TY - JOUR
T1 - Cationic half-sandwich iron(II) and iron(III) complexes with N-heterocyclic carbene ligands
AU - Cardoso, João M S
AU - Fernandes, Ana
AU - Cardoso, Bernardo De P
AU - Carvalho, Maria Deus
AU - Ferreira, Liliana P.
AU - Calhorda, Maria José
AU - Cantabrana, Beatriz Royo
N1 - WOS:000343849700008
PY - 2014/10/27
Y1 - 2014/10/27
N2 - The cationic piano-stool iron complexes containing the N-heterocyclic carbene ligand tethered to a tetramethylcyclopentadienyl ring [(Cp∗-NHC)Fe(CO)(L)][X] (L = NCMe, DMSO; X = BF4, OTf) have been prepared and analyzed by spectroscopic, electrochemical, and crystallographic methods. Oxidation reactions of the cationic complex [(Cp∗-NHC)Fe(CO)(NCMe)][BF4] (2) with silver tetrafluoroborate and tert-butyl hydroperoxide in acetonitrile yield the dicationic iron(III) complexes [(Cp∗-NHC)Fe(NCMe)2][BF4]2 and [(Cp∗-NHC)Fe(H2O)][BF4]2, respectively. When the reaction of 2 with AgBF4 is performed in dichloromethane, the cationic complex [(Cp∗-NHC)FeCl][BF4] is obtained. These new iron(III) complexes have been characterized by Mössbauer spectroscopy and in one case by X-ray diffraction studies. DFT calculations were used to rationalize experimental results. The cationic complex [(Cp∗-NHC)Fe(CO)(NCMe)][OTf] is catalytically active toward the reduction of benzaldehyde and acetophenone using phenylsilane under neat conditions and in the absence of visible light irradiation.
AB - The cationic piano-stool iron complexes containing the N-heterocyclic carbene ligand tethered to a tetramethylcyclopentadienyl ring [(Cp∗-NHC)Fe(CO)(L)][X] (L = NCMe, DMSO; X = BF4, OTf) have been prepared and analyzed by spectroscopic, electrochemical, and crystallographic methods. Oxidation reactions of the cationic complex [(Cp∗-NHC)Fe(CO)(NCMe)][BF4] (2) with silver tetrafluoroborate and tert-butyl hydroperoxide in acetonitrile yield the dicationic iron(III) complexes [(Cp∗-NHC)Fe(NCMe)2][BF4]2 and [(Cp∗-NHC)Fe(H2O)][BF4]2, respectively. When the reaction of 2 with AgBF4 is performed in dichloromethane, the cationic complex [(Cp∗-NHC)FeCl][BF4] is obtained. These new iron(III) complexes have been characterized by Mössbauer spectroscopy and in one case by X-ray diffraction studies. DFT calculations were used to rationalize experimental results. The cationic complex [(Cp∗-NHC)Fe(CO)(NCMe)][OTf] is catalytically active toward the reduction of benzaldehyde and acetophenone using phenylsilane under neat conditions and in the absence of visible light irradiation.
UR - http://www.scopus.com/inward/record.url?scp=84908632296&partnerID=8YFLogxK
U2 - 10.1021/om500528p
DO - 10.1021/om500528p
M3 - Article
AN - SCOPUS:84908632296
VL - 33
SP - 5670
EP - 5677
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 20
ER -