3d-4f heterometallic complexes by the reduction of transition metal carbonyls with bulky Ln$^{II}$ amidinates

The redox chemistry between divalent lanthanide complexes bearing bulky amidinate ligands has been studied with 3d transition metal carbonyl complexes (iron and cobalt). The reaction of [(DippForm)$_{2}$Sm$^{ǁ}$(thf)$_{2}$] (DippForm = N,N′-bis(2,6-diisopropylphenyl)formamidinate) with [Co$_{2}$(CO)$_{8}$] resulted in the formation of a tetranuclear Sm–Co complex, [{(DippForm)$_{2}$Sm$^{ǁǀ}$(thf)}$_{2}${(μ-CO)$_{2}$Co(CO)$_{2}$}$_{2}$]. The product of the reaction of [(DippForm)$_{2}$Yb$^{ǁ}$(thf)$_{2}$] and [Co$_{2}$(CO)$_{8}$] gives the dinuclear Yb–Co complex [{(DippForm)$_{2}$Yb$^{ǁǀ}$(thf)}{(μ-CO)Co(CO)$_{3}$}] in toluene. The reaction of [(DippForm)$_{2}$Sm$^{ǁ}$(thf)$_{2}$] was also carried with the neighbouring group 8 carbonyl complexes [Fe$_{2}$(CO)$_{9}$] and [Fe$_{3}$(CO)$_{12}$], resulting in a pentanuclear Sm$^{ǁǀ}$–Fe complex, [{(DippForm)$_{2}$Sm$^{ǁǀ}$}$_{2}${(μ$_{3}$-CO)$_{2}$Fe$_{2}$(CO)$_{9}$}], featuring a triangular iron carbonyl cluster core