Unique photochemical behavior of novel tetracationic pyrene derivative on the clay surface

2‐ and 2,7‐Substituted para‐N‐Methylpyridinium Pyrenes: Syntheses, Molecular and Electronic Structures, Photophysical, Electrochemical, and Spectroelectrochemical Properties and Binding to Double‐Stranded (ds) DNA

“…Interestingly, the emission of 1M is even more bathochromically shifted than 2M , which is an effect of a larger stabilization of the excited state in 1M due to the larger dipole moment compared to 2M , which has a symmetrical charge distribution. It can be noted that the emission of 2M is hypsochromically shifted compared to analogous 1,6‐bis( N ‐methyl‐3’‐pyridinium)pyrene dichloride ( λ em =591 nm) [49a] and bathochromically shifted compared to [1,3,6,8‐tetrakis( N ‐methyl‐4‐pyridinium)pyrene][PF 6 ] 4 ( λ em =485 nm) [49b] …”

Remarkable Stimulation of Emission Quenching on a Clay Surface

“…Before investigating the Py 4+ /Ru 2+ /SSA systems, we also prepared single-component Py 4+ and Ru 2+ with SSA (Py 4+ / SSA 22 Table S1. The results indicate that loaded Py 4+ or Ru 2+ molecules were efficiently adsorbed onto SSA under experimental conditions.…”

“…The tetracationic pyrene derivative (1,3,6,8-tetrakis(N-methylpyridinium-4-yl)pyrene 4PF 6 − ; Py 4+ ) was synthesized according to the literature method. 22 Cation-exchangeable saponite clay (SSA) was provided by Kunimine Industries Co., Ltd. and was used as received. The SSA was hydrothermally synthesized, and it exhibited a very large surface area (750 m 2 g −1 ) and a cation exchange capacity (CEC) of 0.997 mequiv g −1 .…”

“…The authors referred to this unique phenomenon as the "size-matching effect". 20,21 In recent years, they have reported that other various cationic dyes, 20 such as tetracationic pyrene (Py 4+ ), 22 exhibit this size-matching effect.…”

Light Energy Accumulation from Pyrene Derivative to Tris(bipyridine)ruthenium on Clay Surface

“…To obtain efficient and effective photoreaction systems, a combination of Ru 2+ and an ordinary organic molecule that has strong light absorption and light energy accumulation properties is expected to provide a solution. Pyrene derivatives are promising organic molecules for this purpose because they exhibit intense absorption and a high emission quantum yield and consist of common atoms. − We have reported efficient energy transfer from a light-absorbing and energy-donating cationic pyrene derivative (Py 4+ ) to energy-accepting Ru 2+ on a synthetic clay (Sumecton SA [SSA]) , surface. , In this case, the emission from Py 4+ was quenched and an apparent emission quenching rate constant ( k q,app ) of 7.4 ± 0.7 × 10 15 L mol –1 s –1 was achieved . However, this system requires stoichiometric amounts of Py 4+ and Ru 2+ to achieve emission quenching of ca.…”