Abstract
The tetradentate macrocyclic ligands 1,4,7-triazacyclononane-N-acetate (L1) and N-(2-hydroxybenzyl)-1,4,7-triazacyclononane (HL2) react in methanol with CuCl2 or Cu(ClO4)2·6H2O in the absence or presence of LiOH·H2O with formation of the following complexes containing square based pyramidal Cu(II)ions: [L1CuCl] (1), [L1CuCl]LiCl·2H2O (2), [L1Cu](ClO4) (3) and [L22Cu2](ClO4)2 (4). Complexes 2 and 4 have been characterized by single crystal X-ray crystallography; the structure of 3 has been reported previously [3]. Crystal data: 2, space group P21/c, a = 11.674(4), b = 7.543(2), c = 17.560(5) Å, β = 106.59(8)°, V = 1481.9(7) Å3, Z = 4, Dcalc = 1.63 g cm-3, R = 0.044 based on 2499 reflections; 4, space group Pbca, a = 17.742(4), b = 10.335(2), c = 17.742(4) Å, V = 3253(1) Å3, Dcalc = 1.62, Z = 4, R = 0.048 based on 2147 reflections. From temperature dependent magnetic susceptibility measurements (2-293 K) weak intermolecular antiferromagnetic exchange coupling has been established for 1 and 2, whereas for the helical chain structure 3 weak ferromagnetic exchange coupling has been observed. In dinuclear 4 strong antiferromagnetic intramolecular coupling leads to an S = 0 ground state.
| Original language | English |
|---|---|
| Journal | Inorganica Chimica Acta |
| Volume | 246 |
| Issue number | 1-2 SPEC. ISSUE |
| Pages (from-to) | 387-394 |
| Number of pages | 8 |
| ISSN | 0020-1693 |
| DOIs | |
| Publication status | Published - 01.05.1996 |
Funding
We thank the Deutsche Forschungsgemeinschaft (Schwerpunktprogramm Bianorganische Chemie) and the Fonds der Chemischen Industrie for financial support. Dr. E. Bill (Medizinische Universimt Ltibeck) is thanked for measuring the ESR spectra.
