Molecular Shape Recognition by Using a Switchable Luminescent Nonporous Molecular Crystal

A nonporous molecular
crystal (NMC) has been developed for use
as a host material. The NMC comprises a platinum dibromide complex
with coordinating 9-phenyl-9-arsafluorene ligands. The NMC also contains
chlorobenzene (PhCl) molecules, which quench emissions from the platinum
complex. On exposure to the vapors of several volatile organic compounds
(VOC), the encapsulated PhCl was released. With the loss of PhCl,
the crystal once again showed the intrinsic luminescence of the platinum
complex. Furthermore, the NMC can recognize the molecular shape of
VOCs; consequently, VOCs having small minimum diameters turn on emission,
but large VOCs do not cause the release of the included PhCl quencher,
and emission remains switched off. Interestingly, a wide range of
VOCs (e.g., alcohol, ether, haloalkane, and alkane) could be used,
implying that the shape recognition ability of the present NMC system
is polarity independent. This is the first example of NMCs having
widespread molecular shape recognition properties.

一种致密的分子晶体（NMC）已被开发用作宿主材料。该NMC由含配位9-苯基-9-砜基荧光烯配体的铂二溴化物复合物组成。NMC还包含氯苯（PhCl）分子，这些分子能够淬灭铂复合物的发射。当暴露于多种挥发性有机化合物（VOC）的蒸汽中时，封装的PhCl被释放。随着PhCl的丧失，晶体再次显现出铂复合物的固有发光特性。此外，NMC能够识别VOC的分子形状；因此，具有较小最小直径的VOC会开启发射，而较大的VOC则不会导致所包含的PhCl淬灭剂释放，发射保持关闭。有趣的是，广泛的VOC（例如醇、醚、卤代烷和烷烃）均可被利用，这表明当前NMC系统的形状识别能力与极性无关。这是首次发现的NMC具有广泛分子形状识别特性的例子。