The dimer of methyl 2-naphthoate (I) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation ...The dimer of methyl 2-naphthoate (I) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect. the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.展开更多
Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materi...Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materials for the design and manufacture of advanced devices.Herein,a comb-like photoreactive coordination polymer,formulated as{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-ppe)]·H_(2)O}_(n)(1),was prepared based on the hydrothermal reaction between Zn(NO_(3))2·6H_(2)O,5-chlorobenzene-1,3-dicarboxylic acid(5-Cl-1,3-H_(2)BDC)and 1-(2-pyridyl)-2-(3-pyridyl)-ethylene(2,3-ppe).Upon irradiation with sunlight,the 1H NMR spectroscopy,UV-vis absorption spectroscopy and single crystal X-ray diffraction analyses results indicated that 1 can undergo a[^(2+)2]photocycloaddition reaction and thus generate a unique ladder-like coordination chain{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-bpbpcb)_(0.5)]·H_(2)O}n(1a,2,3-bpbpcb=1,3-bis(2-pyridyl)-2,4-bis(3-pyridyl)cyclobutane)via single-crystal to single-crystal(SCSC)transformation.Upon irradiation of UV light with a wavelength of 254 nm,the newly formed coordination chain 1a can undergo a reversible cycloreversion reaction and return to 1.The reversible photo-controllable cycloaddition-cycloreversion reaction between 1 and 1a also exhibits an interesting behavior of photo-switchable fluorescence.The reversible structural transformation and fluorescence switching behavior of 1 make it a potential photo-controlled intelligent material for optical information storage,optical anti-counterfeiting,fluorescence sensors and other fields.展开更多
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Project supported by the National Natural Science Foundation of China.
文摘The dimer of methyl 2-naphthoate (I) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect. the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.
基金supported by the National Natural Science Foundation of China(21201068)the Major Projects of Natural Science Research in Universities of Jiangsu Province(20KJA150002)+2 种基金the Natural Science Research Program of Huaian Science and Technology Bureau(HAB202156)the Huaishang Talent Program of Huaian,the Open Project of Key Laboratory for Chemistry of Low-Dimensional Materials in Universities of Jiangsu Province(Grant JSKC24027)the Excellent Scientific and Technological Innovation Team of Advanced Energy Materials Chemistry in Universities of Jiangsu Province and the Innovative Training Program for College Students.
文摘Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materials for the design and manufacture of advanced devices.Herein,a comb-like photoreactive coordination polymer,formulated as{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-ppe)]·H_(2)O}_(n)(1),was prepared based on the hydrothermal reaction between Zn(NO_(3))2·6H_(2)O,5-chlorobenzene-1,3-dicarboxylic acid(5-Cl-1,3-H_(2)BDC)and 1-(2-pyridyl)-2-(3-pyridyl)-ethylene(2,3-ppe).Upon irradiation with sunlight,the 1H NMR spectroscopy,UV-vis absorption spectroscopy and single crystal X-ray diffraction analyses results indicated that 1 can undergo a[^(2+)2]photocycloaddition reaction and thus generate a unique ladder-like coordination chain{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-bpbpcb)_(0.5)]·H_(2)O}n(1a,2,3-bpbpcb=1,3-bis(2-pyridyl)-2,4-bis(3-pyridyl)cyclobutane)via single-crystal to single-crystal(SCSC)transformation.Upon irradiation of UV light with a wavelength of 254 nm,the newly formed coordination chain 1a can undergo a reversible cycloreversion reaction and return to 1.The reversible photo-controllable cycloaddition-cycloreversion reaction between 1 and 1a also exhibits an interesting behavior of photo-switchable fluorescence.The reversible structural transformation and fluorescence switching behavior of 1 make it a potential photo-controlled intelligent material for optical information storage,optical anti-counterfeiting,fluorescence sensors and other fields.
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.
