W Tungsten

Counterbalance of the potassium sock away of amido ligand [Ph2Si(NAr)2]2- (L, Ar=2,6-iPr2C6H3) and LnI2(thf)2 (Ln=Sm, Yb) gives sandwich complexes [(L)2Ln{K(Et2O)}2] (Ln=Sm (2), Yb (3)) with potassium-arene [pi] interactions. Counteraction of 2 with azobenzene gave the dimeric samarium collection [(L)2Sm2([mu]-[eta]2:[eta]2-N2Ph2)2{K(thf)2}2] (4) and the tetrameric [(L)Sm4 ([mu]-[eta]2:[eta]2-N2Ph2)3 ([mu]3-NPh)2(thf)3] (5). On the other hand, the feedback of 2 with [alpha]-diimines ligands ArN[double bond]CRCR[double bond]NAr (DAD, R=H, Me) gives two SmIII complexes: polymeric [(L)Sm{(ArN)RC[double bond]CR(NAr)}K]n (R=H (6), Me (7)) assembled Sometimes non-standard due to cation-[pi] interactions and byproduct [{(L)2Sm}{K(thf)6}] (8). Complexes 2-8 must been fully characterized by primal analyses and X-ray crystallography. In particular, crystallographic analyses of 6 and 7 revealed that in both complexes samarium(III) is stabilized by dianionic DAD units <<>>

Reaction of the potassium salt of amido ligand [Ph2Si(NAr)2]2− (L, Ar=2,6-iPr2C6H3) and LnI2(thf)2 (Ln=Sm, Yb) gives sandwich complexes [(L)2Ln{K(Et2O)}2] (Ln=Sm (2), Yb (3)) with potassium–arene π interactions. Reaction of 2 with azobenzene gave the dimeric samarium cluster [(L)2Sm2(μ-η2:η2-N2Ph2)2{K(thf)2}2] (4) and the tetrameric [(L)Sm4 (μ-η2:η2-N2Ph2)3 (μ3-NPh)2(thf)3] (5). On the other hand, the reaction of 2 with α-diimines ligands ArNCRCRNAr (DAD, R=H, Me) gives two SmIII complexes: polymeric [(L)Sm{(ArN)RCCR(NAr)}K]n (R=H (6), Me (7)) assembled through cation–π interactions and byproduct [{(L)2Sm}{K(thf)6}] (8). Complexes 2–8 have been fully characterized by elemental analyses and X-ray crystallography. In particular, crystallographic analyses of 6 and 7 revealed that in both complexes samarium(III) is stabilized by dianionic DAD units.Unusual sandwiches: Heterometallic sandwich complex 1 reacts with azobenzene to afford [(L)2Sm2(μ-η2:η2-N2Ph2)2{K(thf)2}2] (2) and [(L)Sm4(μ-η2:η2-N2Ph2)3(μ3-NPh)2(thf)3] (3), for which crystallographic studies showed that the alkali metal cation–arene π interactions help to stabilize the divalent metal centers. In addition, complex 1 reacts with diazabutadiene ligands to give SmIII complexes that form one-dimensional networks through cation–arene π interactions.