Versatile Coordination of AgI and CuI Ions towards cyclo-As5 Ligands

The reactions of the cyclo-As-5 complex [Cp*Fe(eta(5)-As-5)] (B) with the Ag-I and Cu-I salts of the weakly coordinating anion (WCA) [FAl{OC6F10(C6F5)}(3)](-) ([FAl](-)) are studied. These reactions allow the synthesis of the mononuclear complexes [M(eta(5) : eta(2)-B)(2)][FAl] (M=Ag (1), Cu (2)) when a ratio of B/M(FAl) 2 : 1 is used. Compound 1 shows an unusual disorder of the central Ag-I cation between two pi-coordinating cyclo-As-5 ligands, which is absent in 2 pointing to a weak interaction of the Ag center towards the cyclo-As-5 ligands in B. When the ratio of B/Ag(FAl) is changed to 3 : 1 or 1 : 1, the respective coordination compounds [Ag(eta(2)-B)(3)][FAl] (3) and [Ag-2(eta(2) : eta(2)-B)(2)][FAl](2) (4) are accessible. The coordination modes of the cyclo-As-5 units in 1, 3 and 4 are all different, reflecting the adaptive coordination behavior of B towards Ag-I ions. The optimized geometries in the gas phase of 1-4 are determined by DFT calculations to support the bonding situation observed in their solid-state structures.

Automated summary

The study investigated the reactions of cyclo-As-5 complex with Ag-I and Cu-I salts, leading to the synthesis of various coordination compounds exhibiting different coordination modes of Ag-I ions. DFT calculations were employed to support the observed bonding situation in the solid-state structures.