Photoluminescent coordination nanosheets (CONASHs) comprising three-way terpyridine (tpy) ligands and zinc(II) ions are created by allowing the two constitutive components to react with each other at a liquid/liquid interface. Taking advantage of bottom-up CONASHs, or flexibility in organic ligand design and coordination modes, we demonstrate the diversity of the tpy-zinc(II) CONASH in structures and photofunctions. A combination of 1,3,5-tris[4-(4'-2,2':6',2″-terpyridyl)phenyl]benzene (1) and Zn(BF) affords a cationic CONASH featuring the bis(tpy)Zn complex motif (1-Zn), while substitution of the zinc source with ZnSO realizes a charge-neutral CONASH with the [Zn(μ-OSO)(tpy)] motif [1-Zn(SO)]. The difference stems from the use of noncoordinating (BF) or coordinating and bridging (SO) anions. The change in the coordination mode alters the luminescence (480 nm blue in 1-Zn; 552 nm yellow in 1-Zn(SO)). The photophysical property also differs in that 1-Zn(SO) shows solvatoluminochromism, whereas 1-Zn does not. Photoluminescence is also modulated by the tpy ligand structure. 2-Zn contains triarylamine-centered terpyridine ligand 2 and features the bis(tpy)Zn motif; its emission is substantially red-shifted (590 nm orange) compared with that of 1-Zn. CONASHs 1-Zn and 2-Zn possess cationic nanosheet frameworks with counteranions (BF), and thereby feature anion exchange capacities. Indeed, anionic xanthene dyes were taken up by these nanosheets, which undergo quasi-quantitative exciton migration from the host CONASH. This series of studies shows tpy-zinc(II) CONASHs as promising potential photofunctional nanomaterials.

We systematically examined the effects of π‐electron systems on the chiroptical activity of atomically precise gold clusters [Au11(DP)4L2]+, where DP and L represent chiral diphosphines and achiral anionic ligands, respectively. Reducing the distance between the π‐electron systems of the chiral DP and the Au11 core enhanced the anisotropy factor of [Au11(DP)4L2]+ in the range of 300–450 nm while extension of the π‐electron system of the achiral L did not. This tendency supports our previous proposal that the proximity of the chiral π‐electron system to the gold core amplifies the optical activity.

Localized surface plasmon resonance (LSPR) sensors based on plasmonic nanoparticles are sensitive to changes in local refractive index, so that they are used for affinity-based chemical sensing and biosensing. Conventional LSPR sensors are generally based on transmission of light through the sensor and a sample solution, which could be colored or turbid. In this study, we develop backward-scattering-based LSPR sensors that can be applied to colored or turbid sample solutions. Au nanospheres (100 nm diameter) and Au nanoshells (25 nm thick) with SiO2 cores (80 nm diameter) are used as plasmonic nanoparticles and immobilized on a glass substrate. The refractive index sensitivities of the Au nanospheres and nanoshells are 128 and 278 nm RIU -1 , respectively, which are in good agreement with simulated values and the values for conventional transmission-based LSPR sensors. The Au nanoshells require a lower amount of Au for the same scattering intensity in comparison with the Au nanospheres. The backward-scattering-based LSPR sensing is possible with the Au nanospheres and nanoshells even in coffee as a colored and turbid sample.