Totally synthetic heme protein models based on complexes with superstructure ligands

Copper(II) and Nickel(II) Complexes of N,N‐Bis(2‐hydroxyethyl)octamethyl‐1,4,8,11‐tetraazacyclotetradecane

“…[1,2] The design and synthesis of macrocyclic systems carrying such functional groups, mimicking the properties of their natural counterparts, is thus a multifarious problem.…”

Iron and Cobalt "Lacunar" Complexes as Dioxygen Carriers

“…A general view of the molecular structure of lacunar dioxygen carriers defines the portion of the ligand that binds the metal ion as the parent ligand or platform and the additional structural features that produce the lacuna as superstructure. 2 The most common platforms for lacunar complexes are macrocyclic or acyclic tetradentate and pentadentate ligands (Figure 1). This summary considers only lacunar complexes that are strictly of synthetic origin; the many superstructured porphyrins are specifically excluded.…”

Synthesis and structure of totally synthetic coboglobin models

“…Using the templating action of nickel(II), we have recently prepared and reported a new family of superstructure ligands (structure I) that have been I designed to emulate the active sites of heme proteins. 2 We report here the synthesis and characterization of the cobalt complexes of these unusual ligands, wherein the bridge group R' provides a protected void, or "dry cave", near the metal atom, which is intended to shelter small ligands from interactions with other cobalt centers or with solvent. Two critical questions that we faced in developing the dry cave ligand system were (1) can the ligand be removed intact from the Ni(II) 0002-7863/80/1502-3283S01.00/0 Scheme I h2o , nh4pf6 I template and, more importantly, can it be chelated around the more interesting (from a bioinorganic standpoint) Co(II), again without degradation or isomerization and (2) does the dry cave structure that we have designed into these ligands actually perform the desired function-is the bridging group sufficiently rigid and appropriately positioned to permit the coordination of small molecules in the cavity while restricting the entry and coordination mode of other potential ligands?…”