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

A series of 1D coordination polymers (CPs), [MnX 2 (L)] n (X = Cl, Br, I), made of MnX 2 units bridged by 1,7-[Ph 2 P(O)] 2 - meta -carborane ligands (L) through the O–Mn–O linkages, have been designed. At ambient temperature, these CPs manifest green phosphorescence with quantum yields of up to 60%, which is the highest value for Mn( ii ) CPs. CP [MnI 2 (L)] n and its structurally different solvate [MnI 2 (L)·CH 2 Cl 2 ] n also exhibit bright triboluminescence. Thermochromic luminescence of the designed CPs appears as reversible shifting of their emission color, when the temperature varies from 350 to 77 K and back. Moreover, [MnI 2 (L)·CH 2 Cl 2 ] n reversibly changes its emission properties during desolvation-solvation processes thus featuring solvatochromic luminescence. According to photophysical and EPR data, the observed phosphorescence originates from the ligand-sensitized 4 T 1 → 6 A 1 transition in Mn 2+ ions. Enhanced robustness of the title CPs is demonstrated by retaining their emission properties after prolonged heating at 210 °C.