Unusual oxygen…oxygen dichalcogen bond in an oxo-centered trinclear iron coordination cluster

Abstract

An oxo-centred, carboxylate bridged trinuclear iron(III) coordination cluster, [Fe3O(2-furoate)6(H2O)1.8(NCS)1.2].H2O (1) was prepared by the reaction of FeCl2·4H2O with 2- Furoic acid, and KSCN in mixed solvents (CH3CN: CH2Cl2). The structure of the compound was identified by FTIR, elemental analysis and Single X-ray Crystallography. The trinuclear iron complex is planar in structure with weak intermolecular interactions i.e. O…O, C-H…π or O…π or π…π, can be seen in the structure to form more stable 3D supramolecular architecture with cavity-channels (O…O distance between furoic oxygen = 4.214 Å). Theoretical investigation has been executed and confirmed about the oxygen…oxygen dichalcogen bond. The energy of unconventional O···O chalcogen bond calculated as 0.6 kcal/mole. Further, QTAIM and NCI methods also expose non-covalent interactions. The QTAIM also confirms about the presence of weaker C-H···S hydrogen bonds of ρ oscillating around 0.005 au. The studied iron complex is a rare example of a system stabilized by O ···O dichalcogen bonding interactions.