Energy Transfer in the Azobenzene-Naphthalene Light Harvesting System

被引:21
作者
Abdallah, Dalia [1 ]
Whelan, Jamie [2 ]
Dust, Julian M. [3 ,4 ]
Hoz, Shmaryahu [5 ]
Buncel, Erwin [1 ]
机构
[1] Queens Univ, Dept Chem, Kingston, ON K7L 3N6, Canada
[2] Royal Mil Coll Canada, Dept Chem & Chem Engn, Kingston, ON K7K 7B4, Canada
[3] Mem Univ Newfoundland, SWGC, Dept Chem, Corner Brook, NF A2H 6P9, Canada
[4] Mem Univ Newfoundland, SWGC, Dept Environm Sci, Corner Brook, NF A2H 6P9, Canada
[5] Bar Ilan Univ, Dept Chem, Ramat Gan, Israel
关键词
FUNCTIONALIZED UNIMOLECULAR INITIATORS; STARBURST DENDRIMER SYNTHESIS; FREE-RADICAL POLYMERIZATION; PHOTOINDUCED MOTIONS; AZO; SPIROPYRAN; REDUCTION; POLYMERS; WALLACH; ISOMERIZATION;
D O I
10.1021/jp901596t
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We have investigated the model light harvesting systems (LHSs) A and B typifying energy transfer (ET) between a naphthalene, Np (donor, D), and an azobenzene, Az (acceptor, A), shown schematically in Scheme 2. These models were actualized as the naphthyl azo molecules 1 and 4 containing a methylene tether (Scheme 1). The methoxy azo molecules 2 and 5, respectively, served as benchmarks for the assessment of ET. Photophysical data, including initial rate constants for photoisomerization (trans to cis, t-1 -> c-1, and cis to trans, c-1 -> t-1), the relevant c-1 -> t-1 quantum yields, and fluorescence quenching with free naphthalene, 3, as D were measured. Therefore, (1) irradiation of 3 at (270 nm) to give 3* generates fluorescence at 340 nm that is 65% quenched by the trans isomer of 2 (t-2) and 15% quenched by c-2. Comparable naphthalenic fluorescence of c-1 (LH model A) is quenched beyond detectability. (2) Rates of photoisomerization were determined spectrophotometrically for c-1 -> t-1 starting from the c-1 photostationary state as compared with the c-2 -> t-2 benchmark. (3) Progressing toward more complex LH systems, the initial rate constants, k(i), for c-4 -> t-4 (LH model B), were measured as compared with the c-5 -> t-5 benchmark. (4) A new criterion for ET (D -> A) efficiency emerges that combines k(i) (c -> t) ratios and light absorption on irradiation (at 270 nm) ratios. On the basis of this new criterion, both I and 4 exhibit virtually quantitative ET efficiency. (5) Quenching data of I (almost complete) and 4 (95%) and ET are discussed by comparison with the relevant model azoarenes, 2 and 5, respectively, and in terms of geometrical considerations. Implications for the extension of the results, notably the new criterion for ET efficiency, in these LH models A and B to the polymer and block copolymer D-(CRR')(n)-A and D-(CRR')(n)-A-(CR '' R''')(m)-D targets are considered.
引用
收藏
页码:6640 / 6647
页数:8
相关论文
共 96 条
  • [1] Multi-armed, TEMPO-functionalized unimolecular initiators for starburst dendrimer synthesis via stable free radical polymerization. 1. Tri azo-functionalized unimer
    Abdallah, D
    Ghani, MAA
    Cunningham, MF
    Kazmaier, PM
    Keoshkerian, B
    Buncel, E
    [J]. CANADIAN JOURNAL OF CHEMISTRY, 2004, 82 (09) : 1393 - 1402
  • [2] Stoichiometric complexes of polyelectrolyte and azo-functionalized surfactant
    Abdallah, Dalia
    Cully, Matthew J.
    Li, Yuzhuo
    Shipp, Devon A.
    [J]. COLLOID AND POLYMER SCIENCE, 2008, 286 (6-7) : 739 - 745
  • [3] Light harvesting and energy transfer in laser-dye-labeled poly(aryl ether) dendrimers
    Adronov, A
    Gilat, SL
    Fréchet, JMJ
    Ohta, K
    Neuwahl, FVR
    Fleming, GR
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (06) : 1175 - 1185
  • [4] A new approach to light-harvesting with dendritic antenna
    Aida, T
    Jiang, DL
    Yashima, E
    Okamoto, Y
    [J]. THIN SOLID FILMS, 1998, 331 (1-2) : 254 - 258
  • [5] Gelation-assisted light harvesting by selective energy transfer from an oligo(p-phenylenevinylene)-based self-assembly to an organic dye
    Ajayaghosh, A
    George, SJ
    Praveen, VK
    [J]. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2003, 42 (03) : 332 - +
  • [6] Mechanistic principles and applications of resonance energy transfer
    Andrews, David L.
    [J]. CANADIAN JOURNAL OF CHEMISTRY, 2008, 86 (09) : 855 - 870
  • [7] [Anonymous], 1999, Resonance Energy Transfer
  • [8] Asakawa M, 1999, CHEM-EUR J, V5, P860, DOI 10.1002/(SICI)1521-3765(19990301)5:3<860::AID-CHEM860>3.0.CO
  • [9] 2-K
  • [10] Photochemical conversion of solar energy
    Balzani, Vincenzo
    Credi, Alberto
    Venturi, Margherita
    [J]. CHEMSUSCHEM, 2008, 1 (1-2) : 26 - 58