To account for the charge transfer and covalent character in bonding between P and Bi centers, the electronic structures of [P(C6H4-o-CH2SCH3)(3)BiCln]((3-n)+) (n = 0-3) model species have been investigated computationally. On the basis of this survey a synthetic target compound with a dative P -> Bi bond has been selected. Consecutively, the highly reactive bismuth cage [P(C6H4-o-CH2SCH3)(3)Bi](3+) has been accessed experimentally and characterized. Importantly, our experiments (single-crystal X-ray diffraction and solid-state NMR spectroscopy) and computations (NBO and AIM analysis) reveal that the P center dot center dot center dot Bi bonding in this trication can be described as a dative bond. Here we have shown that our accordion-like molecular framework allows for tuning of the interaction between P and Bi centers.