| Abstract: | The structural study of Sc complexes containing dianions of anthracene and tetraphenylethylene should shed some light on the nature of rare‐earth metal–carbon bonding. The crystal structures of (18‐crown‐6)bis(tetrahydrofuran‐κO)sodium bis(η6‐1,1,2,2‐tetraphenylethenediyl)scandium(III) tetrahydrofuran disolvate, Na(C4H8O)2(C12H24O6)]Sc(C26H20)2]·2C4H8O or Na(18‐crown‐6)(THF)2]Sc(η6‐C2Ph4)2]·2(THF), ( 1b ), (η5‐1,3‐diphenylcyclopentadienyl)(tetrahydrofuran‐κO)(η6‐1,1,2,2‐tetraphenylethenediyl)scandium(III) toluene hemisolvate, Sc(C17H13)(C26H20)(C4H8O)]·0.5C7H8 or (η5‐1,3‐Ph2C5H3)Sc(η6‐C2Ph4)(THF)]·0.5(toluene), ( 5b ), poly(μ2‐η3:η3‐anthracenediyl)bis(η6‐anthracenediyl)bis(η5‐1,3‐diphenylcyclopentadienyl)tetrakis(tetrahydrofuran)dipotassiumdiscandium(III)] tetrahydrofuran monosolvate], {K2Sc2(C14H10)3(C17H13)2(C4H8O)4]·C4H8O}n or K(THF)2]2(1,3‐Ph2C5H3)2Sc2(C14H10)3]·THF, ( 6 ), and 1,4‐diphenylcyclopenta‐1,3‐diene, C17H14, ( 3a ), have been established. The Sc(η6‐C2Ph4)2]? complex anion in ( 1b ) contains the tetraphenylethylene dianion in a symmetrical bis‐η3‐allyl coordination mode. The complex homoleptic Sc(η6‐C2Ph4)2]? anion retains its structure in THF solution, displaying hindered rotation of the coordinated phenyl rings. The 1D 1H and 13C{1H}, and 2D COSY 1H–1H and 13C–1H NMR data are presented for MSc(Ph4C2)2]·xTHF M = Na and x = 4 for ( 1a ); M = K and x = 3.5 for ( 2a )] in THF‐d8 media. Complex ( 5b ) exhibits an unsymmetrical bis‐η3‐allyl coordination mode of the dianion, but this changes to a η4 coordination mode for (1,3‐Ph2C5H3)Sc(Ph4C2)(THF)2, ( 5a ), in THF‐d8 solution. A 45Sc NMR study of ( 2a ) and UV–Vis studies of ( 1a ), ( 2a ) and ( 5a ) indicate a significant covalent contribution to the Sc—Ph4C2 bond character. The unique Sc ate complex, ( 6 ), contains three anthracenide dianions demonstrating both a η6‐coordination mode for two bent ligands and a μ2‐η3:η3‐bridging mode of a flat ligand. Each (1,3‐Ph2C5H3)2Sc2(C14H10)3]2? dianionic unit is connected to four neighbouring units via short contacts with K(THF)2]+ cations, forming a two‐dimensional coordination polymer framework parallel to (001). |
