One of the ways to rationally synthesize heterometallic systems having the magnetic sponge property is to adopt the "building block" strategy where precursors can be used to control the dimensionality of the final complex. Cyanide-based precursors provide tremendous opportunities here as the cyanide ligand facilitates strong magnetic interactions via bridging metal centres. Likewise, in recent literature, there have been some reports of cyanide bridged magnetic sponge systems using hexacyanometallate and octacyanometallate building blocks which show considerable improvement in the magnetic ordering temperatures, upon desolvation . High-spin hexacyanometallates of the formula [M(CN)6] 3-(M=Fe, Cr) have been used in the past because of their paramagnetic ground state. For example, in [Cr(CN)6] 3-, Cr(III) has three unpaired electrons (t2g 3 (Oh)) to function as a cyanide-donor ligand to form heterometallic higherdimensional molecular systems that show high TC molecular magnetism property with long range magnetic ordering. On the other side, Mn(II) (t2g 3 eg 2 (Oh)) in high-spin state having five unpaired electrons enables the strong ferromagnetic interactions at high and low temperatures through the Cr III -CN-Mn II bridges. In this regard, the PBA of CrMn with the molecular formula V II [Cr III (CN)6]0.86.2.8H2O 7 reported by Verdauger et al shows a remarkable TC of 315 K, hence molecular systems based on CrMn are also expected to show TC at high temperatures. Herein, we report for the first time, a heterometallic cyanide-bridged twodimensional [CrMn2] coordination network using monodentate ligand, that shows strong ferromagnetic interactions and long-range magnetic ordering at low temperatures.