title: Photocontrollable J-aggregation of a diarylethene-phthalocyanine hybrid and its aggregation-stabilized photochromic behavior.
abstract: The photocontrollable J-aggregation of a diarylethene-phthalocyanine hybrid (T-ZnPc) and its aggregation-stabilized photochromic behavior were investigated by various techniques. T-ZnPc initially exhibited slight J-aggregation tendency in solvents such as chloroform and toluene through conformational planarization effect, but formed much stronger J-aggregates upon the illumination of 254 nm UV light. In darkness, the UV-irradiated solutions gradually returned to their initial state. These phenomena can be explained by the pronounced change in molecular planarity accompanying the reversible isomerization of the diarylethene units of T-ZnPc. Besides, we have found that the thermal stability of the closed-ring diarylethene isomers in molecularly dispersed T-ZnPc is much poorer than that in aggregates. As long as the aggregates were broken, they converted to corresponding open-ring form instantly. This study provided an example of fully photocontrollable aggregation of phthalocyanines and paved a new way for improving the stability of the photochromic systems.
authors.affiliation: The Key Lab of Organic Photoelectrons & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
authors.forename: Jiaxiang
authors.initials: J
authors.lastname: Yi
authors.forename: Zihui
authors.initials: Z
authors.lastname: Chen
authors.forename: Junhui
authors.initials: J
authors.lastname: Xiang
authors.forename: Fushi
authors.initials: F
authors.lastname: Zhang
mesh_terms: D005030:Ethylenes / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry*; D054833:Isoindoles; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010316:Particle Size; D055668:Photochemical Processes; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties; D014466:Ultraviolet Rays; D017967:Zinc Compounds
chemical_list: D005030:Ethylenes; D007211:Indoles; D054833:Isoindoles; D009942:Organometallic Compounds; D017967:Zinc Compounds; C052159:Zn(II)-phthalocyanine