Fast and stable photochromic oxazines

Massimiliano Tomasulo, Salvatore Sortino, Andrew J P White, Francisco Raymo

Research output: Contribution to journalArticle

114 Citations (Scopus)

Abstract

We have designed and synthesized two photochromic compounds incorporating fused indoline and benzooxazine fragments. Variable-temperature 1H NMR spectroscopy demonstrates that their central [1,3]oxazine ring opens thermally with free energy barriers ranging from 14 to 19 kcal mol -1. The ring-opened species reverts rapidly to the original isomer and can only be detected after chemical trapping. Specifically, the nucleophilic attack of a hydroxide anion to the indolium cation of the ring-opened species prevents re-isomerization. Laser excitation of both compounds induces the opening of the [1,3]oxazine ring in less than 6 ns with quantum yields up to 0.1. The photoinduced ring opening generates a 4-nitrophenolate chromophore, which absorbs strongly at 440 nm. The photogenerated species reverts to the original form with a lifetime of 22 ns for both compounds. Thus, these transformations can be exploited to interconvert the two isomers of each species with nanosecond switching speeds. Furthermore, thousands of switching cycles can be repeated consecutively without any sign of degradation, even in the presence of molecular oxygen. These processes can be reproduced efficiently in poly(methyl methacrylate) matrixes. Under these conditions, the thermal re-isomerization occurs with biexponential kinetics in submillisecond time scales. In principle, the fast isomerization kinetics and excellent fatigue resistance of both compounds offer the opportunity to modulate rapidly and efficiently a variety of molecular and macroscopic properties. Thus, our molecular design can evolve into the realization of a new family of photochromic compounds and materials with promising photoresponsive character.

Original languageEnglish
Pages (from-to)8180-8189
Number of pages10
JournalJournal of Organic Chemistry
Volume70
Issue number20
DOIs
StatePublished - Sep 20 2005

Fingerprint

Oxazines
Isomerization
Isomers
Kinetics
Laser excitation
Molecular oxygen
Energy barriers
Quantum yield
Polymethyl Methacrylate
Chromophores
Nuclear magnetic resonance spectroscopy
Free energy
Anions
Cations
Fatigue of materials
Degradation
Temperature

ASJC Scopus subject areas

  • Organic Chemistry

Cite this

Tomasulo, M., Sortino, S., White, A. J. P., & Raymo, F. (2005). Fast and stable photochromic oxazines. Journal of Organic Chemistry, 70(20), 8180-8189. https://doi.org/10.1021/jo051417w

Fast and stable photochromic oxazines. / Tomasulo, Massimiliano; Sortino, Salvatore; White, Andrew J P; Raymo, Francisco.

In: Journal of Organic Chemistry, Vol. 70, No. 20, 20.09.2005, p. 8180-8189.

Research output: Contribution to journalArticle

Tomasulo, M, Sortino, S, White, AJP & Raymo, F 2005, 'Fast and stable photochromic oxazines', Journal of Organic Chemistry, vol. 70, no. 20, pp. 8180-8189. https://doi.org/10.1021/jo051417w
Tomasulo, Massimiliano ; Sortino, Salvatore ; White, Andrew J P ; Raymo, Francisco. / Fast and stable photochromic oxazines. In: Journal of Organic Chemistry. 2005 ; Vol. 70, No. 20. pp. 8180-8189.
@article{7370193cdc96424eb61a9856cf251288,
title = "Fast and stable photochromic oxazines",
abstract = "We have designed and synthesized two photochromic compounds incorporating fused indoline and benzooxazine fragments. Variable-temperature 1H NMR spectroscopy demonstrates that their central [1,3]oxazine ring opens thermally with free energy barriers ranging from 14 to 19 kcal mol -1. The ring-opened species reverts rapidly to the original isomer and can only be detected after chemical trapping. Specifically, the nucleophilic attack of a hydroxide anion to the indolium cation of the ring-opened species prevents re-isomerization. Laser excitation of both compounds induces the opening of the [1,3]oxazine ring in less than 6 ns with quantum yields up to 0.1. The photoinduced ring opening generates a 4-nitrophenolate chromophore, which absorbs strongly at 440 nm. The photogenerated species reverts to the original form with a lifetime of 22 ns for both compounds. Thus, these transformations can be exploited to interconvert the two isomers of each species with nanosecond switching speeds. Furthermore, thousands of switching cycles can be repeated consecutively without any sign of degradation, even in the presence of molecular oxygen. These processes can be reproduced efficiently in poly(methyl methacrylate) matrixes. Under these conditions, the thermal re-isomerization occurs with biexponential kinetics in submillisecond time scales. In principle, the fast isomerization kinetics and excellent fatigue resistance of both compounds offer the opportunity to modulate rapidly and efficiently a variety of molecular and macroscopic properties. Thus, our molecular design can evolve into the realization of a new family of photochromic compounds and materials with promising photoresponsive character.",
author = "Massimiliano Tomasulo and Salvatore Sortino and White, {Andrew J P} and Francisco Raymo",
year = "2005",
month = "9",
day = "20",
doi = "10.1021/jo051417w",
language = "English",
volume = "70",
pages = "8180--8189",
journal = "Journal of Organic Chemistry",
issn = "0022-3263",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - Fast and stable photochromic oxazines

AU - Tomasulo, Massimiliano

AU - Sortino, Salvatore

AU - White, Andrew J P

AU - Raymo, Francisco

PY - 2005/9/20

Y1 - 2005/9/20

N2 - We have designed and synthesized two photochromic compounds incorporating fused indoline and benzooxazine fragments. Variable-temperature 1H NMR spectroscopy demonstrates that their central [1,3]oxazine ring opens thermally with free energy barriers ranging from 14 to 19 kcal mol -1. The ring-opened species reverts rapidly to the original isomer and can only be detected after chemical trapping. Specifically, the nucleophilic attack of a hydroxide anion to the indolium cation of the ring-opened species prevents re-isomerization. Laser excitation of both compounds induces the opening of the [1,3]oxazine ring in less than 6 ns with quantum yields up to 0.1. The photoinduced ring opening generates a 4-nitrophenolate chromophore, which absorbs strongly at 440 nm. The photogenerated species reverts to the original form with a lifetime of 22 ns for both compounds. Thus, these transformations can be exploited to interconvert the two isomers of each species with nanosecond switching speeds. Furthermore, thousands of switching cycles can be repeated consecutively without any sign of degradation, even in the presence of molecular oxygen. These processes can be reproduced efficiently in poly(methyl methacrylate) matrixes. Under these conditions, the thermal re-isomerization occurs with biexponential kinetics in submillisecond time scales. In principle, the fast isomerization kinetics and excellent fatigue resistance of both compounds offer the opportunity to modulate rapidly and efficiently a variety of molecular and macroscopic properties. Thus, our molecular design can evolve into the realization of a new family of photochromic compounds and materials with promising photoresponsive character.

AB - We have designed and synthesized two photochromic compounds incorporating fused indoline and benzooxazine fragments. Variable-temperature 1H NMR spectroscopy demonstrates that their central [1,3]oxazine ring opens thermally with free energy barriers ranging from 14 to 19 kcal mol -1. The ring-opened species reverts rapidly to the original isomer and can only be detected after chemical trapping. Specifically, the nucleophilic attack of a hydroxide anion to the indolium cation of the ring-opened species prevents re-isomerization. Laser excitation of both compounds induces the opening of the [1,3]oxazine ring in less than 6 ns with quantum yields up to 0.1. The photoinduced ring opening generates a 4-nitrophenolate chromophore, which absorbs strongly at 440 nm. The photogenerated species reverts to the original form with a lifetime of 22 ns for both compounds. Thus, these transformations can be exploited to interconvert the two isomers of each species with nanosecond switching speeds. Furthermore, thousands of switching cycles can be repeated consecutively without any sign of degradation, even in the presence of molecular oxygen. These processes can be reproduced efficiently in poly(methyl methacrylate) matrixes. Under these conditions, the thermal re-isomerization occurs with biexponential kinetics in submillisecond time scales. In principle, the fast isomerization kinetics and excellent fatigue resistance of both compounds offer the opportunity to modulate rapidly and efficiently a variety of molecular and macroscopic properties. Thus, our molecular design can evolve into the realization of a new family of photochromic compounds and materials with promising photoresponsive character.

UR - http://www.scopus.com/inward/record.url?scp=25444477027&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=25444477027&partnerID=8YFLogxK

U2 - 10.1021/jo051417w

DO - 10.1021/jo051417w

M3 - Article

C2 - 16277345

AN - SCOPUS:25444477027

VL - 70

SP - 8180

EP - 8189

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 20

ER -