Fundamentals of Porphyrin Chemistry 2022
DOI: 10.1002/9781119129301.ch14
|View full text |Cite
|
Sign up to set email alerts
|

Spin States in Iron Porphyrins

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
1
1
1

Citation Types

2
5
0

Year Published

2023
2023
2024
2024

Publication Types

Select...
5

Relationship

0
5

Authors

Journals

citations
Cited by 6 publications
(7 citation statements)
references
References 97 publications
2
5
0
Order By: Relevance
“…The new band at 1591 cm –1 can be assigned to either a component vibration associated with the Pyr-1 linker component (Figure S7) or the v 10 marker band of the reduced Fe II species. The blue shift in the v 2 band (1551 to 1555 cm –1 ) suggests that when the Fe III surface species is reduced, the spin state changes from high-spin Fe III to a low-spin Fe II state, with a sixth axial ligand, possibly an H 2 O molecule from the solvent or a more complicated interaction with the buffer source itself. , The observation of this low-spin, six-coordinate Fe II complex suggests that the Pyr-1 linker bound axially to the Fe porphyrin unit pushes electron density to the iron center and promotes a low-spin state . However, beginning at −0.4 V vs Ag/AgCl, a shoulder peak at 1346 cm –1 emerges, corresponding to a high-spin Fe II species, , presumably not directly bound to the Pyr-1 modified surface or formed as a result of adventitious oxygen present within the system.…”
Section: Resultsmentioning
confidence: 99%
See 1 more Smart Citation
“…The new band at 1591 cm –1 can be assigned to either a component vibration associated with the Pyr-1 linker component (Figure S7) or the v 10 marker band of the reduced Fe II species. The blue shift in the v 2 band (1551 to 1555 cm –1 ) suggests that when the Fe III surface species is reduced, the spin state changes from high-spin Fe III to a low-spin Fe II state, with a sixth axial ligand, possibly an H 2 O molecule from the solvent or a more complicated interaction with the buffer source itself. , The observation of this low-spin, six-coordinate Fe II complex suggests that the Pyr-1 linker bound axially to the Fe porphyrin unit pushes electron density to the iron center and promotes a low-spin state . However, beginning at −0.4 V vs Ag/AgCl, a shoulder peak at 1346 cm –1 emerges, corresponding to a high-spin Fe II species, , presumably not directly bound to the Pyr-1 modified surface or formed as a result of adventitious oxygen present within the system.…”
Section: Resultsmentioning
confidence: 99%
“…40,41 The observation of this low-spin, six-coordinate Fe II complex suggests that the Pyr-1 linker bound axially to the Fe porphyrin unit pushes electron density to the iron center and promotes a low-spin state. 42 However, beginning at −0.4 V vs Ag/AgCl, a shoulder peak at 1346 cm −1 emerges, corresponding to a high-spin Fe II species, 40,43 presumably not directly bound to the Pyr-1 modified surface or formed as a result of adventitious oxygen present within the system. The band fitting assignments as well as the trends of the v 4 species as a function of potential can be found in Figure S8 and S9.…”
Section: ■ Introductionmentioning
confidence: 99%
“…9a,d,e,h In our calculations, a quintet ground state 10 was found for the intermediate A, which is in line with previously reported experimental observations. 11 Starting from the resting state intermediate A, coordination of diazirine 1 via one of the nitrogen lone pairs results in the formation of intermediate B in a closed-shell singlet (css) spin state via spin-crossover (Figure 1). The subsequent ring-opening of the diazirine motif via transition state TS(B-D) has an activation free energy of 34.3 kcal mol −1 on the closed-shell singlet surface to lead to intermediate D. The isomerization via TS(B-D) takes place on the css surface and does not represent a stable stationary point in other spin states.…”
Section: ■ Results and Discussionmentioning
confidence: 99%
“…We initiated our investigation by studying the formation of phenyldiazomethane ( 3 ) via isomerization of 3-phenyl-3 H -diazirine ( 1 ) at the B3LYP-D3­(BJ)/def2-TZVP+CPCM­(Et 2 O)//B3LYP-D3­(BJ)/6-31G­(d),LANL2DZ­(Fe) level of theory . In the calculations, an iron­(II) porphyrin complex bearing an imidazole ligand in the axial position was employed as a model for the histidine-coordinated iron­(II) heme active site in the enzyme, which is formed in the presence of Na 2 S 2 O 4 as reductant. , The implicit CPCM solvation model with Et 2 O as the solvent was employed to simulate the hydrophobic environment found inside the active site of the enzyme. ,,, In our calculations, a quintet ground state was found for the intermediate A , which is in line with previously reported experimental observations . Starting from the resting state intermediate A , coordination of diazirine 1 via one of the nitrogen lone pairs results in the formation of intermediate B in a closed-shell singlet (css) spin state via spin-crossover (Figure ).…”
Section: Resultsmentioning
confidence: 99%
“…Fe IV O porphyrins also exclusively adopt the S = 1 configuration of the metal center. 158 The reactivity of iron( iv )–oxo complex 42 in C–H bond activation and further details on the electronic properties of 42 are discussed in 4.4.…”
Section: Reactivitymentioning
confidence: 99%