A series of titanium dichloro and di(isopropoxy) complexes with a 1,4-dithiabutanediyllinked bis(4,6-disubstituted phenolato) ligand [Ti(OC6H2-6-R1-4-R2)2{S(CH2)2S}X2] (X ) Cl, 2a-i, OiPr, 3a-i; R1 ) H, Me, iPr, tBu, 2-phenyl-2-propyl; R2 ) H, Me, tBu, OMe, 2-phenyl-2-propyl) were synthesized by reacting the corresponding linked bis(phenol) (HOC6H2-6-R1-4-R2)2{S(CH2)2S} (1a-i) with the titanium precursor TiX4. The NMR spectra of the dichloro complexes Ti(OC6H2-6-R1-4-R2)2{S(CH2)2S}Cl2] (2a-d) with small ortho substituents R1 ) H, Me, iPr are in agreement with a C2-symmetrical helical structure, but the complexes become fluxional at higher temperatures. The corresponding di(isopropoxy) complexes [Ti(OC6H2-6-R1-4-R2)2{S(CH2)2S}(OiPr)2] (3a-d) are fluxional in solution at room temperature due to rapid interconversion between the delta and lambda isomers. In contrast, both dichloro and di(isopropoxy) complexes 2e-i and 3e-i with bulky ortho substituents R1 ) tBu and 2-phenyl- 2-propyl exhibit a rigid C2-symmetrical helical structure in solution up to 100 °C. The helical structure with trans-O,O, cis-S,S, cis-Cl,Cl (“alpha-cis”) is confirmed by the single-crystal structure analysis of two dichloro complexes [Ti(OC6H2-6-R1-4-R2)2{S(CH2)2S}Cl2] (2e, R1 ) tBu, R2 ) Me; 2i, R1, R2 ) 2-phenyl-2-propyl). Related dichloro and di(isopropoxy) complexes that contain a 1,5-dithiapentanediyl-linked bis(4,6-disubstituted phenolato) ligand [Ti(OC6H2-6-R1-4-R2)2{S(CH2)3S}X2] (R1 ) tBu; R2 ) Me, tBu, OMe; X ) Cl, 5a-c; OiPr, 6a-c) were synthesized in an analogous fashion and shown by NMR spectroscopy to be conformationally flexible at room temperature. This fluxionality can be explained by a twisting of one fivemembered chelate ring, converting the trans-O,O (“alpha-cis”) to the cis-O,O (“beta-cis”) isomer. A crystal structure determination of ligand [Ti(OC6H2tBu2-4,6)2{S(CH2)3S}(OiPr)2] (6b) revealed the trans-O,O, cis-S,S, cis-Cl,Cl (“alpha-cis”) isomer. Upon activation with methylaluminoxane, the stereorigid derivatives 2e-i efficiently polymerize styrene to give isotactic polystyrene, whereas the conformationally flexible complexes 2a-d produce atactic polystyrene with negligible activity. Under the same conditions, complexes with the 1,5-dithiapentanediyllinked ligand 5a,b and 6b,c polymerized styrene syndiospecifically with low activity

Italian shows large phonetic and prosodic variations that depend on the geographical and dialectal area the speakers come from. The chapter explicitly focuses on the intonational variation occurring in Italian and offers (1) the key elements of a shared transcription system able to take this into account and (2) an overview of the intonation patterns of thirteen varieties, spoken in cities and towns located in various areas of the Italian peninsula, i.e. Milan, Turin, Florence, Siena, Pisa, Lucca, Rome, Pescara, Naples, Salerno, Cosenza, Bari, and Lecce. The main novelty of the chapter is the clear and explicit effort made in offering analyses and transcriptions that always keep in mind cross-variety comparison to finally facilitate cross-language comparison as well. Importantly, this is the first work on Italian in which this is systematically achieved on the basis of a wide and representative set of sentence types, apart from the number of varieties considered.

Laparoscopic intracorporeal side-to-side EJS is a safe and feasible technique. It represents a valid method for performing a reconstruction of the digestive tract in laparoscopic surgery after TLG, especially in presence of a narrow esophagus.

We report a fast-track computationally-driven discovery of new SARS-CoV2 Main Protease M$pro inhibitors whose potency range from mM for initial non-covalent ligands to sub-μM for the final covalent compound (IC50=830...