Abstract: Octahedral cluster complexes [{M6X8}L6]m– (M = Re, Mo, W; X = Cl, Br, I, S, Se, Te; L = organic or inorganic ligand, m – charge) have demonstrated potential in a range of fields, including biology and medicine. They can be utilized as radiocontrast agents and as active components of photodynamic therapy systems [1]. These complexes, comprising six metal atoms linked by metal-metal bonds and stabilized by internal X and external L ligands, effectively absorb X-rays due to their high concentration of heavy atoms. They also exhibit red luminescence under light and X-ray exposure and can generate reactive singlet oxygen in the presence of molecular oxygen. However, their application is limited by low solubility or instability in aqueous media, spurring interest in finding water-soluble forms or stabilizing them in various organic [2] and inorganic polymer matrices [3]. Compared to similar molybdenum and rhenium complexes, tungsten cluster complexes have been less studied, largely due to the more labor-intensive synthesis methods required. This research introduces a novel synthesis method for the tungsten bromide octahedral cluster complex [{W6Br8}Br6]2– using accessible starting materials. It also covers the preparation and characterization of tungsten bromide and iodide complexes with various substituted external ligands. Moreover, the synthesis of water-soluble complexes [W6X8Y6]2– (X = Br, I; Y = Cl, Br) is described in detail, including their stabilization in aqueous solutions using gamma-cyclodextrin. The binding of the complexes to gamma-cyclodextrin is primarily achieved through hydrogen bonding, which enhances the solubility and stability of the complexes.

Cite: Evtushok D.V.
Enhancing the stability of water-soluble octahedral tungsten cluster complexes using gamma-cyclodextrin
III Международный симпозиум «Нековалентные взаимодействия в синтезе, катализе и кристаллохимическом дизайне» 19-25 авг. 2024