An Oxalate‐Bridged Copper(II) Dimer and a Mononuclear Cobalt(III) Azide Complex Containing N ‐Nitrile‐Functionalized 1, 4, 7‐Triazacyclononane Terminals: Synthesis, Crystal Structure, and Magnetic Characterization

The stable dinuclear [Cu(μ‐C 2 O 4 )Cu] 2+ entity is facially coordinated at each end by a N ‐nitrile functionalized triazamacrocycle, 1, 4, 7‐tris(cyanomethyl)‐1, 4, 7‐triazacyclononane ( L ), to generate a centrosymmetric compound [Cu 2 L 2 (μ‐C 2 O 4 )](ClO 4 ) 2 · 4DMF ( 1 ) containing a bis‐bidentate oxalate bridge. The variable‐temperature magnetic measurement for the crystallographically characterized compound exhibits quite strong antiferromagnetic coupling interaction between two oxalate‐linked Cu II atoms separated by 5.149 Å with a singlet‐triplet energy gap of –345.5 cm –1 . On the other hand, a mononuclear Co III compound [Co L (N 3 ) 3 ] · 2.5H 2 O ( 2 ) with monodentate azide terminal groups was synthesized. Structural elucidation by X‐ray diffraction shows that the compound has crystallographically imposed C 3 symmetry. Enantiomerically pure crystals were obtained upon crystallization indicated by a Flack parameter of 0.04(5).