College of Chemistry and Materials Science , Jinan University , Guangzhou 510632 , People's Republic of China.
ACS Appl Mater Interfaces. 2019 Oct 23;11(42):38503-38509. doi: 10.1021/acsami.9b14121. Epub 2019 Oct 9.
Solvothermal reaction of zinc -tetra(4-carboxyphenyl)porphyrin and 2,6-diaminopurine with zinc salt in DMF affords a three-dimensional bioMOF (). Its infinite rod-shaped building block features an alternation of octahedral ZnO and paddle-wheel Zn clusters bridged by 2,6-diaminopurines. The paddle-wheel Zn cluster undergoes reversible transformation with half into quasi-paddle-wheel Zn cluster and the other half into two tetrahedral mononuclear clusters upon release/uptake of guest molecules, resulting in a new phase . This single-crystal to single-crystal transformation is accompanied by luminescence on/off switching, possibly associated with the structural conversion between the porphyrin-ligand-based photoactive and the porphyrin-stacking-caused non-photoactive . Interestingly, exhibits quick luminescence turn-on in alcohol vapor instead of other volatile organic solvents by transforming into an intermediate phase , which shows a partial luminescence enhancing likely due to the intermittent porphyrin π-π stacking. In view of experimental results and theoretical calculations, this distinctive alcohol-vapor-induced luminescence turn-on is attributed to the coordination ability to porphyrin-bound zinc ion, molecular size, and vapor pressure, in which methanol and ethanol are particularly favored.
水热条件下，锌-四(4-羧基苯基)卟啉与 2,6-二氨基嘌呤在 DMF 中与锌盐反应，得到了一个具有三维结构的生物 MOF（）。其无限的棒状构筑单元由交替的八面体 ZnO 和 paddle-wheel Zn 簇通过 2,6-二氨基嘌呤桥联而成。当客体分子释放/吸收时，paddle-wheel Zn 簇发生可逆转变，其中一半转变为准 paddle-wheel Zn 簇，另一半转变为两个四面体形单核簇，从而产生新相。这种单晶到单晶的转变伴随着发光的开/关切换，可能与基于卟啉配体的光活性和卟啉堆积引起的非光活性之间的结构转换有关。有趣的是，通过转变为中间相，在醇蒸气中而不是其他挥发性有机溶剂中表现出快速的发光开启，这显示出部分发光增强，可能归因于间歇性的卟啉π-π堆积。鉴于实验结果和理论计算，这种独特的醇蒸气诱导的发光开启归因于与卟啉结合的锌离子的配位能力、分子尺寸和蒸气压，其中甲醇和乙醇特别有利。
