Conjugation length control in soluble poly[2-methoxy-5-((2′-ethylhexyl)oxy)-1,4-phenylenevinylene] (MEHPPV):: Synthesis, optical properties, and energy transfer

被引:186
作者
Padmanaban, G [1 ]
Ramakrishnan, S [1 ]
机构
[1] Indian Inst Sci, Dept Inorgan & Phys Chem, Bangalore 560012, Karnataka, India
关键词
D O I
10.1021/ja9932481
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Poly[2-methoxy-5-((2'-ethylhexyl)oxy)-1,4-phenylenevinylene] (MEHPPV) of varying conjugation length was prepared by the selective thermal elimination of one of the substituents in a suitable precursor polymer. The precursor, a dialkoxy poly(1,4-xylylene) derivative with varying amounts of acctoxy and methoxy groups, was prepared by a competitive nucleophilic substitution of the Wessling polyelectrolyte, using methanol and sodium acetate in acetic acid as nucleophiles. Selective thermal elimination (in solution) of the acetate groups alone yielded MEHPPV of varying conjugation lengths. The selective nature of the acetate elimination was confirmed by H-1 NMR spectroscopy. As expected, both the absorption and emission maxima of the eliminated samples shifted to the red with increasing conjugation length. While there was very little difference between the absorption spectra of thin film and solutions of MEHPPV-x. there was a significant bathochromic shift in the emission spectra of the thin films when compared to their dilute solution spectra. Additionally, separate emission from the various oligomers, which are occasionally visible in solution, is absent in thin films. Energy transfer from short to longer conjugated segments, within a single polymer chain in solution, was inferred by comparison of the fluorescence spectra of the partially conjugated polymers with those expected from a system where simultaneous independent emission occurs from a similar collection of noninteracting oligophenylenevinylene (OPV) molecules. The latter was calculated assuming a statistically random substitution/elimination process of the precursor in conjunction with the fluorescence spectral data of OPV's reported by previous workers. The extent of energy transfer increases as the average conjugation length increases. Furthermore, unlike in the model oligomers, in the case of polymers the fluorescence quantum yield in solution rapidly decreases with increase in the average conjugation length.
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页码:2244 / 2251
页数:8
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共 55 条
  • [1] Blue electroluminescent polymers:: Control of conjugation length by kink linkages and substituents in the poly(p-phenylenevinylene)-related copolymers
    Ahn, T
    Jang, MS
    Shim, HK
    Hwang, DH
    Zyung, T
    [J]. MACROMOLECULES, 1999, 32 (10) : 3279 - 3285
  • [2] Fluorescence quantum yield of poly(p-phenylenevinylene) prepared via the paracyclophene route: Effect of chain length and interchain contacts
    Bazan, GC
    Miao, YJ
    Renak, ML
    Sun, BJ
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1996, 118 (11) : 2618 - 2624
  • [3] PHOTOLUMINESCENCE AND ELECTROLUMINESCENCE EFFICIENCY IN POLY(DIALKOXY-P-PHENYLENEVINYLENE)
    BRAUN, D
    STARING, EGJ
    DEMANDT, RCJE
    RIKKEN, GLJ
    KESSENER, YARR
    VENHUIZEN, AHJ
    [J]. SYNTHETIC METALS, 1994, 66 (01) : 75 - 79
  • [4] VISIBLE-LIGHT EMISSION FROM SEMICONDUCTING POLYMER DIODES
    BRAUN, D
    HEEGER, AJ
    [J]. APPLIED PHYSICS LETTERS, 1991, 58 (18) : 1982 - 1984
  • [5] ELECTROLUMINESCENCE FROM MULTILAYER CONJUGATED POLYMER DEVICES - SPATIAL CONTROL OF EXCITON FORMATION AND EMISSION
    BROWN, AR
    GREENHAM, NC
    BURROUGHES, JH
    BRADLEY, DDC
    FRIEND, RH
    BURN, PL
    KRAFT, A
    HOLMES, AB
    [J]. CHEMICAL PHYSICS LETTERS, 1992, 200 (1-2) : 46 - 54
  • [6] BLUE-SHIFTED ELECTROLUMINESCENCE FROM A STABLE PRECURSOR TO POLY(P-PHENYLENE VINYLENE)
    BROWN, AR
    BURN, PL
    BRADLEY, DDC
    FRIEND, RH
    KRAFT, A
    HOLMES, AB
    [J]. MOLECULAR CRYSTALS AND LIQUID CRYSTALS, 1992, 216-18 : 111 - 116
  • [7] CHEMICAL TUNING OF ELECTROLUMINESCENT COPOLYMERS TO IMPROVE EMISSION EFFICIENCIES AND ALLOW PATTERNING
    BURN, PL
    HOLMES, AB
    KRAFT, A
    BRADLEY, DDC
    BROWN, AR
    FRIEND, RH
    GYMER, RW
    [J]. NATURE, 1992, 356 (6364) : 47 - 49
  • [8] PRECURSOR ROUTE CHEMISTRY AND ELECTRONIC-PROPERTIES OF POLY(P-PHENYLENE-VINYLENE), POLY[(2,5-DIMETHYL-P-PHENYLENE)VINYLENE] AND POLY[(2,5-DIMETHOXY-P-PHENYLENE)VINYLENE]
    BURN, PL
    BRADLEY, DDC
    FRIEND, RH
    HALLIDAY, DA
    HOLMES, AB
    JACKSON, RW
    KRAFT, A
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 1992, (23): : 3225 - 3231
  • [9] CHEMICAL TUNING OF THE ELECTRONIC-PROPERTIES OF POLY(P-PHENYLENEVINYLENE)-BASED COPOLYMERS
    BURN, PL
    KRAFT, A
    BAIGENT, DR
    BRADLEY, DDC
    BROWN, AR
    FRIEND, RH
    GYMER, RW
    HOLMES, AB
    JACKSON, RW
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (22) : 10117 - 10124
  • [10] Insoluble poly[2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] for use in multilayer light-emitting diodes
    Burn, PL
    Grice, AW
    Tajbakhsh, A
    Bradley, DDC
    Thomas, AC
    [J]. ADVANCED MATERIALS, 1997, 9 (15) : 1171 - &