Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities

Synthesis of thermally stable new polyurethanes containing nitro-substituted 1,3,4-oxadiazole chromophores for second order nonlinear optical applications

“…M a n u s c r i p t 15 Thermogravimetric analysis was carried out for all the polyurethanes and the patterns thus obtained are presented in Fig. 3.…”

“…Therefore, to achieve better hyperpolarizability so as to enhance the second-order NLO properties, attempts have been made to design the chromophores with less aromatic characteristics in the ground state by replacing the benzene ring in stilbene and azoconjugated derivatives with easily delocalizable five-membered heteroaromatic rings [9,[15][16][17][18][19][20][21][22][23][24][25]. Further, it is also pointed out that the hyperpolarizability could be enhanced with increasing the length of the bridge [18,26].…”

Development of polyurethanes with azo‐type chromophores for second‐order nonlinear optical applications

“…The solution was cooled to 0 C, and glacial acetic acid (22 mL) was added dropwise with stirring while the temperature was maintained below 15 C. The resulting solution was cooled below 0 C, and to this, 2-amino-5-nitrothiazole (0.73 g, 5 mmol) was added portionwise with stirring. The stirring was continued at this temperature for 2 h. The resulting reaction mixture was poured into crushed ice to obtain a diazonium salt solution, which was slowly poured into a methanol/water (10 mL/5 mL) mixture containing N-phenyldiethanolamine (0.91 g, 5 mmol).…”

“…[9][10][11] This is due to the delocalization energy of heteroaromatics, which is lower than that of six-membered rings. Chromophores containing aromatic pentaatomic heterocycles or their derivatives, such as thiophene, [12][13][14] thiazole, 15,16 benzothiazole, 16,17 and benzoxazole, 18,19 are among the most studied systems. In addition, it is also necessary to give primary importance to other ancillary properties that may play an important role by influencing material processing and performance (e.g., film making, poling deficiency, durability, and thermal and photochemical stability).…”

Synthesis, Spectral and Computational Studies of some 2-(2-(3-Methyl-2,4-Diphenyl-3-Azabicyclo[3.3.1]Nonan-9-Ylidene)Hydrazinyl)Benzo[d]Thiazole Derivatives

“…Recently, second order NLO effects of organic molecules have been extensively investigated for their advantages over inorganic crystals. The organic NLO materials play an important role in second harmonic generation, frequency mixing and electro-optic modulation [4], Most π-conjugated systems play a major role in determining second-order NLO response [5]. Searching organic materials with non-linear optical (NLO) properties is usually concentrated on molecules with donor-acceptor π-conjugation (D-π-A) and deals with the substituent effects on the degree of π-conjugation, steric hindrance and the hyperpolarisability of the substances [6].…”