Nickel(II) complexes with tetraaza macrocyclic ligands
Abstract
The Ni(II) complexes of 1,5,9,13-tetraazacyclohexadecane ([16]aneN 4) and 1,4,8,12 tetraazacyclopentadecane ([15]aneN 4) ligands have been synthesized and characterized by X-ray crystallography. Crystal data for orange [Ni([16]aneN 4)](ClO 4) 2 ( 1) at 213 K: monoclinic space group P2 1/ c, a=13.38(1), b=17.818(6), c=16.579(6) Å, β=90.80(6)°, V=3952(4) Å3; for [Ni([15]aneN 4)[ClO 4) 2] (3) at 173 K: monoclinic space group P2 1/ n, a=8.072(2), b=17.857(2), c=12.923(2) Å, β=95.92(1)°, V=1852.8(7) Å3. Compound 1 has the ligand in the ch,ch,ch,ch,+-+-conformation, but the nitrogen atoms are practically coplanar. In 3, the ligand conformation is again planar, but octahedral coordination about the nickel ion is completed by two unidentate ClO-4 ions and the compound is purple with (presumably) high-spin nickel(II). There is an orange precursor, 2, to 3 in which the ClO -4 ions are not coordinated and the structure is planar.
- Publication:
-
Journal of Molecular Structure
- Pub Date:
- October 1998
- DOI:
- 10.1016/S0022-2860(98)00478-5
- Bibcode:
- 1998JMoSt.470..161C