Base Hydrolysis of Pentaaminecobalt(III) Complexes: The [CoX(dien) (dapo)]n+ system. Part 1. Syntheses,structures, configuration,and spectroscopy

Oxygentation of aqueous solutions of Co^III in presence of stoichiometric amounts of N-(2-aminoethyl)ethane-1,2-diamine (dien) and 1,3-diaminopropan-2-ol (dapo) produces μ-peroxocobalt(III) dimers. Acid cleavage (HCI) yields mer-exo(H)-, mer-endo (H)-, unsym-fac-exo(OH)-, and unsym-fac-endo(OH)-CoCl(dien)(dapo)]²⁺ ( A–D )(X = Cl), resp. and unsym-fac-Co-(dien)(dapo-N,N′,O)]³⁺ ( G ). Isomer seperation was achieved by fractional crystallization as ZnCl and ClO salts and by ion-exchange chromatography. The corresponding bromo, azido, nitrito-O, nitro-N, thiocyanato, hydroxo, and aqua complexes were also synthesized. Optically resolved samples were prepared for chiral compounds, and the complexes were structurally characterized by X-ray analyses ($ \mathop {\it \Lambda} \limits^ \to $(?)_436(CD) -A (X = N₃)), ($ \mathop {\it \Delta} \limits^ \to $(?)₄₃₆(CD) -B ). (X = N₃), $ \mathop {\it \Delta} \limits^ \to $ (+)₄₃₆(CD) -B by their chiroptical properties, and by ¹³C-NMR spectroscopy supported by ¹H-NMR, IR, CD, and UV/VIS spectroscopy. $ \mathop {\it \Lambda} \limits^ \to $(?)_436(CD)-mer-exo(H)-Co(N₃)(dien)(dapo)](hydrogen di-O-benzoyl-L-tartrate)₂.4 H₂O crystallizes in the orthorhombic space group P2₁2₁2₁, a = 7.676(1) Å, b = 19.457(1) Å, c = 34.702(2) Å. $ \mathop {\it \Lambda} \limits^ \to $(?)_436(CD)-mer-endo(H)-Co(N₃)(dien)(dapo)] (hydrogen di-O-benzoyl-L-tartrate)₂.2.75 H₂O crystallizes in the triclinic space group P1, a = 8.062(3) Å b = 10.296(1) Å, c = 15.056(2) Å, alpha = 80.55(1)°, β = 85.18(2)°, γ = 89.10(2)°. $ \mathop {\it \Delta} \limits^ \to $(+)_436(CD)-mer-endo(H)-Co(N₃)(dien)(dapo)](hydrogen di-O-benzoyl-L-tartrate)₂. 5.75 H₂O crystallizes in the triclinic space group P1, a = 7.742(1) Å, b = 10.014(1) Å, c = 18.045(2) Å, α = 99.57(1)°, β = 92.87(1)°, γ = 102.56(1)°. The absolute configurations of the three cations were determined unambiguously. Interconversions of the various isomers and derivatives and structural, configurational, and spectroscopic aspects are discussed in detail.