Long-range heterogeneous electron transfer between ferrocene and gold mediated by n-alkane and N-alkyl-carboxamide bridges

被引:133
作者
Sumner, JJ [1 ]
Weber, KS [1 ]
Hockett, LA [1 ]
Creager, SE [1 ]
机构
[1] Clemson Univ, Dept Chem, Clemson, SC 29634 USA
关键词
D O I
10.1021/jp000992v
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
Electron-transfer rates between ferrocene and gold were measured for two series of ferrocene-based alkanethiolate monolayers on Sold electrodes. In one series, the bridge linking the ferrocene group to gold consisted of a simple alkane chain, and in the other, the bridge was modified such that the two methylene linkages immediately adjacent to the ferrocene group were replaced by a carboxamide linkage. Monolayers in both series were studied using a novel ac voltammetry method to measure the standard electron-transfer rate constants for oxidation/reduction of the ferrocene groups. Rate constants were nearly the same for pairs of molecules in the two series when the number of bonds in the direct pathway linking ferrocene to gold was the same, regardless of whether the group immediately adjacent to ferrocene was a pair of methylene units or a carboxamide unit. This observation suggests that the contribution of the carboxamide group to the overall bridge-mediated electronic coupling is not greatly different from that of a pair of methylene groups. An unusual "even-odd effect" in the diminution of rate with chain length for both monolayer series was also noted. Several factors that could cause such an alternation in rate are proposed, including an unusual quantum interference effect in the bridge-mediated coupling that has been predicted theoretically.
引用
收藏
页码:7449 / 7454
页数:6
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共 42 条
[11]   Application of the sequential formula: the electronic coupling and the distance dependence in the electron transfer of ferrocene-terminated alkanethiol monolayers [J].
Hsu, CP .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1997, 438 (1-2) :27-35
[12]   A sequential formula for electronic coupling in long range bridge-assisted electron transfer: Formulation of theory and application to alkanethiol monolayers [J].
Hsu, CP ;
Marcus, RA .
JOURNAL OF CHEMICAL PHYSICS, 1997, 106 (02) :584-598
[13]   In situ monitoring of diffuse double layer structure changes of electrochemically addressable self-assembled monolayers with an atomic force microscope [J].
Hu, K ;
Chai, Z ;
Whitesell, JK ;
Bard, AJ .
LANGMUIR, 1999, 15 (09) :3343-3347
[14]   Effect of electrolytes on the electrochemical behaviour of 11-(ferrocenylcarbonyloxy)undecanethiol SAMs on gold disk electrodes [J].
Ju, HX ;
Leech, D .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 1999, 1 (07) :1549-1554
[15]   Host-guest interaction at a self-assembled monolayer/solution interface: An electrochemical analysis of the inclusion of 11-(ferrocenylcarbonyloxy)undecanethiol by cyclodextrins [J].
Ju, HX ;
Leech, D .
LANGMUIR, 1998, 14 (02) :300-306
[16]   Electrochemical control of the second harmonic generation property of self-assembled monolayers containing a trans-ferrocenyl-nitrophenyl ethylene group on gold [J].
Kondo, T ;
Horiuchi, S ;
Yagi, I ;
Ye, S ;
Uosaki, K .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1999, 121 (02) :391-398
[17]   Effects of alkylchain length on the efficiency of photoinduced electron transfer at gold electrodes modified with self-assembled monolayers of molecules containing porphyrin, ferrocene and thiol separated each other by alkylchains [J].
Kondo, T ;
Kanai, T ;
Iso-o, K ;
Uosaki, K .
ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS, 1999, 212 :23-30
[18]   Overpotential-induced lability of the electronic overlap factor in long-range electrochemical electron transfer: charge and distance dependence [J].
Kornyshev, AA ;
Kuznetsov, AM ;
Nielsen, JU ;
Ulstrup, J .
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2000, 2 (01) :141-144
[19]   COMPARISON OF THE STRUCTURES AND WETTING PROPERTIES OF SELF-ASSEMBLED MONOLAYERS OF NORMAL-ALKANETHIOLS ON THE COINAGE METAL-SURFACES, CU, AG, AU [J].
LAIBINIS, PE ;
WHITESIDES, GM ;
ALLARA, DL ;
TAO, YT ;
PARIKH, AN ;
NUZZO, RG .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1991, 113 (19) :7152-7167
[20]   STRUCTURE AND WETTING PROPERTIES OF OMEGA-ALKOXY-N-ALKANETHIOLATE MONOLAYERS ON GOLD AND SILVER [J].
LAIBINIS, PE ;
BAIN, CD ;
NUZZO, RG ;
WHITESIDES, GM .
JOURNAL OF PHYSICAL CHEMISTRY, 1995, 99 (19) :7663-7676