Strong Magnetically-Responsive Circularly Polarized Phosphorescence and X-Ray Scintillation in Ultrarobust Mn(II)-Organic Helical Chains.

Abstract

Over recent years, Mn(II)-organic materials showing circularly polarized luminescence (CPL) have attracted great interest because of their eco-friendliness, cheapness, and room temperature phosphorescence. Using the helicity design strategy, herein, chiral Mn(II)-organic helical polymers are constructed featuring long-lived circularly polarized phosphorescence with exceptionally high g_lum and Φ_PL magnitudes of 0.021% and 89%, respectively, while remaining ultrarobust toward humidity, temperature, and X-rays. Equally important, it is disclosed for the first time that the magnetic field has a remarkably high negative effect on CPL for Mn(II) materials, suppressing the CPL signal by 4.2-times at <math xmlns="http://www.w3.org/1998/Math/MathML"> <semantics><mover><mi>B</mi> <mo>⃗</mo></mover> <annotation>$\vec{B}$</annotation></semantics> </math>  = 1.6 T. Using the designed materials, UV-pumped CPL light-emitting diodes are fabricated, demonstrating enhanced optical selectivity under right- and left-handed polarization conditions. On top of all this, the reported materials display bright triboluminescence and excellent X-ray scintillation activity with a perfectly linear X-ray dose rate response up to 174 µGy_air  s^-1 . Overall, these observations significantly contribute to the CPL phenomenon for multi-spin compounds and promote the design of highly efficient and stable Mn(II)-based CPL emitters.