Colella, L. published the artcileOutside rules inside: the role of electron-active substituents in thiophene-based heterophenoquinones, Application of 5,5′-Bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,2′-bithiophene, the publication is Physical Chemistry Chemical Physics (2015), 17(16), 10426-10437, database is CAplus and MEDLINE.
The biradicaloid vs. quinoidal character of the ground state of thiophene-based heterophenoquinones bearing donor or acceptor groups is investigated. Keeping the conjugation length fixed, namely, the 5,5′-bis(3,5-di-tert-butyl-4-oxo-2,5-cyclohexadiene-1-ylidene)-2,2′-dihydroxy bithiophene backbone, an opposite effect occurs depending on the donating or withdrawing nature of the substituents. The character of the ground state depends not only on the electronic nature of the substituents but also on their position on the mol. skeleton: donor groups on the 3,3′-positions of the bithiophene central core stabilize a quinoidal ground state, whereas a biradicaloid electronic structure results from the introduction of the same donor groups onto the lateral phenones. Withdrawing groups behave similar to donors, but in the opposite direction.
Physical Chemistry Chemical Physics published new progress about 239075-02-6. 239075-02-6 belongs to alcohols-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Boronate Esters, name is 5,5′-Bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,2′-bithiophene, and the molecular formula is C20H28B2O4S2, Application of 5,5′-Bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,2′-bithiophene.
Referemce:
https://en.wikipedia.org/wiki/Alcohol,
Alcohols – Chemistry LibreTexts