Preparation and structures of some tetraazamacrocyclic complexes of In(III)

Treatment of the dibenzo-tetraaza macrocycle, C22H24N4 (H(2)tmtaa) (I), with triethylindium yields the diethylindium-macrocycle complex [Et2In(Htmtaa)] (IV). On heating (IV) is converted quantitatively into the monoethyl complex [EtIn(tmtaa)](V). A single crystal X-ray diffraction study on (V) shows the EtIn fragment to be bonded to the four planar nitrogen atoms of the macrocycle, with a square-pyramidal geometry around the metal. Reaction of the dilithio salt of(I), [Li-2(tmtaa)], with InCl3, yields [ClIn(tmtaa)] (VI), and further reaction of (VI) with equimolar quantities of LiR [R=C5H5(Cp), Me, N(SiMe3)(2), OSiMe3] yields the corresponding [RIn(tmtaa)] derivatives [R = Cp (VII) Me (VIII), N(SiMe3)(2) (IX), OSiMe3 (X)]. An X-ray diffraction study on (VII) shows an eta(1)-bonded Cp group, with the metal atom also bound to the four nitrogen atoms of the tmtaa ligand. (C) 1998 Elsevier Science S.A.