${\mathrm{PtCl}}_4.6{\mathrm{H}}_2\mathrm{O}$ can exist as a hydrated complex 1 molal aq. solution has depression in freezing point of $3.{72}^o$. Assume 100% ionization and ${\mathrm{K}}_{\mathrm{f}}\left({\mathrm{H}}_2\mathrm{O}\right)=1{.86}^{\mathrm{o}} {\mathrm{mol}}^{-1} \mathrm{kg}$, then complex is