Synthesis, crystal structure, Hirshfeld surface and void analysis of bis-(μ 2 -4-amino-benzoato-κ 2 O : O ')bis-[bis-(4-amino-benzoato-κ 2 O , O ')di-aquathulium(III)] dihydrate.

The asymmetric unit of the title compound, [Tm 2 (C 7 H 6 NO 2 ) 6 (H 2 O) 4 ]·2H 2 O, contains three 4-amino-benzoate ( 4ABA ) ligands, two coordinated water mol-ecules, a thulium metal ion, and a water mol-ecule of crystallization. The overall structure of the complex ( 4ABA-Tm ) is in the form of a dimer. In the dinuclear thulium complex, symmetry-relevant TmO 8 coordination polyhedra are formed by the O atoms of two chelating 4-amino-benzoate ligands, the O atoms of two non-chelating 4-amino-benzoate ligands, and two water mol-ecules. The Tm-O bond lengths range from 2.216 (3) to 2.471 (3) Å with the Tm⋯Tm separation in the dinuclear complex being 4.7863 (5) Å. The crystal structure features O-H⋯N, N-H⋯O, and O-H⋯O hydrogen-bonding inter-actions. Further stabilization of the crystal packing is due to C-H⋯π and off-set π-π stacking inter-actions. Hirshfeld surface analysis indicates that H⋯H contacts are the most significant contributors to the crystal packing (45.9%). In addition, a void analysis was performed to check the strength of the crystal packing.