The incorporation of organic dyes into host matrices has attracted great interest for developing new functional materials.In this work,two Cd-based layered metal–organic complexes(Cd-LMOCs),i.e.[Cd_(3)(BTB)_(2)(DEF_(...The incorporation of organic dyes into host matrices has attracted great interest for developing new functional materials.In this work,two Cd-based layered metal–organic complexes(Cd-LMOCs),i.e.[Cd_(3)(BTB)_(2)(DEF_(4)]_(n),(1-DEF)and[Cd_(3)(BTB)_(2)(DMF)_(4)·2DMF]_(n),(2-DMF),were synthesized,and three different organic stilbazolium-type dyes were incorporated into the layered Cd-LMOCs:CMAS^(+),which contains an electron-withdrawing group(–CN)on the amine,and DAST^(+)and HMAS^(+),which contain electron-donating groups(–CH_(3),–OH)on their amines.Interestingly,solvent-dependent luminescence chromisms were observed;these only occurred in DMA solvent.The dye@Cd-MOC composites obtained from DMA solvent have been fully characterized by IR,UV-Vis,PXRD,SEM,TEM and TGA;they exhibit blue-shift photoemissions and enhanced quantum yields compared with the pristine Cd-LMOCs and dye samples.After loading with dyes,the photocurrents were diminished by 2 to 6 times.Based on a combination of experimental and theoretical simulations of the dye@Cd-LMOC systems,a two-step solvent-dependent chromism mechanism was proposed:solvent exchange reactions occur firstly,and the dyes then enter the Cd-LMOCs via direct or semi-coordinated bonds between the Cd centers and vip dyes.Specifically,(CMAS)I@1-DMA with direct Cd–N bonds exhibits the highest quantum yield,and a new electron transfer route from the metal centers of the host skeletons to the side groups of the vip dyes has been found.In all,the introduction of electron-withdrawing groups on dyes is beneficial for host–vip interactions.展开更多
Chromism focuses on the phenomena of color change,and the studies in the related area have conventionally been centered on organic dyes.In recent decades,noble metal nanostructures,featured with rich optical propertie...Chromism focuses on the phenomena of color change,and the studies in the related area have conventionally been centered on organic dyes.In recent decades,noble metal nanostructures,featured with rich optical properties arising from their characteristic localized surface plasmon resonances,have emerged as an alternative family of color-rendering agents,and have therefore been introducing new trends into the research realm of chromisms.Here in this review we summarize the related studies on noble metal plasmonic nanostructure related chromisms,which are sorted into four major categories,namely,solvatochromism,sorptiochromism,aggregachromism and chronochromism.For each category,the basic principles(some with comparison to those for dye-related systems)are delineated,followed with examples illustrating the performances and utilizations of representative systems.Of note,we put particular emphasis on the category of chronochromism,which,in our opinion,has not received as much deserved attention yet promises great potential in practical applications.In the final section,we discuss the challenges that plasmonic nanostructures are currently facing,and outlook the opportunities that may emerge in the near future.展开更多
The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as ...The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.展开更多
Dye molecules often change colors(so-called “chromism”) according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coord...Dye molecules often change colors(so-called “chromism”) according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coordination cage(PCC-2), Rhodamine B(1) is transformed from red quinonoid form(1q) into colorless lactone form(1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncommon zwitterion intermediate(1z), followed by converting to 1l, thus accelerating the equilibrium. The chromism is catalyzed by 0.25 mol% of PCC-2, and the reaction rate is improved by 80,400times. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional intermediate by a catalytic amount of the coordination cage provides fundamental insights into molecular isomerization and has potential use in chemical sensing.展开更多
Viologen,as a type of strong electron acceptor,is prone to undergo electron transfer(ET)and change color under external stimuli.However,due to the easy aggrega-tion of viologen molecules,they usually suffer from poorfl...Viologen,as a type of strong electron acceptor,is prone to undergo electron transfer(ET)and change color under external stimuli.However,due to the easy aggrega-tion of viologen molecules,they usually suffer from poorfluorescence emission in the condensed phase.Herein,a new viologen derivative of VioCl_(2)⋅2Cl(1^(2+)⋅2Cl)was designed and synthesized,in which thefluorescence was enhanced by intro-ducing Me-β-CD to weaken the interactions between viologen molecules.Then a viologen-based host-vip supramolecule of 1^(2+)@Me-β-CD was obtained by elec-trostatic interactions.Photo-/chemo-responded vip 1^(2+)supplies 1^(2+)@Me-β-CD,a green and dark purple caused by intramolecular and intermolecular ET.Further-more,1^(2+)@Me-β-CD displays an additional thermal responsive purple color.The triple chromic behaviors all exhibit excellent reversibility and cycling stability.As expected,1^(2+)@Me-β-CD exhibits strong photoluminescence(PL)in solid-liquid dual states,presenting an improved quantum yield(Φ)from 1^(2+)(Φ_(s)=0.37%,Φ_(1)= 16.74%)to=1^(2+)@Me-β-CD(Φ_(s)= 10.45%,Φ_(1)= 25.86%),and thefluores-=cence intensity can be dynamically modulated by light,heat,and acid/base vapors.The multi-responsive chromism and tunablefluorescence of 1^(2+)@Me-β-CD allow for potential applications in information security and smart windows.展开更多
基金supported by the National Natural Science Foundation of China(no.:21771038)National Natural Science Foundation of Fujian Province(2018J01684,2016J01221).
文摘The incorporation of organic dyes into host matrices has attracted great interest for developing new functional materials.In this work,two Cd-based layered metal–organic complexes(Cd-LMOCs),i.e.[Cd_(3)(BTB)_(2)(DEF_(4)]_(n),(1-DEF)and[Cd_(3)(BTB)_(2)(DMF)_(4)·2DMF]_(n),(2-DMF),were synthesized,and three different organic stilbazolium-type dyes were incorporated into the layered Cd-LMOCs:CMAS^(+),which contains an electron-withdrawing group(–CN)on the amine,and DAST^(+)and HMAS^(+),which contain electron-donating groups(–CH_(3),–OH)on their amines.Interestingly,solvent-dependent luminescence chromisms were observed;these only occurred in DMA solvent.The dye@Cd-MOC composites obtained from DMA solvent have been fully characterized by IR,UV-Vis,PXRD,SEM,TEM and TGA;they exhibit blue-shift photoemissions and enhanced quantum yields compared with the pristine Cd-LMOCs and dye samples.After loading with dyes,the photocurrents were diminished by 2 to 6 times.Based on a combination of experimental and theoretical simulations of the dye@Cd-LMOC systems,a two-step solvent-dependent chromism mechanism was proposed:solvent exchange reactions occur firstly,and the dyes then enter the Cd-LMOCs via direct or semi-coordinated bonds between the Cd centers and vip dyes.Specifically,(CMAS)I@1-DMA with direct Cd–N bonds exhibits the highest quantum yield,and a new electron transfer route from the metal centers of the host skeletons to the side groups of the vip dyes has been found.In all,the introduction of electron-withdrawing groups on dyes is beneficial for host–vip interactions.
基金the funding from NSFC(No.21371011,21331001,and 21321001)MOST of China(No.2014CB643800).
文摘Chromism focuses on the phenomena of color change,and the studies in the related area have conventionally been centered on organic dyes.In recent decades,noble metal nanostructures,featured with rich optical properties arising from their characteristic localized surface plasmon resonances,have emerged as an alternative family of color-rendering agents,and have therefore been introducing new trends into the research realm of chromisms.Here in this review we summarize the related studies on noble metal plasmonic nanostructure related chromisms,which are sorted into four major categories,namely,solvatochromism,sorptiochromism,aggregachromism and chronochromism.For each category,the basic principles(some with comparison to those for dye-related systems)are delineated,followed with examples illustrating the performances and utilizations of representative systems.Of note,we put particular emphasis on the category of chronochromism,which,in our opinion,has not received as much deserved attention yet promises great potential in practical applications.In the final section,we discuss the challenges that plasmonic nanostructures are currently facing,and outlook the opportunities that may emerge in the near future.
基金support and facilities to carry out the research work provided by King Khalid University are greatly acknowledged
文摘The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.
基金supported by the Fujian Province Natural Science Foundation (2023J01294)the Natural Science Basic Research Program of Shaanxi (2023-JC-YB-088)+1 种基金the National Natural Science Foundation of China (21501133, 22371067)the China Hunan Provincial Science&Technology Department (2020RC3020, 2021JJ20021,2023JJ40119)。
文摘Dye molecules often change colors(so-called “chromism”) according to the environment variation. However, they are rarely induced by a catalytic amount of cavity. Through encapsulation in the cavity of a porous coordination cage(PCC-2), Rhodamine B(1) is transformed from red quinonoid form(1q) into colorless lactone form(1l) in aprotic polar solutions. The μ4-OH groups in the cavity of PCC-2 are shown to stabilize the uncommon zwitterion intermediate(1z), followed by converting to 1l, thus accelerating the equilibrium. The chromism is catalyzed by 0.25 mol% of PCC-2, and the reaction rate is improved by 80,400times. 1@PCC-2 can be further fabricated to a sol-gel that exhibits ion recognition properties. The resulting encapsulation and stabilization of an unconventional intermediate by a catalytic amount of the coordination cage provides fundamental insights into molecular isomerization and has potential use in chemical sensing.
基金National Natural Science Foundation of China,Grant/Award Numbers:21571126,62271299Shanghai Key Laboratory of High Temperature Superconductors。
文摘Viologen,as a type of strong electron acceptor,is prone to undergo electron transfer(ET)and change color under external stimuli.However,due to the easy aggrega-tion of viologen molecules,they usually suffer from poorfluorescence emission in the condensed phase.Herein,a new viologen derivative of VioCl_(2)⋅2Cl(1^(2+)⋅2Cl)was designed and synthesized,in which thefluorescence was enhanced by intro-ducing Me-β-CD to weaken the interactions between viologen molecules.Then a viologen-based host-vip supramolecule of 1^(2+)@Me-β-CD was obtained by elec-trostatic interactions.Photo-/chemo-responded vip 1^(2+)supplies 1^(2+)@Me-β-CD,a green and dark purple caused by intramolecular and intermolecular ET.Further-more,1^(2+)@Me-β-CD displays an additional thermal responsive purple color.The triple chromic behaviors all exhibit excellent reversibility and cycling stability.As expected,1^(2+)@Me-β-CD exhibits strong photoluminescence(PL)in solid-liquid dual states,presenting an improved quantum yield(Φ)from 1^(2+)(Φ_(s)=0.37%,Φ_(1)= 16.74%)to=1^(2+)@Me-β-CD(Φ_(s)= 10.45%,Φ_(1)= 25.86%),and thefluores-=cence intensity can be dynamically modulated by light,heat,and acid/base vapors.The multi-responsive chromism and tunablefluorescence of 1^(2+)@Me-β-CD allow for potential applications in information security and smart windows.
