Achieving a one-pot synthesis of porous HgSeordered structures endures a challenging and unexplored goal, necessitating a straightforward protocol. Contextually, the present study describes a single-source molecular precursor approach for the synthesis of self-assembled porous HgSe rod superstructures (SSs) built by HgSe nanorods via hot injection of [HgCl(SeC 4 H 3 N 2 )tmeda] in oleylamine (OAm). Both the molecular precursor and the pristine HgSe rod SSs were characterized by multiple experimental tools. Furthermore, the mechanism for superstructure formation has been elucidated through crystal packing analysis using single crystal X-ray diffraction, supported by small-angle X-ray scattering (SAXS) measurements. The photoresponsive application of superstructures was assessed by using a liquid junction photoelectrochemical cell.