Crystal structure of [trans-1,2-cyclohexanediaminetriacetato(2-)]ethylenediaminecobalt(III) perchlorate monohydrate, [CoEn(HCydtra)]ClO4 center dot H2O, and [ethylenediaminetri-3-propionato(2-)]ethylenediaminecobalt(III) pentachlorodimercurate(II), [CoEn(HEdtrp)]Hg2Cl5: Unusual coordination of the diaminetricarboxylate-type ligands

X-ray analysis was performed for [Co(C2H8N2)(C12H18N2O6)]ClO4 . H2O (I, R = 0.0330 for 2591 reflections) and [Co(C2H8N2)(C11H18N2O6)]Hg2Cl5 (II, R = 0 .0552 for 1799 reflections). The protonated ethylenediaminetri-3-propionate or trans-1,2-cyclohexanediaminetriacetate ion is bound to the Co atom thro ugh two N atoms and two O atoms, in conjunction with two N atoms of ethylen ediamine, this results in the cis-CoN4O2 coordination for I and trans-CoN4O 2 coordination for II. Unlike all previously studied complexes of analogous type, the coordinated carboxyl groups in I and II are bound to one N atom. The Co-N bond lengths are equal to 1.941(3)-1.99(2) and Co-O are 1.86(3)-1 .93(3) Angstrom. Structure II contains the [Cl2HgClHgCl2](-) groups [Hg-Cl 2.23(2)-2.36(2) Angstrom for the terminal Cl atoms and 2.63(3) and 2.68(3) Angstrom for the bridging Cl atom]. These groups are combined with the comp lexed cations through two Hg-O bonds [2.59(3) and 2.61(3) Angstrom] to form infinite chains.