Photoreactivity, Optical Behavior and DFT Studies of 2,5-Bis[4-choloro-acetyl(thiophen-2-ylmethylene)]cyclopentanone BCTCP in Different Solvents.

Diarylidenecyclopentanone compound namely, 2,5-bis[4-choloroacetyl-(thiophen-2-ylmethylene)]cyclopentanone (BCTCP) was firstly synthesized using the normal condition of Friedel-Crafts method by reacting 2,5-bis(thiophen-2-ylmethylene)cyclopentanone (BTCP) with chloroacetyl chloride in the presence of aluminum chloride anhydrous. The structure of this compound was confirmed by elemental and spectral analyses including FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. The electronic absorption and emission properties of BCTCP were studied in different solvents. BCTCP displays a slight solvatochromic effect of the absorption and emission spectrum, indicating a small change in dipole moment of BCTCP upon excitation. BCTCP displayed photodecomposition in chlorinated solvents upon irradiating with 365 nm light. Ground and excited states electronic geometric optimizations were performed using density functional theory (DFT) and time-dependent density functional theory (TD-DFT), respectively. A DFT natural bond orbital (NBO) analysis complemented the intramolecular charge transfer (ICT). The simulated maximum absorption and emission wavelengths are in line the observed ones in trend, and were proportionally red-shifted with the increase of the solvent polarity. The stability, hardness and electrophilicity of BCTCP in different solvents were correlated with the polarity of the elected solvents.

Experimental determination of ground and excited state dipole moments of N, N-bis (2, 5-di-tert-butylphenyl)-3, 4:9, 10-perylenebis (dicarboximide) (DBPI) a photostable laser dye.

In the present work, the absorption, emission spectra and dipole moments(µ(g), µ(e)) of N, N-bis (2, 5-di-tert-butylphenyl)-3, 4:9, 10- perylenebis (dicarboximide) (DBPI) have been studied in solvents of various polarities at room temperature. Using the methods of solvatochromism, the difference between the first excited singlet state (µ(e)) and ground state (µ(g)) dipole moments was estimated from Lippert - Mataga,, Bakhshiev, Kawski - Chamma - Viallet equations. The change in dipole moment (Δµ) was also calculated using the variation of the Stokes shift with microscopic solvent polarity parameter (E(T)(N)). It was observed that the value of excited singlet state dipole moment is higher (3.53 Debye) than the ground state one (1.92Debye), showing that the excited state of DBPI is more polar than the ground state.

Spectral properties and inclusion of 3-(4'-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one in organized media of micellar solutions, beta-cyclodextrin and viscous medium.

On the line of a previous work on the spectral properties of some of heteroaryl chalcone, the absorption and fluorescence emission spectral properties of 3-(4'-dimethylaminophenyl)-1-(2-furanyl)prop-2-en-1-one (DMAFP), have been investigated in organized media of aqueous micellar and beta-cyclodextrin (beta-CD) solutions. While the absorption spectra are less sensitive to the nature of the added surfactant or beta-CD, the characteristics of the intramolecular charge transfer (ICT) fluorescence are highly sensitive to the properties of the medium. The ICT maximum is strongly blue-shifted with a great enhancement in the fluorescence quantum yield on adding micellar or beta-CD. This indicates the solubilization of DMAFP in the micellar core and formation of an inclusion complex with beta-CD. The critical micelle concentrations (CMC) as well as the polarity of the micellar core of SDS, CTAB and TX-100 have been determined. The CMC values are in good agreement with the reported values while the polarity is lower indicating that DMAFP molecules are incorporated in the micellar core not at the micellar interface. The inclusion constants of binding of DMAFP in micellar or beta-CD have been also determined. The thermodynamic parameters of formation of DMAFP:CD inclusion complex have been calculated from the temperature dependence of the fluorescence spectra of the formed complex. The highly negative value of formation entropy (DeltaS=-98.0Jmol(-1)K(-1)) reflects the high restrictions imposed on the movement of both the host and included guest molecules which is consistent with the increase of the fluorescence yield and blue shift of the fluorescence maximum.

Spectral properties and inclusion of a hetero-chalcone analogue in organized media of micellar solutions and beta-cyclodextrin.

The absorption and fluorescence emission spectral properties of 3-(4'-dimethylaminophenyl)-1-(2-thienyl)prop-2-en-1-one, abbreviated as DMATP, have been investigated in organized media of aqueous micellar and beta-cyclodextrin (CD) solutions. While the absorption spectra are less sensitive to the nature of the added surfactant or CD, the characteristics of the intramolecular charge transfer (ICT) fluorescence are highly sensitive to the properties of the medium. The ICT maximum is strongly blue-shifted with a great enhancement in the fluorescence quantum yield on adding micellar or CD solutions. This indicates the solubilization of DMATP in the micellar core and formation of an inclusion complex with beta-CD. The critical micelle concentration (CMC) as well as the polarity of the micellar core of SDS, CTAB and TX-100 have been determined. The CMC values are in good agreement with the reported values while the polarity is lower indicating that DMATP molecules are incorporated in the micellar core not at the micellar interface. The inclusion constants of binding of DMATP in micellar or CD have been also determined. The thermodynamic parameters of formation of DMATP:CD inclusion complex have been calculated from the temperature dependence of the fluorescence spectra of the formed complex. The negative enthalpy and free energy of formation indicate that the inclusion process is energetically favorable. The highly negative value of formation entropy (DeltaS = -162.3 J mol(-1) K(-1)) reflects the high restrictions imposed on the movement of both the host and included guest molecules which is consistent with the increase of the fluorescence yield and blue shift of the fluorescence maximum.

Spectroscopic studies of 4-(4,6-dimethylpyrimidin-2-ylazo) benzene-1,3-diol and its Cu(II) complexes.

The electronic absorption spectra of 4-(4,6-dimethylpyrimidin-2-ylazo)benzene-1,3-diol have been studied in organic solvents of different polarities as well as in buffer solutions of varying pH. The observed UV-vis absorption bands are assigned to the corresponding electronic transitions. The effect of methanol ratio on the pK-value is discussed. Also, semiemperical molecular orbital calculations at the AM1 level have been performed to investigate the molecular and electronic structures of the free ligand in the ground state. According to these calculations, an intramolecular hydrogen bond leads to increasing of the molecular stability. The important bands in the IR spectrum as well as the main signals in the (1)H NMR spectrum are also assigned. The interaction of Cu(II) ion with the titled azo-dye in solution is studied spectrophotometrically and conductometrically. Optimization of the various experimental conditions is also described. Beer's law is obeyed in the range 0-11.43 ppm while that obtained applying Ringbom is 1.26-6.61 ppm. The use of the titled azo-dye as an indicator for determination of Cu(II) is considered. The solid Cu(II) complexes are synthesized and characterized by spectral, magnetic, conductance and thermal studies (TGA and DTA). The results indicate the formation of 1:1 and 1:2 (M:L) complexes. The kinetic parameters (n, E, A, DeltaS, DeltaH and DeltaG) of the thermal decomposition stages were computed and discussed.

Spectral properties of (5-phenyl-1,3,4-oxadiazol-2-yl)-7-hydroxycoumarin (POHC).

The electronic absorption, emission and excitation spectra of POHC were measured in different solvents and are affected by solvent polarity. The fluorescence quantum yield of POHC decreases with increasing Richardt and Dimorth solvent parameter (E(T)) value of the solvent. In dilute solutions POHC is almost totally present in its protonated nitrogen tautomer form. The deprotonation is a reversible process. A shoulder in the absorption spectra at approximately 473 nm indicates the presence of a portion of the tautomer (s) that disappears on lowering the temperature. Molecular oxygen acts as a quencher with quenching rate constant of 1.8 x 10(10) M(-1) s(-1) in DMF. Energy transfer from POHC to rhodamine 6G in ethanol was also studied. POHC is relatively photostable in ethanol (phic approximately 1.7 x 10(-4)). Quantum chemical calculations were carried out and correlated to experimental observations.

Evaluation of the Kato-Katz thick smear and formol ether sedimentation techniques for quantitative diagnosis of Schistosoma mansoni infection.

The present study compared the Kato-Katz thick smear and formol ether sedimentation techniques in the diagnosis of Schistosoma mansoni infections. A stool specimen was collected from 915 individuals representing a high prevalence community (63.3%) and from 471 individuals representing a relatively low prevalence village (40%). The overall sensitivity of a single Kato-Katz smear was 70.8%, and it increased with each additional slide to reach 91.7% on examining four smears. However, the sensitivity was 83.3% when using the formol ether sedimentation technique. In terms of quantitative analysis, the geometric mean egg count was 94 eggs per gram (epg) of stool by two Kato-Katz smears, and 43 epg by the sedimentation technique. This means that more than 50% of eggs were missed when using the sedimentation technique, a fact that should be taken into consideration when relating infection level with morbidity.

Studies on Lymnaea snails and their trematode parasites in Abis II village, Alexandria.

Lymnaea snails in Abis II village were studied as regard their species, monthly distribution, density and infection rates in different water bodies. The trematode parasites in L. cailliaudi, the only species of Lymnaea in Abis II village were xiphidio in 40% of snails and Fasciola in 10%. Echinostome cercariae were detected from few snails outside Abis II village. The morphological characters of the different larval stages of the detected parasites were described.

Human fascioliasis in Egypt: effect of infection and efficacy of bithionol treatment.

The present study was conducted on 14 patients with established fascioliasis. The effect of infection on the haematological and biochemical parameters was determined and the liver and gall bladder were studied by ultrasonography. Bithionol was given in the dose of 30 mg kg-1 body weight every other day for 5 doses. The therapeutic efficacy was assessed by egg and eosinophilic counts and quantitative estimation of antibody titres by indirect haemagglutination test. Results revealed that fascioliasis caused normocytic hypochromic anaemia and eosinophilia. Serum bilirubin, ALT and AST were within normal range. Ultrasonography showed a normal echogenic pattern of the liver and gall bladder. One case showed thickness of the gall bladder wall which was tender under the transiducer. Fasciola eggs disappeared completely after the 5th dose giving a cure rate of 100%. Antibody titres reached a normal level at the end of the 3rd month post treatment. Bithionol proved to be a potent fasciolicidal drug with minimal side-effects.