Metallocorroles as sensing components for gas sensors: remarkable affinity and selectivity of cobalt(iii) corroles for CO vs. O₂and N₂

Abstract

Most commercially available CO detectors are based upon metal oxides or electrochemical cell technologies. None of these approaches use the selective adsorption of CO gas on a molecular complex. Conversely, cobalt(III) corroles can bind small gaseous molecules allowing them for an application as sensing components for gas detectors. Here we describe the ability of cobalt corroles to selectively coordinate carbon monoxide vs. dinitrogen and dioxygen. The coordination properties were determined in the solid state and the adsorption characteristics were compared to those of the reference compound (To-PivPP)Fe(1,2-Me2Im), known for its remarkable CO binding properties. The adsorption data evidence that the selectivity, affinity and capacity of the cobalt(III) corroles for CO are larger than those of the porphyrin complex. However, from a chemical point of view, the selectivity of cobalt(III) corroles for CO vs. O2 is infinite since these derivatives do not bind O2 while (To-PivPP)Fe(1,2-Me2Im) does with an M value (PO2(1/2)/PCO(1/2)) equal to 51. In this manuscript we also show that the affinity of cobalt(III) corroles for CO is closely related to the Lewis acid character of the central cobalt(III) ion and therefore to the nature of the substituents at the periphery of the corrole macroring.

Room‐Temperature Autoconversion of Free‐Base Corrole into Free‐Base Porphyrin

“…To further confirm this hypothesis, four parallel experiments were carried out in benzene solutions with 13 CH 3 OH, CD 3 OD, CH 3 OD, and CH 3 OH, respectively, as cosolvents. In all cases, a molecular ion peak at m/z 667.8 was observed, showing clearly that the mesocarbon atom at the 5-position of porphyrin 2 did not originate from a methanol molecule.…”

“…[13,14] Corrole macrocycles are generally less stable in solution than their porphyrin analogues. Indeed, a photocatalyzed ring opening of the corrole usually occurs in the presence of dioxygen, leading to the corresponding biliverdin species when the free-base corrole is substituted at the 10-meso position by an aryl group (e.g.…”

Surface Acoustic Wave Sensors for the Detection of Hazardous Compounds in Indoor Air

“…For the functionalization of the CO sensors, we took advantage of the great capabilities of cobalt corroles to trap this molecule [5,6]. Because of the structure of the corroles, small molecules such as N2, O2 and CO can be trapped within by mean of weak interactions.…”

Study of Structure−Properties Relationship for Lanthanide Tetrapyrrolic Macrocycles Modified with Aminopolycarboxylate Substituents

“…[2] Until that time corroles had obtained by complexed multi-step pathway, with a total yield of compounds (even the most simple structure) less than 0.1 %. [3] Both porphyrins and corroles already prove itself as efficient catalysts for oxidation [4] and reduction reactions, [5] as a basis for carbon monoxide sensors, [6] as optodes for determination the pH, [7] as ion-selective electrodes, [8] as dyesensitized solar cells [9] and also in medicine as fluorescent markers. [10] Application of corroles in most cases is based on their fluorescent properties.…”