Said M. Teleb

Preparation, thermal and vibrational studies of [UO2(acac-o-phdn)(L)] (L=H2O, py, DMF and Et3N)

Four new dioxouranium(VI) complexes, [UO2(acac-o-phdn)(L)] where L = H2O, py, DMF and Et3N, with the tetradentate dibasic Schiff base (acac-o-phdn), derived from condensation of acetylacetone with o-phenylene diamine have been synthesized. The infrared spectra were obtained and full assignments of all the observed vibrations are proposed on the basis of C2v symmetry for H2O and py complexes and Cs for the other two complexes, respectively. The bond stretching force constant and bond length of the U=O bond for the four complexes were calculated. Differential thermal analysis (DTA) and thermogravimetric (TG) analysis of the complexes were also carried out.

Synthesis and Spectroscopic Studies of NN-O-Phenylenebis (Salicylideneiminato) Dioxouranium (VI) Solvates (L) CL = DMF and PY)

Abstract The two new complexes [UO2 (sal-o-phdn) (DMF)] and [UO2 (sol-o-phdn) (py)] (sal-o-phdn = N′-o-phenylenebis (salicylideneiminato) have been synthesized and their infrared and electronic spectra have been obtained and assigned beside those of the related complex [UO2 (sal -o-phdn)(EtOH)]. The values of both the bond stretching force constant of the uranyl bond, FU=O′ and U = O bond length have been calculated for each complex. The structure and geometry for each of the newlv prepared DMF and py complexes are discussed and compared with those known for the EtOH complex.

A Novel Method for the Synthesis of Metal Carbonates. I. Synthesis and Infrared Spectrum of Manganese Carbonate, MnCO3.H2O, Formed by the Reaction of Urea with Manganese(II) Salts

Abstract Manganese(II) carbonate, MnCO3.H2O, is obtained by a new synthetic method involving the reaction of aqueous solutions of MnCl2, Mn(NO3)2, MnSO4 or Mn(CH3COO)2 with urea at ∼80°C. The infrared spectrum of the formed product clearly indicates the absence of bands due to urea and shows the characteristic bands of carbonate ion. A general mechanism describing the formation of manganese carbonate, MnCO3.H2O, is suggested. Referee I: K. V. Katti Referee II: J. S. Thayer

Spectroscopic studies on the reaction of 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane

Abstract The interaction of iodine with the nitrogen cyclic base 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane (TMTACTD) is studied spectrophotometrically in CHCl 3 and the resonance Raman spectrum of the solid product is recorded. The results indicate the formation of the polyiodide species with the formula [(TMTACTD)I] + . I 9 − . The resonance Raman spectrum of the product suggests that the enneaiodide, I 9 − , does indeed contain the I 5 unit and this implies that I 9 − exists as (I 5 − ) (2I 2 ) where the I 5 − portion has a bent configuration with C 2 ν symmetry. All bond vibrations for the I 5 and I 2 units are observed and assigned.

Preparation and infrared spectrum of the bridged diacetato complex [Cu2(O)(H2O)2(OOCCH3)2 formed by the reaction of urea with copper (II) acetate

Abstract The bridged diacetato complex [Cu2(O)(H2O)2(OOCCH3)2] has been obtained by reacting aqueous solutions of Cu(OOCCH3)2 · H2O and urea at about 70°C. The reaction product was characterized through elemental analysis and i.r. measurements. The i.r. spectrum shows the characteristic bands of coordinated acetate ions and water, and was interpreted on the basis of C2v symmetry for the complex. A general mechanism describing the formation of [Cu2(O)(H2O)2(OOCCH3)2] is proposed.

Synthesis, spectroscopic properties, and antimicrobial activity of some new 5-phenylazo-6-aminouracil-vanadyl complexes

Six complexes, [VO(L1-H)2] · 5H2O (1), [VO(OH)(L2,3−H)(H2O)] · H2O (2,3), [VO(OH)(L4,5−H)(H2O)] · H2O (4,5), [VO(OH)(L6−H)(H2O)] · H2O (6), were prepared by reacting different derivatives of 5-phenylazo-6-aminouracil ligands with VOSO4 · 5H2O. The infrared and 1H NMR spectra of the complexes have been assigned. Thermogravimetric analyses (TG, DTG) were also carried out. The data agree quite well with the proposed structures and show that the complexes were finally decomposed to the corresponding divanadium pentoxide. The ligands and their vanadyl complexes were screened for antimicrobial activities by the agar-well diffusion technique using DMSO as solvent. The minimum inhibitory concentration (MIC) values for 1–4 and 6 were calculated at 30°C for 24–48 h. The activity data show that the complexes are more potent antimicrobials than the parent ligands.

Synthesis and Vibrational Studies of Oxovanadium (IV) - Tetradentate Schiff Base Complexes

Abstract The two new Schiff base complexes of oxovanadium (IV) [VO(acac-en)] (acac-en = bisacetylactone-ethylenediimino) and [VO(sal-o-phdn)] (sal-o-phdn = N,N′-o-phenylenebis (salicylideneiminato) have been prepared. The infrared spectra of the solid complexes have been obtained and assigned on the bases of Cs symmetry. A polymeric chain structure with V-O-V bridge has been adopted for the both complexes.

Infrared spectra of new dioxouranium (VI) solid complexes with tridentate schiff bases [UO2(sal-OAP)(L)] (L = H2O, Py, DMF and Et3N)

Abstract The new dioxouranhun (VI) Schiff base complexes [UO 2 sal-OAP)H 2 O)], [UO 2 (sal-OAP)(py)], [UO 2 (sal-OAP)(DMF)] and [UO 2 (sal-OAP)(Et 3 N)](sal-OAP = orthoaminophenolsalicylideneiminato) have been prepared, and their i.r. spectra recorded and assigned on the basis of C s , symmetry. The bond stretching force constants of the uranyl bonds, F u = 0, were calculated as 661.7 Nm −1 , 676.1 Nm −1 , 674.5 Nm −1 and 674.5 Nm −1 for [UO 2 sal-OAP)(H 2 O)], [UO 2 sal-OAP)(DMF)], [UO 2 (sal-OAP)(py)] and [UO 2 (sal-OAP)(Et 3 N)], respectively. The corresponding values of the U = O bond lengths were calculated to be 1.745 A, 1.741 A, 1.742 A and 1.742 A.

Preparation, spectroscopic and thermal studies on the new solid complex Co2(NH2)2(H2O)2(SO4)2

The preparation and characterization is reported of the new solid bimolecular Co(III)-bridged sulphato complex Co2(NH2)2(H2O)2(SO4)2 formed by the reaction of urea with CoSO4 · 7H2O in aqueous media at 85°C. The infrared spectrum of the complex was recorded and the observed bands are assigned. Thermogravimetric (TG) and differential thermal analysis (DTA) measurements on the complex, and the infrared spectrum of the final decomposition product were also recorded. The data obtained agree quite well with the expected structure and show that the complex finally decomposes to form CoSO4. Detailed mechanisms for the complex formation and its thermal decomposition are given, together with the activation energy for each decomposition step.

Synthesis and characterization of some uranyl and zirconyl nitrilotriacetic acid (NTA) chelates

Four new complexes [UO2(HNTA)(H2O)]·3H2O, Na[UO2(NTA)]·(H2O), [ZrO(HNTA) (H2O)]·3H2O and Na[ZrO(NTA)]·H2O were obtained by the reactions of and ZrO2+ salts with nitrilotriacetic acid (NTA) dissolved in water and NaOH aqueous solution. Infrared spectra of the solid complexes have been obtained and assigned on the basis of C s symmetry. Octahedral and polymeric chain structures are adopted for the uranyl and zirconyl NTA complexes, respectively. Thermogravimetric (TG) and differential thermal analysis (DTA) data are in accordance with the proposed structures and show that the complexes decompose to metal oxides.