当前位置：
X-MOL 学术
›
J. Phys. Chem. A
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Formation and Reaction Kinetics of Biradicals and Triplet States in a Series of Carboxylated 1,4,5,8-Naphthalene Diimides.
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2020-08-26 , DOI: 10.1021/acs.jpca.0c06639 Stacey Sova 1 , Lisa A Kelly 1
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2020-08-26 , DOI: 10.1021/acs.jpca.0c06639 Stacey Sova 1 , Lisa A Kelly 1
Affiliation
|
The singlet-state deactivation products in a series of alkyl carboxylate substituted 1,4,5,8-naphthalene diimide (NDI) compounds were characterized using fluorescence and phosphorescence spectroscopies, as well as nanosecond laser flash photolysis. The reactive intermediates were quantified as a function of the number of methylenes in the alkyl linker. Rate constants for photoinduced electron transfer (PET) to the singlet excited state of the NDIs varied from 1.2 × 1010 to 4.9 × 1010 s–1. The yield of the long-lived amino ketyl radical ranged from 15% to 60% in compounds having 4 to 1 intervening methylenes between the NDI chromophore and the covalently attached carboxylic acid. A predominantly triplet state was observed upon direct excitation of the compound having the slowest PET. This T1 state of the NDIs was reductively quenched by DABCO electron donor. The amino ketyl radical was unreactive toward electron donors but was found to react with the hydrogen atom donor β-mercaptoethanol. The compounds comprise a novel class of long-wavelength and strongly absorbing UV-activated chromophores that generate carbon-centered biradicals via direct 355 nm excitation in the absence of a cosensitizer.
中文翻译：
一系列羧基化的1,4,5,8-萘二酰亚胺中双自由基和三重态的形成和反应动力学。
使用荧光和磷光光谱以及纳秒激光闪光光解法表征了一系列烷基羧酸取代的1,4,5,8-萘二酰亚胺（NDI）化合物中的单重态失活产物。将反应性中间体定量为烷基接头中亚甲基的数量的函数。光诱导电子转移（PET）到NDI的单重激发态的速率常数从1.2×10 10到4.9×10 10 s –1不等。在NDI之间含有4至1个中间亚甲基的化合物中，长寿命氨基酮基的产率为15％至60％生色团和共价连接的羧酸。直接激发具有最慢PET的化合物时，观察到主要为三重态。NDI的T 1状态被DABCO电子给体还原性淬灭。氨基酮基自由基对电子供体没有反应性，但发现它与氢原子供体β-巯基乙醇反应。这些化合物包括一类新型的长波长和强吸收性紫外线激活发色团，它们在不存在增敏剂的情况下通过直接355 nm激发产生以碳为中心的双自由基。
更新日期：2020-09-18
中文翻译：
一系列羧基化的1,4,5,8-萘二酰亚胺中双自由基和三重态的形成和反应动力学。
使用荧光和磷光光谱以及纳秒激光闪光光解法表征了一系列烷基羧酸取代的1,4,5,8-萘二酰亚胺（NDI）化合物中的单重态失活产物。将反应性中间体定量为烷基接头中亚甲基的数量的函数。光诱导电子转移（PET）到NDI的单重激发态的速率常数从1.2×10 10到4.9×10 10 s –1不等。在NDI之间含有4至1个中间亚甲基的化合物中，长寿命氨基酮基的产率为15％至60％生色团和共价连接的羧酸。直接激发具有最慢PET的化合物时，观察到主要为三重态。NDI的T 1状态被DABCO电子给体还原性淬灭。氨基酮基自由基对电子供体没有反应性，但发现它与氢原子供体β-巯基乙醇反应。这些化合物包括一类新型的长波长和强吸收性紫外线激活发色团，它们在不存在增敏剂的情况下通过直接355 nm激发产生以碳为中心的双自由基。
京公网安备 11010802027423号