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Organometallic Cerium Complexes from Tetravalent Coordination Complexes
Author(s) -
Arnold Polly L.,
Casely Ian J.,
Zlatogorsky Sergey,
Wilson Claire
Publication year - 2009
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200900152
Subject(s) - chemistry , cerium , metathesis , medicinal chemistry , carbene , trifluoromethanesulfonate , alkoxide , protonolysis , deprotonation , oxidation state , adduct , salt metathesis reaction , polymer chemistry , catalysis , inorganic chemistry , organic chemistry , polymerization , ion , polymer
The use of tetravalent cerium alkoxides, nitrates, and triflates was studied as a direct route to [Ce IV (carbene)] complexes. Protonolysis reactions between 1 H ‐imidazolium‐ or imidazoline (=4,5‐dihydro‐1 H ‐imidazole)‐containing alkoxide proligands HL (L=OCMe 2 CH 2 [1‐C(NCHCHN i Pr)]) and HL S (L S =OCMe 2 CH 2 [1‐C(NCH 2 CH 2 N i Pr)]) and Ce IV tert ‐butoxide, triflate, and nitrate compounds were studied to target [Ce IV (N‐heterocyclic carbene)] complexes (of unsaturated and saturated carbenes, resp.). Instead, tetravalent cerium imidazolium [(O t Bu) 3 Ce( μ ‐O t Bu) 2 ( μ ‐HL)Ce(O t Bu) 3 ], or imidazolinium adducts [(O t Bu) 3 Ce( μ ‐O t Bu) 2 ( μ ‐HL S )Ce(O t Bu) 3 ] were isolated. However, the salt metathesis of cerium triflate with KL provided a simple route to [CeL 4 ], which was significantly improved if an external oxidant, benzoquinone, was included in the mixture to maintain oxidation‐state integrity. Likewise, the salt metathesis of cerium triiodide with KL and added benzoquinone provided a straightforward route to [CeL 4 ].