Ytterbocenes as one- and two-electron reductants in their reactions with diazadienes: YbIII mixed-ligand bent-sandwich complexes containing a dianion of diazabutadiene

Alexander A Trifonov; Ivan A Borovkov; Elena A Fedorova; Georgii K Fukin; Joulia Larionova; Nikolai O Druzhkov; Vladimir K Cherkasov

doi:10.1002/chem.200601481

Ytterbocenes as one- and two-electron reductants in their reactions with diazadienes: YbIII mixed-ligand bent-sandwich complexes containing a dianion of diazabutadiene

Chemistry. 2007;13(17):4981-7. doi: 10.1002/chem.200601481.

Authors

Alexander A Trifonov¹, Ivan A Borovkov, Elena A Fedorova, Georgii K Fukin, Joulia Larionova, Nikolai O Druzhkov, Vladimir K Cherkasov

Affiliation

¹ Institute of Organometallic Chemistry, Russian Academy of Sciences, Tropinina 49, 603950, Nizhny Novgorod, GSP-445, Russia. trif@imoc.sinn.ru

PMID: 17366494
DOI: 10.1002/chem.200601481

Abstract

Ytterbocene [Yb(C(5)MeH(4))(2)(thf)(2)] reacts with diazabutadiene 2,6-iPr(2)C(6)H(3)-N=CH-CH=N-C(6)H(3)iPr(2)-2,6 (DAD) as a one-electron reductant to afford a bis(cyclopentadienyl) Yb(III) derivative containing a DAD radical anion [Yb(C(5)MeH(4))(2)(dad(-.))]. However, ytterbocenes [YbCp*(2)(thf)(2)] (Cp*=C(5)Me(5), C(5)Me(4)H) coordinated by sterically demanding cyclopentadienyl ligands act as two-electron reductants in their reactions with DAD. These reactions occur by abstraction of one Cp* ring and result in the formation of novel Yb(III) mixed-ligand bent-sandwich complexes, [YbCp*(dad)(thf)], in which the dianion of DAD has an uncommon terminal eta(4)-coordination to the ytterbium atom. The variable-temperature magnetic measurements of complex [Yb(C(5)Me(5))(dad)(thf)] suggest the existence of redox tautomerism for this compound.