Propellane consists of three wings separated by a saturated common C−C linkage. This makes it an ideal system to design a molecule that can absorb in three different wavelength regions, each corresp-onding to one of the wings. Additionally, if the wings are chosen to be nonlinear optically active then it can pave a path to design an interesting nonlinear optically active material.
The aim of this work is to demonstrate the possibility of using propellane in designing a molecule that can absorb in three different wavelength regions and their nonlinear optical (NLO) activity can be fine-tuned by varying the three wings. We considered 22 tailor-made propellane derivatives consisting of phenyl, naphthyl, and biphenyl wings for this purpose. Using the state-of-the-art linear and quadratic response methods within TD-DFT and RI-CC2 theories and a suitable generalized few-state model that quantifies the effect of orientation of different transition moments on NLO properties, we discussed how and why the linear and nonlinear optical activity of propellane vary when the three wings are assembled successively to construct a full-propellane.Zum Volltext