TY - JOUR
T1 - Ruthenium complexes with non-innocent ligands
T2 - Electron distribution and implications for catalysis
AU - Boyer, Julie L.
AU - Rochford, Jonathan
AU - Tsai, Ming Kang
AU - Muckerman, James T.
AU - Fujita, Etsuko
PY - 2010/2
Y1 - 2010/2
N2 - Ruthenium complexes with the non-innocent ligands (NILs) benzoquinone, iminobenzoquinone and benzoquinonediimine and their redox derivatives exhibit intriguing electronic properties. With the proper ligand set the NIL π* orbitals mix extensively with the ruthenium dπ orbitals resulting in delocalized electron distributions and non-integer oxidation states, and in most of these systems a particular ruthenium oxidation state dominates. This review critically examines the electronic structure of Ru-NIL systems from both an experimental and computational (DFT) perspective. The electron distribution within these complexes can be modulated by altering both the ancillary ligands and the NIL, and in a few cases the resultant electron distributions are exploited for catalysis. The Ru-NIL systems that perform alcohol oxidation and water oxidation catalysis are discussed in detail. The Tanaka catalyst, an anthracene-bridged dinuclear Ru complex, is an intriguing example of a Ru-NIL framework in catalysis. Unlike other known ruthenium water oxidation catalysts, the two Ru atoms remain low valent during the catalytic cycle according to DFT calculations, some experimental evidence, and predictions based on the behavior of the related mononuclear species.
AB - Ruthenium complexes with the non-innocent ligands (NILs) benzoquinone, iminobenzoquinone and benzoquinonediimine and their redox derivatives exhibit intriguing electronic properties. With the proper ligand set the NIL π* orbitals mix extensively with the ruthenium dπ orbitals resulting in delocalized electron distributions and non-integer oxidation states, and in most of these systems a particular ruthenium oxidation state dominates. This review critically examines the electronic structure of Ru-NIL systems from both an experimental and computational (DFT) perspective. The electron distribution within these complexes can be modulated by altering both the ancillary ligands and the NIL, and in a few cases the resultant electron distributions are exploited for catalysis. The Ru-NIL systems that perform alcohol oxidation and water oxidation catalysis are discussed in detail. The Tanaka catalyst, an anthracene-bridged dinuclear Ru complex, is an intriguing example of a Ru-NIL framework in catalysis. Unlike other known ruthenium water oxidation catalysts, the two Ru atoms remain low valent during the catalytic cycle according to DFT calculations, some experimental evidence, and predictions based on the behavior of the related mononuclear species.
KW - Catalysis
KW - Non-innocent ligands
KW - Oxidation
KW - Quinone
KW - Redox-active ligands
KW - Ruthenium complexes
UR - http://www.scopus.com/inward/record.url?scp=71649092554&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=71649092554&partnerID=8YFLogxK
U2 - 10.1016/j.ccr.2009.09.006
DO - 10.1016/j.ccr.2009.09.006
M3 - Review article
AN - SCOPUS:71649092554
VL - 254
SP - 309
EP - 330
JO - Coordination Chemistry Reviews
JF - Coordination Chemistry Reviews
SN - 0010-8545
IS - 3-4
ER -