Triple 1D
1D superatomic bonding. Au22(dppo)6 as a Π4- and Δ2-triply bonded cluster based on Au11 assembled units†
Abstract
δ-Bonds have been intimately related to metal–metal bonds of d-elements since the archetypal d4–d4 [Re2Cl8]2− ion with a σ2π4δ2 bond. Currently, the notion of multiple superatom arrangements as initial steps toward molecular materials within the building-up approach is dominated by P-shell characteristics, as given in the well-described Au25(SR)18 ligand protected cluster. In this work we rationalize the Au22(dppo)6 cluster as a triple-bonded 22-valence electron (ve) supermolecule, featuring a bonding scheme based on 1D + 1D shell combinations, which largely contrasts with the 14-ve Au38(SR)24 with mainly 1P + 1P patterns mimicking a F2 molecule. The resulting Π4Δ2-bonding pattern shows an unprecedented superatomic counterpart of a d-shell based bond inherently related to transition-metal dimers, adding useful key aspects to the understanding of species based on cluster-assembly.