Molecular structure before and after

As the produced carbene dimerizes readily, the photolysis and collection of X-ray data were performed for a sample at 80 K. The crystal was irradiated at 365 nm for 2h using a high-pressure mercury lamp and a band-pass filter in combination. Although the crystal turned from yellow to red, there was no evidence for deterioration of the crystal quality. Figure 5-12 shows the molecular structures before and after irradiation. The dihedral angle between the two phenyl rings before irradiation is 70.2(1)°. 

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