Recent advancements in synthesis, characterization, X-ray structure, and applications of Zn/Cd–OCN complexes with N/O-donor ligands: A panoramic review

The review of less-explored Zn/Cd-OCN complexes with N/O-donor ligands is a challenging task from current research perspectives in the coordination chemistry community. Still, challenges are well acknowledged for the review consideration of Zn/Cd-OCN complexes with nitrogen and oxygen donor ligands. Accordingly, this review presents a fresh perspective on the synthesis, X-ray crystallographic features, characterization, supramolecular noncovalent interactions (SNCIs), and applications of Zn/Cd-OCN complexes, drawing on available X-ray structures from 2009 to 2025. The article successfully discusses the scope and objectives, as well as the μ-bridging propensity of OCN - co-ligands with Zn/Cd metal ions. Further, the review covers applications in antimicrobial, fluorescence, CO 2 sorption, and DFT-based limited studies, including MEP/ESP, HOMO-LUMO, Hirshfeld surfaces, semiconducting, and band properties. Additionally, this article sheds light on the limited Spodium bonding features. Investigations such as QTAIM/NCI plots, RDG, BCP, AIM, and NBO characterize the presence of a Spodium bond in the complexes. Overall, the article highlights the limited characterization, biological, and DFT-based properties of Zn/Cd-OCN complexes. It discusses the challenges and future outlooks through a critical discussion of refining synthetic strategy and the potential for complex applications in materials science. It explores promising future studies in biological fields that use AI or bioinformatics. This review provides novel research ideas into current trends in the coordination chemistry of Zn/Cd-OCN complexes. Therefore, the article is a valuable resource for frontier researchers investigating the X-ray structure-based bridging propensity of OCN - ion in transition-metal complexes with N/O-donor ligands. 1. A comprehensive review of Zn/Cd-OCN complexes with N/O-donor ligands. 2. Highlights the synthesis, characterization, X-ray structure, and applications. 3. The review explored noncovalent interactions (NCIs) within complex crystal networks. 4. DFT characterization, including Hirshfeld surfaces, MEP, NBO, AIM, BCP, and QTAIM/NCI plots. 5. The review reveals weaknesses, challenges, and future outlooks.