Structural and magnetic properties of Co3(dpa)4Br2

Abstract

Eleven crystal structures have been determined for the trinuclear Co₃(dpa)₄Br₂ (1) (dpa = di(2-pyridyl)amide anion) molecule in the following solvates: 1·CH₂Cl₂ (at 111, 147 and 240 K), 1·C₆H₁₂ (at 110, 150, 213 and 298 K) and 1·1.75C₇H₈·0.5C₆H₁₄ (at 110, 170, 213 and 295 K). Their magnetic behavior has been measured over the temperature range 5–350 K. In nearly every respect their behavior closely parallels that of their chloro analogs, although certain crystallographic and magnetic details differ. Of particular importance is that both symmetrical and unsymmetrical structures are observed in different crystalline forms and that the unsymmetrical forms display marked temperature dependence. It is, therefore, clear that the highly unconventional behavior of the chloro analog is not restricted to that one compound.

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