Boron difluoride formazanates with thiophene and 3,4-ethylenedioxythiophene capping and their electrochemical polymerization

We report here the first example of BF2 formazanates with thiophene capping and their π-conjugated polymers in the form of electroactive uniform thin films by electrochemical polymerization. These new formazanates and their polymers possess panchromatic absorption with low lying frontier molecular orbitals. With small band gaps (1.5-1.8 eV), they are good candidates for organic electronics and light-harvesting applications. A computational study on the charge transport properties of BF2 formazanates with 3,4-ethylenedioxythiophene (EDOT) indicates an ambipolar semiconductor nature.