LIPOPHILIC HEXADENTATE GALLIUM, INDIUM AND IRON COMPLEXES OF NEW PHENOLATE-DERIVATIZED CYCLOHEXANETRIAMINES AS POTENTIAL IN-VIVO METAL-TRANSFER REAGENTS

1,3,5-Tris(5-substituted salicylamino)cyclohexanes (H(3)L; R = H, NO2 or OMe) have been synthesized by Schiff-base condensation between cis-1,3,5-triaminocyclohexane and a substituted salicylaldehyde. followed by reduction with KBH4. Reaction of these compounds with gallium(III), indium(III) and iron(III) salts gave neutral six-co-ordinate N3O3 complexes of type [ML] (M = Ga, In or Fe). The complexes have been characterized by a combination of infrared, H-1 and C-13-{H-1} NMR and mass spectroscopy. The distribution coefficients between octan-1-ol and water indicate that the complexes are lipophilic. The electronic absorption spectra of the high-spin iron(III) complexes show ligand-to-metal charge-transfer bands in the 450-500 nm range. The structures of five of the complexes have been confirmed by single-crystal X-ray crystallography.