Fundamental reactions of imino-phosphine ligands were elucidated through studies on Ph2PC6H4CH=NC6H4-4-Cl (PCHNArCl) complexes of iron(0), iron(I), and iron(II). The reaction of PCHNArCl with Fe(bda)(CO)3 gives Fe(PCHNArCl)(CO)3 (1), featuring an η2-imine. DNMR studies, its optical properties, and DFT calculations suggest that 1 racemizes on the NMR time scale via an achiral N-bonded imine intermediate. The N-imine isomer is more stable in Fe(PCHNArOMe)(CO)3 (1OMe), which crystallized despite being the minor isomer in solution. Protonation of 1 by HBF4·Et2O gave the iminium complex [1H]BF4. The related diphosphine complex Fe(PCHNArCl)(PMe3)(CO)2 (2), which features an η2-imine, was shown to also undergo N protonation. Oxidation of 1 and 2 with FcBF4 gave the Fe(I) compounds BF4 and BF4. The oxidation-induced change in hapticity of the imine from η2 in 0 to κ1 in + was verified crystallographically. Substitution of a CO ligand in 1 with PCHNArCl gave Fe[P2(NArCl)2](CO)2 (3), which contains the tetradentate diamidodiphosphine ligand. This C-C coupling is reversed by chemical oxidation of 3 with FcOTf. The oxidized product of [Fe(PCHNArCl)2(CO)2]2+ (2+) was prepared independently by the reaction of +, PCHNArCl, and Fc+. The C-C scission is proposed to proceed concomitantly with the reduction of Fe(II) via an intermediate related to +.
Chu, W., Richers, C., Kahle, E., Rauchfuss, T., Arrigoni, F., & Zampella, G. (2016). Imine-Centered Reactions in Imino-Phosphine Complexes of Iron Carbonyls. ORGANOMETALLICS, 35(17), 2782-2792.
|Citazione:||Chu, W., Richers, C., Kahle, E., Rauchfuss, T., Arrigoni, F., & Zampella, G. (2016). Imine-Centered Reactions in Imino-Phosphine Complexes of Iron Carbonyls. ORGANOMETALLICS, 35(17), 2782-2792.|
|Tipo:||Articolo in rivista - Articolo scientifico|
|Carattere della pubblicazione:||Scientifica|
|Presenza di un coautore afferente ad Istituzioni straniere:||Si|
|Titolo:||Imine-Centered Reactions in Imino-Phosphine Complexes of Iron Carbonyls|
|Autori:||Chu, W; Richers, C; Kahle, E; Rauchfuss, T; Arrigoni, F; Zampella, G|
ARRIGONI, FEDERICA (Penultimo)
ZAMPELLA, GIUSEPPE (Ultimo)
|Data di pubblicazione:||2016|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/acs.organomet.6b00318|
|Appare nelle tipologie:||01 - Articolo su rivista|