Mercury supramolecular architectures constructed from flexible unsymmetrical bis(pyridyl) ligands: Structural motif mediated by mercury-halide clusters, ligand conformations and non-covalent interactions

A Potential Mercury Polymer Mass Tag Probe for Mass Cytometry

A novel mercury(II) polymer with pendant dipicolylamine (DPA) chelators carrying Hg2+ ions was prepared as a potential mass tag for mass cytometry (MC) applications. The polymer itself, with DP ≈ 22 had a mixture of PEG24 (provides stealth) and PEG23-azide groups attached to the pendant groups, with ca. 3 azide groups per polymer for antibody conjugation. The initial Hg-DPA complex had 2 Cl atoms attached to each Hg2+ ion (Cl2-Hg-DPA). An approach to replace the two Hg-Cl bonds via ligand exchange reactions by treating the Hg-DPA polymer with monothiol ligands (glutathione, cysteine, and thioglycolic acid) led to a loss of Hg, while Hg polymers treated with dithiol ligands (2,3-dimercapto-1-propanol and 2,3-dimercapto-1-propanesulfonic acid sodium salt monohydrate) led to polymers 2d and 2f, respectively, in which both polymers largely retained their Hg content. These polymers showed relatively low levels of nonspecific binding to suspensions of peripheral blood mononuclear cells (PBMCs). Both polymers were conjugated to anti-CD8a via strain-promoted azide-alkyne coupling, and the conjugates were employed in a 10-plex assay of PBMCs along with Maxpar reagents. Polymer 2d-CD8a showed excellent specificity to target CD8a antigens, even at a low titer of 0.56 μg/mL, and the ability to differentiate CD8a T cells from other components of the PBMC sample. In contrast, polymer 2f-CD8a gave no Hg signal suggesting loss of Hg from the polymer during Ab conjugation or PBMC staining steps. Polymer 2d represents an important step forward in the development of Hg mass tags for MC.

Influence of Aromatic Cations on the Structural Arrangement of Hg(II) Halides

Understanding the structure and arrangement of hybrid metal halides and their contribution to the optoelectronic properties is, thus far, a challenging topic. In particular, new materials composed of d¹⁰ metal halides and pyridinium cations are still largely unexplored. Therefore, we report the synthesis and characterization of six Hg(II) salts built up from (Hg₂Cl₆)^2- or (HgX₄)^2- anions (X = Cl, Br, I) and 2,2'-bipyridium (2,2'-Hbipy)⁺, 2,2'-bipyridine-1,1'-diium (2,2'-H₂bipy)²⁺, or 1,10-phenantrolinium (1,10-Hphen)⁺ cations, using the same experimental conditions. All of them have been characterized by PXRD, EA, FTIR-ATR, and ¹H NMR spectroscopies; single-crystal X-ray diffraction; and TG/DTA determinations. The study of their packing via Hirshfeld surface analysis and 3D deformation density mapping revealed the contributions of the intermolecular interactions to the structural arrangement, notably, the effect of the cation planarity on them. Successively, periodic DFT calculations showed that (i) the valence and conducting bands are mainly composed of the p orbitals of the halide and the organic cation, respectively, and (ii) the corresponding band gap depends mainly on the halide.