Coordination chemistry of aliphatic, tripodal ligands with zinc salts

The unsymmetrical, aliphatic tripods N(CH2CH2CH2NH2)(2)(CH2CH2OH)(H-5-2) and N(CH2CH2CH2NH2)(2)(CH2CH2CH2OH) (H-5-4) were prepared and their coordination chemistry with zinc salts was studied. The reactivity of the ligands with zinc chloride, zinc perchlorate and zinc bis(tetrafluoroborate) depends on the anion present.Ligand H-5-2 reacts with Zn(ClO4)(2) under formation of the dinuclear centrosymmetric complex [(H-4-2)Zn](2)(ClO4)(2) (5) containing bridging eta(2)-alkoxy functions. Ligand H-5-2 reacts with Zn(BF4)(2) under formation of the trigonal-bipyramidal complex [(H-5-2)ZnF]BF4 (7), while the reaction of (H-5-4) with ZnCl2 yields the mononuclear, tetrahedral complex [(H-5-4)ZnCl]Cl (8) with an uncoordinated alcohol donor group. Complexes 5, 7 and 8 were characterized by X-ray diffraction and NMR and IR spectroscopy.