Design And Synthesis Of New Type Of D-D-π-A Chromophore Based On Thiopheno-pyrrole

After entering the new century,all kinds of communication technologies have brought rapid changes to people with extremely rapid development.In the field of communication,the conversion speed of photoelectric signal determines the bandwidth of communication as well as the speed of communication.At present,the conversion of electro-optical signals is mainly based on inorganic nonlinear materials such as lithium niobate,which cannot meet the communication needs of today’s world due to their poor performance.Organic nonlinear materials based on push-pull electronic structure caused more and more attention by researchers for their characteristics of high electro-optical coefficient,fast corresponding speed,low price and convenient processing.Chromophores are active components of organic nonlinear materials.At present,the chromophore structure is mainly D-π-A type,which is composed of donor(D),conjugate bridge(π)and receptor(A).After a long period of research on this kind of chromophores,researchers have a very thorough understanding of this kind of chromophores,and its performance become more and more difficult to improve.The reduction of dipole-dipole interaction,which is unfavorable to chromophores polarization,is one of the important problems that researchers are eager to solve.Some new type of chromophores,such as the type of D-D-π-A,have shown A good ability to reduce this adverse effect.Three D-D-π-A chromophores were designed as additional donors to investigate the reduction of the interaction between D-D-π-a chromophores and thiopheno pyrrole(TI structure).The study is divided into two parts,the first part is to design the donor(TI)with excellent performance,and the second part is to design and synthesize three D-D-π-A chromophores with TI structure as an additional donor,and characterize them.In the first part,the thermal stability of chromophores was measured by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).The results show that the chromophores with TI structure as donor exhibited very high thermal stability.UV-vis also show TI structure as donor chromophores show good performance of the intramolecular charge transfer,the better the performance of the chromophores in general also has good nonlinear performance.theory calculation also suggests that TI structure as donor chromophores has high nonlinear performance.In the second part,after verifying that the TI structure can be used as A good donor structure of chromophores,three D-D-π-A chromophores are designed as additional donors.DSC and TGA tests show that the three chromophores have sufficient thermal stability.UV-vis test show that the D-D-π-A chromophore with TI structure as additional donor has good intramolecular charge transfer property and may have good microcosmic nonlinearity.The final calculation shows that the designed three D-D-π-A chromophores can significantly reduce the dipole-dipole interaction which is unfavorable to the polarization,and have good nonlinearity.The final quantum mechanical calculation shows that the designed three D-D-π-A chromophores can significantly reduce the dipole-dipole interaction which is unfavorable to the polarization,and have good microscopic nonlinearity.