Study On Photochromic Properties Of N-heterocyclic Aromatic Compounds

Photochromic materials have been widely applied in many fields such as glare protection,smart windows,photocatalysis,solar energy conversion,photo data storage,photo switches,and so on.M.Irie,the International photochromic researcher authority,has published the book named "New Frontiers in Photochromism" and points out exploring new photochromic materials,improving the photochromic reaction performance,developing the undiscovered light response in this book.These contents are still an significant frontier research fields of photochromism.This paper mainly focuses on the study of electron-transfer photochromic properties of N-heterocyclic aromatic compounds,expanding the "mentallviologen" photochromic system.In addition,creating a new material system of singlet oxygen generation,and also carrying out the study of viologen compounds with two-photon absorption discoloration properties for the first time.The main discoveries and innovations:1.Surrounding by the scientific problems namely "what is the smallest electron acceptor of stable free radical",finding monocyclic aromatic molecules,such as pyrazine,can effectively serve as an electron acceptor of electron-transfer photochromic materials,and can control the changing color of materials and the free radicals stability of color material products by changing the coordination way for the first time.This work enriches the "mentallviologen" photochromic system which is expanded by our previous work,additionally,providing a new candidate ligand in photochromism.These results have been published in the journal called Chem.Commun.(IF = 6.57).2.One the basis of the work mentioned above,a new photochromic compound is accidentally discovered.It has many advantages compared to others,which is easy synthesized,has simple structure,good water-stability and photo induced singlet oxygen generation.What's more,pointing out that the singlet oxygen generates from the energy-transfer process between single excited states of photochromic materials and triple ground states of oxygen.The work develops the new material system with photoproduction of singlet oxygen,and also provides candidate materials for photosynthesis and photodynamic therapy.3.In the research of "what is the structure beneficial for the red/near-infrared light induced photochromism",the research approach by two-photon absorption which is used to expanding the response of light band is put forward.Interestingly,the first electron-transfer photochromic compound has been synthesized,whose light response spectrum to red light area.The work extends the application of the elelectron-transfer photochromic materials,and provides a new technical solutions for the materials with improvement of response performance of light.The main contents of this paper:In the first chapter,it introduces the related background of this work,topic basis and purposes,and also the main scientific discoveries and research progresses;in the second chapter,we mainly show the experimental reagents,apparatus and test conditions;in the third chapter,it mainly introduces about monocyclic aromatic molecules with photochromic phenomenon research;as for the fourth chapter,we introduce the photochromic process with singlet oxygen generation;in the fifth chapter,it mainly explores the synthesis of near-infrared electron-transfer photochromic compounds;in the sixth chapter,it presents the summary and prospect of the whole work of this thesis.