Estimation of ground and excited state dipole moments of synthesized coumarin derivative [N-(2-oxo-2H-chromen-4-yl)imino]triphenyl-phosphorane
作者:Sunita Joshi、Santosh Kumari、Rituparna Bhattacharjee、Rajeev Sakhuja、Debi D. Pant
DOI:10.1016/j.molliq.2014.09.054
日期:2014.12
triphenyl phosphorane was characterized by 1H and 13C NMR, and FT-IR spectral studies. The ground and excited state dipolemoments of molecule were obtained from Bakhshiev's and Bilot–Kawski's equations by means of the solvatochromic shift method. Very high value of dipole moment is observed for excited state as compared to ground state value and this is attributed to more polar excited state of the molecule
在室温下,在各种极性不同的溶剂中,香豆素衍生物[ N-(2-oxo-2 H -chromen-4-yl)亚氨基]三苯基膦的电子吸收和荧光光谱已被记录下来。随着溶剂极性的增加,最大吸收值几乎保持不变,而观察到最大荧光发射发生红移。合成的化合物[ N-(2-oxo-2 H -chromen-4-yl)亚氨基]三苯基磷烷的特征在于1 H和1313 C NMR和FT-IR光谱研究。分子的基态和激发态偶极矩是通过溶剂变色位移法从Bakhshiev和Bilot-Kawski方程获得的。与基态值相比,观察到激发态的偶极矩值非常高,这归因于分子的极性更强的激发态。使用B3LYP / 6-31G +(d)和B3LYP / 6-31G(d)进行高斯03基态理论水平的数值计算。还使用CPCM方法和相同水平的UA0半径在不同溶剂中进行研究理论。对于基态,还进行了气相偶极矩值与各种溶剂之间的严格分析。
Thermal or Lewis acid-promoted electrocyclisation and hetero Diels–Alder cycloaddition of α,β-unsaturated (conjugated) carbodiimides: a facile synthesis of nitrogen-containing heterocycles
β-styrylcarbodiimide was entirely unreactive toward either the electrocyclisation or the Diels–Alderreaction even under severe reaction conditions. 4-Coumarylcarbodiimide underwent an inverse electron-demand Diels–Alderreaction with an enamine either thermally or in the presence of a Lewis acid catalyst to afford chromenopyridines. Thus experimentally observed reactivity differences of the substituted
In the presence of a Lewis acid conjugated carbodiimides smoothly react as 2-azadienes with various dienophiles such as acetylenic compound, enamine, vinyl ether, and aldehyde under mild reaction conditions to give good yields of nitrogen heterocycles as cycloadducts.