crown-6)] + (KC) cations are used for cocrystallization with manganese halides, producing isostructural single crystals of organic− inorganic hybrid complexes, [K(dibenzo-18-crown-6)] 2 MnX 4 (abbreviated (KC) 2 MnX 4 ) (X = Cl, Br), which feature one-dimensional morphology and green phosphorescence with considerable photoluminescence quantum yields accompanied by excellent optical waveguide behavior with a low loss coefficient. More interestingly, (KC) 2 MnX 4 crystallizes in the monoclinic space group Cc belonging to the achiral point group m (C s ), where the non-centrosymmetric arrangement of racemic units, with right-and left-handed rotating optical axes, endows these achiral single crystals with circularly polarized luminescence, observed for the first time.

Micro/nanoscale photonic barcodes based on multicolor luminescent segmented heterojunctions hold potential for applications in information security. However, such multicolor heterojunctions reported thus far are exclusively based on static luminescent signals, thus restricting their application in advanced confidential information protection. Reported here is a strategy to design responsive photonic barcodes with heterobimetallic (Tb3+/Eu3+) metal—organic framework multicolor heterostructures. The spatial colors could be precisely controlled by thermally manipulating the energy‐transfer process between the two lanthanides, thus achieving responsive covert photonic barcodes. Also demonstrated is that spatially resolved responsive barcodes with multi‐responsive features could be created in a single heterostructure. These findings offer unique opportunities to purposely design highly integrated responsive microstructures and smart devices toward advanced anti‐counterfeiting applications.

Organic-inorganic metal-halide materials (OIMMs) with zero-dimensional (0D) structures offer useful optical properties with a wide range of applications. However, successful examples of 0D structural OIMMs with well-defined optical performance at the micro-/nanometer scale are limited. We prepared one-dimensional (1D) (DTA) 2 SbCl 5 •DTAC (DTAC = dodecyl trimethyl ammonium chloride) single-crystal microrods and 2D microplates with a 0D structure in which individual (SbCl 5 ) 2À quadrangular units are completely isolated and surrounded by the organic cation DTA + . The organic molecular unit with a long alkyl chain (C 12 ) and three methyl groups enables microrod and -plate formation. The singlecrystal microrods/-plates exhibit a broadband orange emission peak at 610 nm with a photoluminescence quantum yield (PLQY) of ca. 90 % and a large Stokes shift of 260 nm under photoexcitation. The broad emission originates from selftrapping excitons. Spatially resolved PL spectra confirm that these microrods exhibit an optical waveguide effect with a low loss coefficient (0.0019 dB mm À1 ) during propagation, and linear polarized photoemission with a polarization contrast (0.57).Organic-inorganic metal-halide materials (OIMMs), a bulk crystal with 0D structure at the molecular level, have attracted tremendous attentions due to their potential optoelectronic applications as light-emitting materials. [1] These materials though in bulk; but can have bright emission and also retain as high as near unity photoluminescence quantum yield (PLQY). [2] Among different applications these could also serve as a potential optical materials in micro-/ nanosized optical waveguides. [3] To date, research on optical