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

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 glum and ΦPL 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 atB ⃗ $\vec{B}$  = 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 µGyair  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.

Manganese(II) Bromide Compound with Diprotonated 1-Hydroxy-2-(pyridin-2-yl)-4,5,6,7-tetrahydrobenzimidazole: Dual Emission and the Effect of Proton Transfers

An organic–inorganic cation–anion manganese(II) tetrabromide compound with diprotonated 1-hydroxy-2-(pyridin-2-yl)-4,5,6,7-tetrahydrobenzimidazole, [H3L][MnBr4][H2O], has been synthesized and investigated. The compound has a few possible pathways for proton transfers, which play an important role in the observed luminescence, optical, and magnetic properties. The proton transfers result in the appearance of two-band luminescence. One band is caused by the Mn(II) d-d transitions. The other band is caused by the transition from the triplet state of organic cation and the d-d transition of manganese(II) coupled through {[H3L]}-{[MnBr4]}-{[H2O]} vibrations. The optical absorption spectra of [H3L][MnBr4][H2O] indicate the presence of two direct and one indirect band transitions. The reason for the two-band luminescence and complex optical absorption in [H3L][MnBr4][H2O] were additionally considered using the DFT calculations.

New Approach toward Dual-Emissive Organic-Inorganic Hybrids by Integrating Mn(II) and Cu(I) Emission Centers in Ionic Crystals

Inorganic-organic hybrid luminescent materials have received great attention for their potential applications in a wide range of clean/renewable energy-related areas, including photovoltaics and solid-state lighting. Herein, we present a unique and general "Mn + Cu" approach by blending two earth-abundant luminogenic metals, manganese and copper, within a single ionic structure to construct a remarkable family of low-cost and multifunctional hybrid materials featuring dual emission, as well as triboluminescence and second-harmonic generation response. The novel hybrid materials are made of diphosphine dioxide-chelated [Mn(O∧O)₃]²⁺ cations and various anionic [Cu_xI_y]^(y-x)- clusters, ensuring manifestation of dual phosphorescence streamed from octahedral Mn²⁺ ions (605-648 nm) and iodocuprate anions (480-728 nm). Noteworthily, the relative ratio of the emission bands, and hence a resulting emission chromaticity, can be tuned in a wide range through modification of cluster [Cu_xI_y]^(y-x)- modules. The structural diversity, enhanced robustness, and up to 100% luminescence quantum yield make the designed materials promising phosphors for lighting and sensing applications.

Photoluminescence Behavior of Zero-Dimensional Manganese Halide Tetrahedra Embedded in Conjugated Organic Matrices

Zero-dimensional hybrid manganese halides with the type-I band alignment between the manganese halide tetrahedra and organic matrices have attracted much attention as highly efficient narrow-band green emitters. Herein we study the photoluminescence (PL) behavior of hybrid manganese bromides with type-II band alignment, where the lowest unoccupied molecular orbital (LUMO) level can be tuned by employing quaternary phosphonium dications with different degrees of conjugation. For low-conjugated organic matrices, the band alignment can shift from type II in the ground state to type I in the excited state, which enables high photoluminescence quantum yields. In contrast, for high-conjugated organic matrices, the band alignment cannot convert to type I in the excited state because the LUMO lies too low, and thus, the excited electrons are transferred from the tetrahedra to the matrices, which leads to severe PL quenching. Our results show the importance of the excited-state band alignment for understanding the PL behavior of hybrid metal halide semiconductors.

Synthesis and photoluminescence of manganese(II) naphtylphosphonic diamide complexes

Manganese(ii) halide complexes with N,N,N',N'-tetramethyl-P-naphtalen-2-ylphosphonic diamide were synthesized from anhydrous MnX2 salts (X = Cl, Br, I) and characterized. Single-crystal X-ray diffraction revealed in all the cases slightly distorted tetrahedral geometry of the coordination sphere. The photoluminescence spectra showed the superimposition of a green emission, related to the 4T1(4G) → 6A1(6S) transition of Mn(ii), with a band in the red range. Different possible attributions to the lowest-energy emission were taken into account. The emission spectra of the isolated products are dependent upon the nature of the halide and, in the case of X = Br, also upon the excitation wavelength.

Manganese(ii) bromo- and iodo-complexes with phosphoramidate and phosphonate ligands: synthesis, characterization and photoluminescence

Phosphoramidates and phosphonates are suitable ligands for the preparation of tetrahedral mono- and polynuclear Mn(ii) complexes characterized by green luminescence, influenced by the symmetry of the compounds and by the P-bonded substituents.

Photo- and triboluminescent robust 1D polymers made of Mn(ii) halides and meta-carborane based bis(phosphine oxide)

The 1D CPs of [Mn(L)X₂]_n type (X = Cl, Br, I), designed on 1,7-bis(diphenylphosphinyl)-m-carborane (L), show bright phosphorescence and triboluminescence, as well as exhibit thermo- and solvatochromic luminescence.

A family of Mn(ii) complexes exhibiting strong photo- and triboluminescence as well as polymorphic luminescence

New Mn(ii) complexes supported by diphosphine dioxides exhibit strong room-temperature phosphorescence as well as bright triboluminescence and polymorphic luminescence.