文摘
The results of a series of DFT and DFT-D calculations are reported with the aim to predict the physicochemicalproperties (equilibrium structures, stabilization energies, redox potentials, excitation and CD spectra, electronicconductivity, and elasticity) of elongating helical structures (i.e., [n]helicenes, n = 1-14). It was shown thatmany of them are converged at [14]helicene with an interpitch distance of Rpitch = 3.75 Å, an incrementalstabilization energy of Gn = 11 kJ mol-1 (thus suggesting the inherent destabilization of the growing helicalstructures), an S0-S1 energy difference to the estimated band gap of 2.60 eV, and redox potentials,corresponding to the reduction of [n]helicenes, of E0 = -2.2 V. The elasticity was shown to decrease as alinear function of m (i.e., k m) with k = 0.01056 a.u. for [14]helicene. Moreover, the conductivity propertieswere discussed in terms of hole and excess electron densities. Possible implications of the calculated data innanoscience are discussed.