The anion of [K(crypt-222)] 3 [Sb(AuMe) 4 ]•py ( 1; crypt-222 = 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo-[8.8.8]hexacosane;py= pyridine) represents arare example of ah omoleptic heavy p-block metal atom being surrounded by four free-standing transition metal complex fragments,and the thirdexample for acorresponding Sb compound. In contrast to all reported complexes of this type,t he transition metal atoms possess twofold coordination only,h ence the complex as aw hole does not exhibit

more »

... nt steric shielding or further linkage of the metal atoms.This is reflected in ahigh flexibility, as confirmed by slight deviations from atetrahedral coordination of the Sb atom in the crystal and soft vibrational modes. An alternative pyramidal conformer,o bserved for ar elated arsenic compound with terminal phosphine ligands,i sa pparently disfavored owing to electron correlation effects.T he compound is formed in areaction that in another solvent or at other reactant concentrations yields salts of ternary cluster anions.B yacombined experimental and theoretical study of different reaction conditions and previously unidentified sideproducts,weprovideinsight into multimetallic cluster synthesis reactions.