Selective Chemisorption of Carbon Monoxide by Organic–Inorganic Hybrid Materials Incorporating Cobalt(III) Corroles as Sensing Components

Abstract

Twenty-one hybrid materials incorporating cobalt(III) corrole complexes were synthesized by a sol-gel process or by grafting the metallocorrole onto a mesostructured silica of the SBA-15 type. All the materials show an almost infinite selectivity for carbon monoxide with respect to dinitrogen and dioxygen in the low-pressure domain where the chemisorption phenomenon is predominant. This peculiar property is of prime importance for an application as a CO sensor. The selectivity slightly decreases at high pressures where nonselective physisorption phenomena mainly occur. The percentage of active sites for CO chemisorption ranges from 22 to 64 %. This low percentage may be attributable to interactions between the cobalt(III) corroles with silanol or siloxane groups remaining at the surface of the materials which prevent further coordination of the CO molecule. Notably, the most efficient materials are those prepared in the presence of a protecting ligand (pyridine) during the gelation or the grafting process. The removal of this ligand after the gelation process releases a cavity around the cobalt ion that favors the coordination of a carbon monoxide molecule. The CO adsorption properties of the SBA-15 hybrid were not affected over a period of several months thus indicating a high stability of the material. Conversely, the xerogel capacities slowly decrease owing to the evolution of the material structure.

Carbon monoxide – physiology, detection and controlled release

“…99,104 In addition, colourimetric CO sensing is an important alternative, 101,105 in particular if the aim is to monitor CO in living cells, organs or whole organisms.…”

Synthesis, characterization and solvent/structural effects on spectral and redox properties of cobalt triphenylcorroles in nonaqueous media

“…One of the most frequently studied groups of metallocorroles are the cobalt derivatives which have been characterized as to their spectral and electrochemical properties under many different solution conditions [1,2,6,[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40].Part of our own research effort has been directed towards the synthesis and electrochemical characterization of four and five coordinate cobalt corroles with different macrocyclic substituents [14-18, 21-23, 25-27, 41]. This ABSTRACT: Five cobalt(III) triphenylcorroles with different electron-withdrawing or electrondonating substituents and an axially bound triphenylphosphine ligand were synthesized and characterized by spectroscopic and electrochemical techniques.…”

Origin of the Individual Basicity of Corrole NH-Tautomers: A Quantum Chemical Study on Molecular Structure and Dynamics, Kinetics, and Thermodynamics

“…[1][2][3] Because of their peculiar photophysical properties and chelating abilities, corroles are investigated for numerous applications, such as novel catalysts, antitumor and imaging agents, as molecular sensors and in optoelectronic devices. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] -3 -Scheme 1: Energetically favorable and alternative core configurations of the corrole NH-tautomers T1 and T2 investigated in the present paper (R 1 = mesityl, R 2 = 4,6-dichloropyrimidin-5-yl).…”