Electron transfer driven by proton fluctuations in a hydrogen-bonded donor - Acceptor assembly

Justin M. Hodgkiss; Niels H. Damrauer; Steve Pressé; Joel Rosenthal; Daniel G. Nocera

doi:10.1021/jp056703q

Electron transfer driven by proton fluctuations in a hydrogen-bonded donor - Acceptor assembly

Justin M. Hodgkiss, Niels H. Damrauer, Steve Pressé, Joel Rosenthal, Daniel G. Nocera

Research output: Contribution to journal › Article › peer-review

53 Scopus citations

Abstract

The temperature-isotope dependence of proton-coupled electron transfer (PCET) for a noncovalent molecular dyad is reported. The system consists of an excited-state Zn(II) porphyrin that transfers an electron to a naphthalene diimide acceptor through an amidinium-carboxylate interface. Two different isotope effects are observed for variant temperature regimes. A reverse isotope effect (i.e., k_H/k_D < 1) is observed as T approaches 120 K (k_H/k_D = 0.9, 120 K), whereas a normal isotope effect (i.e., k_H/k_D > 1) is recovered as the temperature is increased (k_H/k_D = 1.2, 300 K). The transition between these limits is smooth, with a crossover temperature of T ∼ 160 K. These observations are in accordance with charge-transfer dynamics that are susceptible to bath-induced fluctuations in the proton coordinate.

Original language	English (US)
Pages (from-to)	18853-18858
Number of pages	6
Journal	Journal of Physical Chemistry B
Volume	110
Issue number	38
DOIs	https://doi.org/10.1021/jp056703q
State	Published - Sep 28 2006
Externally published	Yes

ASJC Scopus subject areas

Physical and Theoretical Chemistry
Surfaces, Coatings and Films
Materials Chemistry

Access to Document

10.1021/jp056703q

Cite this

@article{f7b9269882b1429a8cb24837b6d392ff,

title = "Electron transfer driven by proton fluctuations in a hydrogen-bonded donor - Acceptor assembly",

abstract = "The temperature-isotope dependence of proton-coupled electron transfer (PCET) for a noncovalent molecular dyad is reported. The system consists of an excited-state Zn(II) porphyrin that transfers an electron to a naphthalene diimide acceptor through an amidinium-carboxylate interface. Two different isotope effects are observed for variant temperature regimes. A reverse isotope effect (i.e., kH/kD < 1) is observed as T approaches 120 K (kH/kD = 0.9, 120 K), whereas a normal isotope effect (i.e., kH/kD > 1) is recovered as the temperature is increased (kH/kD = 1.2, 300 K). The transition between these limits is smooth, with a crossover temperature of T ∼ 160 K. These observations are in accordance with charge-transfer dynamics that are susceptible to bath-induced fluctuations in the proton coordinate.",

author = "Hodgkiss, {Justin M.} and Damrauer, {Niels H.} and Steve Press{\'e} and Joel Rosenthal and Nocera, {Daniel G.}",

year = "2006",

month = sep,

day = "28",

doi = "10.1021/jp056703q",

language = "English (US)",

volume = "110",

pages = "18853--18858",

journal = "Journal of Physical Chemistry B",

issn = "1520-6106",

number = "38",

}

TY - JOUR

T1 - Electron transfer driven by proton fluctuations in a hydrogen-bonded donor - Acceptor assembly

AU - Hodgkiss, Justin M.

AU - Damrauer, Niels H.

AU - Pressé, Steve

AU - Rosenthal, Joel

AU - Nocera, Daniel G.

PY - 2006/9/28

Y1 - 2006/9/28

N2 - The temperature-isotope dependence of proton-coupled electron transfer (PCET) for a noncovalent molecular dyad is reported. The system consists of an excited-state Zn(II) porphyrin that transfers an electron to a naphthalene diimide acceptor through an amidinium-carboxylate interface. Two different isotope effects are observed for variant temperature regimes. A reverse isotope effect (i.e., kH/kD < 1) is observed as T approaches 120 K (kH/kD = 0.9, 120 K), whereas a normal isotope effect (i.e., kH/kD > 1) is recovered as the temperature is increased (kH/kD = 1.2, 300 K). The transition between these limits is smooth, with a crossover temperature of T ∼ 160 K. These observations are in accordance with charge-transfer dynamics that are susceptible to bath-induced fluctuations in the proton coordinate.

AB - The temperature-isotope dependence of proton-coupled electron transfer (PCET) for a noncovalent molecular dyad is reported. The system consists of an excited-state Zn(II) porphyrin that transfers an electron to a naphthalene diimide acceptor through an amidinium-carboxylate interface. Two different isotope effects are observed for variant temperature regimes. A reverse isotope effect (i.e., kH/kD < 1) is observed as T approaches 120 K (kH/kD = 0.9, 120 K), whereas a normal isotope effect (i.e., kH/kD > 1) is recovered as the temperature is increased (kH/kD = 1.2, 300 K). The transition between these limits is smooth, with a crossover temperature of T ∼ 160 K. These observations are in accordance with charge-transfer dynamics that are susceptible to bath-induced fluctuations in the proton coordinate.

UR - http://www.scopus.com/inward/record.url?scp=33749639818&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33749639818&partnerID=8YFLogxK

U2 - 10.1021/jp056703q

DO - 10.1021/jp056703q

M3 - Article

C2 - 16986876

AN - SCOPUS:33749639818

SN - 1520-6106

VL - 110

SP - 18853

EP - 18858

JO - Journal of Physical Chemistry B

JF - Journal of Physical Chemistry B

IS - 38

ER -

Electron transfer driven by proton fluctuations in a hydrogen-bonded donor - Acceptor assembly

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this