SYNTHESIS AND COORDINATION CHEMISTRY OF THE STERICALLY DEMANDING PENDANT-ARM MACROCYCLE N,N',N''-TRIS[(2R)-2-HYDROXY-3-METHYLBUTYL]-1,4,7-TRIAZACYCLONONANE

The sterically demanding pendant-arm macrocycle N,N',N''-tris[(2R)-2-hydroxy-3-methylbutyl]-1,4,7-triazacyclononane H-3L has been synthesised. Owing to its bulky isopropyl arms the formation of dimeric species is prevented which is in contrast to the behaviour of the analogous ligand with methyl substituted arms, N,N',N''-tris[(2S)-2-hydroxypropyl]-1,4,7-triazacyclononane (H-3L'). The preparation of complexes of V(IV), Cr(III), Mn(IV) Ni(II), Cu(II) and Zn(II) with H-3L is described and the crystal structures and some spectroscopic properties of [Mn(IV)L] [PF6].H2O and [Ni(II)(H3L)] [NO3] [PF6] determined.