In the recent years, chiral hybrid organic inorganic perovskites (HOIPs) have emerged as auspicious materials for optoelectronics, spintronics, photodetection, energy harvesting and more, allowing for the absorption and subsequent emission of polarized light with an enhanced tunability over the electromagnetic spectrum [1, 2]. In this growing field, a plethora of 2D and quasi-2D materials have been reported, as well as few 1D and 0D ones, demonstrating the attainment of promising chiroptoelectronic and spin-polarization features [3]. However, all these materials lack of metal-halide octahedra interconnection in the three dimensions, issue reasonably affecting their 3D conductivity thus limiting the practical applications, as the layers of organic cations behave as dielectrics [4]. Hence, development of such 3D-interconnected materials is a current research challenge, since the steric hindrance of many organic cations prevents the accordance with the Goldschmidt tolerance factor and only allows 3D chiral HOIPs to remain in the theoretical development stage.

In the present work, we report for the first time the attainment of a chiral AB₂X₆ perovskitoid, incorporating the chiral diamine R/S-3-aminoquinuclidine (R/S-3-AQ) and featuring 3D interconnection of the octahedra. Managing the reaction conditions, (R/S-3-AQ)Pb₂Br₆ as well as the 2D counterpart [(R/S-3-AQ)₂PbBr₄]·2Br were obtained, enabling us to investigate the role of dimensionality on the chiroptical response and conductivity. By UV-Vis absorption spectra we observed sharp absorption edges at ca. 410 and 390 nm for (R/S-3-AQ)Pb₂Br₆ and [(R/S-3-AQ)₂PbBr₄]·2Br, respectively, values resulting in a direct bandgap of ca. 3.0 and 3.2 eV. The CD signals indicated a substantially higher maximum for the 2D materials, in terms of mdeg, along with a g_CD of 4·10^-4 (R) and -3·10^-4 (S), almost on order of magnitude larger than the 3D perovskitoid, namely 6·10^-5 (R) and -9·10^-5 (S). This issue was expected and ascribed to the minor content of chiral molecules per formula unit of (R/S-3-AQ)Pb₂Br₆. Resistivity measurement as well as theoretical calculations are now ongoing to determine the conductivity features of (R/S-3-AQ)Pb₂Br₆ and [(R/S-3-AQ)₂PbBr₄]·2Br, thus the influence of material dimensionality on the charge transport. With this pioneering work we aim to disclose new parameters, i.e. dimensionality and consequently octahedra interconnection, on the conductivity of chiral perovskite-related materials, potentially enriching the application fields of this promising class of compounds.