Flash photolysis studies of the ruthenium(II) porphyrins RU(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide

Ivan M. Lorković, Katrina M Miranda, Brian Lee, Stefan Bernhard, Jon R. Schoonover, Peter C. Ford

Research output: Contribution to journalArticle

88 Citations (Scopus)

Abstract

Described are the spectra and kinetics of transients formed by laser flash photolysis of the ruthenium nitrosyl nitrito complexes Ru(P)(NO)(ONO), P= TPP (meso-tetraphenylporphyrin), OEP (octaethylporphyrin), TmTP (tetra(m- tolyl)porphyrin); and FTTP (tetra(m-trifluoromethylphenyl)porphyrin)in benzene solutions. Two transient decay processes are seen on the time frame (< 1 ms) of the flash photolysis experiment, and a residual difference spectrum, which decays to baseline on a longer time frame, is noted as well. The accumulated evidence points to the formation of two primary photoproducts, Ru(P)(ONO) (A) formed by NO photolabilization and Ru(P)(NO) (B) formed by NO2 photolabilization. Both decay by NO dependent pathways, the reaction of A with NO to re-form Ru(P)(NO)(ONO) being substantially faster (2.4-5.5 x 108 M-1 s-1 in ambient temperature benzene) than the reaction of B with NO (2.4-10 x 107 M-1 s-1). The product of the latter reaction is apparently the dinitrosyl complex Ru(P)(NO)2, which undergoes a much slower thermal reaction with excess NO to give again Ru(P)(NO)(ONO). The possibility of B being the oxo complex O=Ru(P)(No) formed by NO loss from coordinated nitrite was considered but concluded to be a minor pathway at best. Isotopic exchange reactions using either labeled complex or labeled NO in cyclohexane demonstrate photochemical exchange of NO into both the nitrosyl and nitrito complexes, and time-resolved infrared experiments are consistent with formation of a long-lived nitrosyl-containing intermediate. Flash photolysis studies of the respective nitrosyl chloro complexes Ru(TPP)(NO)Cl and Ru(OEP)(NO)Cl indicate that only a single transient species, presumably Ru(P)Cl, is formed in each case, and this decays by a single NO dependent pathway back to starting material.

Original languageEnglish (US)
Pages (from-to)11674-11683
Number of pages10
JournalJournal of the American Chemical Society
Volume120
Issue number45
DOIs
StatePublished - Nov 18 1998
Externally publishedYes

Fingerprint

Ruthenium
Photolysis
Porphyrins
Nitric oxide
Nitric Oxide
Benzene
Cyclohexane
Nitrites
Lasers
Hot Temperature
Experiments
Infrared radiation
Kinetics
Temperature
octaethylporphyrin
tetraphenylporphyrin

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Flash photolysis studies of the ruthenium(II) porphyrins RU(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide. / Lorković, Ivan M.; Miranda, Katrina M; Lee, Brian; Bernhard, Stefan; Schoonover, Jon R.; Ford, Peter C.

In: Journal of the American Chemical Society, Vol. 120, No. 45, 18.11.1998, p. 11674-11683.

Research output: Contribution to journalArticle

Lorković, Ivan M. ; Miranda, Katrina M ; Lee, Brian ; Bernhard, Stefan ; Schoonover, Jon R. ; Ford, Peter C. / Flash photolysis studies of the ruthenium(II) porphyrins RU(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide. In: Journal of the American Chemical Society. 1998 ; Vol. 120, No. 45. pp. 11674-11683.
@article{89c6ea85b3474210888d3dacda7146f8,
title = "Flash photolysis studies of the ruthenium(II) porphyrins RU(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide",
abstract = "Described are the spectra and kinetics of transients formed by laser flash photolysis of the ruthenium nitrosyl nitrito complexes Ru(P)(NO)(ONO), P= TPP (meso-tetraphenylporphyrin), OEP (octaethylporphyrin), TmTP (tetra(m- tolyl)porphyrin); and FTTP (tetra(m-trifluoromethylphenyl)porphyrin)in benzene solutions. Two transient decay processes are seen on the time frame (< 1 ms) of the flash photolysis experiment, and a residual difference spectrum, which decays to baseline on a longer time frame, is noted as well. The accumulated evidence points to the formation of two primary photoproducts, Ru(P)(ONO) (A) formed by NO photolabilization and Ru(P)(NO) (B) formed by NO2 photolabilization. Both decay by NO dependent pathways, the reaction of A with NO to re-form Ru(P)(NO)(ONO) being substantially faster (2.4-5.5 x 108 M-1 s-1 in ambient temperature benzene) than the reaction of B with NO (2.4-10 x 107 M-1 s-1). The product of the latter reaction is apparently the dinitrosyl complex Ru(P)(NO)2, which undergoes a much slower thermal reaction with excess NO to give again Ru(P)(NO)(ONO). The possibility of B being the oxo complex O=Ru(P)(No) formed by NO loss from coordinated nitrite was considered but concluded to be a minor pathway at best. Isotopic exchange reactions using either labeled complex or labeled NO in cyclohexane demonstrate photochemical exchange of NO into both the nitrosyl and nitrito complexes, and time-resolved infrared experiments are consistent with formation of a long-lived nitrosyl-containing intermediate. Flash photolysis studies of the respective nitrosyl chloro complexes Ru(TPP)(NO)Cl and Ru(OEP)(NO)Cl indicate that only a single transient species, presumably Ru(P)Cl, is formed in each case, and this decays by a single NO dependent pathway back to starting material.",
author = "Lorković, {Ivan M.} and Miranda, {Katrina M} and Brian Lee and Stefan Bernhard and Schoonover, {Jon R.} and Ford, {Peter C.}",
year = "1998",
month = "11",
day = "18",
doi = "10.1021/ja981907o",
language = "English (US)",
volume = "120",
pages = "11674--11683",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "45",

}

TY - JOUR

T1 - Flash photolysis studies of the ruthenium(II) porphyrins RU(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide

AU - Lorković, Ivan M.

AU - Miranda, Katrina M

AU - Lee, Brian

AU - Bernhard, Stefan

AU - Schoonover, Jon R.

AU - Ford, Peter C.

PY - 1998/11/18

Y1 - 1998/11/18

N2 - Described are the spectra and kinetics of transients formed by laser flash photolysis of the ruthenium nitrosyl nitrito complexes Ru(P)(NO)(ONO), P= TPP (meso-tetraphenylporphyrin), OEP (octaethylporphyrin), TmTP (tetra(m- tolyl)porphyrin); and FTTP (tetra(m-trifluoromethylphenyl)porphyrin)in benzene solutions. Two transient decay processes are seen on the time frame (< 1 ms) of the flash photolysis experiment, and a residual difference spectrum, which decays to baseline on a longer time frame, is noted as well. The accumulated evidence points to the formation of two primary photoproducts, Ru(P)(ONO) (A) formed by NO photolabilization and Ru(P)(NO) (B) formed by NO2 photolabilization. Both decay by NO dependent pathways, the reaction of A with NO to re-form Ru(P)(NO)(ONO) being substantially faster (2.4-5.5 x 108 M-1 s-1 in ambient temperature benzene) than the reaction of B with NO (2.4-10 x 107 M-1 s-1). The product of the latter reaction is apparently the dinitrosyl complex Ru(P)(NO)2, which undergoes a much slower thermal reaction with excess NO to give again Ru(P)(NO)(ONO). The possibility of B being the oxo complex O=Ru(P)(No) formed by NO loss from coordinated nitrite was considered but concluded to be a minor pathway at best. Isotopic exchange reactions using either labeled complex or labeled NO in cyclohexane demonstrate photochemical exchange of NO into both the nitrosyl and nitrito complexes, and time-resolved infrared experiments are consistent with formation of a long-lived nitrosyl-containing intermediate. Flash photolysis studies of the respective nitrosyl chloro complexes Ru(TPP)(NO)Cl and Ru(OEP)(NO)Cl indicate that only a single transient species, presumably Ru(P)Cl, is formed in each case, and this decays by a single NO dependent pathway back to starting material.

AB - Described are the spectra and kinetics of transients formed by laser flash photolysis of the ruthenium nitrosyl nitrito complexes Ru(P)(NO)(ONO), P= TPP (meso-tetraphenylporphyrin), OEP (octaethylporphyrin), TmTP (tetra(m- tolyl)porphyrin); and FTTP (tetra(m-trifluoromethylphenyl)porphyrin)in benzene solutions. Two transient decay processes are seen on the time frame (< 1 ms) of the flash photolysis experiment, and a residual difference spectrum, which decays to baseline on a longer time frame, is noted as well. The accumulated evidence points to the formation of two primary photoproducts, Ru(P)(ONO) (A) formed by NO photolabilization and Ru(P)(NO) (B) formed by NO2 photolabilization. Both decay by NO dependent pathways, the reaction of A with NO to re-form Ru(P)(NO)(ONO) being substantially faster (2.4-5.5 x 108 M-1 s-1 in ambient temperature benzene) than the reaction of B with NO (2.4-10 x 107 M-1 s-1). The product of the latter reaction is apparently the dinitrosyl complex Ru(P)(NO)2, which undergoes a much slower thermal reaction with excess NO to give again Ru(P)(NO)(ONO). The possibility of B being the oxo complex O=Ru(P)(No) formed by NO loss from coordinated nitrite was considered but concluded to be a minor pathway at best. Isotopic exchange reactions using either labeled complex or labeled NO in cyclohexane demonstrate photochemical exchange of NO into both the nitrosyl and nitrito complexes, and time-resolved infrared experiments are consistent with formation of a long-lived nitrosyl-containing intermediate. Flash photolysis studies of the respective nitrosyl chloro complexes Ru(TPP)(NO)Cl and Ru(OEP)(NO)Cl indicate that only a single transient species, presumably Ru(P)Cl, is formed in each case, and this decays by a single NO dependent pathway back to starting material.

UR - http://www.scopus.com/inward/record.url?scp=0032544948&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032544948&partnerID=8YFLogxK

U2 - 10.1021/ja981907o

DO - 10.1021/ja981907o

M3 - Article

AN - SCOPUS:0032544948

VL - 120

SP - 11674

EP - 11683

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 45

ER -