It takes more than an imine

The role of the central atom on the electron-accepting ability of benzotriazole and benzothiadiazole oligomers

Dinesh G. Patel, Fude Feng, Yu Ya Ohnishi, Khalil A. Abboud, So Hirata, Kirk S. Schanze, John R. Reynolds

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

We report on the comparison of the electronic and photophysical properties of a series of related donor-acceptor-donor oligomers incorporating the previously known 2H-benzo[d]-[1,2,3]triazole (BTz) moiety as the acceptor and the recently reported BTzTD acceptor, a hybrid of BTz and 2,1,3-benzothiadiazole (BTD). Although often implied in the polymer literature that BTz has good acceptor character, we show that this moiety is best described as a weak acceptor. We present electrochemical, computational, and photophysical evidence supporting our assertion that BTzTD is a strong electron acceptor while maintaining the alkylation ability of the BTz moiety. Our results show that the identity of the central atom (N or S) in the benzo-fused heterocyclic ring plays an important role in both the electron-accepting and the electron-donating ability of acceptor moieties with sulfur imparting a greater electron-accepting ability and nitrogen affording greater electron-donating character. We report on the X-ray crystal structure of a BTzTD trimer, which exhibits greater local aromatic character in the region of the triazole ring and contains an electron-deficient sulfur that imparts strong electron-accepting ability. Additionally, we examine the transient absorption spectra of BTzTD and BTz oligomers and report that the BTz core promotes efficient intersystem crossing to the triplet state, while the presence of the thiadiazole moiety in BTzTD leads to a negligible triplet yield. Additionally, while BTz does not function as a good acceptor, oligomers containing this moiety do function as excellent sensitizers for the generation of singlet oxygen.

Original languageEnglish (US)
Pages (from-to)2599-2612
Number of pages14
JournalJournal of the American Chemical Society
Volume134
Issue number5
DOIs
StatePublished - Feb 8 2012

Fingerprint

Imines
Oligomers
Electrons
Atoms
Triazoles
Sulfur
Thiadiazoles
Singlet Oxygen
Alkylation
benzo-1,2,3-thiadiazole
benzotriazole
Absorption spectra
Polymers
Nitrogen
Crystal structure
X-Rays
X rays
Oxygen

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Patel, Dinesh G. ; Feng, Fude ; Ohnishi, Yu Ya ; Abboud, Khalil A. ; Hirata, So ; Schanze, Kirk S. ; Reynolds, John R. / It takes more than an imine : The role of the central atom on the electron-accepting ability of benzotriazole and benzothiadiazole oligomers. In: Journal of the American Chemical Society. 2012 ; Vol. 134, No. 5. pp. 2599-2612.
@article{a25d45ede6784320958245b3988fbed3,
title = "It takes more than an imine: The role of the central atom on the electron-accepting ability of benzotriazole and benzothiadiazole oligomers",
abstract = "We report on the comparison of the electronic and photophysical properties of a series of related donor-acceptor-donor oligomers incorporating the previously known 2H-benzo[d]-[1,2,3]triazole (BTz) moiety as the acceptor and the recently reported BTzTD acceptor, a hybrid of BTz and 2,1,3-benzothiadiazole (BTD). Although often implied in the polymer literature that BTz has good acceptor character, we show that this moiety is best described as a weak acceptor. We present electrochemical, computational, and photophysical evidence supporting our assertion that BTzTD is a strong electron acceptor while maintaining the alkylation ability of the BTz moiety. Our results show that the identity of the central atom (N or S) in the benzo-fused heterocyclic ring plays an important role in both the electron-accepting and the electron-donating ability of acceptor moieties with sulfur imparting a greater electron-accepting ability and nitrogen affording greater electron-donating character. We report on the X-ray crystal structure of a BTzTD trimer, which exhibits greater local aromatic character in the region of the triazole ring and contains an electron-deficient sulfur that imparts strong electron-accepting ability. Additionally, we examine the transient absorption spectra of BTzTD and BTz oligomers and report that the BTz core promotes efficient intersystem crossing to the triplet state, while the presence of the thiadiazole moiety in BTzTD leads to a negligible triplet yield. Additionally, while BTz does not function as a good acceptor, oligomers containing this moiety do function as excellent sensitizers for the generation of singlet oxygen.",
author = "Patel, {Dinesh G.} and Fude Feng and Ohnishi, {Yu Ya} and Abboud, {Khalil A.} and So Hirata and Schanze, {Kirk S.} and Reynolds, {John R.}",
year = "2012",
month = "2",
day = "8",
doi = "10.1021/ja207978v",
language = "English (US)",
volume = "134",
pages = "2599--2612",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "5",

}

It takes more than an imine : The role of the central atom on the electron-accepting ability of benzotriazole and benzothiadiazole oligomers. / Patel, Dinesh G.; Feng, Fude; Ohnishi, Yu Ya; Abboud, Khalil A.; Hirata, So; Schanze, Kirk S.; Reynolds, John R.

In: Journal of the American Chemical Society, Vol. 134, No. 5, 08.02.2012, p. 2599-2612.

Research output: Contribution to journalArticle

TY - JOUR

T1 - It takes more than an imine

T2 - The role of the central atom on the electron-accepting ability of benzotriazole and benzothiadiazole oligomers

AU - Patel, Dinesh G.

AU - Feng, Fude

AU - Ohnishi, Yu Ya

AU - Abboud, Khalil A.

AU - Hirata, So

AU - Schanze, Kirk S.

AU - Reynolds, John R.

PY - 2012/2/8

Y1 - 2012/2/8

N2 - We report on the comparison of the electronic and photophysical properties of a series of related donor-acceptor-donor oligomers incorporating the previously known 2H-benzo[d]-[1,2,3]triazole (BTz) moiety as the acceptor and the recently reported BTzTD acceptor, a hybrid of BTz and 2,1,3-benzothiadiazole (BTD). Although often implied in the polymer literature that BTz has good acceptor character, we show that this moiety is best described as a weak acceptor. We present electrochemical, computational, and photophysical evidence supporting our assertion that BTzTD is a strong electron acceptor while maintaining the alkylation ability of the BTz moiety. Our results show that the identity of the central atom (N or S) in the benzo-fused heterocyclic ring plays an important role in both the electron-accepting and the electron-donating ability of acceptor moieties with sulfur imparting a greater electron-accepting ability and nitrogen affording greater electron-donating character. We report on the X-ray crystal structure of a BTzTD trimer, which exhibits greater local aromatic character in the region of the triazole ring and contains an electron-deficient sulfur that imparts strong electron-accepting ability. Additionally, we examine the transient absorption spectra of BTzTD and BTz oligomers and report that the BTz core promotes efficient intersystem crossing to the triplet state, while the presence of the thiadiazole moiety in BTzTD leads to a negligible triplet yield. Additionally, while BTz does not function as a good acceptor, oligomers containing this moiety do function as excellent sensitizers for the generation of singlet oxygen.

AB - We report on the comparison of the electronic and photophysical properties of a series of related donor-acceptor-donor oligomers incorporating the previously known 2H-benzo[d]-[1,2,3]triazole (BTz) moiety as the acceptor and the recently reported BTzTD acceptor, a hybrid of BTz and 2,1,3-benzothiadiazole (BTD). Although often implied in the polymer literature that BTz has good acceptor character, we show that this moiety is best described as a weak acceptor. We present electrochemical, computational, and photophysical evidence supporting our assertion that BTzTD is a strong electron acceptor while maintaining the alkylation ability of the BTz moiety. Our results show that the identity of the central atom (N or S) in the benzo-fused heterocyclic ring plays an important role in both the electron-accepting and the electron-donating ability of acceptor moieties with sulfur imparting a greater electron-accepting ability and nitrogen affording greater electron-donating character. We report on the X-ray crystal structure of a BTzTD trimer, which exhibits greater local aromatic character in the region of the triazole ring and contains an electron-deficient sulfur that imparts strong electron-accepting ability. Additionally, we examine the transient absorption spectra of BTzTD and BTz oligomers and report that the BTz core promotes efficient intersystem crossing to the triplet state, while the presence of the thiadiazole moiety in BTzTD leads to a negligible triplet yield. Additionally, while BTz does not function as a good acceptor, oligomers containing this moiety do function as excellent sensitizers for the generation of singlet oxygen.

UR - http://www.scopus.com/inward/record.url?scp=84856759258&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84856759258&partnerID=8YFLogxK

U2 - 10.1021/ja207978v

DO - 10.1021/ja207978v

M3 - Article

VL - 134

SP - 2599

EP - 2612

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 5

ER -