文摘
Two polymorphs of 2,7-dihydrobenzo[1,2,3-cd:4,5,6-c鈥?i>d鈥瞉diindazole (鈥渄ipyrazoloanthracene鈥? 伪 and 尾; DBDI) were isolated and fully characterized by means of structural X-ray powder diffraction methods, thermal, and extended spectroscopic analyses. Different interconversion paths between the two species were evidenced. UV鈥搗is absorption, emission, and excitation spectra were measured, while time-resolved fluorescence studies allowed for the detection of multiple decay processes. In the two species, NH路路路N hydrogen bonds give rise to manifestly different structures, which, in the rhombohedral 尾 phase, generate permanent porosity. This feature has been further characterized by CO2/N2/CH4 sorption isotherms at different temperatures, highlighting a significant selectivity favoring CO2 trapping.