In the past years, heavier main group elements have become increasingly popular for the activation of small molecules. In this context, bismuth is of great interest due to its low toxicity and rich redox chemistry, the latter showing parallels with transition metal chemistry. Due to the inert pair effect, the 6s 2 orbital is low in energy, resulting in the low basicities of Bi(III) compounds and highly oxidative behaviour of the +V oxidation state. Recently, interest in the reduced oxidation state +I of bismuth has significantly increased. Pioneering work by Dostal has given access to bismuthinidenes, compounds in which the bismuth atom in the formal oxidation state +I is stabilized by a NCN pincer framework. The second lone pair associated with Bi(I) is localized in a p-orbital which lies perpendicular to the plane of the pincer ligand. Besides fundamental studies regarding the electronic structure of Bi(I) compounds the increased nucleophilicity of Bi(I) compounds allows them to act as donor ligands to metals. Furthermore, they have also been shown to mediate important organic transformations, e.g. transfer hydrogenations or hydrodefluorination reactions. Additionally, bismuthinidenes have been reported to undergo oxidative addition of alkyl iodides and aryl halides. Whereas halogen bonding between aryl iodides and nitrogen-based molecules has found widespread use in many areas of crystal engineering, compounds of the heavier pnictogens have rarely been used as halogen bond acceptors. Only very few examples have been reported in the past years, e.g. using tertiary phosphines. In a seminal work, Friščić and Cinčić reported the successful cocrystallization of the halogen bond donor 1,3,5-trifluoro-2,4,6-triiodobenzene with Ph3P, Ph3As and Ph3Sb. However, no adduct could be isolated in case of Ph3Bi. Recently, Bujak and Mitzel reported cocrystals of Me3As/Me3Sb with C6F5I. The fact that no solid-state structures with a bismuth compound acting as a halogen bond acceptor have been reported, and such structural motifs are typically not even considered in theoretical investigations, prompted us to pursue this synthetic challenge. Bismuth's primary challenge lies in the inert pair effect, which refers to the low energy of the 6s orbital, resulting in the diminished nucleophilicity of Bi(III) compounds. The Molecular Electrostatic Potential (MEP) surface plots of Et3Bi and Ph3Bi (Figure , top), reveal its unsuitability as a halogen bond acceptor. For Ph3Bi, the minima/electron-rich regions are concentrated on the aryl rings, with a MEP value of -16.3 kcal/mol, being compared to that of the bismuth 6s lone pair (LP), -2.3 kcal/mol. Despite the presence of electron-donating alkyl substituents in Et3Bi, its MEP value remains modest (< 10 kcal/mol). To counteract the inert pair effect, we shifted our focus to Bi(I) compounds instead of Bi(III). Nonetheless, the MEP of the basic PhBi model compound indicates an anisotropic MEP surface at Bi (Figure ). This surface displays two π-holes (positive areas) and two negative areas, attributed to the stereo-active lone pairs positioned coplanar with the aromatic ring. As expected, the MEP values at these LPs are significantly more negative (-23.2 kcal/mol) than those found in the Bi(III) compounds. Furthermore, the pronounced MEP maximum values (53.6 kcal/mol, representing π-holes) reveal Bi(I)'s dominant electrophilic nature over its nucleophilic one, rendering it unsuitable as a halogen bond acceptor. To circumvent this limitation, we considered using the NCN-stabilized bismuthinidene 1. We reasoned that the LPs on the imine N-atoms could engage with the π-holes at Bi, positioning the stereo-active lone pairs above and below the plane of the aromatic ring (as shown in Figure ). Within this configuration, Bi(I) demonstrates pronounced nucleophilicity, as evidenced by a MEP value of -25.0 kcal/mol.