Université de Fribourg

Insights into the mechanism of photosynthetic H 2 evolution catalyzed by a heptacoordinate cobalt complex

Lucarini, Fiorella ; Fize, Jennifer ; Morozan, Adina ; Marazzi, Marco ; Natali, Mirco ; Pastore, Mariachiara ; Artero, Vincent ; Ruggi, Albert

In: Sustainable Energy & Fuels, 2020, vol. 4, no. 2, p. 589–599

H2 evolution catalyzed by a heptacoordinate complex under both electro- (1) and photo-chemical (2) conditions is analyzed in detail in order to gain insights into the mechanism of the processes. The complex shows high catalytic activity for hydrogen production in acetonitrile, in the presence of trifluoroacetic acid and triethylammonium tetrafluoroborate as proton sources. Foot-of-the-wave...

Université de Fribourg

Correlation of MLCTs of Group 7 fac-[M(CO)3]+ complexes (M = Mn, Re) with bipyridine, pyridinylpyrazine, azopyridine, and pyridin-2-ylmethanimine type ligands for rational photoCORM design

Kottelat, Emmanuel ; Lucarini, Fiorella ; Crochet, Aurélien ; Ruggi, Albert ; Zobi, Fabio

In: European Journal of Inorganic Chemistry, 2019, vol. 2019, no. 33, p. 3758–3768

A mathematical correlation of the MLCT absorption maxima of structurally related fac‐ [M(CO)3L2Br] complexes (M = Mn, Re; L2 = bidentate ligand) is obtained by the comparison of a total of 50 species bearing bipyridine, pyridinylpyrazine, azopyridine and pyridin‐2‐ylmethanimine L2 type ligands. The empirical relationship is first derived by the initial comparison of the MLCT absorption...

Université de Fribourg

Heptacoordinate Co(II) catalyst for light-driven hydrogen production in fully aqueous medium

Lucarini, Fiorella ; Ruggi, Albert

In: CHIMIA International Journal for Chemistry, 2018, vol. 72, no. 4, p. 203–206

Photocatalytic hydrogen production is an appealing way to store solar energy as chemical fuel. The most studied molecular catalysts for H2 production are based on earth-abundant metals such as Ni, Co and Fe. Efforts have been recently focused on the design of Co complexes with distorted octahedral geometries induced by tetra- or pentapyridyl ligands. We synthesized a new Co(II) complex based...

Université de Fribourg

Functional metathesis catalyst through ring closing enyne metathesis: one pot protocol for living heterotelechelic polymers

Pal, Subhajit ; Lucarini, Fiorella ; Ruggi, Albert ; Kilbinger, Andreas F. M.

In: Journal of the American Chemical Society, 2018, vol. 140, no. 9, p. 3181–3185

Enyne ring closing metathesis has been used to synthesize functional group carrying metathesis catalysts from a commercial (Ru-benzylidene) Grubbs’ catalysts. The new Grubbs-type ruthenium carbene was used to synthesize living heterotelechelic ROMP polymers without any intermediate purification. Olefin metathesis with a mono substituted alkyne followed by ring closing metathesis with an...

Université de Fribourg

Cis- and trans-9,10-di(1H-imidazol-1-yl)-anthracene based coordination polymers of ZnII and CdII: synthesis, crystal structures and luminescence properties

Vasylevskyi, Serhii I. ; Regeta, Khrystyna ; Ruggi, Albert ; Petoud, Stéphane ; Piguet, Claude ; Fromm, Katharina M.

In: Dalton Transactions, 2018, vol. 47, no. 2, p. 596–607

New functional coordination polymers based on the semi-flexible 9,10-di(1H-imidazol- 1-yl)-anthracene ligand (L) with ZnII and CdII, namely {[Zn(μ2-L)2] (ClO4)2·m(MeOH)·n(DCM)}n (1), {[Zn(μ2-L)2](BF4)2·m(MeOH)·n(DCM)}n (2), {[Zn(μ2-L)2(p-Tos)2]·m(DCM)·n(MeOH)}n (3), {[Cd(μ2-L)2(p-Tos)2]·m(DCM)}n (4) {[Cd(μ2-L)2(p-Tos)2]·m(MeOH)·n(Dioxane)}n (5) and {[Zn(μ2-...

Université de Fribourg

Synthesis of hydrophilic and hydrophobic carbon quantum dots from waste of wine fermentation

Varisco, Massimo ; Zufferey, Denis ; Ruggi, Albert ; Zhang, Yucheng ; Erni, Rolf ; Mamula, Olimpia

In: Royal Society Open Science, 2017, vol. 4, no. 12, p. 170900

Wine lees are one of the main residues formed in vast quantities during the fermentation of wine. While toxic when applied to plants and wetlands, it is a biodegradable material, and several alternatives have been proposed for its valorization as: dietary supplement in animal feed, source for various yeast extracts and bioconversion feedstock. The implementation of stricter environment...

Université de Fribourg

Heterotelechelic polymers by ring‐opening metathesis and regioselective chain transfer

Yasir, Peng Liu, Mohammad ; Ruggi, Albert ; Kilbinger, Andreas F. M.

In: Angewandte Chemie International Edition, 2018, vol. 57, no. 4, p. 914–917

Heterotelechelic polymers were synthesized by a kinetic telechelic ring-opening metathesis polymerization method relying on the regioselective cross-metathesis of the propagating Grubbs’ first-generation catalyst with cinnamyl alcohol derivatives. This procedure allowed the synthesis of hetero-bis-end-functional polymers in a one- pot setup. The molecular weight of the polymers could be...

Université de Fribourg

Heptacoordinate Coii complex: a new architecture for photochemical hydrogen production

Lucarini, Fiorella ; Pastore, Mariachiara ; Vasylevskyi, Serhii ; Varisco, Massimo ; Solari, Euro ; Crochet, Aurélien ; Fromm, Katharina M. ; Zobi, Fabio ; Ruggi, Albert

In: Chemistry - A European Journal, 2017, vol. 23, no. 28, p. 6768-6771

The first heptacoordinate cobalt catalyst for light-driven hydrogen production in water has been synthesized and characterized. Photochemical experiments using [Ru(bpy)₃]²⁺ as photosensitizer gave a turnover number (TON) of 16300 mol H₂ (mol cat.)⁻¹ achieved in 2 hours of irradiation with visible (475 nm) light. This promising result provides a path forward in the...

Université de Fribourg

Red-light activated photoCORMs of Mn(I) species bearing electron deficient 2,2′-azopyridines

Kottelat, Emmanuel ; Ruggi, Albert ; Zobi, Fabio

In: Dalton Transactions, 2016, vol. 45, no. 16, p. 6920–6927

The realization of CO releasing molecules triggered by light (photoCORMs) within the phototherapeutic window (λ > 600 nm) constitutes an important goal for potential therapeutic applications of the molecules. The activation of photoCORMs with red/NIR light would enable exploiting the higher depth of penetration of this radiation with respect to higher energy photons. In this article we...