Search

The photophysical tuning is reported for a series of tetraphenylphosphonium (TPP) metal halide hybrids containing distinct metal halides, TPP 2 MX n (MX n =SbCl 5 , MnCl 4 , ZnCl 4 , ZnCl 2 Br 2 , ZnBr 4 ), from efficient phosphorescence to ultralong afterglow. The afterglow properties of TPP + cations could be suspended for the hybrids containing low band gap emissive metal halide species, such as SbCl 5 2- and MnCl 4 2- , but significantly enhanced for the hybrids containing wide band gap non-emissive ZnCl 4 2- . Structural and photophysical studies reveal that the enhanced afterglow is attributed to stronger π-π stacking and intermolecular electronic coupling between TPP + cations in TPP 2 ZnCl 4 than in the pristine organic ionic compound TPPCl. Moreover, the afterglow in TPP 2 ZnX 4 can be tuned by controlling the halide composition, with the change from Cl to Br resulting in a shorter afterglow due to the heavy atom effect., (© 2020 Wiley-VCH GmbH.)

Zero-dimensional (0D) organic metal halide hybrids, in which organic and metal halide ions cocrystallize to form neutral species, are a promising platform for the development of multifunctional crystalline materials. Herein we report the design, synthesis, and characterization of a ternary 0D organic metal halide hybrid, (HMTA) 4 PbMn 0.69 Sn 0.31 Br 8 , in which the organic cation N-benzylhexamethylenetetrammonium (HMTA + , C 13 H 19 N 4 + ) cocrystallizes with PbBr 4 2- , MnBr 4 2- , and SnBr 4 2- . The wide band gap of the organic cation and distinct optical characteristics of the three metal bromide anions enabled the single-crystalline "host-guest" system to exhibit emissions from multiple "guest" metal halide species simultaneously. The combination of these emissions led to near-perfect white emission with a photoluminescence quantum efficiency of around 73 %. Owing to distinct excitations of the three metal halide species, warm- to cool-white emissions could be generated by controlling the excitation wavelength., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)