Novel ?-conjugated Compounds Based On Phthalonitrile Derivatives:Synthesis And Characterization

Phthalonitrile and its derivatives are the most important precusors of phthalocyanines.Meanwhile,symmetrical benzo-fused aza-BODIPYs could also be prepared from phthalonitrile.Several parts of this thesis are connected to each other by this molecule.Based on the reaction started from phthalonitrile,novel methods have been developed while novel complexes obtained and studied.The works in this thesis are more focused on the study of synthesis methods,mechanism and molecule structure,so the applications of the novel complexes do not play an important role.Double-decker lanthanide(?)phthalocyanines are currently the subject of multiple investigations as a consequence of their exceptional physical and chemical properties.Due to the presence of 7c-radical,these double-decker phthalocyanine complexes show electrochromic properties in both visible region and near-infrared region.Meanwhile,the absorption spectra could been tuned by changing the substituents of Pc rings,which make double-decker phthalocyanines potential electrochromic materials covering all the region from 380 to 2500 nm.There are various methods to synthesize phthalocyanine with both single and double decker structure.Most of these reactions are performed at high temperature,which requires lots of energy.Several reports have been devoted to the low temperature synthesis of phthalocyanines.However,those procedures require prolonged reaction times or excess base.It is necessary to develop a method that can produce phthalocyanine in a rapid,low temperature and atom-economic way.Based on their excellent photophysical properties,BODIPY complexes have been widely used in various applications.Although numerous BODIPYs have been reported,the methods to prepare these compounds are limited.Especially for aza-BODIPYs,there are only several way to obtain them.Moreover,the substituents and symmetrical manners are also restricted.The synthesis of Asymmetric aza-BODIPY analogues are challenges,while there is not any report about asymmetrical benzo-fused aza-BODIPY.The absence of this asymmetric type might limit the development of aza-BODIPY.Chapter 1:We introduce the basic concepts of phthalocyanines and BODIPYs and applications of these dyes.Methods to synthesize these compounds are summarized in detail.Chapter 2:Phthalonitrile has been successfully prepared by retro Diels-Alder reaction.Double-decker lanthanide phthalocyanines with octa-pinene groups are also obtained.The pinene group is a bulky and rigid alkyl rings with remarkable steric hindrance.The introduction of these groups decreases the interaction of molecules and leads to the existence of isomers,which resulting in excellent solubility.Moreover,the bulky groups could also increase the distance between macrocycles in double-decker phthalocyanie molecule,so the absorption in near-infrared region shows significant red shift.The spectra change upon application of voltage could cover both the visible and near-infrared region.Pinene groups also enhance the film-forming ability.Therefore,we are able to fabricate solid film state electrochromic devices with good stability and high color efficiency.Chapter 3:Phthalocyaniene could be prepared at room temperature started from lithium diisopropylamide(LDA)and phthalonitrile.This method is facile and atom-economic.Various phthalonitrile derivatives have been used to verifying the feasibility of the low temperature method.The results show that some phthalonitrile with substituents could also been transformed to phthalocyanines by this way.Chapter 4:By using phthalonitrile and potassium tert-butoxide as reactants,novel asymmetric aza-diisoindolylmethene complexes have been obtained through a new reaction.The further reaction leads to the first asymmetric benzo-fused aza-BODIPY.The aza-BODIPY exhibits a distinctive chromic process upon addition of trifluoroacetic acid.This process can be reversed by adding a very small amount of proton-accepting componds.According to the theory calculation and experimental data,such a TFA-induced process can be attributed to the cleavage and formation of B-N bonds in BODIPY molecules.The chromic phenomenon could be very useful in discrimination between compounds with similar structure.Chapter 5:Novel kinds of condensed ring compounds could be obtained by intramolecular reaction of aza-diisoindolylmethene complexes in Chapter 4.For these unreported structures,numerous work are focused on the mechanism of synthesis and electronic spectra.