Marin Dawn M, Payerpaj Sonia, Collier Graham S, Ortiz Angy L, Singh Gaurav, Jones Marcus, Walter Michael G
Department of Chemistry, Burson 200, 9201 University City Blvd., Charlotte, NC 28223-0001, USA.
Phys Chem Chem Phys. 2015 Nov 21;17(43):29090-6. doi: 10.1039/c5cp04359j.
Sensitizers with high triplet quantum yields are useful for generating photovoltaics, photocatalysts and photodynamic therapy agents with increased efficiency. In this study, the heavy atom effect was used to optimize the triplet and singlet oxygen quantum yields of 5,10,15,20-tetrakis(4-carbomethoxyphenyl)porphyrin (1-TCM4PP). The triplet quantum yields, determined using delayed fluorescence, was calculated as 0.35 for 1-TCM4PP, 0.75 for 5,10,15-tris(4-carbomethoxyphenyl)-20-(4-bromophenyl)porphyrin (2-TBCM3PP) and 0.88 for 5,10,15-tris(4-carbomethoxyphenyl)-20-(4-iodophenyl)porphyrin (3-TCM3IPP). Chemical quenching of 1,3-diphenylisobenzofuran and singlet oxygen emission studies rendered an average singlet oxygen quantum yield of 0.51, 0.75, and 0.90 for TCM4PP, TBCM3PP and TCM3IPP respectively. These photophysical properties indicate that a single halogen atom is capable of transforming TCM4PP into a sensitizer with strong triplet character. This is useful for generating singlet oxygen for photodynamic therapy, creating a long lasting reactive species for catalysis and for extending diffusion lengths in photovoltaic applications while retaining three molecular modification points for further functionalization.
具有高三重态量子产率的敏化剂可用于更高效地制备光伏材料、光催化剂和光动力治疗剂。在本研究中，利用重原子效应优化了5,10,15,20-四（4-甲氧羰基苯基）卟啉（1-TCM4PP）的三重态和单线态氧量子产率。通过延迟荧光测定的三重态量子产率，1-TCM4PP为0.35，5,10,15-三（4-甲氧羰基苯基）-20-（4-溴苯基）卟啉（2-TBCM3PP）为0.75，5,10,15-三（4-甲氧羰基苯基）-20-（4-碘苯基）卟啉（3-TCM3IPP）为0.88。1,3-二苯基异苯并呋喃的化学猝灭和单线态氧发射研究表明，TCM4PP、TBCM3PP和TCM3IPP的平均单线态氧量子产率分别为0.51、0.75和0.90。这些光物理性质表明，单个卤原子能够将TCM4PP转化为具有强三重态特征的敏化剂。这对于光动力治疗中产生单线态氧、催化中产生持久的活性物种以及在光伏应用中延长扩散长度同时保留三个分子修饰点以进行进一步功能化很有用。
