Anion Encapsulation and Geometric Changes in Hepta- and Hexanuclear Copper(I) Dichalcogeno Clusters: A Theoretical and Experimental Investigation

Abstract

Whereas stable octanuclear clusters of the type M^I₈(E^∩E)₆ (M = Cu, Ag; E^∩E = dithio or diseleno ligand) are known for being able to encapsulate a hydride or main-group anion under some circumstances, only the related hydride-containing heptanuclear [M^I]₇(H)­(E^∩E)₆ and empty hexanuclear [M^I]₆(E^∩E)₆ species have been characterized so far. In this paper we investigate by the means of theoretical calculations and experiments the viability of empty and anion-centered clusters of the type [Cu^I]₇(X)­(E^∩E)₆ and [Cu^I]₆(X)­(E^∩E)₆ (X = vacancy, H or a main-group atom). The theoretical prediction for the existence of anion-containing heptanuclear species, the shape of which is modulated by the anion nature and size, have been fully confirmed by the synthesis and characterization of [Cu₇(X)­{S₂P­(OⁱPr)₂}₆] (X = H, Br). This consistency between experiment and theory allows us to predict the stability and shape-modulated structure of a whole series of [Cu^I]₇(X)­(E^∩E)₆ (X = vacancy, H, O, S, halogen) and [Cu^I]₆(X)­(E^∩E)₆ (X = H, halogen) clusters