Environment effect on spectral and charge distribution characteristics of some drugs of folate derivatives

Solvent polarity sensitive characteristics of various tautomers of azo compounds: Linear and nonlinear optical properties

Solvents as complex environments can induce considerable effects on the physical, chemical and biological properties of solute molecules. In this work, solvent polarity sensitive characteristics of two tautomers of different azo compounds were studied by using of spectroscopic and Z-scan techniques. In this case, nature and various molecular interactions contribution on the spectral behaviors of azo and hydrazone forms of selected samples were investigated by Kamlet-Abboud-Taft and Catalan models. Moreover, the obtained results of Z-scan indicate that self-defocusing, saturable and reverse saturable absorption features of azo dyes depend highly on substituents and molecular environment polarity characteristic. In this case, media polarity properties have the same effects on the third order nonlinear absorption coefficient and nonlinear refractive index values. Therefore, by measuring one of the third order nonlinear optical coefficients, it is possible to predict solvent polarity effects on the other nonlinear optical coefficient. The calculated dipole moments with high values in the molecular excited state also reveal the probability of molecular charge transfer characteristics. In this case, by excitation process, sample I indicate high dipole moment values in comparison to other samples. Therefore, the results can give useful information about the application of selected samples for designing various optical devices.

Studying Media Polarity Effects on the Photo-Physical Behaviors of Organometallic Complexes with Azo-Containing Schiff-Base Ligands

Solvent molecules as an important factor can modify the photo-physical behavior of organometallic complexes. For precise investigation, in this paper, the spectral behavior of some groups of copper complexes with different substituents were studied in various solvent media. In this case, the linear solvation energy relationships concept was used for determination of various contribution of media induced specific and non-specific interactions on the photo-physical behavior of various forms of organometallic complexes with azo-containing Schiff-base dyes. Moreover, the calculated dipole moments indicate that samples with different forms tend to have polar structure in the excited state as compared to those in the ground state. By exploiting of calculated dipole moments and obtained quantitative results in the ground and excited states, the dominant solvent induced resonance structures were also estimated. The obtained experimental results can give more information about how these samples can behave in various physical, chemical and biological phenomena.