[Cu@Sn9]3- and [Cu@Pb9]3-:: Intermetalloid clusters with endohedral Cu atoms in spherical environments

A study was conducted to demonstrate the structural and spectroscopic characterization of the first representatives of clusters, containing endohedral copper (Cu) atoms in spherical environment of nine tin or lead atoms. The compounds used in the study included (K(2,2,2)crypt)3(Cu@E9)(dmf)2 and lead that crystallized in the monoclinic space group, with two dimethylformamide (dmf) solvate molecules per formula unit. It was observed that the unit cell parameter of the lead compound are about 0.07 Å longer than those of the isomorphic tin compound. Nine crystallographically independent E atoms of the anions built a distorted tricapped trigonal prism, with approximate C2v symmetry.