Ultrafast nonadiabatic photoisomerization dynamics study of molecular motor based on the synthetic indanylidene-ppyrrolinium frameworks

[Display omitted] •• Electric neutrality motor featuring a significant unidirectionality rotary motion approximately reached to 78.8% is designed.•• A very small pretwist (ca.0.9 degree) of the reactive C = C bond in molecular motor is sufficient to lead high probability of unidirectional.•• The fluorescence emission quenching accompanied by red shift of wavelength is predicted. Control of the relative unidirectional of motion is an essential feature for improve the operational efficiency of light-driven molecular motor. Here we present an improved electric neutrality motor featuring a significant unidirectionality rotary motion approximately reached to 78.8%. Most importantly, we found that a very small pretwist (ca.0.9 degree) of the reactive C = C bond is sufficient to lead such high probability of unidirectional rotational motion. Furthermore, the quantitative investigation of excited state light-driven nonadiabatic dynamics of the synthetic molecular motors are performed. The fluorescence emission quenching accompanied by red shift of wavelength were observed.