Observation of triplet intraligand excited states through nanosecond step-scan Fourier transform infrared spectroscopy

Dmitry Polyansky, Evgeny O. Danilov, Felix N. Castellano

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Nanosecond step-scan Fourier transform infrared spectroscopy permits the observation of triplet intraligand (3IL) character in the excited states of [Ru(bpy)2(PNI-phen)]2+ and [Ru(PNI-phen) 3]2+ where PNI is 4-piperidinyl-1,8-naphthalimide. After pulsed 355-nm laser excitation, the two ground-state imide C=O bands in each compound are bleached and two substantially lower energy vibrations are produced; the lower energy feature appears as two distinct bands split by an overlapping transient bleach. Model studies confirm that the time-resolved vibrational data are consistent with photoinduced sensitization of the 3IL excited state. Density functional theory calculations also support these assignments because localization of triplet electron density on the PNI moiety is expected to lead to red-shifted C=O vibrations of magnitude similar to those measured experimentally. The current results illustrate that triplet electron density can be directly tracked by time-resolved infrared measurements in metal-organic chromophores and that frequency shifts comparable to those observed in charge-transfer systems can be realized.

Original languageEnglish
Pages (from-to)2370-2372
Number of pages3
JournalInorganic Chemistry
Volume45
Issue number6
DOIs
Publication statusPublished - Mar 20 2006

Fingerprint

Excited states
Carrier concentration
Naphthalimides
infrared spectroscopy
Imides
Laser excitation
Chromophores
Ground state
excitation
Density functional theory
Charge transfer
vibration
Metals
imides
Infrared radiation
chromophores
frequency shift
charge transfer
density functional theory
ground state

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Observation of triplet intraligand excited states through nanosecond step-scan Fourier transform infrared spectroscopy. / Polyansky, Dmitry; Danilov, Evgeny O.; Castellano, Felix N.

In: Inorganic Chemistry, Vol. 45, No. 6, 20.03.2006, p. 2370-2372.

Research output: Contribution to journalArticle

@article{b4ad7184ef5e405380ac699e4a024e7a,
title = "Observation of triplet intraligand excited states through nanosecond step-scan Fourier transform infrared spectroscopy",
abstract = "Nanosecond step-scan Fourier transform infrared spectroscopy permits the observation of triplet intraligand (3IL) character in the excited states of [Ru(bpy)2(PNI-phen)]2+ and [Ru(PNI-phen) 3]2+ where PNI is 4-piperidinyl-1,8-naphthalimide. After pulsed 355-nm laser excitation, the two ground-state imide C=O bands in each compound are bleached and two substantially lower energy vibrations are produced; the lower energy feature appears as two distinct bands split by an overlapping transient bleach. Model studies confirm that the time-resolved vibrational data are consistent with photoinduced sensitization of the 3IL excited state. Density functional theory calculations also support these assignments because localization of triplet electron density on the PNI moiety is expected to lead to red-shifted C=O vibrations of magnitude similar to those measured experimentally. The current results illustrate that triplet electron density can be directly tracked by time-resolved infrared measurements in metal-organic chromophores and that frequency shifts comparable to those observed in charge-transfer systems can be realized.",
author = "Dmitry Polyansky and Danilov, {Evgeny O.} and Castellano, {Felix N.}",
year = "2006",
month = "3",
day = "20",
doi = "10.1021/ic0518374",
language = "English",
volume = "45",
pages = "2370--2372",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "6",

}

TY - JOUR

T1 - Observation of triplet intraligand excited states through nanosecond step-scan Fourier transform infrared spectroscopy

AU - Polyansky, Dmitry

AU - Danilov, Evgeny O.

AU - Castellano, Felix N.

PY - 2006/3/20

Y1 - 2006/3/20

N2 - Nanosecond step-scan Fourier transform infrared spectroscopy permits the observation of triplet intraligand (3IL) character in the excited states of [Ru(bpy)2(PNI-phen)]2+ and [Ru(PNI-phen) 3]2+ where PNI is 4-piperidinyl-1,8-naphthalimide. After pulsed 355-nm laser excitation, the two ground-state imide C=O bands in each compound are bleached and two substantially lower energy vibrations are produced; the lower energy feature appears as two distinct bands split by an overlapping transient bleach. Model studies confirm that the time-resolved vibrational data are consistent with photoinduced sensitization of the 3IL excited state. Density functional theory calculations also support these assignments because localization of triplet electron density on the PNI moiety is expected to lead to red-shifted C=O vibrations of magnitude similar to those measured experimentally. The current results illustrate that triplet electron density can be directly tracked by time-resolved infrared measurements in metal-organic chromophores and that frequency shifts comparable to those observed in charge-transfer systems can be realized.

AB - Nanosecond step-scan Fourier transform infrared spectroscopy permits the observation of triplet intraligand (3IL) character in the excited states of [Ru(bpy)2(PNI-phen)]2+ and [Ru(PNI-phen) 3]2+ where PNI is 4-piperidinyl-1,8-naphthalimide. After pulsed 355-nm laser excitation, the two ground-state imide C=O bands in each compound are bleached and two substantially lower energy vibrations are produced; the lower energy feature appears as two distinct bands split by an overlapping transient bleach. Model studies confirm that the time-resolved vibrational data are consistent with photoinduced sensitization of the 3IL excited state. Density functional theory calculations also support these assignments because localization of triplet electron density on the PNI moiety is expected to lead to red-shifted C=O vibrations of magnitude similar to those measured experimentally. The current results illustrate that triplet electron density can be directly tracked by time-resolved infrared measurements in metal-organic chromophores and that frequency shifts comparable to those observed in charge-transfer systems can be realized.

UR - http://www.scopus.com/inward/record.url?scp=33645508347&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33645508347&partnerID=8YFLogxK

U2 - 10.1021/ic0518374

DO - 10.1021/ic0518374

M3 - Article

C2 - 16529447

AN - SCOPUS:33645508347

VL - 45

SP - 2370

EP - 2372

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 6

ER -