Triplet-state optical spectra of highly concentrated isotopically mixed crystals of anthracene A-h10: A-d10

Photoexcitation spectroscopy with a dye laser is applied to study highly concentrated isotopically mixed crystals of anthracene A-h₁₀: A-d₁₀ in the region of the T₁ ← S_v 0-0 transition. The spectra of the separated A-h₁₀ and A-d₁₀ subbands are measured in polarized light at 6 K. The concentration-dependent intensities and energetic positions of the subbands are described quantitatively using the moment-expansion method of the mixed-crystal Green's function.