Narrowing the band of green emission in manganese hybrids by reducing the hydrogen bond strength and structural distortion. Issue 44 (2nd November 2022)

• Record Type: Journal Article
• Authors: Lin, Jiawei; Zhang, Muwei; Sun, Niu; He, Shihui; Zhang, Xusheng; Guo, Zhongnan; Zhao, Jing; Liu, Quanlin; Yuan, Wenxia
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 44(2022)
• Page Start: 16773
• Page End: 16780
• Publication Date: 2022-11-02
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc03481f
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Two 0D hybrid Mn(ii ) bromides with narrow-band green emission and triboluminescence emission are reported, and the relationship between structural distortion, hydrogen bond strength and fwhm of PL in this 0D hybrid system is described. Abstract : Zero-dimensional (0D) tetrahedral Mn(ii ) hybrids as narrow-band green emitters show great potential for the backlighting of liquid crystal displays. However, the factors influencing the full-width at half-maximum (fwhm) of green emission in the 0D Mn hybrid systems still need to be understood in depth. In this work, the regulation of the fwhm of green-emitting tetrahedral Mn(ii ) hybrids has been investigated from the structural distortion and hydrogen bond strength points of view. Two 0D Mn-based OIMHs with cyclic organic cations, (MDPA)2 MnBr4 (1, MDPA = N -methyldiphenylaminium) and (MTPP)2 MnBr4 (2, MTPP = methyltriphenylphosphonium), have been synthesized. Both of them contain isolated [MnBr4 ] 2− tetrahedra and show green emission at 540 and 518 nm upon 450 nm excitation. It is found that the fwhm of compound 2 (48 nm) is much narrower than that of 1 (62 nm), and we demonstrate that it is associated with the smaller distortion of the Mn(ii ) tetrahedron in 2 . Furthermore, Hirshfeld surface calculations suggest that this smaller distortion could be contributed by the weak hydrogen bonds between the organic cations and the [MnBr4 ] 2− units in 2 compared to that in 1 . We found that the other tetrahedral Mn(ii ) bromides reported in previous literature also show this behavior. Meanwhile, the triboluminescence emission is observed in both 1 and 2, ascribed to the polarized charges on the crystal surface. A white light-emitting diode device was fabricated using compound 2 with a high PLQY (55.66% upon 450 nm). Our work not only provides an insight to understand in depth the role of structural distortion and hydrogen bond strength in regulating the fwhm of the Mn(ii ) tetrahedron, but also provides feasible rules to explore the new narrow-band green-emitting OIMHs.