We report the first room-temperature stable triplet pi-aryl based carbene, 2,2’,4,4’,6,6’,-hexabromodiphenylmethylene 2 in both crystals and fluid solutions. This paper describes ESR detection of 2 in the crystal of the diazo precursor 1 and the molecular and crystal structure of the precursor obtained by X-ray diffraction at room temperature. The crystal is monoclinic with cell dimensions, a = 9.993 Angstrom, b = 13.261 Angstrom, c = 12.743 Angstrom, theta = 91.88 degrees, Z = 4, and the space group P21/n. The two phenyl rings of 2,4,6-bromo-substitution make bent perpendicular conformation with 139 degree of the bond angle at the diazo methane. Non-bonded contacts shorter than the van der Waals radii were found between the nitrogen and bromine atoms of the nearest neighboring molecules.