Weak intermolecular interactions in aniline-pyrrole dimer clusters have been studied by the dispersion-corrected density functional theory(DFT) calculations. Two distinct types of hydrogen bonds are demonstrated with optimized geometric structures and largest interaction energy moduli. Comprehensive spectroscopic analysis is also addressed revealing the orientation-dependent interactions by noting the altered red-shifts of the infrared and Raman activities. Then we employ natural bond orbital(NBO)analysis and atom in molecules(AIM) theory to have determined the origin and relative energetic contributions of the weak interactions in these systems. NBO and AIM calculations confirm the V-shaped dimer cluster is dominated by N.H···N and C.H···π hydrogen bonds, while the J-aggregated isomer is stabilized by N.H···π, n→π* and weak π···π* stacking interactions.The noncovalent interactions are also demonstrated via energy decomposition analysis associated with electrostatic and dispersion contributions.
Chengqian YuanPan AnJing ChenZhixun LuoJiannian Yao
We present a study of spectroscopic identification towards the molecular aggregates of zinc tetraphenylporphyrin(ZnTPP) illustrating how the energy states and intermolecular interactions determine the tunable properties of functional materials in condensation processes. Distinguishable fingerprints of ZnTPP nanorods and nanosheets are addressed utilizing X-ray diffraction(XRD), Raman and UV-vis absorption spectroscopies. Although these ZnTPPs are assigned to J-aggregation at different extent, the spectral analysis reveals a significant role of the intermolecular interactions associated with varying mesoscale architectures. Energy decomposition analysis(EDA) revealed that the varied ZnTPP aggregates are stabilized by altered dispersion interactions due to the dominant π…π stacking between the monomers.
