Bis(4-chloro-pyridine){2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}cobalt(III) perchlorate methanol monosolvate

Investigation of nitro-nitrito photoisomerization: crystal structures of trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}(pyridine/4-methyl-pyridine)-nitro-cobalt(III)

The reaction cavities of the nitro groups in the title compounds, trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-κ4 O,N,N',O'}(nitro-κN)(pyridine-κN)cobalt(III), [Co(C16H14N2O2)(NO2)(C5H5N)], (I), and trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-κ4 O,N,N',O'}(4-methyl-pyridine-κN)(nitro-κN)cobalt(III), [Co(C16H14N2O2)(NO2)(C6H7N)], (II), have been investigated to reveal that the inter-molecular CMe-H⋯O(nitro) contacts in (II) are unfeasible for the nitro-nitrito photochemical linkage isomerization process. In (I), there are two independent complexes showing similar conformations, and the central five-membered chelate ring of the tetra-dentate salen ligand adopts the same absolute configuration. This is the result of pseudo-spontaneous resolution, since the configuration of the five-membered chelate ring may frequently be reversed in solution. In the crystals of (I) and (II), the mol-ecules are linked into three-dimensional networks by C-H⋯O hydrogen bonds.

Bis(2-{[2-(2-hydroxybenzylamino)ethyl]aminomethyl}phenolato-κ3N,N′,O1)cobalt(III) nitrate monohydrate

In the title compound, [Co(C₁₆H₁₉N₂O₂)₂]NO₃·H₂O, the Co^III ion is located on an inversion center and is six-coordinated by two phenolate O atoms and four amino N atoms from two diamine ligands, forming an octa­hedral geometry. The water mol­ecule and the nitrate anion are located close to an inversion center, and are thus equally disordered by symmetry. The crystal packing is stabilized by inter­molecular O—H⋯O hydrogen bonds involving the uncoordinated water mol­ecule and the free phenol hydroxyl group with the nitrate anion. N—H⋯O hydrogen bonds involving the amino groups and the nitrate anions connect the complex mol­ecules along the c axis.