Structures and Reactivity Patterns of Group 9 Metallocorroles
Abstract
Group 9 metallocorroles 1-M(PPh_3) and 1-M(py)_2 [M = Co(III), Rh(III), Ir(III); 1 denotes the trianion of 5,10,15-tris-pentafluorophenylcorrole] have been fully characterized by structural, spectroscopic, and electrochemical methods. Crystal structure analyses reveal that average metal−N(pyrrole) bond lengths of the bis-pyridine metal(III) complexes increase from Co (1.886 Å) to Rh (1.957 Å)/Ir (1.963 Å); and the average metal−N(pyridine) bond lengths also increase from Co (1.995 Å) to Rh (2.065 Å)/Ir (2.059 Å). Ligand affinities for 1-M(PPh_3) axial coordination sites increase dramatically in the order 1-Co(PPh_3) < 1-Rh(PPh_3) < 1-Ir(PPh_3). There is a surprising invariance in the M(+/0) reduction potentials within the five- and six-coordinate corrole series, and even between them; the average M(+/0) potential of 1-M(PPh_3) is 0.78 V vs Ag/AgCl in CH_2Cl_2 solution, whereas that of 1-M(py)_2 is 0.70 V under the same conditions. Electronic structures of one-electron-oxidized 1-M(py)_2 complexes have been assigned by analysis of electron paramagnetic resonance spectroscopic measurements: oxidation is corrole-centered for 1-Co(py)_2 (g = 2.008) and 1-Rh(py)_2 (g = 2.003), and metal-centered for 1-Ir(tma)_2 (g_(zz) = 2.489, g_(yy) = 2.010, g_(xx) = 1.884, g_(av) = 2.128) and 1-Ir(py)_2 (g_(zz) = 2.401, g_(yy) = 2.000, g_(xx) = 1.937, g_(av) = 2.113).
Additional Information
Copyright © 2009 American Chemical Society. Received June 17, 2009. Publication Date (Web): September 8, 2009. This work was supported by the Center for Chemical Innovation Grant NSF CHE-0802907, U.S.−Israel BSF (Z.G. and H.B.G.), BP, CCSER (Gordon and Betty Moore Foundation), and the Arnold and Mabel Beckman Foundation. We thank Dr. Angelo Di Bilio for help with measurements of low-temperature EPR spectra; and Drs. Lawrence M. Henling and Michael W. Day for assistance with the acquisition and analysis of crystallographic data. Supporting Information: Additional information as noted in the text. This material is available free of charge via the Internet at http://pubs.acs.org.Attached Files
Supplemental Material - ic901164r_si_001.pdf
Supplemental Material - ic901164r_si_002.pdf
Files
Name | Size | Download all |
---|---|---|
md5:8049af5cf3c1eeebbe65aaa671be5d50
|
238.6 kB | Preview Download |
md5:68cbe4cd1c03c48a9d6019e466cc98a6
|
858.9 kB | Preview Download |
Additional details
- Eprint ID
- 16309
- Resolver ID
- CaltechAUTHORS:20091013-093451813
- CHE-0802907
- NSF
- Binational Science Foundation (USA-Israel)
- BP
- Gordon and Betty Moore Foundation
- Arnold and Mabel Beckman Foundation
- Created
-
2009-10-18Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- CCI Solar Fuels