Photochromism due to organometallic ring-closure through C−C linkage has never been attained.In this work,we report a preliminary approach to achieve T-type photochromism by creating a metallacyclopentadiene biradical...Photochromism due to organometallic ring-closure through C−C linkage has never been attained.In this work,we report a preliminary approach to achieve T-type photochromism by creating a metallacyclopentadiene biradical under light irradiation.A class of CuPt2 phenylacetylide compounds was prepared with distinguished photochromic recyclability and durability,which involved the formation of thermally sensitive copper(I)-butadienyl,five-membered ring through copper(I)-participated ring-closure.Upon UV light irradiation,the metallacyclopentadiene with copper(I)center chelated by 1,3-butadiene-1,4-diyl biradical was generated through photochemical C-C linkage of two face-to-face oriented ethynyl units in close proximity,giving rise to a drastic change in UV-vis absorption spectrum.When UV light irradiation was ceased,decoloration occurred through thermal cycloreversion,which endowed the photochromic CuPt2 complexes with self-recovery characteristics.Electron paramagnetic resonance(EPR)spectral study confirmed a biradical feature of a ring-closed isomer.The thermal decoloration half-lives at ambient temperature were regulated from seconds to hours by increasing F substituents in phenylethynyl ligands.展开更多
基金This work was supported by the National Natural Science Foundation of China(grant nos.92061202,22175181,and 21531008)the Fujian Science and Technology Project(grant no.2020L3022)the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB20000000).
文摘Photochromism due to organometallic ring-closure through C−C linkage has never been attained.In this work,we report a preliminary approach to achieve T-type photochromism by creating a metallacyclopentadiene biradical under light irradiation.A class of CuPt2 phenylacetylide compounds was prepared with distinguished photochromic recyclability and durability,which involved the formation of thermally sensitive copper(I)-butadienyl,five-membered ring through copper(I)-participated ring-closure.Upon UV light irradiation,the metallacyclopentadiene with copper(I)center chelated by 1,3-butadiene-1,4-diyl biradical was generated through photochemical C-C linkage of two face-to-face oriented ethynyl units in close proximity,giving rise to a drastic change in UV-vis absorption spectrum.When UV light irradiation was ceased,decoloration occurred through thermal cycloreversion,which endowed the photochromic CuPt2 complexes with self-recovery characteristics.Electron paramagnetic resonance(EPR)spectral study confirmed a biradical feature of a ring-closed isomer.The thermal decoloration half-lives at ambient temperature were regulated from seconds to hours by increasing F substituents in phenylethynyl ligands.
