Solution configuration of stereogenic hydroxide bridges in the di-μ-hydroxo-tetrakis(S-arginine)dicobalt(III) complex ion

The solution structure of the hydroxide bridges in the anti(N)-Δ-cis(N),cis(O)-Λ-cis(N),cis(O)-di-μ-hydroxo-tetrakis(S-arginine)dicobalt(III) ion complex was determined utilizing 2D NMR NOE spectroscopy. The measured inter-proton distances in the core of the dicobalt complex reveal a non-coplanar, stereogenic, anti(H,Cα) orientation of the bridge hydrogens.