We have reported the crystal structure, bulk magnetic properties, magnetic ground state and magnetic excitations of a new coordination polymer, CrCl 2 (pym). We have shown that the oxidation state of chromium in this compound is Cr 2+ , remaining S = 2, unlike related CrCl 2 derived MOMs which undergo redox to form triplet Cr 3+ -radical ligand pairs. CrCl 2 (pym) is found to be a S = 2 quasi-one-dimensional antiferromagnet, with an order of magnitude separation in energy scales of superexchange, | J 1 J 2 | = 11(2). However we did not find clear evidence of the Haldane gap in the disordered phase, suggesting the small Fisher Scientific, 99.9%) and pyrimidine (500 mg, 6.24 mmol; Sigma-Aldrich, ≥ 98.0%) in 50 mL methanol (MeOH) rapidly precipitates an orange-brown microcrystalline powder. The CrCl 2 (pym) product was then dried in vacuo giving a ca. 90% total yield. The measured (calculated) elemental composition was: C, 23.45% (23.67%); H, 1.99% (2.40%); N, 12.94% (13.80%). This procedure, with quantities scaled up (CrCl 2 , 3.0 g; pyrimidine, 4.0 g; MeOH, 300 mL), was used to synthesise the sample used for neutron-scattering measurements. Crystals of sufficient size for X-ray diffraction studies (127 × 46 × 26 µm) were grown by vapour diffusion of pyrimidine (100 mg, 1.25 mmol) into a concentrated solution of CrCl 2 in 1 mL MeOH (10 mg, 0.08 mmol).