RESUMO
The substitution of 2,7-dibromo-9-fluorenyl phosphaalkenes with heteroaromatic substituents (bithiophene, benzothiophene, pyridine) offers access to interesting push-pull dye molecules. Steric shielding due to the bulky P-substituent gives marked different reactivities at the 2- and 7-positions, allowing the synthesis of mixed/asymmetric derivatives. Further functionalization via gold(I) coordination was demonstrated and increased the acceptor character, concomitant with a red-shifted absorption.
RESUMO
A P[double bond, length as m-dash]C heavy-alkene analogue that is unreactive towards the addition of strong acids on its double-bond is presented; instead, a strategically located imine nitrogen on the periphery forms protonated adducts displaying hydrogen bonding interactions. These materials are significantly more stable than the parent species, demonstrating an unprecedented approach towards the stabilisation of a multiple-bonded heavy main group fragment, in this case, a phosphaalkene. An HCl adduct self-assembles with H2O into a dimeric network displaying a discrete quadrilateral hydrogen-bonded arrangement.
RESUMO
Stable phospha- and arsaalkenes were used to synthesize polymers containing unsaturated P[double bond, length as m-dash]C and As[double bond, length as m-dash]C moieties. The composition, chemical environment, structure, optical, and electronic properties of the monomers and polymers were elucidated. The incorporation of the heteroatom-carbon double bonded units efficiently perturbs the optoelectronics and solid state features of both monomeric and polymeric scaffolds. Proof-of principle work supports their responsive character through post-functionalisation and electrochromic behaviour. To the best of our knowledge, this is the first example of a polymer containing arsenic-carbon double bonds.
