A second distinction between these two compounds is the potential for tuning the interactions through substitution of the ligands. Replacing pyrimidine by a larger bridging ligand may reduce inter-chain exchange, suppressing long-range order and allowing access to the paramagnetic S = 2 quasi-1D AFM at lower temperatures. For example, in NiCl 2 L substituting pyrazine for 1,2-bis(4-pyridyl)ethane reduces T N from 10.2 K to 5.6 K. Equally, optimisation of the octahedral coordination environment can minimise D, for example in a family of closely related Ni 2+ compounds, matching of the ligand field strengths reduces the size of the easy-plane anisotropy by a factor of 4. Our measurements of the INS data already suggest that the interlayer interactions are not significant, but delamination of these van der Waals sheets, as demonstrated for other magnetic metal-organic nanosheets, may provide an alternative route to better magnetic isolation. These results suggest therefore that bridging CrCl 2 spin chains with organic ligands may provide promising future candidates for S = 2 Haldane chains.