摘要
Pressure, as a thermodynamic parameter, provides an appropriate method to detect weak intermolecular interactions. The C–H···H–B dihydrogen bond is so weak that the experimental evidence of this interaction is still limited. A combination of in situ high pressure Raman spectra and angle-dispersive X-ray diffraction(ADXRD) experiments was utilized to explore the dihydrogen bonds in dimethylamine borane(DMAB). Both Raman and ADXRD measurements suggested that the crystal structure of DMAB is stable in the pressure region from 1 atm(1 atm=1.01325×10~5 Pa) to 0.54 GPa. The red shift of CH stretching and CH_3 distortion modes gave strong evidence for the existence of C–H···H–B dihydrogen bonds. Further analysis of Raman spectra and Hirshfeld surface confirmed our proposal. This work provided a deeper understanding of dihydrogen bonds.And we wish that high pressure could be applied to identify other unconfirmed hydrogen or dihydrogen bond.
Pressure, as a thermodynamic parameter, provides an appropriate method to detect weak intermolecular interactions. The C–H···H–B dihydrogen bond is so weak that the experimental evidence of this interaction is still limited. A combination of in situ high pressure Raman spectra and angle-dispersive X-ray diffraction（ADXRD） experiments was utilized to explore the dihydrogen bonds in dimethylamine borane（DMAB）. Both Raman and ADXRD measurements suggested that the crystal structure of DMAB is stable in the pressure region from 1 atm（1 atm=1.01325×10~5 Pa） to 0.54 GPa. The red shift of CH stretching and CH_3 distortion modes gave strong evidence for the existence of C–H···H–B dihydrogen bonds. Further analysis of Raman spectra and Hirshfeld surface confirmed our proposal. This work provided a deeper understanding of dihydrogen bonds.And we wish that high pressure could be applied to identify other unconfirmed hydrogen or dihydrogen bond.
基金
supported by the National Natural Science Foundation of China(21725304,21673100,91227202,11774120,11774125)
the Chang Jiang Scholars Program of China(T2016051)
Changbai Mountain Scholars Program(2013007)
Program for Innovative Research Team(in Science and Technology)in University of Jilin Province and Graduate Innovation Fund of Jilin University(2017050)
ADXRD experiments were performed at Beijing Synchrotron Radiation Facility(4W2 beamline)
which is supported by Chinese Academy of Sciences(KJCX2-SW-N20,KJCX2-SW-N03)
