Synthesis, Crystal Structure, and Hirshfeld Surface Analysis of Rubidium trans-Bis(N-methyliminodiacetato)chromate(III)

A new rubidium salt, Rb[Cr(C5H7NO4)2] (C5H7NO4 = mida, methyliminodiacetate), was prepared and its molecular structure was determined from synchrotron X-ray data at 173 K. The complex crystallizes in the space group C2/c of the monoclinic system with four mononuclear formula units in a cell with dimensions a = 16.905(3) A, b = 6.483(2) A, c = 13.906(3) A, and β = 113.95(3)°. The Cr atom is located in a center of symmetry with one independent Cr–N bond length of 2.081(2) A and two Cr–O bond lengths of 1.9534(18) and 1.9628(18) A. The Cr(III) ion is coordinated by two N atoms and four O atoms of symmetrical-facial mida ligands, displaying a distorted octahedral geometry. Hirshfeld surface analysis with 2D fingerprint plots revealed that the O···H, H···H, and O···Rb interactions are the main intermolecular interactions. The crystal structure is stabilized by the O···H, H···H, and O···Rb interactions among rubidium cation, the H atoms and the O atoms of carboxylate group from neighboring mida groups.