Spontaneous self-assembly is one of the available synthetic routes to achieve structurally versatile and unique crystal complexes with selected metal–ligand combinations in the spirit of pseudohalides. In this endeavour, we designed a novel 1D coordination polymer (CP), [(Cd)(Pb)(L)(η¹-NCS)(η¹-SCN)]_n (1), using a compartmental Salen ligand (H₃L) in the presence of NaSCN. The characterization of the CP was accomplished using several spectroscopic techniques: MALDI-TOF, PXRD, SEM, EDX mapping, and single-crystal X-ray crystallography. The CP crystallizes in the monoclinic space group P2₁/c with Z = 4. SCXRD reveals Cd(II) and Pb(II) metal ions fulfilled distorted square pyramidal and hemi-directed coordination spheres. Cd(II) is placed in the inner N₂O₂ and heavier Pb(II) in the outer O₄ compartments of the de-protonated form of the ligand [L]²⁻. Supramolecular interactions in the intricate crystal structure produced attractive molecular architectures of the compound. The flexible aliphatic –OH pendent group coordinates with the Pb(II) ions. This unique binding further elevates the supramolecular crystal topographies. The supramolecular interactions were authenticated by Hirshfeld surface analysis (HSA). The observation of the recurring unconventional tetrel bonds was rationalized by DFT calculations and surface plots of molecular electrostatic potential (MEP). In the 1D polymeric chain in the complex, the O-atom of the –OH groups shows a tetrel bonding interaction with the Pb atom. We have found that the combination of QTAIM/NCI and QTAIM/ELF plots helps reveal the nature of these contacts. Moreover, the QTAIM/ELF plot determines the donor–acceptor interaction between the O-atom and the Pb atom, establishing the σ-hole. Agreeably, the σ-hole interaction also helps Pb(II) serve as a Lewis acid in the complex. Finally, spodium and tetrel bonds are formed, possible thanks to a hemi-directional coordination sphere of the Pb atoms in the polymer described.

Accommodating disparate spin centres within a single ensemble is a valuable synthetic strategy to obtain interesting molecular magnetic materials. 3d–4f heterometallic complexes are one such subclass that has been extensively explored for the last three decades owing to their interesting magnetic properties. The primary reason is that the bridging ligand mediates magnetic super-exchange between 3d and 4f ions to considerably reduce the prevalent quantum tunnelling of magnetisation (QTM) in such complexes. Among the 3d–4f family, Cr^III–Ln^III assemblies nicely demonstrate the pivotal role played by strong exchange interactions between these two individual spin carriers to engender interesting single-molecule magnet (SMM) properties. In fact, this part of heterometallic chemistry has flourished greatly in the last decade despite its late development. In this review we provide an extensive synthetic, structural, magnetic, and magnetocaloric description of various Cr^III–Ln^III complexes along with their fundamental mechanisms of exchange interaction. Finally, we provide some possible solutions to improve the SMM properties of the Cr^III–Ln^III and other heterometallic complexes.

Advanced catalytic strategies for CO ₂ to MeOH conversion focus on approaches utilizing noble metals. These methods leverage noble metal catalysts to facilitate CO ₂ molecule activation and promote reduction to MeOH under mild conditions.