Which of the following is not isostructural with $\mathrm{SiCl}_4$ ?

$\mathrm{SCl}_4$ is not isostructural with $\mathrm{SiCl}_4$ because it shows a square planar structure due to the repulsion between lone pair and bond pair of electrons. $\mathrm{SO}_4^{2-}, \mathrm{PO}_4^{3-}, \mathrm{NH}_4^{+}$shows tetrahedral structure because of $s p^3$ hybridisation. Related Theory Isostructural species are those which have the same shape and hybridization. Isoelectronic species have the same number of electrons which is the sum of electrons of all the atoms present in the ion.