TY - JOUR
T1 - Four-electron oxidative dehydrogenation induced by proton-coupled electron transfer in ruthenium(III) complex with 2-(1,4,5,6-tetrahydropyrimidin-2-yl) phenolate
AU - Mitsuhashi, Ryoji
AU - Suzuki, Takayoshi
AU - Sunatsuki, Yukinari
PY - 2013/9/2
Y1 - 2013/9/2
N2 - New ruthenium(II or III) complexes with general formula [Ru(O-N)(bpy) 2]n+ (O-N = unsymmetrical bidentate phenolate ligand; bpy = 2,2'-bipyridine) were synthesized, and their crystal structures and electrochemical properties were characterized. RuII complexes with 2-(2-imidazolinyl)phenolate (Himn-) or 2-(1,4,5,6- tetrahydropyrimidin-2-yl)phenolate (Hthp-) could be deprotonated by addition of excess KOtBu, although the deprotonated species were easily reprotonated by exposure to air. Unlike these RuII complexes, their RuIII analogs showed interesting ligand oxidation reactions upon addition of bases. With [RuIII(Himn)(bpy)2] 2+, two-electron oxidation of Himn- and reduction of the RuIII center resulted in conversion of the 2-imidazolinyl group to a 2-imidazolyl group. On the other hand, the corresponding Hthp- complex exhibited four-electron oxidation of the ligand to form 2-(2-pyrimidyl)phenolate (pym-). These aromatization reactions of imidazolinyl and 1,4,5,6-tetrahydropyrimidyl groups were also achieved by the electrochemically generated RuIII complexes.
AB - New ruthenium(II or III) complexes with general formula [Ru(O-N)(bpy) 2]n+ (O-N = unsymmetrical bidentate phenolate ligand; bpy = 2,2'-bipyridine) were synthesized, and their crystal structures and electrochemical properties were characterized. RuII complexes with 2-(2-imidazolinyl)phenolate (Himn-) or 2-(1,4,5,6- tetrahydropyrimidin-2-yl)phenolate (Hthp-) could be deprotonated by addition of excess KOtBu, although the deprotonated species were easily reprotonated by exposure to air. Unlike these RuII complexes, their RuIII analogs showed interesting ligand oxidation reactions upon addition of bases. With [RuIII(Himn)(bpy)2] 2+, two-electron oxidation of Himn- and reduction of the RuIII center resulted in conversion of the 2-imidazolinyl group to a 2-imidazolyl group. On the other hand, the corresponding Hthp- complex exhibited four-electron oxidation of the ligand to form 2-(2-pyrimidyl)phenolate (pym-). These aromatization reactions of imidazolinyl and 1,4,5,6-tetrahydropyrimidyl groups were also achieved by the electrochemically generated RuIII complexes.
UR - http://www.scopus.com/inward/record.url?scp=84883527555&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84883527555&partnerID=8YFLogxK
U2 - 10.1021/ic401667v
DO - 10.1021/ic401667v
M3 - Article
C2 - 23967872
AN - SCOPUS:84883527555
VL - 52
SP - 10183
EP - 10190
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 17
ER -