Progressive acylation of pyrene engineers solid state packing and colour via C–H⋯H–C, C–H⋯O and π–π interactions
作者:Shinaj K. Rajagopal、Abbey M. Philip、Kalaivanan Nagarajan、Mahesh Hariharan
DOI:10.1039/c4cc01897d
日期:——
Sandwich herringbone–herringbone-brickwork-columnar crystal ordering, achieved through successive Friedel–Crafts acylation of pyrene, forms the basis for diverse solid-state colouring and blue–green–orange fluorescent crystals.
作者:Shinaj K. Rajagopal、Ajith R. Mallia、Mahesh Hariharan
DOI:10.1039/c7cp04834c
日期:——
Ultrafast intersystemcrossing of carbonylpyrenes in chloroform was investigated by femtosecond pump–probe spectroscopy. When compared to the dominant fluorescence decay pathway in pyrene, carbonyl functionalized pyrenes display near-unity triplet formation upon photoexcitation. The excited singlet state (Sp) undergoes rapid intersystemcrossing (kISC) concomitantly with internal conversion (kIC) to
飞秒泵浦-探针光谱法研究了氯仿中羰基py的超快速系统间穿越。当与pyr中的主要荧光衰变途径进行比较时,羰基官能化的display在光激发后显示出几乎统一的三重态。激发单重态(S p)经历快速间跨越(ķ ISC)伴随地内部转换(ķ IC),以降低激发单重态(S Ñ 5-11 PS(1 /的时间范围内)τ 2 = ķ IC + k ISC)。此外,从较低的激发单重态(S n)通过与接收机三重态耦合,最终导致高三重量子产率(前进Φ Ť tetraacetylpyrene)= 97%。在三重态歧管中进行内部转换之后,从发射三重态观察到磷光在微秒级的时间衰减。