Five- and six-coordinate adducts of nitrosamines with ferric porphyrins: Structural models for the type II interactions of nitrosamines with ferric cytochrome P450

Nan Xu, Lauren E. Goodrich, Nicolai Lehnert, Douglas R. Powell, George B. Richter-Addo

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

Nitrosamines are well-known for their toxic and carcinogenic properties. The metabolic activation of nitrosamines occurs via interaction with the heme-containing cytochrome P450 enzymes. We report the preparation and structural characterization of a number of nitrosamine adducts of synthetic iron porphyrins. The reactions of the cations [(por)Fe(THF)2]ClO 4 (por = TPP, TTP, OEP) with dialkylnitrosamines (R2NNO; R2 = Me2, Et2, (cyclo-CH2) 4, (cyclo-CH2)5, (PhCH2) 2) in toluene generate the six-coordinate high-spin (S = 5/2) [(por)Fe(ONNR2)2]ClO4 compounds and a five-coordinate intermediate-spin (S = 3/2) [(OEP)Fe(ONNMe2)]ClO 4 derivative in 57-72% yields (TPP = 5,10,15,20- tetraphenylporphyrinato dianion, TTP = 5,10,15,20-tetra-p-tolylporphyrinato dianion, OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion). The N-O and N-N vibrations of the coordinated nitrosamine groups in [(por)Fe(ONNR 2)2]ClO4 occur in the 1239-1271 cm-1 range. Three of the six-coordinate [(por)Fe(ONNR2) 2]ClO4 compounds and one five-coordinate [(OEP)Fe(ONNMe2)]ClO4 compound have been characterized by single crystal X-ray crystallography. All the nitrosamine ligands in these complexes bind to the ferric centers via a sole η1-O binding mode. No arylnitrosamine adducts were obtained from the reactions of the precursor compounds [(por)Fe(THF)2]ClO4 with three arylnitrosamines (Ph2NNO, Ph(Me)NNO, Ph(Et)NNO). However, prolonged exposure of [(por)Fe(THF)2]ClO4 to these arylnitrosamines resulted in the formation of the known five-coordinate (por)Fe(NO) derivatives. The latter (por)Fe(NO) compounds were obtained more readily by the reactions of the three arylnitrosamines with the four-coordinate (por)FeII precursors.

Original languageEnglish (US)
Pages (from-to)4405-4419
Number of pages15
JournalInorganic chemistry
Volume49
Issue number10
DOIs
StatePublished - May 17 2010

Fingerprint

nitrosamine
Nitrosamines
cytochromes
Porphyrins
porphyrins
Cytochrome P-450 Enzyme System
adducts
interactions
Derivatives
Poisons
X ray crystallography
Toluene
Heme
crystallography
toluene
perchlorate
Cations
enzymes
Iron
Chemical activation

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

Cite this

Xu, Nan ; Goodrich, Lauren E. ; Lehnert, Nicolai ; Powell, Douglas R. ; Richter-Addo, George B. / Five- and six-coordinate adducts of nitrosamines with ferric porphyrins : Structural models for the type II interactions of nitrosamines with ferric cytochrome P450. In: Inorganic chemistry. 2010 ; Vol. 49, No. 10. pp. 4405-4419.
@article{ca51964a648d43ceac3df942067e3f16,
title = "Five- and six-coordinate adducts of nitrosamines with ferric porphyrins: Structural models for the type II interactions of nitrosamines with ferric cytochrome P450",
abstract = "Nitrosamines are well-known for their toxic and carcinogenic properties. The metabolic activation of nitrosamines occurs via interaction with the heme-containing cytochrome P450 enzymes. We report the preparation and structural characterization of a number of nitrosamine adducts of synthetic iron porphyrins. The reactions of the cations [(por)Fe(THF)2]ClO 4 (por = TPP, TTP, OEP) with dialkylnitrosamines (R2NNO; R2 = Me2, Et2, (cyclo-CH2) 4, (cyclo-CH2)5, (PhCH2) 2) in toluene generate the six-coordinate high-spin (S = 5/2) [(por)Fe(ONNR2)2]ClO4 compounds and a five-coordinate intermediate-spin (S = 3/2) [(OEP)Fe(ONNMe2)]ClO 4 derivative in 57-72{\%} yields (TPP = 5,10,15,20- tetraphenylporphyrinato dianion, TTP = 5,10,15,20-tetra-p-tolylporphyrinato dianion, OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion). The N-O and N-N vibrations of the coordinated nitrosamine groups in [(por)Fe(ONNR 2)2]ClO4 occur in the 1239-1271 cm-1 range. Three of the six-coordinate [(por)Fe(ONNR2) 2]ClO4 compounds and one five-coordinate [(OEP)Fe(ONNMe2)]ClO4 compound have been characterized by single crystal X-ray crystallography. All the nitrosamine ligands in these complexes bind to the ferric centers via a sole η1-O binding mode. No arylnitrosamine adducts were obtained from the reactions of the precursor compounds [(por)Fe(THF)2]ClO4 with three arylnitrosamines (Ph2NNO, Ph(Me)NNO, Ph(Et)NNO). However, prolonged exposure of [(por)Fe(THF)2]ClO4 to these arylnitrosamines resulted in the formation of the known five-coordinate (por)Fe(NO) derivatives. The latter (por)Fe(NO) compounds were obtained more readily by the reactions of the three arylnitrosamines with the four-coordinate (por)FeII precursors.",
author = "Nan Xu and Goodrich, {Lauren E.} and Nicolai Lehnert and Powell, {Douglas R.} and Richter-Addo, {George B.}",
year = "2010",
month = "5",
day = "17",
doi = "10.1021/ic901751z",
language = "English (US)",
volume = "49",
pages = "4405--4419",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "10",

}

Five- and six-coordinate adducts of nitrosamines with ferric porphyrins : Structural models for the type II interactions of nitrosamines with ferric cytochrome P450. / Xu, Nan; Goodrich, Lauren E.; Lehnert, Nicolai; Powell, Douglas R.; Richter-Addo, George B.

In: Inorganic chemistry, Vol. 49, No. 10, 17.05.2010, p. 4405-4419.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Five- and six-coordinate adducts of nitrosamines with ferric porphyrins

T2 - Structural models for the type II interactions of nitrosamines with ferric cytochrome P450

AU - Xu, Nan

AU - Goodrich, Lauren E.

AU - Lehnert, Nicolai

AU - Powell, Douglas R.

AU - Richter-Addo, George B.

PY - 2010/5/17

Y1 - 2010/5/17

N2 - Nitrosamines are well-known for their toxic and carcinogenic properties. The metabolic activation of nitrosamines occurs via interaction with the heme-containing cytochrome P450 enzymes. We report the preparation and structural characterization of a number of nitrosamine adducts of synthetic iron porphyrins. The reactions of the cations [(por)Fe(THF)2]ClO 4 (por = TPP, TTP, OEP) with dialkylnitrosamines (R2NNO; R2 = Me2, Et2, (cyclo-CH2) 4, (cyclo-CH2)5, (PhCH2) 2) in toluene generate the six-coordinate high-spin (S = 5/2) [(por)Fe(ONNR2)2]ClO4 compounds and a five-coordinate intermediate-spin (S = 3/2) [(OEP)Fe(ONNMe2)]ClO 4 derivative in 57-72% yields (TPP = 5,10,15,20- tetraphenylporphyrinato dianion, TTP = 5,10,15,20-tetra-p-tolylporphyrinato dianion, OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion). The N-O and N-N vibrations of the coordinated nitrosamine groups in [(por)Fe(ONNR 2)2]ClO4 occur in the 1239-1271 cm-1 range. Three of the six-coordinate [(por)Fe(ONNR2) 2]ClO4 compounds and one five-coordinate [(OEP)Fe(ONNMe2)]ClO4 compound have been characterized by single crystal X-ray crystallography. All the nitrosamine ligands in these complexes bind to the ferric centers via a sole η1-O binding mode. No arylnitrosamine adducts were obtained from the reactions of the precursor compounds [(por)Fe(THF)2]ClO4 with three arylnitrosamines (Ph2NNO, Ph(Me)NNO, Ph(Et)NNO). However, prolonged exposure of [(por)Fe(THF)2]ClO4 to these arylnitrosamines resulted in the formation of the known five-coordinate (por)Fe(NO) derivatives. The latter (por)Fe(NO) compounds were obtained more readily by the reactions of the three arylnitrosamines with the four-coordinate (por)FeII precursors.

AB - Nitrosamines are well-known for their toxic and carcinogenic properties. The metabolic activation of nitrosamines occurs via interaction with the heme-containing cytochrome P450 enzymes. We report the preparation and structural characterization of a number of nitrosamine adducts of synthetic iron porphyrins. The reactions of the cations [(por)Fe(THF)2]ClO 4 (por = TPP, TTP, OEP) with dialkylnitrosamines (R2NNO; R2 = Me2, Et2, (cyclo-CH2) 4, (cyclo-CH2)5, (PhCH2) 2) in toluene generate the six-coordinate high-spin (S = 5/2) [(por)Fe(ONNR2)2]ClO4 compounds and a five-coordinate intermediate-spin (S = 3/2) [(OEP)Fe(ONNMe2)]ClO 4 derivative in 57-72% yields (TPP = 5,10,15,20- tetraphenylporphyrinato dianion, TTP = 5,10,15,20-tetra-p-tolylporphyrinato dianion, OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion). The N-O and N-N vibrations of the coordinated nitrosamine groups in [(por)Fe(ONNR 2)2]ClO4 occur in the 1239-1271 cm-1 range. Three of the six-coordinate [(por)Fe(ONNR2) 2]ClO4 compounds and one five-coordinate [(OEP)Fe(ONNMe2)]ClO4 compound have been characterized by single crystal X-ray crystallography. All the nitrosamine ligands in these complexes bind to the ferric centers via a sole η1-O binding mode. No arylnitrosamine adducts were obtained from the reactions of the precursor compounds [(por)Fe(THF)2]ClO4 with three arylnitrosamines (Ph2NNO, Ph(Me)NNO, Ph(Et)NNO). However, prolonged exposure of [(por)Fe(THF)2]ClO4 to these arylnitrosamines resulted in the formation of the known five-coordinate (por)Fe(NO) derivatives. The latter (por)Fe(NO) compounds were obtained more readily by the reactions of the three arylnitrosamines with the four-coordinate (por)FeII precursors.

UR - http://www.scopus.com/inward/record.url?scp=77952206729&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77952206729&partnerID=8YFLogxK

U2 - 10.1021/ic901751z

DO - 10.1021/ic901751z

M3 - Article

C2 - 20392126

AN - SCOPUS:77952206729

VL - 49

SP - 4405

EP - 4419

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 10

ER -