AUTHOR=Jiang Xiaomei , Chen Zhaolai , Tao Xutang 

TITLE=(1-C5H14N2Br)2MnBr4: A Lead-Free Zero-Dimensional Organic-Metal Halide With Intense Green Photoluminescence

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00352

DOI=10.3389/fchem.2020.00352

ISSN=2296-2646

ABSTRACT=<p>Low-dimensional organic-inorganic hybrid materials have attracted tremendous attentions due to their fascinating properties as emerging star materials for light-emitting applications. Taking advantage of their rich chemical composition and structural diversity, here, a novel lead-free organic-manganese halide compound, (1-mPQBr)<sub>2</sub>MnBr<sub>4</sub> (1-mPQ = 1-methylpiperazine, 1-C5H14N2) with zero-dimensional structure has been rationally designed and successfully synthesized through solvent-evaporation method. Systematical characterizations were carried out to investigate the structure, thermal and photophysical properties. The (1-mPQBr)<sub>2</sub>MnBr<sub>4</sub> was found to crystallized into an orthorhombic crystal (P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub>) with lattice parameters of a = 8.272(6) Å, b = 15.982(10) Å and c = 17.489(11) Å. The structure consists of isolated [MnBr<sub>4</sub>]<sup>2−</sup> clusters and free Br<sup>−</sup> ions as well as [C5H14N2]<sup>2+</sup> molecules. Thermal analysis indicates that it is stable up to 300°C. Upon ultraviolet photoexcitation, the (1-mPQBr)<sub>2</sub>MnBr<sub>4</sub> exhibits intense green emission centered at 520 nm with a narrow full width at half-maximum of 43 nm at room temperature, which should be assigned to the spin-forbidden internal transition (<sup>4</sup>T<sub>1</sub>(G) to <sup>6</sup>A<sub>1</sub>) of tetrahedrally coordinated Mn<sup>2+</sup> ions. The superior photoluminescence properties coupled with facile and efficient synthesis method of this material suggest its considerable promise to be utilized as light-emitting materials.</p>