A Chromo-Fluorogenic Synthetic “Canary” for CO Detection Based on a Pyrenylvinyl Ruthenium(II) Complex

Abstract

The chromo-fluorogenic detection of carbon monoxide in air has been achieved using a simple, inexpensive system based on ruthenium(II). This probe shows exceptional sensitivity and selectivity in its sensing behavior in the solid state. A color response visible to the naked eye is observed at 5 ppb of CO, and a remarkably clear color change occurs from orange to yellow at the onset of toxic CO concentrations (100 ppm) in air. Even greater sensitivity (1 ppb) can be achieved through a substantial increase in turn-on emission fluorescence in the presence of carbon monoxide, both in air and in solution. No response is observed with other gases including water vapor. Immobilization of the probe on a cellulose strip allows the system to be applied in its current form in a simple optoelectronic device to give a numerical reading and/or alarm.

Ruthenium(II) and Osmium(II) Vinyl Complexes as Highly Sensitive and Selective Chromogenic and Fluorogenic Probes for the Sensing of Carbon Monoxide in Air

“…Suitable crystals were obtained for single X‐ray diffraction studies (Figure 1) by the diffusion of ethanol into (CO‐infused in the case of 5⋅CO ) solutions of the complexes in dichloromethane. The crystal structures of BTD‐containing complexes with three different vinyl ligands were obtained ( 1 was reported recently15 and 4 and 6 are reported herein), and two dicarbonyl complexes formed after the addition of CO (i.e., 1⋅CO and 5⋅CO reported in previous and the present work, respectively).…”

“…The structures reported herein and those reported previously15 allow a comparison between a series of analogous [M(CHCHR)Cl(CO)(L)(PPh 3 ) 2 ] (L=BTD, CO) compounds that differ only at the metal centre (M=Ru or Os) and in the vinyl substituents (R=Pyr‐1, Nap‐2, or C 6 H 4 Me‐4). Table 3 collects the main metal–ligand structural data.…”

“…By taking into account the facts mentioned above and following our interest in the design of novel chromo‐fluorogenic systems,13 we present herein the application of ruthenium(II) and osmium(II) vinyl complexes as sensitive, selective, colorimetric, and fluorimetric probes for sensing CO using the well‐known ability of these metal species to react with small molecules, such as CO 14. We recently reported preliminary data on the development of a chromo‐fluorogenic probe based on the ruthenium(II) pyrenylvinyl complex [Ru(CHCHPyr‐1)Cl(CO)(BTD)(PPh 3 ) 2 ] (BTD=2,1,3‐benzothiadiazole; 1 ) 15. Based on the initial sensing results obtained for this ruthenium complex in terms of selectivity and sensitivity, we report herein an extended study on a set of synthetically accessible and relatively inexpensive ruthenium(II) and osmium(II) vinyl complexes of the general formula [M(CHCHR)Cl(CO)(BTD)(PPh 3 ) 2 ] containing the BTD chromophore and various different vinyl ligands.…”

Development of a colorimetric and NIR fluorescent dual probe for carbon monoxide

“…Our overall strategy for this probe relies on CO-induced in-situ generation of Pd 0 , which consequently mediate the Tsuji-Trost reaction. 22 Naphthofluorescein was chosen as a signaling fluorophore due to its long excitation and emission wavelengths (> 600 nm), relatively large Stokes shift and easy availability. [23][24][25] Based on the literature and our previous work, allyl chloroformate was linked to the hydroxyl groups of naphthofluorescein as the response site to trap Pd 0 according to the Tsuji-Trost reaction.…”

Multimetallic Alkenyl Complexes Bearing Macrocyclic Dithiocarbamate Ligands

“…Ruthenium (and to a lesser extent osmium) alkenyl complexes 7 4c,i,5,15i,s,18 The facile generation of the alkenyl complexes themselves from insertion of both terminal and internal alkynes into the Ru-H bond allows for the introduction of alkenyl substituents known for their electrochemical (ferrocene) 4c or photophysical (pyrene) 19,20 properties, for example. This route has been exploited by Winter and co-workers to join ruthenium alkenyl centers within a conjugated system.…”