Altering the optoelectronic properties of boron difluoride formazanate dyes via conjugation with platinum(ii)-acetylides. Issue 45 (10th October 2019) - Dhindsa, Jasveer S.
Abstract : The absorption, emission, and electrochemical properties of conjugates of boron difluoride formazanate dyes and Pt(ii )-acetylides are systematically studied. Abstract : The combination of π-conjugated organic compounds and Pt(ii )-acetylides is a powerful strategy for the production of functional optoelectronic materials. The presence of the heavy element, Pt, in these compounds enhances electronic delocalization generally resulting in low-energy absorption and emission maxima and often leads to intersystem crossing, resulting in phosphorescence. When boron complexes of N-donor ligands, such as boron dipyrromethenes (BODIPYs), are involved the molecular and polymeric materials produced have properties that are advantageous for their use as oxygen-sensors, in triplet–triplet annihilation, and as the functional components of photovoltaics. Based on these exciting results, we endeavored to thoroughly examine the effect of Pt(ii )-acetylide conjugation on the properties of BF2 formazanate dyes, which offer improved redox properties and red-shifted absorption and emission bands compared to many structurally related BODIPYs. The results showed that phosphine-supported Pt(ii )-acetylide incorporation enhanced electronic conjugation, rendering the electrochemical reduction of the BF2 formazanate dyes more difficult, while also red-shifting their absorption and emission maxima. Unlike similar BODIPYs, the presence of Pt(ii ) did not facilitate phosphorescence, but rather quenched fluorescence. This study provides significant insights into structure–property relationships and guiding principles for the design of BF2 formazanate dyes, a rapidly emerging family of readily accessible optoelectronic materials.