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Antonella Ciccarese
Ruolo
Professore Associato
Organizzazione
Università del Salento
Dipartimento
Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali
Area Scientifica
Area 03 - Scienze chimiche
Settore Scientifico Disciplinare
CHIM/03 - Chimica Generale e Inorganica
Settore ERC 1° livello
Non Disponibile
Settore ERC 2° livello
Non Disponibile
Settore ERC 3° livello
Non Disponibile
In the [ABrnIm] (A = C, Si, Ge, Sn; n + m = 4) compounds, with the heavier halides bonded to the central IV group elements, the experimental 13C, 29Si, 73Ge and 119Sn NMR chemical shifts of the central atoms were found to be strictly linearly proportional to the bonded halides ionic radii overall sum Σ(rh). Based on this, calibration lines relating the chemical shifts to Σ(rh) could be built for the considered subgroup of [ABrnIm] compounds. Using such calibration lines we could calculate the equivalent NMR radius, NMRrH–A, attributable to each of the bonded hydrogens in [AH4] species, according to the overall NMR shielding produced on the central A atom. Interestingly, the calculated NMRrH–A value resulted to be almost constant in all [AH4] examined systems (A = 13C, 29Si, 73Ge, 119Sn) with an average NMRrH–A value equal to 194.6 ± 1.6 pm. Based on this approach, we could calculate the 207Pb NMR chemical shift of the unstable [PbH4] complex using the value of 192.7 pm calculated for NMRrH–Sn in the stable closest hydride [SnH4]. The obtained unprecedented NMR value is in accord with the 207Pb NMR chemical shift estimation, independently calculated for [PbH4] from the [SnH4] data, using the Pb/Sn chemical shift correlation defined in the Mitchell equation.
New perylene monoimides, diimides and bis-diimides have been designed and synthetized. A detailed investigation of the synthesis of these compounds has also been performed in order to highlight the crucial factors for obtaining a specific class of molecules. Specifically, the attention has been focused on the synthesis of the intermediate perylene monoimides which are very useful precursors for many molecules difficult to obtain. Furthemore, two synthetic pathways have been developed for obtaining the bis-diimides variously substituted. These final compounds are predicted to mimic the excellent electron acceptor properties of fullerene derivatives and they can be used as building blocks to form 3D semiconducting materials.
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