Single-Crystal EPR and X-Ray Studies of Magnetic Exchange Interactions and the Molecular Structure of Dipropylenetriamineethylenediaminecopper(II) Perchlorate, [Cu(dpt)(en)](ClO<inf>4</inf>)<inf>2</inf>

The monomeric copper complexes [Cu(dpt)(en)](ClO4)2 (1) and [Zn/Cu(dpt)(en)](ClO4)2 (2) (dpt = dipropylenetriamine; en = ethylenediamine) were synthesized. The complexes crystallize in space group Pbca with cell parameters a =14.311(5) Å, b = 16.638(2) Å, c = 15.234(4) Å, α = β= γ = 90°, V = 3627(2) Å3, and Z = 8. The molecular structure of the complex tends toward trigonal bipyramidal symmetry. Angular, frequency-dependent EPR line widths and line shapes have been studied in detail to estimate the intrastack (J) as well as the interstack (J) exchange interactions. The calculated correlation time tc for interchain spin diffusion is 1.2 x 10-9 s using the dependence of line width at X- and Q- band frequencies. The ratio J'/J = 6 x 10-2 at 298 K and the line shapes indicate quasi-one-dimensional behavior. The exchange interaction pathway is most probably favored by the perchlorate anion.