A new family of metal-centred and noncentred icosahedral cages with transition metal and main group VI atoms: synthesis and structural-bonding analysis of the nickel-centred [Ni11Se2(CO)18]2–, nickel-centred [Ni10Te3(CO)15]2– and noncentred [Ni8Te4(CO)12]2– icosahedral dianions

Abstract

Three new dianions possessing Ni-centred Ni₁₀Se₂1, Ni-centred Ni₉Te₃2 and noncentred Ni₈Te₄3 cages were synthesized and crystallographically characterized; a structural-bonding analysis indicates that the extra ten cluster valence electrons (CVEs) arising in 1 and 2 from the filled 3d atomic orbitals (AOs) of the centred interstitial Ni(i) atom occupy antibonding radial Ni(i)-cage molecular orbitals (MOs)(in violation of current electron-counting rules) such that the icosahedral frameworks of 1, 2 and 3 possess the expected 13 skeletal electron pairs.