Synthesis And Third-order Optical Nonlinear Properties Of Hyperbranched Metal Phthalocyanines Containing Imide Structure

Phthalocyanines have been extensively applied in various fields including d yes, dielectric materials, catalysis, and optical materials due to the special 18-el ectrons conjugated macrocycle of Pc since their accidental discovery over 70 y ears ago. Among Phthalocyanines, hyperbranched phthalocyanines(HPc) have received considerable attention over the past decade. The highl y branched three-dimensional molecular structure gives it unique physical and c hemical properties, such as good solubility, low solution viscosity, no chain ent anglements, and large conjugated structure. In recent years, HPc have becomeo ne of the most promising candidates for third-order nonlinear optical devices b ecause of their large nonlinear susceptibility with fast response time and othere xcellent properities.Imide structure is the basic structure of polyimide(PI) which is an import ant high-performance plastic with many excellent properties, such as excellentth ermal stability, good mechanical properties and other attractive properties.It is n ot only used in the research of polyimide materials, is also widely used in oth er materials’ modification of molecular structure. With excellent thermodynamic performance and improvement of conjugation effect, imide structure can impro ve thermodynamic properties and optical properties of materials.In this paper, we combinate HPc and imide structure as the basic idea, im ide structure was introduced into the hyperbranched phthalocyanine oligomers. We synthesized a series of novel oligomers hyperbranched metal phthalocyanine s containing imide structure. And we choose the oligomers based on the 6FDA to study the third-order nonlinearities of HMePc I oligomers with different centr al metals. The main results include:1、The cyano-ended monomers containing imide structure were synthetised with 4-aminophthalonitrile and anhydride by the typical two-step method used f or polyimide syntheses. Different structures of hyperbranched zinc phthalocyanine oligomers were obtained under the catalytic action of(NH4)2MoO4. The obt ained HPcs exhibited good thermal stabilities, the 5% weight loss temperature of the oligomers varied from 412 to 481℃, which was improved 50-100℃ co mparied with the same HPcs without imide structure. Meanwhile, it is found th at phthalocyanine terminal cyano group was completely converted into carboxyl.And we can study the molecular structure of HPcs through the carboxyl hydro gen by using 1H-NMR. we can calculate numbers of phthalocyanine rings in ol igomers by theory analysis and formula deduction through the integral calculati on of 1H-NMR spectrum by software. The numbers of phthalocyanine rings in oligomers calculated from the integration of 1H-NMR spectrum was approximat ely consistent with the results of the GPC test.2、Moreover,we are interested in the 3rd NLO behaviors of the novel hy perbranched metal phthalocyanines containing imide structure which are not rep orted yet and how different d electron shell structure of the central metal atom(Zn2+,Cu+,Ni2+) effect its third-order nonlinear optical coefficient. We choose the oligomers based on the 6FDA to study the third-order nonlinearities of HMe PcI oligomers with different central metals because of its high molecularweight and good solubility. The results show that HPcCuI and HPc ZnI approximately have same values of χ3 and larger than that of HPcNi I. The existenceof the c enter metal in the phthalocyanine is beneficial to the improvement of itsoptical properties for the reason that the electronics on the d orbital of the transition metal atom and π-conjugated electrons ring of phthalocyanine occur conjugative effect again. And the more d electronics the center metals have, the larger val ues of χ3 are.