Federico Franco - Academia.edu (original) (raw)
Papers by Federico Franco
New Zealand Journal of Botany
Chemical Society Reviews
An overview of the main strategies for the rational design of transition metal-based catalysts fo... more An overview of the main strategies for the rational design of transition metal-based catalysts for the electrochemical conversion of CO2, ranging from molecular systems to single-atom and nanostructured catalysts.
Frontiers in Sustainable Food Systems
The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained mor... more The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained more interest since the discovery that several species of this genus are able to colonize roots. In general, commercial products with Metarhizium are formulated based on conidia for insect pest control. The process of mass production, harvesting, and formulation of infective conidia can be detrimental for conidial viability. Entomopathogenic fungi such as Metarhizium spp. are able to produce high concentrations of resistant structures, known as microsclerotia, when grown in liquid media. Microsclerotia are desiccation tolerant, with excellent storage stability, and are capable of producing high quantities of infective conidia after rehydration. The aim of this study was to evaluate microsclerotia production by different isolates of Metarhizium spp. and determine the effect of microsclerotia coated onto maize seeds on plant growth in the presence of soil-borne pathogen Fusarium graminearum. ...
Mechanistic understanding of electro- and photocatalytic CO2 reduction is crucial to develop stra... more Mechanistic understanding of electro- and photocatalytic CO2 reduction is crucial to develop strategies to overcome catalytic bottlenecks. In this regard, herein it is presented a new CO2-to-CO reduction cobalt aminopyridine catalyst, a detailed experimental and theoretical mechanistic study toward the identification of bottlenecks and potential strategies to alleviate them. The combination of electrochemical and in-situ spectroelectrochemical (FTIR/UV-Vis SEC) studies together with spectroscopic techniques (NMR, EXAFS) lead us to identify elusive key electrocatalytic intermediates derived from complex [Co(pyMetacn)(OTf)2] (1) (pyMetacn = 1-[2-pyridylmethyl]-4,7-dimethyl-1,4,7-triazacyclononane) such as a highly reactive cobalt (I) (1(I)) and cobalt (I) carbonyl (1(I)-CO) species. 1(I) was obtained by electrochemical reduction of 1(II), and characterized by NMR, EXAFS and FTIR/UV-Vis SEC. The combination of spectroelectrochemical studies under CO2, 13CO2 and CO with DFT disclosed th...
IEEE Transactions on Magnetics
Biocontrol Science and Technology
Current Opinion in Electrochemistry
Angewandte Chemie
The chemical inertness of abundant and commercially available alkyl chlorides precludes their wid... more The chemical inertness of abundant and commercially available alkyl chlorides precludes their widespread use as reactants in chemical transformations. Presented in this work is a metallaphotoredox methodology to achieve the catalytic intramolecular reductive cyclization of unactivated alkyl chlorides with tethered alkenes. The cleavage of strong C(sp 3)ÀCl bonds is mediated by a highly nucleophilic lowvalent cobalt or nickel intermediate generated by visible-light photoredox reduction employing a copper photosensitizer. The high basicity and multidentate nature of the ligands are key to obtaining efficient metal catalysts for the functionalization of unactivated alkyl chlorides.
ChemCatChem
The image shows aP ortuguese caravel as as ymbol of the Portuguesed iscoveries in the Renaissance... more The image shows aP ortuguese caravel as as ymbol of the Portuguesed iscoveries in the Renaissance,h ighlighting the fact that this Special Issue is dedicated to the "Portuguese Conference on Catalysis". The unexpected flourishing of manganese as ac atalyst reminded us of the tale of the black swan. We have also included an image of the catalytic transformation of ak etone into the corresponding alcoholm ediated by am anganese-basedc atalyst, represented by the black swan. What future opportunities do you see basedo nt he findingsd escribed in this paper?
Angewandte Chemie
We report here the first purely organometallic fac-[Mn I (CO) 3 (bis-Me NHC)Br] complex with unpr... more We report here the first purely organometallic fac-[Mn I (CO) 3 (bis-Me NHC)Br] complex with unprecedented activity for the selective electrocatalytic reduction of CO 2 to CO,e xceeding 100 turnovers with excellent faradaic yields (h CO % 95 %) in anhydrous CH 3 CN.U nder the same conditions,amaximum turnover frequency (TOF max)of2100 s À1 was measured by cyclic voltammetry,w hichc learly exceeds the values reported for other manganese-based catalysts.M oreover,t he addition of water leads to the highest TOF max value (ca. 320 000 s À1)ever reported for amanganese-based catalyst. AMn I tetracarbonyl intermediate was detected under catalytic conditions for the first time.
Chemical science, Jan 7, 2018
A new family of cobalt complexes with the general formula [Co(OTf)(Pytacn)] ( , Pytacn = 1-[(4-X-... more A new family of cobalt complexes with the general formula [Co(OTf)(Pytacn)] ( , Pytacn = 1-[(4-X-3,5-Y-2-pyridyl)methyl]-4,7-dimethyl-1,4,7-triazacyclononane, (X = CN ( ), COEt ( ), Cl ( ), H ( ), NMe ( )) where (Y = H, and X = OMe when Y = Me ( )) is reported. We found that the electronic tuning of the Pytacn ligand not only has an impact on the electronic and structural properties of the metal center, but also allows for a systematic water-reduction-catalytic control. In particular, the increase of the electron-withdrawing character of the pyridine moiety promotes a 20-fold enhancement of the catalytic outcome. By UV-Vis spectroscopy, luminescence quenching studies and Transient Absorption Spectroscopy (TAS), we have studied the direct reaction of the photogenerated [Ir(ppy)(bpy˙)] ( ) species to form the elusive Co intermediates. In particular, our attention is focused on the effect of the ligand architecture in this elemental step of the catalytic mechanism. Finally, kinetic iso...
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 3, 2018
Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devic... more Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95 %) and high current densities. Combination of experiments and DFT calculations reveals that the presence of carboxylic groups triggers such electrocatalytic activity in a bioinspired manner. Analogously to the known Hantzsch esters, the oxidized carbon fiber material is able to transfer hydrides, which can react with protons, generating H2 , or with organic substrates resulting in their hydrogenation. A plausible mechanism is proposed based on DFT calculations on model systems.
Chemistry - A European Journal
Faraday discussions, Jun 23, 2017
Leif Hammarström opened discussion of the paper by Licheng Sun: You indicated using separate pane... more Leif Hammarström opened discussion of the paper by Licheng Sun: You indicated using separate panels for PV and solar heating on the same roof top which compete for space in the sun. Instead, have you considered using the heat that is generated from the PV and circulating the water to the electrolyzer? Then you also increase the efficiency of the PV. Licheng Sun responded: That is an even better idea, and solves the problem of competing roof area. Masayuki Yagi asked: I am interested in the temperature dependence of the water oxidation catalysis. The linear relationship between the current density and temperature shows that the enhanced water oxidation is not ascribed to an activation process. If it involves the usual activation process, there is a linear relationship between the logarithm of the current density and the inverse of the temperature. How could you explain the enhancement of the water oxidation catalysis? Licheng Sun replied: In addition to the thermodynamic reasons, kinetics processes are the major contributors to these temperature effects. Masayuki Yagi remarked: Diffusion of H + and proton acceptors (if needed) could be important for electrochemical water oxidation. Is the enhanced water oxidation catalysis temperature due to diffusion of H + and proton acceptors? Did
![Research paper thumbnail of Local Proton Source in Electrocatalytic CO2 Reduction with [Mn(bpy-R)(CO)3 Br] Complexes](https://attachments.academia-assets.com/74376605/thumbnails/1.jpg)
](Chemistry (Weinheim an der Bergstrasse, Germany), Jan 20, 2017
The electrochemical behavior of fac-[Mn(pdbpy)(CO)3 Br] (pdbpy=4-phenyl-6-(phenyl-2,6-diol)-2,2&#... more The electrochemical behavior of fac-[Mn(pdbpy)(CO)3 Br] (pdbpy=4-phenyl-6-(phenyl-2,6-diol)-2,2'-bipyridine) (1) in acetonitrile under Ar, and its catalytic performances for CO2 reduction with added water, 2,2,2-trifluoroethanol (TFE), and phenol are discussed in detail. Preparative-scale electrolysis experiments, carried out at -1.5 V versus the standard calomel electrode (SCE) in CO2 -saturated acetonitrile, reveal that the process selectivity is extremely sensitive to the acid strength, producing CO and formate in different faradaic yields. A detailed spectroelectrochemical (IR and UV/Vis) study under Ar and CO2 atmospheres shows that 1 undergoes fast solvolysis; however, dimer formation in acetonitrile is suppressed, resulting in an atypical reduction mechanism in comparison with other reported Mn(I) catalysts. Spectroscopic evidence of Mn hydride formation supports the existence of different electrocatalytic CO2 reduction pathways. Furthermore, a comparative investigation p...
ChemElectroChem, 2015
ABSTRACT Tetracarbonyl complexes of low-valent Group VI transition metals (Mo and W), containing ... more ABSTRACT Tetracarbonyl complexes of low-valent Group VI transition metals (Mo and W), containing diimine bidentate ligands, namely W(CO)4(4,6-diphenyl-2,2′-bipyridine) (1), W(CO)4(6-(2,6-dimethoxyphenyl)-4-phenyl-2,2′-bipyridine) (2), Mo(CO)4(2,2′-dipyridylamine) (3), and W(CO)4(2,2′-dipyridylamine) (4), were synthesized and tested as homogeneous catalysts for the electrochemical reduction of CO2 in nonaqueous media. Cyclic voltammetry performed under a CO2 atmosphere, revealed that these complexes have significant catalytic activity in acetonitrile, and gas chromatographic measurements together with exhaustive electrolysis showed that CO is the major reduction product. Mechanistic insights were obtained by IR-spectroelectrochemical measurements. The substantially different electrocatalytic performances obtained for the two classes of catalysts are compared and discussed.
New Zealand Journal of Botany
Chemical Society Reviews
An overview of the main strategies for the rational design of transition metal-based catalysts fo... more An overview of the main strategies for the rational design of transition metal-based catalysts for the electrochemical conversion of CO2, ranging from molecular systems to single-atom and nanostructured catalysts.
Frontiers in Sustainable Food Systems
The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained mor... more The commercial use of the entomopathogenic fungi Metarhizium spp. in biopesticides has gained more interest since the discovery that several species of this genus are able to colonize roots. In general, commercial products with Metarhizium are formulated based on conidia for insect pest control. The process of mass production, harvesting, and formulation of infective conidia can be detrimental for conidial viability. Entomopathogenic fungi such as Metarhizium spp. are able to produce high concentrations of resistant structures, known as microsclerotia, when grown in liquid media. Microsclerotia are desiccation tolerant, with excellent storage stability, and are capable of producing high quantities of infective conidia after rehydration. The aim of this study was to evaluate microsclerotia production by different isolates of Metarhizium spp. and determine the effect of microsclerotia coated onto maize seeds on plant growth in the presence of soil-borne pathogen Fusarium graminearum. ...
Mechanistic understanding of electro- and photocatalytic CO2 reduction is crucial to develop stra... more Mechanistic understanding of electro- and photocatalytic CO2 reduction is crucial to develop strategies to overcome catalytic bottlenecks. In this regard, herein it is presented a new CO2-to-CO reduction cobalt aminopyridine catalyst, a detailed experimental and theoretical mechanistic study toward the identification of bottlenecks and potential strategies to alleviate them. The combination of electrochemical and in-situ spectroelectrochemical (FTIR/UV-Vis SEC) studies together with spectroscopic techniques (NMR, EXAFS) lead us to identify elusive key electrocatalytic intermediates derived from complex [Co(pyMetacn)(OTf)2] (1) (pyMetacn = 1-[2-pyridylmethyl]-4,7-dimethyl-1,4,7-triazacyclononane) such as a highly reactive cobalt (I) (1(I)) and cobalt (I) carbonyl (1(I)-CO) species. 1(I) was obtained by electrochemical reduction of 1(II), and characterized by NMR, EXAFS and FTIR/UV-Vis SEC. The combination of spectroelectrochemical studies under CO2, 13CO2 and CO with DFT disclosed th...
IEEE Transactions on Magnetics
Biocontrol Science and Technology
Current Opinion in Electrochemistry
Angewandte Chemie
The chemical inertness of abundant and commercially available alkyl chlorides precludes their wid... more The chemical inertness of abundant and commercially available alkyl chlorides precludes their widespread use as reactants in chemical transformations. Presented in this work is a metallaphotoredox methodology to achieve the catalytic intramolecular reductive cyclization of unactivated alkyl chlorides with tethered alkenes. The cleavage of strong C(sp 3)ÀCl bonds is mediated by a highly nucleophilic lowvalent cobalt or nickel intermediate generated by visible-light photoredox reduction employing a copper photosensitizer. The high basicity and multidentate nature of the ligands are key to obtaining efficient metal catalysts for the functionalization of unactivated alkyl chlorides.
ChemCatChem
The image shows aP ortuguese caravel as as ymbol of the Portuguesed iscoveries in the Renaissance... more The image shows aP ortuguese caravel as as ymbol of the Portuguesed iscoveries in the Renaissance,h ighlighting the fact that this Special Issue is dedicated to the "Portuguese Conference on Catalysis". The unexpected flourishing of manganese as ac atalyst reminded us of the tale of the black swan. We have also included an image of the catalytic transformation of ak etone into the corresponding alcoholm ediated by am anganese-basedc atalyst, represented by the black swan. What future opportunities do you see basedo nt he findingsd escribed in this paper?
Angewandte Chemie
We report here the first purely organometallic fac-[Mn I (CO) 3 (bis-Me NHC)Br] complex with unpr... more We report here the first purely organometallic fac-[Mn I (CO) 3 (bis-Me NHC)Br] complex with unprecedented activity for the selective electrocatalytic reduction of CO 2 to CO,e xceeding 100 turnovers with excellent faradaic yields (h CO % 95 %) in anhydrous CH 3 CN.U nder the same conditions,amaximum turnover frequency (TOF max)of2100 s À1 was measured by cyclic voltammetry,w hichc learly exceeds the values reported for other manganese-based catalysts.M oreover,t he addition of water leads to the highest TOF max value (ca. 320 000 s À1)ever reported for amanganese-based catalyst. AMn I tetracarbonyl intermediate was detected under catalytic conditions for the first time.
Chemical science, Jan 7, 2018
A new family of cobalt complexes with the general formula [Co(OTf)(Pytacn)] ( , Pytacn = 1-[(4-X-... more A new family of cobalt complexes with the general formula [Co(OTf)(Pytacn)] ( , Pytacn = 1-[(4-X-3,5-Y-2-pyridyl)methyl]-4,7-dimethyl-1,4,7-triazacyclononane, (X = CN ( ), COEt ( ), Cl ( ), H ( ), NMe ( )) where (Y = H, and X = OMe when Y = Me ( )) is reported. We found that the electronic tuning of the Pytacn ligand not only has an impact on the electronic and structural properties of the metal center, but also allows for a systematic water-reduction-catalytic control. In particular, the increase of the electron-withdrawing character of the pyridine moiety promotes a 20-fold enhancement of the catalytic outcome. By UV-Vis spectroscopy, luminescence quenching studies and Transient Absorption Spectroscopy (TAS), we have studied the direct reaction of the photogenerated [Ir(ppy)(bpy˙)] ( ) species to form the elusive Co intermediates. In particular, our attention is focused on the effect of the ligand architecture in this elemental step of the catalytic mechanism. Finally, kinetic iso...
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 3, 2018
Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devic... more Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95 %) and high current densities. Combination of experiments and DFT calculations reveals that the presence of carboxylic groups triggers such electrocatalytic activity in a bioinspired manner. Analogously to the known Hantzsch esters, the oxidized carbon fiber material is able to transfer hydrides, which can react with protons, generating H2 , or with organic substrates resulting in their hydrogenation. A plausible mechanism is proposed based on DFT calculations on model systems.
Chemistry - A European Journal
Faraday discussions, Jun 23, 2017
Leif Hammarström opened discussion of the paper by Licheng Sun: You indicated using separate pane... more Leif Hammarström opened discussion of the paper by Licheng Sun: You indicated using separate panels for PV and solar heating on the same roof top which compete for space in the sun. Instead, have you considered using the heat that is generated from the PV and circulating the water to the electrolyzer? Then you also increase the efficiency of the PV. Licheng Sun responded: That is an even better idea, and solves the problem of competing roof area. Masayuki Yagi asked: I am interested in the temperature dependence of the water oxidation catalysis. The linear relationship between the current density and temperature shows that the enhanced water oxidation is not ascribed to an activation process. If it involves the usual activation process, there is a linear relationship between the logarithm of the current density and the inverse of the temperature. How could you explain the enhancement of the water oxidation catalysis? Licheng Sun replied: In addition to the thermodynamic reasons, kinetics processes are the major contributors to these temperature effects. Masayuki Yagi remarked: Diffusion of H + and proton acceptors (if needed) could be important for electrochemical water oxidation. Is the enhanced water oxidation catalysis temperature due to diffusion of H + and proton acceptors? Did
Chemistry (Weinheim an der Bergstrasse, Germany), Jan 20, 2017
The electrochemical behavior of fac-[Mn(pdbpy)(CO)3 Br] (pdbpy=4-phenyl-6-(phenyl-2,6-diol)-2,2&#... more The electrochemical behavior of fac-[Mn(pdbpy)(CO)3 Br] (pdbpy=4-phenyl-6-(phenyl-2,6-diol)-2,2'-bipyridine) (1) in acetonitrile under Ar, and its catalytic performances for CO2 reduction with added water, 2,2,2-trifluoroethanol (TFE), and phenol are discussed in detail. Preparative-scale electrolysis experiments, carried out at -1.5 V versus the standard calomel electrode (SCE) in CO2 -saturated acetonitrile, reveal that the process selectivity is extremely sensitive to the acid strength, producing CO and formate in different faradaic yields. A detailed spectroelectrochemical (IR and UV/Vis) study under Ar and CO2 atmospheres shows that 1 undergoes fast solvolysis; however, dimer formation in acetonitrile is suppressed, resulting in an atypical reduction mechanism in comparison with other reported Mn(I) catalysts. Spectroscopic evidence of Mn hydride formation supports the existence of different electrocatalytic CO2 reduction pathways. Furthermore, a comparative investigation p...
ChemElectroChem, 2015
ABSTRACT Tetracarbonyl complexes of low-valent Group VI transition metals (Mo and W), containing ... more ABSTRACT Tetracarbonyl complexes of low-valent Group VI transition metals (Mo and W), containing diimine bidentate ligands, namely W(CO)4(4,6-diphenyl-2,2′-bipyridine) (1), W(CO)4(6-(2,6-dimethoxyphenyl)-4-phenyl-2,2′-bipyridine) (2), Mo(CO)4(2,2′-dipyridylamine) (3), and W(CO)4(2,2′-dipyridylamine) (4), were synthesized and tested as homogeneous catalysts for the electrochemical reduction of CO2 in nonaqueous media. Cyclic voltammetry performed under a CO2 atmosphere, revealed that these complexes have significant catalytic activity in acetonitrile, and gas chromatographic measurements together with exhaustive electrolysis showed that CO is the major reduction product. Mechanistic insights were obtained by IR-spectroelectrochemical measurements. The substantially different electrocatalytic performances obtained for the two classes of catalysts are compared and discussed.