A　novel　stilbene-based　salicylhydrazone　com­pound　{systematic　name:　(E)-4,4′-(ethene-1,2-di­yl)bis­[(N′E)-N′-(2-hy­droxy­benzyl­idene)benzohydrazide]　di­methyl　sulfoxide　disolvate,　C　30　H　24　N　4　O　4　·2C　2　H　6　OS　or　L·2DMSO}　was　synthesized　and　characterized　by　single-crystal　X-ray　diffraction,　powder　X-ray　diffraction　and　luminescence　spectroscopy.　The　title　com­pound　crystallizes　in　the　monoclinic　space　group　P2　1　/c,　with　half　a　symmetry-independent　L　mol­ecule　and　one　dimethyl　sulfoxide　(DMSO)　solvent　mol­ecule　in　the　asymmetric　unit.　The　L　molecule　adopts　an　almost　planar　structure,　with　a　small　dihedral　angle　between　the　planes　of　the　stilbene　and　salicylhydrazone　groups.　There　are　multiple　π-π　stacking　inter­actions　between　adjacent　L　mol­ecules.　The　DMSO　solvent　mol­e­cules　act　as　proton　donors　and　acceptors,　forming　hydrogen　bonds　of　various　strengths　with　the　L　mol­ecules.　In　addition,　the　geometry　optimization　of　a　single　mol­ecule　of　L　and　its　luminescence　properties　either　in　solution,　as　a　solvated　solid　or　as　a　desolvated　solid　were　studied.　The　com­pound　shows　an　aggregation-induced　emission　(AIE)　effect　and　exhibits　switchable　luminescence　colouration　in　the　solid　state　by　the　simple　removal　or　re-addition　of　the　DMSO　solvent.　©　2020　Society　of　Photo-Optical　Instrumentation　Engineers　(SPIE).