Vaporchromic Domino Transformation and Polarized Photonic Heterojunctions of Organoplatinum Microrods.

Photonic heterostructures with codable properties have shown great values as versatile information carriers at the micro and nanoscale. These heterostructures are typically prepared by a step-by-step growth or post-functionalization method to achieve varied emission colors among different building blocks. In order to realize high-throughput and multivariate information loading, we report here a strategy to integrate polarization signals into photonic heterojunctions. A U-shaped di-Pt(II) complex is assembled into highly-polarized yellow-phosphorescent crystalline microrods (Y-rod) by strong intermolecular Pt···Pt interaction. Upon end-initiated desorption of the incorporated CH2Cl2 solvents, Y-rod is transformed in a domino fashion into tri-block polarized photonic heterojunctions (PPHs) with alternate red-yellow-red emissions or red-phosphorescent microrods (R-rod). The red emissions of these structures are also highly polarized; however, their polarization directions are just orthogonal to those of the yellow phosphorescence of Y-rod. With the aid of a patterned mask, R-rod is further programmed into multi-block PPHs with precisely-controlled block sizes by side-allowed adsorption of CH2Cl2 vapor. X-ray diffraction analysis and theoretical calculations suggest that the solvent-regulated modulation of intramolecular and intermolecular excited states is critical for the construction of these PPHs.

Boost the Circularly Polarized Phosphorescence of Chiral Organometallic Platinum Complexes by Hierarchical Assembly into Fibrillar Networks.

Circularly polarized luminescence (CPL)-active molecular materials have drawn increasing attention due to their promising applications for next-generation display and optoelectronic technologies. Currently, it is challenging to obtain CPL materials with both large luminescence dissymmetry factor (glum) and high quantum yield (Φ). A pair of enantiomeric N N C-type Pt(II) complexes (L/D)-1 modified with chiral Leucine methyl ester are presented herein. Though the solutions of these complexes are CPL-inactive, the spin-coated thin films of (L/D)-1 exhibit giantly-amplified circularly polarized phosphorescences with |glum| of 0.53 at 560 nm and Φair of ~50 %, as well as appealing circular dichroism (CD) signals with the maximum absorption dissymmetry factor |gabs| of 0.37-0.43 at 480 nm. This superior CPL performance benefits from the hierarchical formation of crystalline fibrillar networks upon spin coating. Comparative studies of another pair of chiral Pt(II) complexes (L/D)-2 with a symmetric N C N coordination mode suggest that the asymmetric N N C coordination of (L/D)-1 are favorable for the efficient exciton delocalization to amplify the CPL performance. Optical applications of the thin films of (L/D)-1 in CPL-contrast imaging and inducing CP light generation from achiral emitters and common light-emitting diode lamps have been successfully realized.