Pressure studies on the intermolecular interactions in biphenyl

摘要: Abstract We investigate the influence of intermolecular interactions on optical and structural properties oligophenyls in solid films polycrystalline nature. To this end, we have performed X-ray powder diffraction (XRD) experiments a pressure range up to 2 kbar yielding lattice constants biphenyl (2P) as function pressure. The optimized geometry 2P molecule — including inter-ring torsion angle is then determined using three-dimensional (3D) band structure calculations within density functional theory (DFT). find red shift upon increasing computed absorption spectra which due conformational changes molecule. A planarization accompanied by reduction bond length increases conjugation, thereby reducing gap. Pressure dependent Raman measurements 2P, terphenyl, quaterphenyl sexiphenyl support calculated changes. Moreover, experimental under hydrostatic were measured 3 kbar. observed red-shift quantitatively agrees with values.