Long-Lived Charge Separation in Novel Axial Donor-Porphyrin-Acceptor Triads Based on Tetrathiafulvalene, Aluminum(III) Porphyrin and Naphthalenediimide
作者:Prashanth K. Poddutoori、Niloofar Zarrabi、Andrey G. Moiseev、Roger Gumbau-Brisa、Serguei Vassiliev、Art van der Est
DOI:10.1002/chem.201202995
日期:2013.2.25
4‐(n‐pentyl)‐4′‐cyanobiphenyl (5CB), a spin‐polarized transient EPR spectrum that is readily assigned to the weakly coupled radical pair TTF.+NDI.− is obtained. The initial polarization pattern indicates that the charge separation occurs through the singlet channel and that singlet–triplet mixing occurs in the primary radical pair. At later time the polarization pattern inverts as a result of depopulation
据报道有两个自组装的超分子供体-受体三联体,包括三价卟啉(AlPor)和轴向结合的萘二酰亚胺(NDI)作为受体,四硫富瓦烯(TTF)作为次级供体。在三单元组中,NDI和TTF单元分别通过共价键和配位键连接到卟啉相对面上的Al III。荧光研究表明,卟啉的最低激发单重态通过电子转移到NDI和空穴转移到TTF猝灭。在二氯甲烷中,空穴转移至TTF占主导,而在苄腈(BN)中,电子转移至NDI是主要的淬灭途径。在液晶溶剂的向列相中4-(n-戊基)-4'-氰基联苯(5CB),它是一种自旋极化的瞬态EPR谱,可以轻松分配给弱耦合的自由基对TTF 。+ NDI .-。初始极化模式表明,电荷分离是通过单线态通道发生的,并且单线态-三重态混合发生在初级自由基对中。在稍后的时间,由于通过重组为基态而使具有单重态特征的状态减少,极化模式反转。TTF 。+ NDI .-的单重态寿命估计为200–300 ns,而X波段EPR光谱仪在大约350