Synthesis, crystal structure and Hirshfeld surface analysis of sodium bis(malonato)borate monohydrate

In the title salt, poly[aqua[mu(4)-bis(malonato)borato]sodium], {[Na(C6H4BO8)]center dot H2O} n or Na+ center dot[B(C3H2O4)(2)] center dot H2O, the sodium cation exhibits fivefold coordination by four carbonyl O atoms of the bis(malonato)borate anions and a water O atom. The tetrahedral B atom at the centre of the anion leads to the formation of a polymeric three-dimensional framework, which is consolidated by C-H center dot center dot center dot O and O-H center dot center dot center dot O hydrogen bonds. A Hirshfeld surface analysis indicates that the most significant contacts in the crystal packing are H center dot center dot center dot O/ O center dot center dot center dot H (49.7%), Na center dot center dot center dot O/O center dot center dot center dot Na (16.1%), O center dot center dot center dot O (12.6%), H center dot center dot center dot H (10.7%) and C center dot center dot center dot O/O center dot center dot center dot C (7.3%).