Group 6 Hexacarbonyls as Ligands for the Silver Cation: Syntheses, Characterization, and Analysis of the Bonding Compared with the Isoelectronic Group 5 Hexacarbonylates

The syntheses of the two novel complexes [Ag{Mo/W(CO)6}2]+[F‐{Al(ORF)3}2]− (RF=C(CF3)3) are reported along with their structural and spectroscopic characterization. The X‐ray structure shows that three carbonyl ligands from each M(CO)6 fragment bend towards the silver atom within binding Ag−C distance range. DFT calculations of the free cations [Ag{M(CO)6}2]+ (M=Cr, Mo, W) in the electronic singlet state give equilibrium structures with C 2 symmetry with two bridging carbonyl groups from each hexacarbonyl ligand. Similar structures with C 2 symmetry (M=Nb) and D 2 symmetry (M=V, Ta) are calculated for the isoelectronic group 5 anions [Ag{M(CO)6}2]− (M=V, Nb, Ta). The electronic structure of the cations is analyzed with the QTAIM and EDA‐NOCV methods, which provide detailed information about the nature of the chemical bonds between Ag+ and the {M(CO)6}2 q (q = −2, M = V, Nb, Ta; q = 0, M = Cr, Mo, W) ligands.
Hexacarbonyls as ligands: The molecules M(CO)6 (M=Mo, W) act as ligands towards the silver ion, giving the title compounds [Ag{M(CO)6}2]+[F‐{Al(ORF)3}2]− (RF=C(CF3)3). Their structures and bonding have been analyzed and compared with those of the very recently prepared isoelectronic complexes [Ag{M(CO)6}2]− (M=Nb, Ta).