Ultraviolet spectroscopy conformation effects

The direct mapping of the electronic structure of the conjugated polymers is possible in photoelectron spectroscopy of thin films. The valence band, which is available from ultraviolet photoelectron spectroscopy, clearly shows shifts as well as a reduction of photoelectron peaks coming from the frontier k orbitals [31—33]. This is consistent with predictions from calculations using a Valence Effective Hamiltonian using a model of conformational twists separating every dimer on the chain. 

The effects of dioxan on the conformation of hen egg-white lysozyme at low pH have been studied by c.d. spectroscopy and viscosimetry. The results indicated that the tertiary structure reflected by the near-ultraviolet c.d. bands was initially disrupted at 20—30 % dioxan with possible slight disorganization of the ordered secondary structure, and then a marked increase in helical structure was induced by high dioxan concentrations. 

---