Reactivity studies of group 15 Zintl ions towards homoleptic post-transition metal organometallics: a ‘bottom-up’ approach to bimetallic molecular clusters

Abstract

Reactions between ethylenediamine (en) solutions of the intermetallic Zintl phases K₃E₇ (E = P, As) and a series of homoleptic post-transition metal organometallics such as Cu₅(Mes)₅, M(C₆H₅)₂ (M = Zn, Cd) and In(C₆H₅)₃ have yielded a family of novel bimetallic cluster anions. These new species were isolated as [K(2, 2,2-crypt)]⁺ salts in [K(2,2,2-crypt)]₄Cu₂E₁₄ (E = P (1), As (2)), [K(2,2,2-crypt)]₄ZnE₁₄ (E = P (3), As (4)), [K(2,2,2-crypt)]₄CdP₁₄·6py (5) and [K(2,2,2-crypt)]₂E₇InPh₂ (E = P (6), As (7)). Species 2, 3, 5 and 6 were crystallographically characterised by single-crystal X-ray diffraction. The stability of all of the cluster anions in solution was confirmed by electrospray mass-spectrometry and by ¹H, ¹³C{¹H} and ³¹P{¹H} NMR spectroscopy when possible.