Spectroscopic FT-IR, FT-Raman and Ultravioleta-visible Studies of the Potassium 5-hydroxypentanoyltrifluorborate salt,

SILVIA A. BRANDÁN; LILIAN DAVIES; MAXIMILIANO A. IRAMAIN

Coimbra

Congreso; XXXIV EUROPEAN CONGRESS ON MOLECULAR SPECTROSCOPY; 2019

Universty of Coimbra

Different weak intermolecular interactions can be seen in the layered structures of some potassium trifluorborate salts in the solid phase depending on the mutual arrangement of the potassium cations [1]. Hence, these salts present interesting structural and vibrational properties [2]. In this work, the potassium 5-hydroxypentanoyltrifluorborate salt was characterized by using FT-IR, FT-Raman and UV-Visible spectroscopies and their structures and properties were studied in gas and aqueous solution phases by using B3LYP/6-31G* and B3LYP/6-311++G** calculations. The anion structure was also studied because it is expected in solution. A dimeric structure was also considered taking into account those layered structures observed for some potassium trifluorborate salts in the solid phase. The complete vibrational assignments were performed for the salt and their anion combining the experimental FT-IR and FT-Raman spectra of the salt with the scaled quantum mechanical force field (SQMFF) methodology [3], the normal internal coordinates and the Molvib program [4]. The dimer justifies some bands not attributed to the monomer. The force fields and force constants are calculated for the salt and their anion. Here, the force constants are compared with those reported for the potassium 3-furoyltrifluoroborate [2] and 2-isonicotinoyltrifluoroborate salts [5]. Good concordance was observed among the predicted spectra and the experimental ones.