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Journal of Applied Spectroscopy - The present work aims to focus on the synthesis and spectral studies of the charge-transfer interaction between the nitro organic acceptors molecules [e.g.,...  相似文献   
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Sertraline (C(17)H(17)Cl(2)N) as an antidepressant drug was investigated using thermal analysis (TA) measurements (TG/DTG and DTA) in comparison with electron impact (EI) mass spectral (MS) fragmentation at 70eV. Semi-empirical MO-calculations, using PM3 procedure, has been carried out on neutral molecule and positively charged species. These calculations included bond length, bond order, bond strain, partial charge distribution and heats of formation (DeltaH(f)). Also, in the present work sertraline-iodine product was prepared and its structure was investigated using elemental analyses, IR, (1)H NMR, (13)C NMR, MS and TA. It was also subjected to molecular orbital calculations (MOC) in order to confirm its fragmentation behavior by both MS and TA in comparison with the sertraline parent drug. In MS of sertraline the initial rupture occurred was CH(3)NH(2)(+) fragment ion via H-rearrangement while in sertraline-iodine product the initial rupture was due to the loss of I(+) and/or HI(+) fragment ions followed by CH(2)NH(+) fragment ion loss. In thermal analyses (TA) the initial rupture in sertraline is due to the loss of C(6)H(3)Cl(2) followed by the loss of CH(3)-NH forming tetraline molecule which thermally decomposed to give C(4)H(8), C(6)H(6) or the loss of H(2) forming naphthalene molecule which thermally sublimated. In sertraline-iodine product as a daughter the initial thermal rupture is due to successive loss of HI and CH(3)NH followed by the loss of C(6)H(5)HI and HCl. Sertraline biological activity increases with the introduction of iodine into its skeleton. The activities of the drug and its daughter are mainly depend upon their fragmentation to give their metabolites in vivo systems, which are very similar to the identified fragments in both MS and TA. The importance of the present work is also due to the decision of the possible mechanism of fragmentation of the drug and its daughter and its confirmation by MOC.  相似文献   
3.
The buspirone drug is usually present as hydrochloride form of general formula C(21)H(31)N(5)O(2).HCl, and of molecular weight (MW)=421.96. It is an analgesic anxiolytic drug, which does not cause sedative or depression of central nervous system. In the present work it is investigated using electron impact mass spectral (EI-MS) fragmentation at 70 eV, in comparison with thermal analyses (TA) measurements (TG/DTG and DTA) and molecular orbital calculation (MOC). Semi-empirical MO calculation, PM3 procedure, has been carried out on buspirone both as neutral molecule (in TA) and the corresponding positively charged species (in MS). The calculated MOC parameters include bond length, bond order, particle charge distribution on different atoms and heats of formation. The fragmentation pathways of buspirone in EI-MS lead to the formation of important primary and secondary fragment ions. The mechanism of formation of some important daughter ions can be illuminated from comparing with that obtained using electrospray ESIMS/MS mode mass spectrometer through the accurate mass measurement determination. The losses of the intermediate aliphatic part (CH2)4 due to cleavage of N-C bond from both sides is the primary cleavage in both techniques (MS and TA). The PM3 provides a base for fine distinction among sites of initial bond cleavage and subsequent fragmentation of drug molecule in both TA and MS techniques; consequently the choice of the correct pathway of such fragmentation knowing this structural session of bonds can be used to decide the active sites of this drug responsible for its chemical, biological and medical reactivity.  相似文献   
4.
A simple and conventional spectrophotometric method is developed for quantitative analysis of fluoxetine. The method is based on the charge transfer 1: 1 complex formation of fluoxetine hydrochloride with electron acceptors: picric acid, dinitrobenzene, p-nitrobenzoic acid, 2,6-dichloroquinone-4-chloroimide, 2,6-dibromoquinone-4-chloroimide and 7,7′,8,8′-tetracyanoquinodimethane. The charge-transfer complexes are isolated and characterized by elemental analysis, conductivity, IR, Raman, 1H NMR spectra, X-ray powder diffraction, scanning electron microscopy and thermogravimetric analysis. The formation constants (K CT), molar extinction coefficients (?CT), standard free energies (ΔG 0), oscillator strengths (f), dipole moments (μ), resonance energies (R N) and ionization potentials (I D) are estimated. Thermodynamic parameters were computed from the thermal decomposition data.  相似文献   
5.
Herein,this article was focused on the synthesis and discussed the spectroscopic characterizations of four new scandium(Ⅲ)sulfa-drug complexes.The nomenclature and symbols of these drugs were sulfadimidine(sulp-1),sulfanilamide(sulp-2),sulfamethoxazole(sulp-3)and sulfadiazine(sulp-4).The microanalytical and spectroscopic analyses which utilized in this study were micro-analyses,magnetic,FT-IR,UV-Vis techniques.The mid infrared spectra deduced that the four sulfa-drug chelates acts as a bidentate chelates with scandium(Ⅲ)ion via two nitrogen atoms of-NH2-Ar and-NH-SO2 groups.Also,the FTIR spectra of Sc3+complexes referred to the existed of new medium weak bands in the range of 500~400 cm^-1 due to stretching vibration bands ofν(M-N).The elemental analysis technique confirmed the 1∶2 stoichiometry between Sc3+ions and sulp ligand with molecular formula[Sc(sulp)2(Cl)2]·Cl.At room temperature,the results of magnetic measurements for the Sc(Ⅲ)complexes indicated that all of the synthesized complexes have a diamagnetic character with octahedral configuration.The electronic spectra of the free sulfa-drug ligands shows band at 275 and 310 nm which are intraligand charge transfer band.The electronic sbsorption spectra of the Sc3+complexes were recorded using DMSO solvent.The spectra of complexes display bands within 275~388 nm,which attributed toπ-π*,n-π*and charge-transfer M-LCT electronic transitions,which strongly favors the octahedral geometry around Sc(Ⅲ)metal ions.1HNMR spectra of complexes referred to the downfield proton shifts of the-NH2 and NHSO2 groups,which supported the place of coordination.The half maximal inhibitory concentration(IC50)of the ScⅢcomplexes was assessed against the human hepato cellular carcinoma(HepG-2)tumor cell line.  相似文献   
6.
A four new penicillinate complexes were prepared through the chemical interactions of penicillin potassium salt (Pin) with YCl3, GeCl4, WCl6 and SiCl4 metal ions. These metal complexes were characterized using spectroscopic techniques (e.g. 1H-NMR, infrared, electronic UV-Vis) as well as elemental, conductivity, and magnetic measurements. The molar conductance values were highly, showing their electrolytic nature. The magnetic and electronic study strongly recommends the octahedral geometry of all penicillinate complexes. A monomeric structures of Pin complexes are proposed with octahedral coordinated metals ions. The metal ions are coordinated toward Pin as tridentate ligand through the amide and β-lactam carbonyls and a carboxylate group from penicillin. The in vitro antimicrobial activity of all the complexes, at concentrations in μg·mL-1, was screened against four bacterial pathogens, namely, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, and two kinds of fungi Aspergillus flavus and Candida albicans showed better activity compared to parent drug and control drug. The anti-cancer inhibition of the tungsten(Ⅵ) complex was assessed against the human hepato cellular carcinoma (HepG-2) tumor cell line with IC50 value is 646 μg·mL-1.  相似文献   
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