SYNTHESIS AND COORDINATION CHEMISTRY OF THE STERICALLY DEMANDING PENDANT-ARM MACROCYCLE )-2-HYDROXY-3-METHYLBUTYL]-1,4,7-TRIAZACYCLONONANE

The sterically demanding pendant-arm macrocycle )-2-hydroxy-3-methylbu tyl]-1,4,7-triazacyclononane H-3L has been synthesised. Owing to its b ulky isopropyl arms the formation of dimeric species is prevented whic h is in contrast to the behaviour of the analogous ligand with methyl substituted arms, 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 a nd some spectroscopic properties of [Mn(IV)L] [PF6].H2O and [Ni(II)(H3 L)] [NO3] [PF6] determined.