The influence of different n-substituted diethylenetriamine ligands on the aggregation of copper(II) monoacetato complexes

Abstract

Complexes with different structural features were formed from the reaction of Cu 2(MeCOO) 4(H 2O) 2 with various N-methyl derivatives of diethylenetriamine (dien) in the presence of ClO 4 − or PF 6 −. Four compounds were obtained and studied by crystallographic methods: [Cu(Me 5dien)(MeCOO)(H 2O)](ClO 4) ( 1), [Cu(1,4-Me 2dien)(MeCOO)](ClO 4) ( 2), [Cu(1,1-Me 2dien)(MeCOO)] n (ClO 4) n ( 3) and [Cu(1,1-Me 2dien)(MeCOO)] n (PF 6) n ( 4). The differences between the three perchlorate compounds arise in the coordination modes exhibited by the acetato groups: monodentate terminal, asymmetric chelating and syn-anti bridging. In 1 the structure consists of discrete ions, containing terminal monodentate acetato ligands. Compounds 2 contains discrete cations interconnected through hydrogen bonds between the acetato ligand and the tridentate amine and 3 is polymeric, forming an infinite chain through acetato bridges. Compound 4 has a structure similar to 3. The four compounds were characterized by EPR, electronic and IR spectroscopy.