Komplexe zweier vierzehngliedriger Tetraazadibenzo-Makrocyclen. Strukturen eines freien Liganden und von Nickel(II)-, Kupfer(II)- und Zink(II)-Komplexen / Complexes of Two 14-Membered N₄ Dibenzo Macrocycles. Crystal Structures of a Free Ligand and of Nickel(II), Copper(II) and Zinc(II) Complexes

Abstract

Macrocyclic N4-Donor Ligands, Transition Metal Complexes, Crystal StructureThe syntheses and structural characterizations of complexes of two 14-membered macrocy clic trans-N4 dibenzo ligands, 5,7,8,9,14,16,17,18-octahydrodibenzo[e,l]-[l,4,8,l ll-tetraazacyclotetradecine-6,15-dimethyl (L3) resp. -6,15-diacetamide (L4), are presented. The crystal structures of five compounds have been determined by single crystal X-ray diffraction. The free ligand L3 has a saddle-shaped structure with intramolecular hydrogen bonds. This conformation of the ligand exists also in the Zn(II) complex in which the metal ion is five-coordinated with the metal center outside the cavity. The coordination polyhedron is intermediate between a trigonal bipyramid and a square pyramid. In c/5-[Ni(L3)(NCS)2] the ligand is folded along an N-• N axis. The nickel ion in this complex shows an approximate octahedral geometry. For Ni(II) and Cu(II) complexes of ligand L the overall geometry is also distorted octahedral. The folding of the ligand causes a d s-N 40 2 coordination.* Sonderdruckanforderungen an Prof. Dr. R. Mattes. sowie die strukturelle und spektroskopische Cha rakterisierung des Liganden L3 und der Komplexe [Zn(L5)Cl]+ (3), [N i(L3)(NCS)2] (4), [Ni(L4)]2+ (5) und [Cu(L4)]2+ (6).Die aus strukturellen Untersuchungen an den Komplexen mit gemischten N 2S2-Donorsätzen 0932-0776/99/0300-0321 $ 06.00