In the course of development of novel capping ligands with variable steric factor which will be used as an organic coating for metal oxide nanoparticles a base-catalyzed nucleophilic oxirane ring-opening addition reaction between dimethyl 5-hydroxyisophthalate and allyl glycidyl ether was studied. diethylene glycol colloids. LILRB4 antibody found that under the reaction conditions used for the synthesis of poly(allyl glycidyl ether) a small fraction of allyl terminal groups isomerized into potassium in Frey’s work.24 Presumably sodium forms a less stable intermediate five-membered chelate ring as compared to potassium used in the reference studies. The difference in isomerization activity of sodium and potassium alkoxides was noticed earlier 29 however this comparison could not be considered valid as different alkoxides (potassium = 4/= fraction of atoms = total number of atoms per particle. The Purmorphamine total number of atoms per Purmorphamine particle was in turn calculated from the particle diameter its volume its mass (density = 4.87 g/cm3) number of mols and formula units per particle.32 Methanol solution of the capping ligand was added Purmorphamine to diethylene glycol γ-Fe2O3 colloid under intensive stirring. The resulting homogeneous solution was left at room temperature for 24 Purmorphamine hours and examined by the Dynamic Light Scattering (DLS). The hydrodynamic particle size (7.5 nm) remained unchanged as compared to the original colloid before the capping ligand was added. In order to further characterize the reaction product we isolated it in a pure form. The colloid was coagulated by addition of equal volume of ethyl acetate the precipitate was separated from the solution using strong permanent magnet washed with isopropanol until the drop evaporation test was negative and dried in vacuum. Synthesis details are given in the supplementary data file p. 7. The IR spectrum of the powdery sample showed features of the coordinated capping ligand (supplementary data p. 88). The obtained organic/inorganic adduct tested negative for water solubility or otherwise reactivity at room temperature. This is a typical behavior for the nanoscale powders after they were freed from the surfactant and solvent. In order to further confirm the identity of this product we performed its high-temperature hydrolysis followed by separation of the organic and inorganic component on an NMR sample scale. A sample of the adduct (100 mg) was heated with 1 mL of D2O at 100°C for ~30 min and then precipitated iron oxide was separated by magnet. The remaining colorless solution was filtered through a 100 nm microfilter. 1H NMR spectrum of this solution showed presence of the free ligand which evidenced the hydrolysis and de-ligation reaction of the γ-Fe2O3-ligand adduct. CONCLUSIONS In a search for novel non-polymeric capping ligands for metal oxide nanoparticles three 5- substituted derivatives of isophthalic acid with ethylene oxide chain substituents were synthesized by reacting dimethyl 5-hydroxyisophthalate (HIP) with allyl glycidyl ether (AGE) in the presence of a base catalyst. The main step an anionic epoxide ring-opening reaction was performed using a solvent-free reaction technique and products with 1 2 and 3 molecules of AGE attached to HIP via its formerly phenolic oxygen were isolated and characterized. HIP-AGE 1-1 adduct can be regarded as a product of the initiation and the 1-2 and 1-3 adducts as the first two products of the chain propagation steps of an anionic ring-opening polymerization. An allyl group of the 1-1 adduct was converted into a 1 2 by aqueous oxidation and resulting product (5-diglyceroxy isophthalic acid) can be regarded as the first homolog of polyglycerol-substituted arene with an unusual linear chain structure. This substance was tested as a capping ligand and found to bind to Purmorphamine the surface of 5 nm γ-Fe2O3 nanoparticles. The ligand-capped nanoparticles form stable colloid in diethylene glycol. The organic/inorganic adduct isolated in a pure powdery form appears to be stable to hydrolysis at ambient temperatures but undergoes de-ligation in boiling water. Colloidal chemistry experiments on the longer-chain isophthalate and other benzenecarboxylate capping ligands are in progress and will be reported elsewhere. The reported method can be extended to the synthesis of O-substituted derivatives of other hydroxyacids of potential applications in biology and medicine. This method is facile and optimized for minimizing waste and it is Purmorphamine therefore consistent with principles of green chemistry. Supplementary.