Absorption spectrophotometric, fluorescence and quantum chemical investigations on non-covalent interaction between PC70BM and designed diporphyrin in solution

作者：Ray Anamika; Bauri Ajoy; Bhattacharya Sumanta^*

来源：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy , 2015, 134: 566-573.

DOI：10.1016/j.saa.2014.06.089

• PC70BM
• Diporphyrin
• Self-assembly
• Binding constant
• MEP calculations

Present work reports the photophysical insights on supramolecular interaction of a C-70 derivative, namely, [6,6]-phenyl C-71 butyric acid methyl ester (PC70BM), with two designed diporphyrin molecules having dithiophene (1) and carbazole (2) spacer in toluene and benzonitrile. Both absorption spectrophotometric and steady state fluorescence investigations reveal efficient complexation of PC70BM with 1 and 2 in both toluene and benzonitrile. The magnitude of average value of binding constant, viz., K-av, for the complexes of PC70BM with 1 and 2 in toluene (benzonitrile) are estimated to be 2.185 x 10(3) dm(3) mol(-1) (3.215 x 10(3) dm(3) mol(-1)) and 10.180 x 10(3) dm(3) mol(-1) (25.405 x 10(3) dm(3) mol(-1)), respectively. Selectivity in binding for the complexation process of PC70BM with 1 and 2 is estimated to be similar to 4.6 and similar to 7.90 as observed in toluene and benzonitrile, respectively. The complexation between PC70BM and diporphyrin is well accounted by a theoretical model which takes into account the electronic subsystems of both acceptor and donor. Ab initio calculations in vacuo establish that size selective orientation pattern of PC70BM towards the cavity of diporphyrin dictates the magnitude of binding and electronic structure of the PC70BM/diporphyrin complexes.

• 出版日期2015-1-5