Investigations on poly(methyl methacrylate)-poly(ethylene oxide) hybrid polymer electrolytes with dioctyl phthalate, dimethyl phthalate and diethyl phthalate as plasticizers

Plasticizers can be used to change the mechanical and electrical properties of polymer electrolytes by reducing the degree of crystallinity and lowering the glass transition temperature. The transport properties of gel-type ionic conducting membranes consisting of poly(ethylene oxide) (PEO), poly(methyl methacrylate) (PMMA), LiClO₄ and dioctyl phthalate, diethyl phthalate or dimethyl phthalate (DMP) are studied. The polymer films are characterized by X-ray diffraction, Fourier transform infrared and impedance spectroscopic studies. It is found that the addition of DMP as the plasticizer in the PEO-PMMA-LiClO₄ polymer complex favours an enhancement in ionic conductivity. The maximum conductivity value obtained for the solid polymer electrolyte film at 305 K is 3.529×10^{– 4} S cm^–1. Electronic Publication     

Immediate release tablets of telmisartan using superdisintegrant-formulation, evaluation and stability studies

Telmisartan (anti-hypertensive) is insoluble in water; hence the drug may be slowly or incompletely dissolved in the gastro intestinal tract. So the rate of dissolution and therefore its bioavailability is less (bioavailability 42%). In the present study an attempt has been made to prepare immediate release tablets of telmisartan by using Polyplasdone XL-10 (Crosspovidone) at intragranular, extragranular and partly intra and extragranular level of addition to increase the rate of drug release from dosage form to increase the dissolution rate and hence its bioavailability. The prepared granules and tablets were evaluated for their physiochemical properties and in-vitro dissolution study was conducted for the prepared tablets. It was concluded that the immediate release tablets with proper hardness, disintegration time and with increase rate of dissolution can be made using Polyplasdone XL-10. Formuation-10 (F10) was selected for stability study and the in-vitro dissolution study showed that was no difference in percent of drug released between initial and sixth month sample.     

Experimental and theoretical comparison of actinide and lanthanide bonding in M[N(EPR(2))(2)](3) complexes (M = U, Pu, La, Ce; E = S, Se, Te; R = Ph, iPr, H)

Treatment of M[N(SiMe3)2]3 (M = U, Pu (An); La, Ce (Ln)) with NH(EPPh2)2 and NH(EPiPr2)2 (E = S, Se), afforded the neutral complexes M[N(EPR2)2]3 (R = Ph, iPr). Tellurium donor complexes were synthesized by treatment of MI3(sol)4 (M = U, Pu; sol = py and M = La, Ce; sol = thf) with Na(tmeda)[N(TePiPr2)2]. The complexes have been structurally and spectroscopically characterized with concomitant computational modeling through density functional theory (DFT) calculations. The An-E bond lengths are shorter than the Ln-E bond lengths for metal ions of similar ionic radii, consistent with an increase in covalent interactions in the actinide bonding relative to the lanthanide bonding. In addition, the magnitude of the differences in the bonding is slightly greater with increasing softness of the chalcogen donor atom. The DFT calculations for the model systems correlate well with experimentally determined metrical parameters. They indicate that the enhanced covalency in the M-E bond as group 16 is descended arises mostly from increased metal d-orbital participation. Conversely, an increase in f-orbital participation is responsible for the enhancement of covalency in An-E bonds compared to Ln-E bonds. The fundamental and practical importance of such studies of the role of the valence d and f orbitals in the bonding of the f elements is emphasized.     

Red Emitting Coumarin—Azo Dyes : Synthesis,Characterization, Linear and Non-linear Optical Properties-Experimental and Computational Approach

The coumarin molecules with 7-(N,N-diethylamino) substitution and aryl azo (Ar–N=N-) at 3-position were synthesized, by reacting diazonium salt of substituted amines and 7-(N, N-diethylamino)-4-hydroxy coumarin under basic conditions. They were found to be fluorescent despite the presence of azo group. The azo group rotation was blocked by complexing with -BF₂, so as to get a red shift in absorption. The azo molecules show charge transfer, whereas BF₂-complexes do not. The dipole moment ratios between the ground and excited states calculated suggest highly polar excited state and an intra-molecular charge transfer at the excited state in the case of azo dyes. The NLO properties were calculated by solvatochromic method and computationally. Second order hyperpolarizability was found to be 46 to 1083 times more than urea. DFT and TDTDF calculations were performed to understand the electronic properties of the molecules at the ground as well as excited states.     

Unfolding ESIPT in Bis-2,5-(2-benzoxazolyl) Hydroquinone and 2,5-Bis(benzo[d]oxazol-2-yl)-4-methoxyphenol: a Comprehensive Computational Approach

The photo-physical behaviour of bis-2,5-(2-benzoxazolyl) hydroquinone and 2,5-bis (benzo[d]oxazol-2-yl)-4-methoxyphenol was studied using the Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT). All the possible rotamers were optimized to obtain global minimum optimized structure. The theoretical absorption and emission values of rotamers estimated by using TD-DFT [TD-B3LYP/6–31G(d)] are in good agreement with experimental absorption and emission wavelengths. Based on the absorption values, the contribution of respective rotamer is determined theoretically.