Photoconversion of 6,13-α-diketopentacene in the crystalline phase

Nanostructures and Nanostructured Networks for Smart Drug Delivery

“…Adsorption of components such as surfactants and interpenetration of an ionic polymer also modify the temperature of collapse [73]. Furthermore, the time required for the phase transition is highly dependent on the overall size of the network [74] and its porosity [75]. The incidence of such variables on the CST should be taken into account when designing dually responsive networks, namely pH-and temperature-sensitive systems [76,77].…”

Visible‐Light‐Induced Heptacene Generation under Ambient Conditions: Utilization of Single‐crystal Interior as an Isolated Reaction Site

“…The observed red emission additionally supports the formation of ap entacenem oiety. [31] Notably,a bsorptions corresponding to the aggregation of the intermediate, which should appear at 625 nm and 663 nm, weren ot observed, unlike in the case of pristine pentacene. [31] This is likely as ar esult of the remaining bulky a-diketone groups preventing pentacene stacking.…”

“…[31] Notably,a bsorptions corresponding to the aggregation of the intermediate, which should appear at 625 nm and 663 nm, weren ot observed, unlike in the case of pristine pentacene. [31] This is likely as ar esult of the remaining bulky a-diketone groups preventing pentacene stacking. Further photoirradiation, and/ori rradiation at ah igher energy (200 mW) exhibited the same trend as seen in solution.…”

“…In this context,w eh ave successfully demonstratedt he photoconversion of ac rystalline phase a-diketone-type pentacene precursor into pentacene, with the use of a4 88 nm CW laser. [31,32] Importantly,t he CW laser selectively irradiates the interioro fasingle crystal, suggesting its potential utility as an isolated site for unstable compounds.T his effective technique was applied herein for the generation of heptacene under ambient conditions.…”

“…The color of the solution changed from yellow to purple, suggesting the conversion of 7-DK2 to the pentacene-containing intermediate. [31] However,f urther photoirradiation, and/or photoirradiation at ah igherp ower (400 mW cm À2 ), could not convert the intermediate to heptacene,a ffording precipitates of the intermediates instead. This result implies that the n-p*t ransition of the intermediate could not be efficientlye xcited further,a st he generated pentacene moiety displays an intensea bsorption in the same region as the n-p*t ransition, which prevents the intermediates from further photoconversion to heptacene.…”