Synthesis of polyfunctional triethoxysilanes by ‘click silylation’

The copper-catalyzed ‘click silylation’ has been exploited for the chemical modification of γ-azidopropyltriethoxysilane (AzPTES) with a wide range of terminal alkynes (1a–1v) in a one-pot operation. The novel 1,2,3-triazole-triethoxysilane derivatives (2a–2v) were synthesized by this procedure and comprehensively characterized by IR spectra, ¹H and ¹³C NMR, and HRMS studies.     

Three-step pathway towards bis(1,2,3-triazolyl-γ-propylsilatranes) as Cu fluorescent sensor,via ‘Click Silylation’

A series of substituted aniline derivatized bis(1,2,3-triazolyl-γ-propylsilatranes) 3a–3f were designed in good yield from their triethoxysilane analogues via Cu(I) ‘Click Silylation’. All the silatranes 3a–3f were characterized by IR, NMR (¹H, ¹³C) and HRMS studies. All these compounds were explored for their thermal stability by thermogravimetric analysis (TGA)/differential thermal analysis (DTA)/differential scanning calorimetry (DSC) study and electronic properties by UV–vis spectroscopy and fluorescence study. The binding of silatranes 3a–3f to Cu²⁺ ion proves them to be good chemosensor. These silatranes were subjected to time dependent hydrolysis under normal atmospheric conditions. IR spectroscopic data support hydrolytic instability of 3a, 3c and 3e.     

Electro-optical features of antiferroelectric liquid crystal material (S)-(+)-4-(1-methylheptyloxycarbonyl) phenyl 4′-(6-octanoyloxyhex-1-oxy) biphenyl-4-carboxylate in its ferro and antiferroelectric phases

A detailed investigation of the electro-optical switching parameters of an antiferroelectric liquid crystal (S)-(+)-4-(1-methylheptyloxycarbonyl) phenyl 4′-(6-octanoyloxyhex-1-oxy) biphenyl-4-carboxylate (abbreviated as S-7H6Bi) has been carried out. S-7H6Bi has paraelectric (SmA^?) and ferroelectric (SmC^?) phases in addition to antiferroelectric (SmC^?_A) phase. Switching parameters viz. spontaneous polarization and switching time were determined by polarization reversal method. The spontaneous polarization (P_s) is found to be highly temperature dependent and decreases with temperature. The maximum value of P_s is found to be ∼90 nC/cm² whereas the switching time (t_s) is found to be of the order 1-2 ms. The temperature dependent torsional viscosity (γ_t) is of the order 10 Pa sec. It increases with decrease in temperature.     

Crystallization kinetics of compatibilized blends of polypropylene and polyethylenimine

Journal of Thermal Analysis and Calorimetry - In this paper, isothermal and non-isothermal crystallization behaviour of neat polypropylene (PP), blends of PP/maleic anhydride grafted polypropylene...