Structures and Reactivity Patterns of Group 9 Metallocorroles
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- 作者：Joshua H. Palmer ; Atif Mahammed ; Kyle M. Lancaster ; Zeev Gross ; Harry B. Gray
- 刊名：Inorganic Chemistry
- 出版年：2009
- 出版时间：October 5, 2009
- 年：2009
- 卷：48
- 期：19
- 页码：9308-9315
- 全文大小：1032K
- 年卷期：v.48,no.19(October 5, 2009)
- ISSN：1520-510X
文摘
Group 9 metallocorroles 1-M(PPh3) 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(PPh3) axial coordination sites increase dramatically in the order 1-Co(PPh3) < 1-Rh(PPh3) < 1-Ir(PPh3). 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(PPh3) is 0.78 V vs Ag/AgCl in CH2Cl2 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 (gzz = 2.489, gyy = 2.010, gxx = 1.884, gav = 2.128) and 1-Ir(py)2 (gzz = 2.401, gyy = 2.000, gxx = 1.937, gav = 2.113).