Abstract
In a systematic study of the activation of As(4) , three [LCo(tol)] (L=β-diiminato) complexes have revealed different steric and electronic influences. 2,6-Diisopropylphenyl (Dipp) and 2,6-dimethylphenyl (dmp) flanking groups were used, one of the ligands with H backbone substituents (β-dialdiminate L(0) ) and two with Me substituents (β-diketiminates L(3) and L(1) ). In the reaction with As(4) , different dinuclear products [(LCo)(2) As(4) ] (LM=L(0) (1), L(1) (2), L(3) (3)) were isolated, with all showing differently shaped [Co(2) As(4) ] cores in the solid state: octahedral in 1, prismatic in 2, and asterane-like in 3. Thermal treatment of 3 leads to the abstraction of one arsenic atom to yield [(L(3) Co)(2) As(3) ] (4). All products were comprehensively characterized by single-crystal X-ray diffraction, FD-MS, and (1) H NMR spectroscopy. A rational explanation for the different reactivity is also proposed and DFT calculations shed light on the nature of the highly flexible [Co(2) As(4) ] cores.