C-H···π and C-H···O Interactions in Coumarin 6 : 3-(2-benzothiazolyl)-7-(diethylamino)-coumarin

Abstract

Abstract-Crystal structure of coumarin 6 has been solved by X-ray diffraction. The crystals are triclinic, space group P-1, with a=8.823(2) Å, b=8.898(2) Å, c=11.025(9) Å, α=86.41(3)°, β=85.39(3)°, γ=76.23(3)°, Mr=350.42, V=837.1(3) Å 3 , Z=2 and R=0.0516. The molecules are packed parallel to each other by weaker π···π and C-H···π interactions. The detailed geometry of C-H···π interactions were discussed. The hydrogen bonds and non-traditional C-H···O interactions join the no-parallel molecules together. All the molecules packed wall-like with the molecular brick.

Characterization of coumarin-6 polycrystalline films growth from vacuum deposition at various substrate temperatures

“…The lattice parameters averaged from the grains with high crystallinity fabricated at T sub = 150 and 165 °C were obtained as followings: a = 8.965 ± 0.005 Å, b = 11.139 ± 0.002 Å, c = 8.920 ± 0.007 Å, α = 95.13 ± 0.02°, β = 104.56 ± 0.01°, and γ = 86.72 ± 0.08°. These data are in agreement with small crystals growth from supersaturated solutions 1 , 14 .…”

“…6(a) . Because of its asymmetric molecular structure, coumarin-6 molecules possess a permanent dipole 14 , and the strong dipole-dipole interactions may enhance the packing of the adhered molecules. The best crystallinity of coumarin-6 grains observed for T sub = 150 °C could be due to a compromise between the increase of the surface diffusion energy for T sub < 150 °C and the thermal agitation of the adhered molecules for T sub > 150 °C.…”

“…While dissolved in various solvents, the absorption maximum ranged from 2.713 eV (in methanol or ethanol) to 2.912 eV (in n-hexane) and photoluminescence (PL) with peak emission maximum from 2.460 eV (in methanol) to 2.702 eV (in n-hexane) were reported 5 . As crystallized from supersaturated solutions, coumarin-6 tiny single crystal has a triclinic structure with lattice parameters a = 8.962 Å, b = 11.136 Å, c = 8.922 Å, α = 95.14°, β = 104.50°, and γ = 86.74° 1 , 14 . Coumarin-6 molecular crystal possesses a relatively high melting point around 220 °C, a high stability of surface morphology, and an efficient light emission, and hence can be considered as an important organic material for optoelectronic devices.…”