Understanding Spectroscopic Features of Trihexyltetradecylphosphonium Chloride

Abstract

A comprehensive structural and spectroscopic characterization of trihexyltetradecylphosphonium chloride, [P 666(14) ][Cl], was conducted by combining experiments with density functional theory (DFT) calculations. The structure of [P 666(14) ][Cl] was first characterized experimentally by IR and NMR spectroscopies. Then, conformer search was performed by DFT calculations at B3LYP/6-31 + G(d) level to elucidate the molecular structure and intermolecular interactions prevailing in the [P 666(14) ][Cl]. Vibrational and 1 H NMR spectra computed on the most stable conformer geometry were used to identify the features in the experimental spectroscopic data. Results revealed that experimental IR and NMR spectra correlated very well with the corresponding computational spectra confirming that the DFToptimized equilibrium geometry of the most-stable conformer represents a probable analogue to the experimental conformation. Consequently, hydrogen bonds between [CI] À and three a-hydrogens of [P 666(14) ] + closest to the anion were identified by Natural Bond Orbital (NBO) analysis confirmed by the shifts in the corresponding IR bands.

[BMIM][PF6] Incorporation Doubles CO2 Selectivity of ZIF-8: Elucidation of Interactions and Their Consequences on Performance

“…Different conformers of [BMIM]­[PF 6 ] were first optimized at the Becke’s three-parameter hybrid exchange functional and the Lee–Yang–Parr correlation functional (B3LYP) method together with the 6-31+G­(d) basis set. The conformer search for [BMIM]­[PF 6 ] was performed according to the methodology previously reported . The lowest energy conformer was further optimized, and the vibration frequencies were calculated both at the B3LYP/6-311+G­(2d,p) level to enhance the accuracy of calculations.…”

“…The lowest energy conformer was further optimized, and the vibration frequencies were calculated both at the B3LYP/6-311+G­(2d,p) level to enhance the accuracy of calculations. Furthermore, binding energies, Δ E B , between anions and cations were calculated and corrected for scaled zero-point vibrational energies (ZPVE) for each conformer, as reported previously . Similarly, the lowest energy conformer of [BMIM]­[PF 6 ] was incorporated into a ZIF-8 cage (obtained from the Cambridge Structure Database, , consisting of 288 atoms) and optimized at the B3LYP/6-31G­(d) level.…”

“…The vibration frequencies of all [BMIM]­[PF 6 ]/ZIF-8 conformers were calculated at the B3LYP/6-31G­(d) level and scaled by a factor of 0.9614 to compensate for harmonic effects. Furthermore, population analysis was conducted with a full Natural Bond Orbital (NBO) analysis using NBO version 3.1, as reported before . In order to investigate the effect of dispersion interactions on the geometry and binding energy of ZIF-8 and [BMIM]­[PF 6 ]/ZIF-8, the D3 version of Grimme’s dispersion with Becke–Johnson (BJ) damping was also included into the standard DFT calculations performed in this study (i.e., B3LYP/6-31G­(d) level).…”

Interactions of [BMIM][BF4] with Metal Oxides and Their Consequences on Stability Limits

“…Moreover, binding energies, ΔE B , between anions and cations were calculated at the same level of theory using following formula: 46,47…”

“…Moreover, binding energies, Δ E B , between anions and cations were calculated at the same level of theory using following formula: , where E IP , E C , and E A are the energies of ion pair, cation, and anion, respectively. Similarly, ZPVE IP , ZPVE C , and ZPVE A are the zero-point vibrational energies of ion pair, cation, and anion, respectively.…”