The preferential inter-staple core-core substitution of PDT observed in the case of 4 could be explained by considering the preferential substitution site for the incoming thiolates. Previous studies by the authors on exchange reactions between chain-like C12 thiolate and [Au24Pd(PET)18] 0 showed that C12 preferentially exchanges with PET moieties at the core position to provide monosubstituted regioisomer [Au24Pd(PET)17(C12)] 0 . Therefore, it is likely that the reaction between PDTH2, which is a chain-like dithiol, and [Au24Pt(SR)18] 0 (SR = PET or TBBT) proceeds with the initial substitution of core-positioned PET or TBBT through one of its two thiolate groups to form intermediate NCs containing thiolate and dithiolate moieties, such as [Au24Pt(TBBT+PET)17(PDTH)] 0 . Dangling Au-S-CH2CH2CH2-SH groups in these NCs are immediately substituted by additional core-positioned PET or TBBT ligand in the nearest inter-staples to form [Au24Pt(TBBT+PET)16(PDT)] 0 . A similar pathway also provides [Au24Pt(TBBT)14(PDT)2] 0 (Figure S19-S21 and Scheme S10) and [Au24Pt(TBBT)12(PDT)3] 0 , in which each PDT moiety was preferentially connected to two nearest staples through inter-staple core-core substitution.