To further assess differences in the physical properties of the samples, additional characterisation was conducted. Electrical conductivity measurements showed no obvious differences with a value of approximately 0.002 S cm -1 recorded for each sample, within the literature range for polycrystalline samples of Cu3(HHTP)2 (SI Table ). Elemental analysis showed that each sample had approximately the expected stoichiometric ratio of Cu to HHTP, further demonstrating successful synthesis of the framework with each modulator (SI Table ). However, nitrogen-containing impurities were present in both A-CuHHTP and C-CuHHTP. Importantly, extended washing of these samples (ca. 14 days in MeOH under N2) resulted in negligible reduction in nitrogen content. This suggests that the nitrogen-containing impurities, hypothesised to be small amounts of ammonia and pyridine, respectively, are incorporated into the framework during crystal formation. As noted above, additional work is required to understand the growth mechanisms of layered conductive MOFs in more detail, including why certain modulators are incorporated into the crystal structures of layered MOFs. Finally, the porosity and Brunauer-Emmett-Teller (BET) areas were evaluated using 77 K N2 sorption isotherms (SI Fig. ). BET areas of 759 ± 32, 314 ± 11, and 293 ± 33 m 2 g -1 were recorded for A-CuHHTP, B-CuHHTP, and C-CuHHTP, respectively. The BET area for A-CuHHTP is in line with that reported previously for this material, while these are the first reported values for B-CuHHTP and C-CuHHTP. These results suggest that A-CuHHTP has a greater nitrogen-accessible porosity than both B-CuHHTP and C-CuHHTP. Pore size distribution analysis showed that all samples had well-defined pore sizes of ca. 14 -16 Å (SI Fig. ). This agrees well with the crystallographically expected value of 16 Å, and illustrates that all samples have the anticipated micropore structure.