Donor-acceptor　(D-A)　hybrid　crystals　are　an　emerging　kind　of　crystalline　hybrid　material　composed　of　semiconductive　inorganic　donors　and　organic　acceptors.　Except　for　the　intrinsic　photochromism,　recently　we　have　reported　that　the　anion-πpolyoxometalate　(POM)/naphthalenediimide　(NDI)　hybrid　crystals　could　produce　an　interesting　room　temperature　phosphorescence　(RTP)　quantum　yield　up　to　7.2%.　Herein,　we　extended　into　core-substituted　NDIs　and　anticipated　the　regulation　of　their　photochromic　and　RTP　properties.　Thus,　two　hybrid　crystals,　namely　(H4BDMPy-Br2NDI)·(NMP)4·(HPW12O40)　(1)　and　(H4BDMPy-I2NDI)·(HPW12O40)　(2)　(H2BDMPy-Br2NDI:　N,N′-bis(3,5-dimethylpyrazolyl)-2,6-dibromo-1,4,5,8-naphthalenediimide　and　H2BDMPy-I2NDI:　N,N′-bis(3,5-dimethylpyrazolyl)-2,6-diiodide-1,4,5,8-naphthalenediimide),　have　been　synthesized　from　phosphotungstic　anions　(PW12O403-)　and　Br　or　I　core-substituted　NDIs.　Compared　to　the　core-unsubstituted　analogues　(H4BDMPy-NDI)·(NMP)4·(HPW12O40)　(3),　2　with　photosensitive　iodine　substituents　is　more　sensitive　to　light,　which　can　become　discolored　under　natural　light.　As　a　result　of　the　heavy-atom　effect,　hybrid　1　exhibits　remarkable　RTP　with　the　quantum　yield　up　to　10.2%　and　a　lifetime　of　1.14　ms.　©　2021　American　Chemical　Society.