A Short Review on the Diverse Interactions in Metal-Organic Complexes: From Covalent to Non-Covalent

Metal-organic complexes are an intriguing intersection of coordination chemistry and supramolecular chemistry, characterised by a wide variety of covalent and non-covalent interactions. Although coordinate covalent bonding remains the backbone of metal-ligand bonding, the spatial arrangement and functionality of these complexes in the solid state are guided by more subtle non-covalent forces such as hydrogen bonding, van der Waals, π–π stacking, and cation–π/anion–π/lone pair–π interactions. These interactions play an important role in determining crystal packing, self-assembly, host–guest chemistry, and extended network formation like metal-organic frameworks and coordination polymers. This review systematically discusses the kinds and geometrical preferences of covalent and non-covalent interactions in Metal-organic complexes. Particular attention is given to π-system interactions and metallophilic forces, which, although relatively weak, have a strong impact on supramolecular architecture. Understanding the interplay of these interactions paves the way for rational design in crystal engineering, catalysis, molecular recognition, and related applications.