π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviolo...π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviologen 3c was modified with a methylnaphthalene group,while 3a and 3b were modified with methyl and benzyl groups,respectively,for comparison.These pyrenoviologens exhibit reversible redox properties and strong fluorescence emission.Electrochromic devices(ECDs)were prepared using pyrenoviologens as the active materials.Notably,naphthalene-containing pyrenoviologen 3c,with its DA-D-A-D conjugated structure,possesses more stable free radicals,enabling it to maintain the radical color for a longer duration after power loss.A series of color-changing devices were successfully assembled.Due to the strong fluorescence of pyrenoviologens and the unique electron transfer effect between them and picric acid(PA),a sensor film with good selectivity and high sensitivity for PA in aqueous solution was prepared using pyrenoviologens as the fluorescent probe.Specifically,3c exhibited the highest sensitivity to PA due to its lowest energy gap.The introduction of the D-A-D-A-D structure is a strategic approach to enhancing photoelectric performance and broadening the application of viologens.展开更多
A series of novel host-vip complexes were synthesized using selenoviologen-based tetracationic cyclophane 1(green box)and various electron-rich vips(G_(1),G_(2),G_(3),and G_(4)).These complexes demonstrated high b...A series of novel host-vip complexes were synthesized using selenoviologen-based tetracationic cyclophane 1(green box)and various electron-rich vips(G_(1),G_(2),G_(3),and G_(4)).These complexes demonstrated high binding affinity and favorable redox properties due to the unique structural characteristics of selenoviologens.Femtosecond transient absorption(fs-TA)spectroscopy revealed that the host-vip complexes exhibited efficient charge separation and enhanced electron transfer.These complexes were subsequently assembled onto the surface of graphitic carbon nitride(g-C_(3)N_(4))through hydrogen bonding interactions between the hydroxyl groups of the vips and the amino groups of g-C_(3)N_(4),forming a series of functionalized composite materials.This assembly strategy facilitated the incorporation of the green box onto the g-C_(3)N_(4)surface,leading to rapid photoinduced electron transfer(PET)and a significant delay in charge recombination.As a result,the photocatalytic hydrogen production efficiency was markedly improved.Notably,the g-C_(3)N_(4)/1⊃G_(4)/Pt composites achieved the highest efficiency for visible-light-driven hydrogen evolution,exhibiting a higher H_(2)evolution rate(2765μmol g^(-1)h^(-1)),an apparent quantum yield(AQY)of 1.08×10^(-2),turnover number(TON)of 216 and turnover frequency(TOF)of 1.5×10^(-2)s^(-1),with a production rate six times greater than that of unmodified g-C_(3)N_(4)/Pt composites.展开更多
基金supported by the Shaanxi Province Technological Innovation Guidance Special(No.2022QFY08-01)the National Key Research and Development Program of China(No.2021YFB3200702)+5 种基金Natural Science Foundation of China(Nos.22201228,22205172,52203240 and 22175138)China Postdoctoral Science Foundation(Nos.2022M712530,2023T160506,and 2022M712497)Fundamental Research Funds for the Central Universities(No.xzy012022017)Young Talent Fund of Association for Science and Technology in Shaanxi(No.20230624)Shaanxi Province Postdoctoral Science Foundation(No.2023b SHTBZZ04)the Youth Innovation Team of Shaanxi Universities。
文摘π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviologen 3c was modified with a methylnaphthalene group,while 3a and 3b were modified with methyl and benzyl groups,respectively,for comparison.These pyrenoviologens exhibit reversible redox properties and strong fluorescence emission.Electrochromic devices(ECDs)were prepared using pyrenoviologens as the active materials.Notably,naphthalene-containing pyrenoviologen 3c,with its DA-D-A-D conjugated structure,possesses more stable free radicals,enabling it to maintain the radical color for a longer duration after power loss.A series of color-changing devices were successfully assembled.Due to the strong fluorescence of pyrenoviologens and the unique electron transfer effect between them and picric acid(PA),a sensor film with good selectivity and high sensitivity for PA in aqueous solution was prepared using pyrenoviologens as the fluorescent probe.Specifically,3c exhibited the highest sensitivity to PA due to its lowest energy gap.The introduction of the D-A-D-A-D structure is a strategic approach to enhancing photoelectric performance and broadening the application of viologens.
基金supported by the National Natural Science Foundation of China(22201228,22205172,22175138)the China Postdoctoral Science Foundation(2022M712530,2023T160506,2022M712497)+4 种基金the Young Talent Fund of Association for Science and Technology in Shaanxi(20230624,20220604)the Shaanxi Province Postdoctoral Science Foundation(2023BSHTBZZ04)the Fundamental Research Funds for the Central Universities(xzy022023009)the Shaanxi Province Technological Innovation Guidance Special(2022QFY08-01)the Youth Innovation Team of Shaanxi Universities.
文摘A series of novel host-vip complexes were synthesized using selenoviologen-based tetracationic cyclophane 1(green box)and various electron-rich vips(G_(1),G_(2),G_(3),and G_(4)).These complexes demonstrated high binding affinity and favorable redox properties due to the unique structural characteristics of selenoviologens.Femtosecond transient absorption(fs-TA)spectroscopy revealed that the host-vip complexes exhibited efficient charge separation and enhanced electron transfer.These complexes were subsequently assembled onto the surface of graphitic carbon nitride(g-C_(3)N_(4))through hydrogen bonding interactions between the hydroxyl groups of the vips and the amino groups of g-C_(3)N_(4),forming a series of functionalized composite materials.This assembly strategy facilitated the incorporation of the green box onto the g-C_(3)N_(4)surface,leading to rapid photoinduced electron transfer(PET)and a significant delay in charge recombination.As a result,the photocatalytic hydrogen production efficiency was markedly improved.Notably,the g-C_(3)N_(4)/1⊃G_(4)/Pt composites achieved the highest efficiency for visible-light-driven hydrogen evolution,exhibiting a higher H_(2)evolution rate(2765μmol g^(-1)h^(-1)),an apparent quantum yield(AQY)of 1.08×10^(-2),turnover number(TON)of 216 and turnover frequency(TOF)of 1.5×10^(-2)s^(-1),with a production rate six times greater than that of unmodified g-C_(3)N_(4)/Pt composites.
