Experimental and Theoretical Quantification of the Lewis Acidity of Iodine(III) Species.

The role of hypervalent iodine reagents as oxidants has been widely recognized for more than 20 years. As electrophilic species, they could also play the role of Lewis acids. While not surprising, this aspect of these reagents has not been fully considered and exploited in the literature.

Experimental and theoretical studies of quadrupolar oligothiophene-cored chromophores containing dimesitylboryl moieties as π-accepting end-groups: syntheses, structures, fluorescence, and one- and two-photon absorption.

Quadrupolar oligothiophene chromophores composed of four to five thiophene rings with two terminal (E)-dimesitylborylvinyl groups (4 V-5 V), and five thiophene rings with two terminal aryldimesitylboryl groups (5 B), as well as an analogue of 5 V with a central EDOT ring (5 VE), have been synthesized via Pd-catalyzed cross-coupling reactions in high yields (66-89%). Crystal structures of 4 V, 5 B, bithiophene 2 V, and five thiophene-derived intermediates are reported. Chromophores 4 V, 5 V, 5 B and 5 VE have photoluminescence quantum yields of 0.