New Wind in Old Sails: Novel Applications of Triphos-based Transition Metal Complexes as Homogeneous Catalysts for Small Molecules and Renewables Activation

Recent developments in the coordination chemistry and applications of Ru-triphos [triphos = 1,1,1-tris-(diphenylphosphinomethyl)ethane] systems are reviewed, highlighting their role as active and selective homogenous catalysts for small molecule activation, biomass conversions and in carbon dioxide utilization-related processes

Phosphorus Coordination Chemistry: A Special Issue in Honor of Maurizio Peruzzini.

The present Article Collection celebrates the outstanding scientific career of Maurizio Peruzzini and his interest in Phosphorus Chemistry. Maurizio was formed as a young chemist at the University of Florence (Italy) under the supervision of Piero Stoppioni and Claudio Bianchini, thus belonging to the numerous heirs of the prestigious chemistry school of Luigi Sacconi. After a period as research assistant at the same University, in 1986 he won a place as researcher at CNR-ISSECC, now CNR-ICCOM, where Maurizio spent most of his further activity as scientist. Since the beginning, he got fascinated by the beauty and complexity of main group and transition metal coordination chemistry, in particular phosphorus in all its allotropic forms. This interest accompanied him throughout his scientific career, that saw promotions first to Senior Researcher (1996–2001) and then to Research Director (2001– 2020). In 2013 he became Director of CNR-ICCOM, after two years as Deputy Director, and in 2017 he took the position of Director of the CNR Department of Chemical Sciences and Materials Technology in Rome, until retirement in 2020. Since then, Maurizio has taken the role of Senior Associate at CNR-ICCOM, and still actively collaborates with his coworkers in various fields of research. His commitment to the development of chemistry in Italy brought him to become President of the Inorganic Chemistry Division of the Italian Chemical Society (2009–2011). He was the mentor of many undergraduate, postgraduate students and postdoctoral fellows coming from all over the world to join his research group in Florence. Maurizio’s bibliometric data are truly outstanding, with more than 400 co-authored peer-reviewed papers, more than 13,000 citations and an h-index of 57 (WoS data, 14th April 2021)

Homogeneous Catalysis and Mechanisms in Water and Biphasic Media

After its discovery in the early 1980s and successful application on an industrial scale (Ruhrchemie/Rhone-Poulenc process) [...

Homogeneous Catalysis and Mechanisms in Water and Biphasic Media

In recent years, water phase chemistry and catalysis has witnessed a renewed interest, also in view of increasing environmental and economical concerns. Novel approaches, materials, and catalysts have been designed, for example, to convey the properties of known transition metal catalysts to their water-soluble analogs, reaching high activities and selectivities. This was possible thanks to new synthetic pathways to molecular catalysts, new mechanistic insights into the role of water as a non-innocent solvent, the use of theoretical methods and advanced engineering techniques, and the application of novel concepts for phase transfer agents in biphasic catalysis. The book contains three review articles and six research articles, addressing topics related to water phase chemistry and catalysis, ranging from the use of cyclodextrins as mass transfer agents in biphasic catalysis, to water-soluble catalyst design for targeted chemical transformation, to the application of ultrasonic monitoring of biocatalysis in water, covering aspects such as chemical synthesis, various aspects of catalysis, and engineering solutions. The range of topics addressed in this book will stimulate the reader’s interest and provide a valuable source of information for researchers in academia and industry

Ruthenium(II)-Arene Complexes of the Water-Soluble Ligand CAP as Catalysts for Homogeneous Transfer Hydrogenations in Aqueous Phase

The neutral Ru(II) complex κP-[RuCl2(η6-p-cymene)(CAP)] (1), and the two ionic complexes κP-[RuCl(η6-p-cymene)(MeCN)(CAP)]PF6 (2) and κP-[RuCl(η6-p-cymene)(CAP)2]PF6 (3), containing the water-soluble phosphine 1,4,7-triaza-9-phosphatricyclo[5.3.2.1]tridecane (CAP), were tested as catalysts for homogeneous hydrogenation of benzylidene acetone, selectively producing the saturated ketone as product. The catalytic tests were carried out in aqueous phase under transfer hydrogenation conditions, at mild temperatures using sodium formate as hydrogen source. Complex 3, which showed the highest stability under the reaction conditions applied, was also tested for C=N bond reduction from selected cyclic imines. Preliminary NMR studies run under pseudo-catalytic conditions starting from 3 showed the formation of κP-[RuH(η6-p-cymene)(CAP)2]PF6 (4) as the pivotal species in catalysis

Oxidation of Thiophene Derivatives with H 2 O 2 in Acetonitrile Catalyzed by [Cp* 2 M 2 O 5 ] (M = Mo, W): A Kinetic Study

International audienceThe oxidation of benzothiophene (BT), dibenzothiophene (DBT), and 4,6-dimethyldibenzothiophene (DMDBT) by H2O2 to the corresponding sulfoxides and sulfones has been studied under homogeneous conditions in MeCN with the compounds [Cp*2M2O5] (M = Mo (1), W (2)) as precatalysts. The W system is ca. 100 times more efficient than the Mo analogue, while the relative reactivity of the thiophene substrates is approximately DBT/DMDBT/BT ≈ 10/5/1. For all reactions rate constants for both steps (thiophene derivative to sulfoxide, k1; sulfoxide to sulfone, k2) were measured. While k1 ≈ k2 for DBT and DMDBT, k1 << k2 for BT, independent of catalyst. Activation parameters for the stepwise oxidations of thiophene derivative to sulfoxide (BT to BTO, ΔH⧧ = 11.4(5) kcal mol−1 and ΔS⧧ = –26.1(1.6) eu; DBT to DBTO, ΔH⧧ = 7.7(6) kcal mol−1 and ΔS⧧ = –33(2) eu) and sulfoxide to sulfone (BTO to BTO2, ΔH⧧ = 10.8(5) kcal mol−1 and ΔS⧧ = –21.8(1.6) eu; DBTO to DBTO2, ΔH⧧ = 10.3(9) kcal mol−1 and ΔS⧧ = –25(3) eu) were calculated from variable temperature studies using [Cp*2W2O5]. DFT calculations suggest that the greater reactivity of DBT relative to BT is not caused by ground-state effects but rather by a transition-state effect associated with the greater thermodynamic gain in DBT oxidation

Counterion-dependent deuteration of pentamethylcyclopentadiene in water-soluble cationic Rh(III) complexes assisted by PTA

[Cp*RhCl(PTA)2]X (PTA = 7-phospha-1,3,5- triazaadamantane) undergoes an H/D exchange process between the methyl groups of Cp* and D2O whose rate depends on the coordinating ability of the counterion X-. Kinetic studies and DFT calculations indicate that deuteration involves the abstraction of a Me-Cp* proton by a coordinated OH-; the formation of the latter seems to be facilitated by the presence of the N-basic centers of PTA. © 2010 The Royal Society of Chemistry

PGSE NMR studies on RAPTA derivatives: Evidence for the formation of H-bonded dicationic species

The self-aggregation tendency of RAPTA complexes [Ru(η6-p- cymene)PTA(-R)Cl2]X, R = H (1BPh4 and IPF6) and Me (2BPh4 and 20Tf), and [Ru(η6-p-cymene)(PTA) 2Cl]X (3BPh4 and 3BF4)] in acetone-de was investigated by means of diffusion NMR spectroscopy. On increasing the concentration, the protonated species (1X) undergoes intercationic self-aggregation driven by hydrogen bonding that leads to the formation of 122+ dications and a small amount of 12X + ion triples. © 2008 American Chemical Society