bases derived from condensation of 3-hydrazino-6-methyl [1,2,4]-triazin-5(4H)one and some aromatic aldehydes ( Figure 1). …”

Section: Introductionmentioning

confidence: 95%

Synthesis and Characterization of Cobalt(II) and Nickel(II) Complexes of Some Schiff Bases Derived from 3-hydrazino-6-methyl[1,2,4] triazin-5(4H)one

Osman

2006

Transition Met Chem

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Cobalt(II) and nickel(II) complexes of bidentate and tridentate Schiff bases derived from the condensation of 3-hydrazino-6-methyl[1,2,4]triazin-5(4H)one and aromatic aldehyde derivatives were synthesized and characterized. Elemental and thermal analyses as well as i.r., electronic spectra, molar conductance and magnetic moment measurements were utilized for the investigation of the complexes. From these investigation data, the structural formulae, the mode of bonding, and geometry of the complexes were obtained. The photolysis of the complexes was investigated. The photolysis is enhanced by the presence of H 2 O 2 due to the hydroxyl radicals generated during the photochemical reaction. Mechanisms of the pyrolysis and the photolysis of the complexes are suggested.

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AN INVESTIGATION OF THE Cu(II) COMPLEXES OF CERTAIN CEPHALOSPORIN ANTIBIOTICS: SPECTRAL, THERMAL, AND PHOTOCHEMICAL STUDIES

Cited by 17 publications

References 12 publications

Spectral, Magnetic, Electrical and Thermal Studies on Malonyl bis(thiosemicarbazide) Complexes

Spectral, Magnetic, Electrical and Thermal Studies on Malonyl bis(thiosemicarbazide) Complexes

Spectrophotometric determination of copper(II) in natural waters, vitamins and certified steel scrap samples using acetophenone-p-chlorophenylthiosemicarbazone

Synthesis and Characterization of Cobalt(II) and Nickel(II) Complexes of Some Schiff Bases Derived from 3-hydrazino-6-methyl[1,2,4] triazin-5(4H)one

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