Coordination Behavior Of [Cp '' Zr-2(Mu(1:1)-As-4)] Towards Lewis Acids

The functionalization of the arsenic transfer reagent [Cp '' Zr-2(eta(1:1)-As-4)] (1) focuses on modifying its properties and enabling a broader scope of reactivity. The coordination behavior of 1 towards different Lewis-acidic transition metal complexes and main group compounds is investigated by experimental and computational studies. Depending on the steric requirements of the Lewis acids and the reaction temperature, a variety of new complexes with different coordination modes and coordination numbers could be synthesized. Depending on the Lewis acid (LA) used, a mono-substitution in [Cp '' Zr-2(mu,eta(1:1:1:1)-As-4)(LA)] (LA = Fe(CO)(4) (4); B(C6F5)(3) (7)) and [Cp '' Zr-2(mu,eta(3:1:1)-As-4)(Fe(CO)(3))] (5) or a di-substitution [Cp '' Zr-2(mu(3),eta(1:1:1:1)-As-4)(LA)(2)] (LA = W(CO)(5) (2); CpMn(CO)(2) (3); AlR3 (6, R = Me, Et, Bu-i)) are monitored. In contrast to other coordination products, 5 shows an eta(3) coordination in which the butterfly As-4 ligand is rearranged to a cyclo-As-4 ligand. The reported complexes are rationalized in terms of inverse coordination.