There are several paths for synthesizing 4,4′-bis(hydroxymethyl) 2,2′-bipyridine, but most of them need strict experimental conditions that are not easy to be overcome. We designed a simple way to prepare this product via the oxidation of 4,4′ bismethyl 2,2′-bipyridine, followed by esterification and reduction. The yield increases and the reaction conditions become genial in contrast to those of other methods. The molecular structure of the final product was confirmed by means of elemental analysis, IR, 1H NMR and MS spectra.
SU Zhong minCHEN Li huaWU Li xinXU Hong binZHU Dong xiaWANG Rong shun
The structures of barbituric acid derivatives substituted with Schiff base were optimized using ab initio HF method at 6-31G basis set. Based on the optimized structures, the electronic spectra were obtained by INDO/CI method. The second-order nonlinear optical (NLO) coefficients mb were calculated according to the sum-over-states (SOS) formula. In addition, the effect of conjugation on electronic spectra and second-order NLO coefficients was investigated. The influence of exchange between C and N atoms as well as the substituted effect on the barbituric acid was discussed. It was indicated that the exchange between C and N atoms on Schiff base is im-portant for enhancing the NLO coefficient of the whole molecule with donor and acceptor (D-A). Meanwhile sig-nificant changes in electron donation and acception were observed as substituents changes positions. Among the designed models, molecule 1b has maximal mb value of 124.65×10-30 esu. About molecule 1b, barbituric acid is considered as an accepted electronic group and the position of N atom on Schiff base is close to it.
