161-166<span style="font-size:
16.0pt;mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman","serif""="">Potassium
pentaborate (KB5) crystals have been grown by solution growth technique. A
structural investigation on the KBS crystal is made, using FTIR and laser Raman
spectra. The molecular structure of KBS belongs to C2v
symmetry considering the hydroxyl group as point mass. The total number of
normal modes of vibration is 39 and are distributed as Γvib=
14A1<span style="font-size:12.5pt;mso-bidi-font-size:5.5pt;
font-family:" arial","sans-serif""=""> <span style="font-size:16.0pt;
mso-bidi-font-size:9.0pt;font-family:" arial","sans-serif""="">+ 5A2
<span style="font-size:16.0pt;mso-bidi-font-size:9.0pt;font-family:
" arial","sans-serif""="">+ 10B1<span style="font-size:12.5pt;
mso-bidi-font-size:5.5pt;font-family:" arial","sans-serif""=""> +
10B<span style="font-size:12.5pt;mso-bidi-font-size:5.5pt;
font-family:" arial","sans-serif""="">2<span style="font-size:12.5pt;
mso-bidi-font-size:5.5pt;font-family:" arial","sans-serif""="">. A
normal coordinate analysis has been carried out with an orthonormal set of
symmetry coordinates following Wilson F-G matrix method. The potential
constants evaluated for this molecule are found to be in good agreement with
literature, thereby, confirming the vibrational assignments. To check whether
the chosen set of vibrational frequencies contributes maximum to
the
potential energy associated with the normal coordinates of the molecule, the
potential energy distribution has been evaluated. Further, the
thermogravimetric analysis (TGA) confirms the decomposition of KBS taking place
in two stages. The differential scanning calorimetry (DSC) curve of KBS
crystals has been recorded in the temperature range 50-580 °C.
The
phase transition temperature and enthalpies of KBS were measured and the
results are discussed.
</span