Teng Li,Ping Jin,Yekai Zhang,Kexin Huang,Jingen Long,Jun Jiang,Shengqin Liu,Ayusman Sen,Weiran Yang
As an important biomass-derived chemical, d-sorbitol can be converted to a variety of useful chemicals and fuels. Because of the strong nucleophilicity of I– and reducibility of hydrogen iodide (HI), hydroiodic acid has been used for polyol hydrogenolysis with high selectivity. Here, d-sorbitol was converted by HI, rhodium, and hydrogen to give a high yield of iodohexanes (94.2%) at 373 K in a water/cyclohexane biphasic system. Rhodium and hydrogen were used to regenerate HI in situ. The reaction mechanism was studied in detail by using model molecules. The substitution–elimination–addition (SEA) mechanism was proven to be the most possible pathway. The high concentration of both proton and iodide was found to be necessary for the efficient conversion of d-sorbitol and the selective formation of iodohexanes. Besides, water could inhibit the conversion of d-sorbitol dramatically. These findings were explained by kinetic study and demonstrated in the reaction kinetic equation. This catalytic system, including HI and RhCl3, was proven to be reusable. In addition, iodohexanes can be quantitatively converted to hexenes over ZrO2 at 473 K.
This study proposed a UV-initiated strategy for the synthesis of magnetic ion exchange resins. Two novel magnetic resins were successfully prepared by suspension polymerization method using 1-iodohexane as a long carbon chain alkylating agent under low-pressure ultraviolet (UV) initiation conditions. The polymerization reaction time of resin was significantly reduced to 2 h due to the UV initiation. MGD resin properties exhibited high synthetic stability and good reproducibility. The prepared resin particles possessed rich micropores and mesopores structure with a particle size of 50–250 um. The long carbon chain alkylating agent (1-iodohexane) could improve increasingly the adsorption capacity for phosphate (69.65 %) compared with the short carbon chain alkylating agent (dichloroethane). Site energy analysis found that the concentrated distribution of high-energy sites and surface homogeneity of resins contributed to their high adsorption capacity. DFT calculations, characterizations of resins before and after adsorption, and stoichiometric experiments revealed the electrostatic attraction and ion exchange dominated the removal mechanisms of phosphate adsorbed on prepared resins. DFT results indicated longer chain lengths enhanced both the non-electrostatic and electrostatic components of the adsorption energies. Therefore, compared to thermal initiation, low-pressure UV initiation offered advantages such as high efficiency, rapidity, low-carbon and environmental friendliness for the preparation strategy of a new generation of high-performance magnetic resin.
危险品化学品经营许可证（带存储）