In　this　article,　the　photophysical　properties　of　DHPs,　including　1,2-DHPs　and　1,4-DHPs,　were　studied　ex-perimentally　and　theoretically.　Their　structural　differences　bring　about　different　photophysical　properties,　and　also　lead　to　different　photochemical　properties.　Specifically,　a　series　of　different　substituted　1,2-DHPs　and　1,4-DHPs　were　synthesized　to　measure　their　UV-Vis　absorption　and　fluorescence　emission　spectra　in　diluted　solutions　and　theoretical　calculations　were　performed　at　the　density　functional　theory　(DFT)　level.　To　describe　the　reactivities　of　the　DHPs,　time-dependent　density　functional　theory　(TDDFT)　was　used　to　optimize　their　ground-and　excited-state　structures,　and　their　electronic　excitation　energies　were　calcu-lated　at　the　B3LYP-D3/def2-TZVP　level.　Frontier　molecular　orbitals　and　electron-hole　distribution　analyses　were　used　to　illustrate　the　electron　transition　types.　The　differences　between　the　ground-and　excited　-state　structures　of　the　different　DHPs　were　characterized　by　carrying　out　a　root-mean-square-deviation　(RMSD)　analysis.　(c)　2023　Elsevier　B.V.　All　rights　reserved.