2 research outputs found
Solvate Structures and Computational/Spectroscopic Characterization of LiPF<sub>6</sub> Electrolytes
Raman spectroscopy is a powerful
method for identifying ion–ion
interactions, but only if the vibrational band signatures for the
anion coordination modes can be accurately deciphered. The present
study characterizes the PF<sub>6</sub><sup>–</sup> anion P–F
Raman symmetric stretching vibrational band for evaluating the PF<sub>6</sub><sup>–</sup>···Li<sup>+</sup> cation
interactions within LiPF<sub>6</sub> crystalline solvates to create
a characterization tool for liquid electrolytes. To facilitate this,
the crystal structures for two new solvatesî—¸(G3)<sub>1</sub>:LiPF<sub>6</sub> and (DEC)<sub>2</sub>:LiPF<sub>6</sub> with triglyme
and diethyl carbonate, respectivelyî—¸are reported. DFT calculations
for Li-PF<sub>6</sub> solvates have been used to aid in the assignments
of the spectroscopic signatures. The information obtained from this
analysis provides key guidance about the ionic association information
which may be obtained from a Raman spectroscopic evaluation of electrolytes
containing the LiPF<sub>6</sub> salt and aprotic solvents. Of particular
note is the overlap of the Raman bands for both solvent-separated
ion pair (SSIP) and contact ion pair (CIP) coordination in which the
PF<sub>6</sub><sup>–</sup> anions are uncoordinated or coordinated
to a single Li<sup>+</sup> cation, respectively
Solvate Structures and Computational/Spectroscopic Characterization of LiPF<sub>6</sub> Electrolytes
Raman spectroscopy is a powerful
method for identifying ion–ion
interactions, but only if the vibrational band signatures for the
anion coordination modes can be accurately deciphered. The present
study characterizes the PF<sub>6</sub><sup>–</sup> anion P–F
Raman symmetric stretching vibrational band for evaluating the PF<sub>6</sub><sup>–</sup>···Li<sup>+</sup> cation
interactions within LiPF<sub>6</sub> crystalline solvates to create
a characterization tool for liquid electrolytes. To facilitate this,
the crystal structures for two new solvatesî—¸(G3)<sub>1</sub>:LiPF<sub>6</sub> and (DEC)<sub>2</sub>:LiPF<sub>6</sub> with triglyme
and diethyl carbonate, respectivelyî—¸are reported. DFT calculations
for Li-PF<sub>6</sub> solvates have been used to aid in the assignments
of the spectroscopic signatures. The information obtained from this
analysis provides key guidance about the ionic association information
which may be obtained from a Raman spectroscopic evaluation of electrolytes
containing the LiPF<sub>6</sub> salt and aprotic solvents. Of particular
note is the overlap of the Raman bands for both solvent-separated
ion pair (SSIP) and contact ion pair (CIP) coordination in which the
PF<sub>6</sub><sup>–</sup> anions are uncoordinated or coordinated
to a single Li<sup>+</sup> cation, respectively