Ligand reactivity in diarylamido/bis(phosphine) PNP complexes of Mn(CO)3 and Re(CO)3.
The syntheses of meridionally ligated tricarbonyl complexes (PNP)Mn(CO)(3) and (PNP)Re(CO)(3) are described (PNP = [2-P(CHMe(2))(2)-4-MeC(6)H(3)](2)N(-)). Cyclic voltammograms show reversible one-electron redox couples for both parent compounds (-0.34 V vs Cp(2)Fe(0/+) for (PNP)Mn(CO)(3), -0.25 V vs Cp(2)Fe(0/+) for (PNP)Re(CO)(3)), and chemical oxidation with AgOTf results in formation of the corresponding paramagnetic triflate salts [(PNP)Mn(CO)(3)]OTf and [(PNP)Re(CO)(3)]OTf. Electron paramagnetic resonance spectra and computational results indicate that this event is primarily ligand centered; allylation of the organic ligand moiety of [(PNP)Mn(CO)(3)]OTf with allyltributylstannane is consistent with this assignment. The oxidation (PNP)Mn(CO)(3) to [(PNP)Mn(CO)(3)]OTf results in a shift in average CO stretching frequency of 30 cm(-1); protonation of (PNP)Mn(CO)(3) with TfOH to form [(PNHP)Mn(CO)(3)]OTf results in a similar magnitude shift.
Radosevich
Alexander T
AT
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Melnick
Jonathan G
JG
Stoian
Sebastian A
SA
Bacciu
Deborha
D
Chen
Chun-Hsing
CH
Foxman
Bruce M
BM
Ozerov
Oleg V
OV
Nocera
Daniel G
DG
D002384:Catalysis; D004563:Electrochemistry; D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D010777:Photochemistry / Q000379:methods*; D012211:Rhenium / Q000737:chemistry*
D008024:Ligands; D010720:Phosphines; D008345:Manganese; D012211:Rhenium; C044646:phosphine; D010100:Oxygen