Tetrahedral complexes of 1,2-dimorpholinoethane and 1,3-dimorpholinopropane: Crystal and molecular structure of dichloro(1,2-dimorpholinoethane)cobalt(II)

Abstract

The ligands 1,2-dimorpholinoethane (DME) and 1,3-dimorpholinopropane (DMP) have been used to prepare Cu(II), Ni(II), Co(II), Hg(II), Zn(II), and Cd(II) complexes having the general formulationMLX ₂ (L=DME and DMP,X=Cl⁻). These complexes exhibit spectral properties indicative of a distorted tetrahedral geometry, with DME or DMP coordinating through two nitrogen atoms and two chloride anions making up the coordination sphere of the central metal atom. This is in contrast to six-coordinated, distorted octahedral geometry exhibited by metal complexes of DME when NO ⁻₂ or NO ⁻₃ were used as counter ions. The tetrahedral geometry was confirmed for [Co(DME)Cl₂] by X-ray structure determination. The structure was solved by the heavy-atom method using CAD4 diffractometer data, and refined to a finalR value of 0.028 for 1097 independent reflections. The morpholine moieties of DME in [Co(DME)Cl₂] are in a chair configuration, forbidding any coordination through ethereal oxygen atoms.