The halogen F---H interaction and their impact on some properties of the Potassium 2-isonicotinoyltrifluoroborate salt

SILVIA ANTONIA. BRANDÁN; MAXIMILIANO ALBERTO. IRAMAIN

Jyväskylä

Congreso; XXII Horizons in Hydrogen Bond Research; 2017

In this work, the potassium 2-isonicotinoyltrifluoroborate salt (ITFB) was characterized by using FT-IR and by FT-Raman spectroscopies. Their structures and electronic, topological and vibrational properties were studied by using theoretical B3LYP/6-31G* and 6-311++G** calculations in gas and aqueous solution phases. The solvation energies for IFTB were predicted by using both levels of calculations and considering the solvent effects with the polarised continuum and solvation models [1,2]. Their properties were compared with those obtained for the potassium 3-furoyltrifluoroborate salt (FTFB).In the potential energy surface four structures were predicted for ITFB by using the two levels of theory with the Gaussian 09 program [3]. Figure 1 shows the most stable structure for this salt optimized with Cs symmetry. In this case, a higher expansion of volume was observed for this salt in relation to FTFB with a higher solvation energy of -85.74 kJ/mol at the 6-31G* level of theory. Then, the stability of this salt was analyzed by means of the donor-acceptor interactions and the topological properties with the NBO and AIM2000 programs [4,5]. The vibrational analyses for the 45 vibration modes were also reported.The AIM calculations reveal that the coordination modes for the B and K atoms were five and four, respectively by using both levels of theory, as also was observed in FTFB and, besides, the study shows formations of F---H interactions in both media. The study of the frontier orbitals have shown that the presence of the (C=O)-BF3K group reduce notably the gap value of the ring in gas phase from 6.2613 eV in pyridine up to 4.5246 eV in the salt by using the B3LYP/6-31G* method, while in aqueous solution this value is reduced from 6.2583 eV up to 4.3532 eV increasing notably the reactivity of this salt in both media. Besides, the change of the furane ring by pyridine increases the reactivity of the ITFB salt probably due to that the electrophilicity index increases. Here, we observed very good correlations among the predicted FTIR and FT-Raman for ITFB with the corresponding experimental ones.