The Sc–Sc bond through the hole of C8H8 in X[Sc–C8H8–Sc]X (X = F∼Br) and the uninterrupted Sc–Sc–Sc–Sc bond-chain with both the Sc–Sc bond through C8H8 and the Sc–Sc bond between two [Sc–C8H8–Sc] units in X[Sc–C8H8–Sc]2X are predicted. The molecules are roughly estimated as potentially electro-conductive by the low HOMO–LUMO gaps.
![Graphical abstract: A metal–metal bond passing through the arene ligand: a theoretical study on inverse sandwiches X[Sc–C8H8–Sc]nX (X = F, Cl, Br; n = 1, 2)](http://hg.y866.cn/compound/lib/scimg/usr/1/C4NJ01832J.jpg)
