*3.7. ECD Calculations*

The ground-state geometries were optimized with density functional theory (DFT) calculations, using Turbomole with the basis set def-SVP for all atoms and the functional B3-LYP. The ground states

were further confirmed by the harmonic frequency calculation. The calculated ECD data corresponding to the optimized structures were obtained with the time-dependent density-functional theory (TD-DFT) at the B3-LYP functional. The ECD spectra were simulated by overlapping Gaussian functions for each transition, where σ is the width of the band at 1/*e* height. Values Δ*Ei* and *Ri* were the excitation energies and rotatory strengths, respectively, for transition *i*. In the current work, the value was 0.10 eV.

$$\Delta \in (\mathcal{E}) = \frac{1}{2.297 \times 10^{-39}} \frac{1}{\sqrt{2\pi\sigma}} \sum\_{i}^{A} \Delta E\_i R\_i e^{\left[-\left(E - \Delta E\_i\right)^2/(2\sigma)^2\right]} \tag{1}$$
