title: Ytterbocenes as one- and two-electron reductants in their reactions with diazadienes: YbIII mixed-ligand bent-sandwich complexes containing a dianion of diazabutadiene.
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.
authors: Institute of Organometallic Chemistry, Russian Academy of Sciences, Tropinina 49, 603950, Nizhny Novgorod, GSP-445, Russia. trif@imoc.sinn.ru
authors: Alexander A
authors: AA
authors: Trifonov
authors: Ivan A
authors: IA
authors: Borovkov
authors: Elena A
authors: EA
authors: Fedorova
authors: Georgii K
authors: GK
authors: Fukin
authors: Joulia
authors: J
authors: Larionova
authors: Nikolai O
authors: NO
authors: Druzhkov
authors: Vladimir K
authors: VK
authors: Cherkasov