Kinetic Destabilization of Metal-Metal Single Bonds: Isolation of a Pentacoordinate Manganese(0) Monoradical.
The 17e(-) monoradical [Mn(CO)5 ] is widely recognized as an unstable organometallic transient and is known to dimerize rapidly with the formation of a MnMn single bond. As a result of this instability, isolable analogues of [Mn(CO)5 ] have remained elusive. Herein, we show that two sterically encumbering isocyanide ligands can destabilize the MnMn bond leading to the formation of the isolable, manganese(0) monoradical [Mn(CO)3 (CNAr(Dipp2) )2 ] (Ar(Dipp2) =2,6-(2,6-(iPr)2 C6 H3 )2 C6 H3 ). The persistence of [Mn(CO)3 (CNAr(Dipp2) )2 ] has allowed for new insights into nitrosoarene spin-trapping studies of [Mn(CO)5 ].
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, CA 92193 (USA).
Douglas W
DW
Agnew
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, CA 92193 (USA).
Curtis E
CE
Moore
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, CA 92193 (USA).
Arnold L
AL
Rheingold
Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive MC 0358, La Jolla, CA 92193 (USA). jsfig@ucsd.edu.
Joshua S
JS
Figueroa
EPR spectroscopy; isocyanide ligands; manganese; radicals; spin trapping