Koli Mrunesh, Gamre Sunita, Ghosh Rajib, Wadawale A P, Ghosh Ayan, Ghanty Tapan K, Mula Soumyaditya
Bio-Organic Division, Bhabha Atomic Research Centre, Mumbai, 400085, India.
Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India.
Chem Asian J. 2024 Dec 2;19(23):e202400975. doi: 10.1002/asia.202400975. Epub 2024 Oct 31.
To develop heavy-atom-free triplet photosensitizers (PSs) based photocatalysts, we designed and synthesized two BODIPY-helicene dyes by fusing the BODIPY core and modified [5]helicene structures. These BODIPY-helicenes structures are twisted and their twisting angles are increased by the developed synthetic method. The BODIPY-helicenes have broad absorption bands over UV-visible region with high triplet conversions and long triplet lifetimes as compared to planar BODIPY dye, PM567. Consequently, these dyes are also highly efficient in generating O by transferring their triplet energy to O. All these are confirmed by dye-sensitised photooxidation reaction, nanosecond transient absorption spectroscopy study, phosphorescence measurement and DFT calculations. Finally, photocatalytic activity of the highest O generating BODIPY-helicene (4 b) was checked. 4 b is highly efficient in photocatalytic oxidative coupling of differently substituted amines through aerobatic oxidation using O generated by its photosensitization. It is also highly efficient photocatalyst for aerobatic oxidation of sulfides to sulfoxides. Importantly, the photocatalyst could be quantitatively recovered and reused for several cycles. All these results confirmed the potential use of the BODIPY-helicenes as PSs for photocatalytic organic reactions and the design strategy will be useful for the future development of heavy-atom-free photocatalyst.
为了开发基于无重原子三线态光敏剂（PSs）的光催化剂，我们通过融合BODIPY核和修饰的[5]螺旋烯结构设计并合成了两种BODIPY-螺旋烯染料。这些BODIPY-螺旋烯结构是扭曲的，并且通过所开发的合成方法其扭曲角度增加。与平面BODIPY染料PM567相比，BODIPY-螺旋烯在紫外-可见光区域具有宽吸收带、高三线态转化率和长三线态寿命。因此，这些染料通过将其三线态能量转移到O₂来高效产生O₂。所有这些都通过染料敏化光氧化反应、纳秒瞬态吸收光谱研究、磷光测量和密度泛函理论计算得到证实。最后，检测了产生O₂效率最高的BODIPY-螺旋烯（4 b）的光催化活性。4 b通过其光致敏产生的O₂进行需氧氧化，在不同取代胺的光催化氧化偶联中效率很高。它也是将硫化物需氧氧化为亚砜的高效光催化剂。重要的是，该光催化剂可以定量回收并重复使用几个循环。所有这些结果证实了BODIPY-螺旋烯作为光催化有机反应的PSs的潜在用途，并且该设计策略将对无重原子光催化剂的未来发展有用。
