The spacing of salen-type ligands by highly flexible permethylated bridges causes the derived coordination compounds to have unexpected material properties (e.g., liquid crystallinity, aggregation-induced emission or negative fluorescence anisotropy).

The specific features of the siloxane bond unify the compounds based on it into a class with its own chemistry and unique combinations of chemical and physical properties. An illustration of their chemical peculiarity is the behavior of 1,3-bis(2-aminoethylaminomethyl)tetramethyldisiloxane (AEAMDS) in the reaction with carbonyl compounds and metal salts, by which we obtain the metal complexes of the corresponding Schiff bases formed in situ. Depending on the reaction conditions, the fragmentation of this compound takes place at the siloxane bond, but, in most cases, it is in the organic moieties in the β position with respect to the silicon atom. The main compounds that were formed based on the moieties resulting from the splitting of this diamine were isolated and characterized from a structural point of view. Depending on the presence or not of the metal salt in the reaction mixture, these are metal complexes with organic ligands (either dangling or not dangling silanol tails), or organic compounds. Through theoretical calculations, electrons that appear in the structure of the siloxane bond in different contexts and that lead to such fragmentations have been assessed.

The metal-to-ligand stoichiometry and metal identity are of primary importance for the development of metal complexes of thiosemicarbazones as effective inhibitors of tubulin polymerization.

In the title complex, [U(C₁₀H₇N₃O₃)O₂(CH₃OH)] _n , the U^VI cation has a typical pentagonal–bipyramidal environment with the equatorial plane defined by one N and two O atoms of one doubly deprotonated 2-[5-(2-hydroxyphenyl)-1H-1,2,4-triazol-3-yl]acetic acid ligand, a carboxylate O atom of the symmetry-related ligand and the O atom of the methanol molecule [U—N/O_eq 2.256 (4)–2.504 (5) Å]. The axial positions are occupied by two oxide O atoms. The equatorial atoms are almost coplanar, with the largest deviation from the mean plane being 0.121 Å for one of the O atoms. The benzene and triazole rings of the tetradentate chelating–bridging ligand are twisted by approximately 21.6 (2)° with respect to each other. The carboxylate group of the ligand bridges two uranyl cations, forming a neutral zigzag chain reinforced by a strong O—H...O hydrogen bond. In the crystal, adjacent chains are linked into two-dimensional sheets parallel to the ac plane by C/N—H...N/O hydrogen bonding and π–π interactions. Further weak C—H...O contacts consolidate the three-dimensional supramolecular architecture. In the solid state, the compound shows a broad medium intensity LMCT transition centred around 463 nm, which is responsible for its red colour.

A new metal–organic framework {[Mn₄(Cx)₃(etdipy)₅]·2ClO₄}_n (1) was prepared via the complexation of manganese ion from a Mn(ClO₄)₂ source with 1,3-bis(carboxypropyl)tetramethyldisiloxane (Cx) and 1,2-di(4-pyridyl)ethylene (etdipy) in the presence of 2,4-lutidine as a deprotonating agent. The single-crystal X-ray diffraction analysis revealed a dense 3D framework structure. The presence in the structure of flexible tetramethyldisiloxane moieties, which tend to orient themselves at the interface with the air, gives the compound a highly hydrophobic character, as indicated by the result of the water vapor sorption analysis in the dynamic regime, as well as the shape and stability of the water droplet on the crystalline mass of the compound. The compound is an electrical insulator, and due to its hydrophobicity, this characteristic is unaffected by environmental dampness. The thermal analysis indicated thermal stability up to about 300 °C and an unusual thermal transition for an MOF structure, more precisely a glass transition at 24 °C, the latter also being attributed to the flexible segments in the structure. The magnetic studies showed dominant antiferromagnetic interactions along the metal ion chain in compound 1.