303089-30-7Relevant academic research and scientific papers
Long-lived triplet excited state in a platinum(ii) perylene monoimide complex
Yarnell, James E.,Chakraborty, Arnab,Myahkostupov, Mykhaylo,Wright, Katherine M.,Castellano, Felix N.
, p. 15071 - 15081 (2018/11/10)
We report the synthesis and solution based photophysical properties of a new Pt(ii)-terpyridine complex coupled to a perylene monoimide (PMI) chromophoric unit through an acetylene linkage. This structural arrangement resulted in quantitative quenching of the highly fluorescent PMI chromophore by introducing metal character into the lowest energy singlet state, thereby leading to the formation of a long-lived PMI-ligand localized triplet excited state (τ = 8.4 μs). Even though the phosphorescence from this triplet state was not observed, highly efficient quenching of this excited state by dissolved oxygen and the observation of singlet oxygen photoluminescence in the near-IR at 1270 nm initially pointed towards triplet excited state character. Additionally, the coincidence of the excited state absorbance difference spectra from the sensitized PMI ligand using a triplet donor and the Pt-PMI complex provided strong evidence for this triplet state assignment, which was further supported by TD-DFT calculations.
A Tightly Coupled Linear Array of Perylene, Bis(Porphyrin), and Phthalocyanine Units that Functions as a Photoinduced Energy-Transfer Cascade
Miller, Mark A.,Lammi, Robin K.,Prathapan, Sreedharan,Holten, Dewey,Lindsey, Jonathan S.
, p. 6634 - 6649 (2007/10/03)
We have prepared a linear array of chromophores consisting of a perylene input unit, a bis(free base porphyrin) transmission unit, and a free base phthalocyanine output unit for studies in artificial photosynthesis and molecular photonics. The synthesis involved four stages: (1) a rational synthesis of trans-AB2C-porphyrin building blocks each bearing one meso-unsubstituted position, (2) oxidative, meso,meso coupling of the zinc porphyrin monomers to afford a bis(zinc porphyrin) bearing one phthalonitrile group and one iodophenyl group, (3) preparation of a bis(porphyrin)-phthalocyanine array via a mixed cyclization involving the bis(free base porphyrin) and 4-tert-butylphthalonitrile, and (4) Pd-mediated coupling of an ethynylperylene to afford a perylene-bis(porphyrin)-phthalocyanine linear array. The perylene-bis(porphyrin)-phthalocyanine array absorbs strongly across the visible spectrum. Excitation at 490 nm, where the perylene absorbs preferentially, results in fluorescence almost exclusively from the phthalocyanine (Φf = 0.78). The excited phthalocyanine forms with time constants of 2 ps (90%) and 13 ps (10%). The observed time constants resemble those of corresponding phenylethyne-linked dyads, including a perylene-porphyrin (0.5 ps) and a porphyrin-phthalocyanine (1.1 ps (70%) and 8 ps (30%)). The perylene-bis(porphyrin)-phthalocyanine architecture exhibits efficient light-harvesting properties and rapid funneling of energy in a cascade from perylene to bis(porphyrin) to phthalocyanine.
