多功能桥试剂四（ω－羟丙氧甲基）甲烷及三（ω－羟丙氧甲基）氨甲烷的合成

报道通过延伸方法解决季戊四醇（１）及三羟甲基氨甲烷（２）末端羟基立体位阻的方法。（１）和（２）末端羟基经氰乙基化、醇解和还原等步骤制得标题化合物四（ω－羟丙氧甲基）甲烷（３）及三（ω－羟丙氧甲基）氨甲烷（４），并合成９个衍生物，以摸索（３）和（４）的酰化、醚化及氯化等反应条件。所合成的化合物（３～１３）及（１５）均未见文献报道，其结构经ＩＲ、１Ｈ－ＮＭＲ和元素分析确证。标题化合物可作为小分子多功能桥试剂，以增大载体的载药量。

Preparation of nitrogen-doped carbon nanoblocks with high electrocatalytic activity for oxygen reduction reaction in alkaline solution

The oxygen reduction reaction （ORR） is traditionally performed using noble‐metals catalysts, e.g. Pt. However, these metal‐based catalysts have the drawbacks of high costs, low selectivity, poor stabili‐ties, and detrimental environmental effects. Here, we describe metal‐free nitrogen‐doped carbon nanoblocks （NCNBs） with high nitrogen contents （4.11%）, which have good electrocatalytic proper‐ties for ORRs. This material was fabricated using a scalable, one‐step process involving the pyrolysis of tris（hydroxymethyl）aminomethane （Tris） at 800℃. Rotating ring disk electrode measurements show that the NCNBs give a high electrocatalytic performance and have good stability in ORRs. The onset potential of the catalyst for the ORR is-0.05 V （vs Ag/AgCl）, the ORR reduction peak potential is-0.20 V （vs Ag/AgCl）, and the electron transfer number is 3.4. The NCNBs showed pronounced electrocatalytic activity, improved long‐term stability, and better tolerance of the methanol crosso‐ver effect compared with a commercial 20 wt%Pt/C catalyst. The composition and structure of, and nitrogen species in, the NCNBs were investigated using Fourier‐transform infrared spectroscopy, scanning electron microscopy, X‐ray photoelectron spectroscopy, and X‐ray diffraction. The pyroly‐sis of Tris at high temperature increases the number of active nitrogen sites, especially pyridinic nitrogen, which creates a net positive charge on adjacent carbon atoms, and the high positive charge promotes oxygen adsorption and reduction. The results show that NCNBs prepared by pyrolysis of Tris as nitrogen and carbon sources are a promising ORR catalyst for fuel cells.

MODIFICATION OF X-5 RESIN AND ADSORPTION PROPERTY OF THE MODIFIED RESINS

Three polymeric adsorbents with hydrogen bonding acceptors, methylamine, N-methyl-acetamide and aminotri(hydroxymethyl)methane modified resins are synthesized from chloromethylated X-5 resin. Adsorption isotherms of phenol and theophylline onto the three modified resins and the original X-5 resin from aqueous solution are measured. The results show that adsorption of compounds with hydrogen bonding donor onto methylamine and N-methylacetamide modified resins is enhanced as compared with that onto X-5 resin, and adsorption mechanism between the adsorbents and the adsorbates is mainly based on hydrogen bonding and hydrophobic interaction. While adsorption of compounds with hydrogen bonding donor onto aminotri(hydroxymethyl)methane modified resin is lowered as compared with that onto X-5 resin, and adsorption mechanism between the adsorbent and the adsorbates is mainly based on hydrophobic interaction.

Polydentate-ligand-supported self-assembly of heterometallic T-shaped Co_4 Dy cluster showing slow magnetic relaxation

A novel mixed-valent heterometallic pentanuclear CoⅢ3 CoⅡ Dy Ⅲ cluster has been rationally assembled taking advantage of a bifunctional ligand with o-vanillin and tripodal tris(hydroxymethyl)aminomethane units. This unique heterometallic cluster represents a rare example of T-shaped molecules exhibiting slow magnetic relaxation.