By mediation of the pH values, three novel inorganic-organic iodoplumbate hybrids, [Me3TPT][Pb3I9] [1; Me3TPT = trimethyl-2,4,6-tris(4-pyridyl)-1,3,5-triazine], [Me3TPT]2[Pb9I24] (2), and [Me3TPT]2[Pb19I44] (3), have been achieved under solvothermal conditions. The large conjugated in situ N-alkylation polypyridine derivatives act as structure-directing agents and electron acceptors, making the materials feature adjustable structural variations with 0D, 1D, and 2D structures and a potential semiconductive performance with narrow energy gaps (1.72, 1.80, and 1.78 eV for 1-3, respectively), which result in their efficient photocatalytic activity under visible-light irradiation. Theoretical calculation reveals that the conjugated organic moieties greatly contribute to the conduction band, leading to narrow band gaps. It is expected that the work will contribute to the exploitation of novel semiconducting halometallates by employing conjugated organic species as structure-directing agents.