Crystal structure and Hirshfeld surface analysis of a new Eu(III)/Cr(III)double-complex salt

Hirshfeld surface analysis and two-dimensional fingerprint plot are used to study theintermolecular interactions in a new double-complex salt: diaqua pentakis (tetramethylurea)europium(III) hexa (isothiocyanato) chromate(III) tetrakis (tetramethylurea) solvate,[Eu(H۲O)۲(C(O)(N(CH۳)۲)۲)۵][Cr(NCS)۶].۴C(O)(N(CH۳)۲)۲ (I). The contacts received by the foursymmetry-different components in the structure, including cationic complex, counter-anioncomplex and two symmetry-independent tetramethylurea molecules are discussed, withconsidering the relative contributions percentages of all contacts existing in the crystal packing.The highlighted interactions are S…C contacts (between cation and anion) and relatively strongEu―O―H···O hydrogen bonds, which are manifested as red spots in the related Hirshfeld surfacemaps. These highlighted contacts in the title structure are compared with those found from theCambridge Structural Database (CSD) [۱] in the structures including similar contacts.