Ricerc@Sapienza

An improved algorithm to generate skeletal mechanisms from the original detailed chemical kinetic mechanisms is proposed. The new algorithm builds on the computational singular perturbation (CSP) framework, by adding an additional layer of automation based on the tangential stretching rate (TSR) and the species’ participation index to TSR. The main advantage of the new approach is that it does not require the specification of a set of target species.

N‐heterocyclic carbenes (NHCs) are key intermediates in a variety of chemical reactions. Owing to their transient nature, the interception and characterization of these reactive species have always been challenging. Similarly, the study of reaction mechanisms in which carbenes act as catalysts is still an active research field. This Minireview describes the contribution of electrospray ionization mass spectrometry (ESI‐MS) to the detection of charge‐tagged NHCs resulting from the insertion of an ionic group into the molecular scaffold.

SO2 has been proposed in solar geoengineering as a precursor of H2SO4 aerosol, a cooling agent active in the stratosphere to contrast climate change. Atmospheric ionization sources can ionize SO2 into excited states of (Formula presented.), which quickly reacts with trace gases in the stratosphere. In this work we explore the reaction of (Formula presented.) with (Formula presented.) excited by tunable synchrotron radiation, leading to (Formula presented.) ((Formula presented.)), where H contributes to O3 depletion and OH formation.

A common problem encountered in enantioselective organocatalysis is the aggregation of the catalyst, which can result in a relevant decrease of the efficiency and selectivity of the process. In the asymmetric synthesis of chiral benzofuranones, recently reported by us, we noted a remarkable increase of the reaction yield upon the addition of one of the reagents in a portionwise manner rather than in a single addition. We investigated this phenomenon by several experimental techniques such as 1D and 2D NMR experiments, UV-Vis spectroscopy, circular dichroism and dynamic light scattering.

Biomimetic models of short-lived enzymatic reaction intermediates can give useful insight into the properties and coordination chemistry of transition metal complexes. In this work we investigate a high-valent iron(IV)-oxo porphyrin cation radical complex, namely [FeIV(O)(TPFPP+•)]+ where TPFPP is the dianion of 5,10,15,20-tetrakis(pentafluorophenyl) porphyrin. The [FeIV(O)(TPFPP+•)]+ ion was studied by ion-molecule reactions in a Fourier transform-ion cyclotron resonance mass spectrometer through reactivities with 1,3,5-cycloheptatriene, 1,3-cyclohexadiene and toluene.

Cisplatin (cis-diamminedichloroplatinum(II), cis-[PtCl2(NH3)2]), widely used drug in cancer treatment,
has been allowed to react with simple molecular targets (L) mimicking biological functional groups.
The selected molecules (L = acetamide, dimethylacetamide, urea and thiourea) react by ligand exchange
leading to cis-[PtCl(NH3)2(L)]+ complexes that have been assayed by ESI-MS, IRMPD spectroscopy and