TY - JOUR
T1 - Electronic properties of N-heterocyclic carbene (NHC) ligands
T2 - Synthetic, structural, and spectroscopic studies of (NHC)platinum(II) complexes
AU - Fantasia, Serena
AU - Petersen, Jeffrey L.
AU - Jacobsen, Heiko
AU - Cavallo, Luigi
AU - Nolan, Steven P.
PY - 2007/11/19
Y1 - 2007/11/19
N2 - N-Heterocyclic carbene complexes of platinum(II) have been synthesized, notably monocarbene complexes cis-[(IPr)Pt(dmso)(Cl)2], 6, cis-[(IMes)Pt(dmso)(Cl)2], 7, cis-[(SIPr)Pt(dmso)(Cl)2], 8, cis-[(SIMes)Pt(dmso)(Cl)2], 9, and cis-[(TTP)Pt(dmso)(Cl) 2], 10. All complexes have been fully characterized by multinuclear NMR spectroscopy. Complex 7, 9, and 10 have been characterized by X-ray crystallography. The data obtained have allowed for the differentiation between electronic contributions (σ and π) present in the Pt-NHC bond. Supported by computational analyses, the percentage of π back-donation from the metal to the NHC is found to be on the order of 10%. More interestingly, we find that saturated NHC (SIPr and SIMes) are more efficient π back-acceptors than their unsaturated NHC congeners (IPr and IMes). The synergistic effect between π back-donation and σ donation present in the saturated NHC systems results in increased electron density at the platinum center compared to the bonding situation in the unsaturated NHC examples.
AB - N-Heterocyclic carbene complexes of platinum(II) have been synthesized, notably monocarbene complexes cis-[(IPr)Pt(dmso)(Cl)2], 6, cis-[(IMes)Pt(dmso)(Cl)2], 7, cis-[(SIPr)Pt(dmso)(Cl)2], 8, cis-[(SIMes)Pt(dmso)(Cl)2], 9, and cis-[(TTP)Pt(dmso)(Cl) 2], 10. All complexes have been fully characterized by multinuclear NMR spectroscopy. Complex 7, 9, and 10 have been characterized by X-ray crystallography. The data obtained have allowed for the differentiation between electronic contributions (σ and π) present in the Pt-NHC bond. Supported by computational analyses, the percentage of π back-donation from the metal to the NHC is found to be on the order of 10%. More interestingly, we find that saturated NHC (SIPr and SIMes) are more efficient π back-acceptors than their unsaturated NHC congeners (IPr and IMes). The synergistic effect between π back-donation and σ donation present in the saturated NHC systems results in increased electron density at the platinum center compared to the bonding situation in the unsaturated NHC examples.
UR - http://www.scopus.com/inward/record.url?scp=36749055134&partnerID=8YFLogxK
U2 - 10.1021/om700857j
DO - 10.1021/om700857j
M3 - Article
AN - SCOPUS:36749055134
VL - 26
SP - 5880
EP - 5889
JO - Organometallics
JF - Organometallics
SN - 0276-7333
IS - 24
ER -