Wydział Chemii

Magdalena Sałdyka

Zofia Mielke

Karolina Haupa

2018

Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy

190

423-432

10.1016/j.saa.2017.09.046

Naukowa

Angielski

Artykuł

An infrared spectroscopic and MP2/6-311++G(2d,2p) study of the complexes between N,N-dimethylformamide (DMF) and nitrogen, carbon dioxide, water, ammonia trapped in solid argon matrices is reported. The 1:1 molecular complexes have been identified in the DMF/B/Ar matrices (B=N2, CO, H2O, NH3); their structures were determined by comparison of the spectra with the results of calculations. The analysis of the experimental and theoretical data indicate that the DMF-N2, CO complexes present in the matrices are stabilized by (C=)O⋯N and (C=)O⋯C van der Waals interactions. In turn, in the DMF-H2O, NH3 complexes the (C=)O⋯H(OH) and (C=)O⋯H(NH2) hydrogen bonding is present in which the carbonyl group of DMF acts as a proton acceptor. In all systems studied the C-H⋯X (X=N, C, O) bonding is a second intermolecular force stabilizing the planar complexes. Some spectral features indicate that for DMF-H2O, DMF-NH3 systems the nonplanar structures with the C=O⋯H interaction are also present. The study demonstrated the strong sensitivity of the CH stretching wavenumber to an involvement of the C-H and/or C=O groups of DMF in an intermolecular interaction.

N,N-dimethylformamide, hydrogen bonds, Van der Waals interaction, Matrix isolation, Ab initio calculations, molecular complexes

https://doi.org/10.1016/j.saa.2017.09.046

http://www.elsevier.com