The first excited triplet state of trans-stilbene, contained as an impurity in diphenylacetylene-TCNB single crystal has been investigated by ENDOR spectroscopy. The hyperfine tensors of six pairs of equivalent protons of trans-stilbene have been measured. They show that in this host crystal the trans-stilbene has a centre of symmetry. The isotropic couplings compare well with those of the trans-stilbene radical anion. The calculated dipolar tensors agree with the experimental ones if the trans-stilbene molecule is assumed as planar and the in-plane principal direction x of the zero-field splitting tensor makes an angle of 12° with the central double bond. With such orientation the trans-stilbene is found to substitute one diphenylacetylene molecule with minimum distortion of the crystal lattice.
Electron nuclear double resonance of the first excited triplet state of trans-stilbene in a diphenylacetylene-TCNB single crystal.
MANIERO, ANNA LISA;
1989
Abstract
The first excited triplet state of trans-stilbene, contained as an impurity in diphenylacetylene-TCNB single crystal has been investigated by ENDOR spectroscopy. The hyperfine tensors of six pairs of equivalent protons of trans-stilbene have been measured. They show that in this host crystal the trans-stilbene has a centre of symmetry. The isotropic couplings compare well with those of the trans-stilbene radical anion. The calculated dipolar tensors agree with the experimental ones if the trans-stilbene molecule is assumed as planar and the in-plane principal direction x of the zero-field splitting tensor makes an angle of 12° with the central double bond. With such orientation the trans-stilbene is found to substitute one diphenylacetylene molecule with minimum distortion of the crystal lattice.Pubblicazioni consigliate
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