Preparation And Nonlinear Optical Properties Of Metal Phthalocyanine Axially Substituted By Anthraquinone

As a very unique and versatile tool,laser has received extensive attention since its birth.However,with the continuous improvement of laser energy and power,while expanding the application field of laser,it also increases the possibility of damage to the human body and precision equipment.Therefore,laser protection becomes particularly important.Nonlinear optical?NLO?material is an ideal material that can realize passive laser protection.Its characterized is by low transmittance when the laser input intensity is low,and low transmittance when the input intensity exceeds a certain level.This characteristic makes NLO materials can be used to reduce laser damage to human eyes and other tissues or organs.The optical limiting device made of NLO material can also protect laser sensitive equipment and instruments.As a promising optical material,the development of NLO materials has always been the focus of research in the field of optics.At present,in the research of NLO materials,the relationship between the nonlinear response and the structure-property of the material,especially the relationship between the construction of the donor-acceptor molecular structure and photoinduced electron/energy transfer and nonlinear absorption performance is an urgent need to explore.In this thesis,anthraquinone is connected to phthalocyanine through covalent bond from the axial direction,and several phthalocyanine compounds with axially substituted anthraquinone are obtained.Based on the design idea of constructing the electron and energy transfer model in the donor-acceptor structure,the photophysical properties,molecular orbital energy levels,and the relationship between molecular structure and NLO performance of the metal phthalocyanines substituted axially by anthraquinone are discussed.The research content is as follows:1)Taking phthalocyanine as the research object,two phthalocyanine compounds?MePc-Aqn?with axial substitution of anthraquinone were prepared.Among them,the lanthanum phthalocyanine axially substituted by anthraquinone?LaPc-Aqn?combines the comprehensive advantages of phthalocyanine,anthraquinone,rare metal heavy atom effect,donor-acceptor structure,such as fast photoelectric response of phthalocyanine,large?conjugated electrons of anthraquinone cloud system,efficient intersystem crossing brought by heavy atom effect,efficient electron migration in molecules,etc.Significant fluorescence quenching,decreased fluorescence lifetime,and decreased fluorescence quantum yield indicate that the intramolecular photoelectron/energy transfer process after anthraquinone modification of phthalocyanine is more efficient.Under the same test conditions,the two new phthalocyanines axially substituted by anthraquinone have a larger nonlinear absorption coefficient(?_eff)than the unmodified phthalocyanine,especially the nonlinear absorption of LaPc-Aqn is significantly enhanced.2)In order to further improve the nonlinear absorption coefficient of the material,combined with the unique three-dimensional structure of the hyperbranched metal phthalocyanine?HMePc?and strong chemical stability,two hyperbranched metal phthalocyanines axially substituted by anthraquinone?HMePc-Aqn?were synthesized in the same way.HMePc-Aqn shows a larger nonlinear absorption coefficient than MePc-Aqn,especially the?_eff value of HLaPc-Aqn reaches 1.52 cm GW^-1,which is 3times higher than LaPc-Aqn.The hyperbranched structure allows HMePc-Aqn to exhibit a more efficient photo-induced electron transfer/energy transfer process than MePc-Aqn,greater intra-molecular energy level differences,and further expand the electron flow capability and range.In addition,by introducing hyperbranched lanthanum phthalocyanines into polyphenylene sulfone?PPSU?to form phthalocyanine-polymer composite films,the films show uniformity and excellent optical limiting performance.In summary,two series of new nonlinear optical phthalocyanine materials were successfully prepared by the method of axially replacing phthalocyanine with anthraquinone.Moreover,through the comparative analysis of the structure and properties of the new phthalocyanine,it was proved that the obtained phthalocyanine materials showed improved nonlinear optical properties,and the prepared phthalocyanine-polymer composite film had good laser protection performance.More importantly,this thesis provides a new idea for the structural design of nonlinear optical materials at the molecular level,and can be improved on the basis.