Doping Anthracene Crystals With Associated Impurities During the Growth From Solution

The paper presents a study on the effect of aging of solutions on the growth features of anthracene crystals. It was found that prolonged storage (3 weeks) of saturated solutions in air leads to their aging, accompanied by the precipitation of accompanying yellow needle-shaped crystals alongside the anthracene crystals. The structure of these accompanying needle-shaped crystals was determined by single-crystal X-ray diffraction in the space group P2/c (Z = 4) and was shown to consist of 9,10-anthraquinone molecules. The formation of solid solutions based on co-crystallization of anthracene and 9,10-anthraquinone molecules was not observed. It is shown that the observed long-wavelength shift in the fluorescence spectrum of crystals, which occurs when using certain commercial grades of anthracene for solution growth, is associated with the presence of a homologous impurity–tetracene–in the starting material. The crystallochemical aspects of the incorporation of concomitant impurity molecules into the crystal structure of anthracene are discussed.