159208-95-4Relevant academic research and scientific papers
Photochemistry of matrix-isolated cyclopentadienylidene revisited
Maier,Endres
, p. 179 - 187 (2000)
Irradiation of diazocyclopentadiene (1) in a matrix at 10 K with the wavelength λ = 366 nm leads - as already known - to rapid loss of nitrogen and the formation of cyclopentadienylidene (T-2). Upon photoexcitation of cyclopentadienylidene (2) with light of the wavelength λ = 313 nm the (s-E)-(E)-conformer of 2-penten-4-yn-1-ylidene (T-7a) can be detected, which is effectively converted into 3-ethynylcyclopropene (6) by using light with a wavelength of λ = 436 nm. The structural elucidation of T-7a and 6 is based on the comparison of the experimental and calculated IR spectra. Irradiation of cyclopentadienylidene (2), isolated together with the eliminated nitrogen in the same matrix cage, with light of wavelengths longer than 570 nm initiates a partial back-reaction to the starting material, diazocyclopentadiene (1) by recapturing the evolved nitrogen molecule.
Cyclopentadienylidene. A Matrix Isolation Study Exploiting Photolysis with Unpolarized and Plane-Polarized Light
Baird, Mark S.,Dunkin, Ian R.,Hacker, Nigel,Poliakoff, Martyn,Turner, James J.
, p. 5190 - 5195 (1981)
Diazocyclopentadiene (1) was photolyzed in N2, CO, and other low-temperature matrices.The resulting carbene, cyclopentadienylidene (2), was characterized by its UV and IR spectra, and its thermal dimerization and reaction with CO were observed.Photolysis of 1 with plane-polarized light gave matrices exhibiting linear dichroism.Comparison of dichroic IR and UV spectra revealed that the photolysis proceeds via an excited A1 state of the diazo compound.Plane-polarized irradiation of the corresponding ketene (4) in CO matrices resulted in photoreorientation of the molecules of 4 without significant loss.
