NON?Ligated <i>N</i> ?Heterocyclic Tetrylenes

We report on the synthesis of N-heterocyclic tetrylenes ligated by NON-donor framework 4,5-bis(2,6-diisopropylphenyl-amino)-2,7-di-tert-butyl-9,9-dimethylxanthene. The molecular structures germylene (3), stannylene (4) and plumbylene (5) where determined X-ray diffraction studies. Furthermore, we present quantum chemical studies ?-donor ?-acceptor properties 3–5. Additionally, reactivity towards transition metal carbonyls [Rh(CO)2Cl]2, [W(CO)6] [Ni(CO)4]. isolated complexes (6 7) show differing NHTs compared to NHCs. Instead just forming anticipated complex [(NON)Sn?Rh(CO)2Cl], 4 inserts into Rh?Cl bond afford [(NON)Sn(Cl)Rh(CO)(C6H6)] (6, additional CO/C6H6 exchange) [(NON)Sn(Cl)Rh2(CO)4Cl] (7). By avoiding halogenated precursors in order prevent insertion reactions, 3 shows “classical” coordination chemistry {Ni(CO)3} [(NON)Ge?Ni(CO)3] (8).