Elucidating the Structure of the Metal–Organic Framework Ru-HKUST‑1

Ru-HKUST-1 (Ru3(btc)2X1.5; btc3– =
1,3,5-benzenetricarboxylate; X– = chloride, acetate,
trimesate, hydroxide) has received considerable
attention as a result of its structure type, tunability, and the redox-active
nature of its constituent metal paddlewheel building units. When compared
to other members of the HKUST-1 family, its surface area is typically
reported as ∼25% lower than expected. In contrast to this,
a related ruthenium-based porous coordination cage, Ru24(tBu-bdc)24Cl12, displays the expected
surface area when compared to Cr2+ and Mo2+ analogs.
Here, we examine the factors that result in this decreased surface
area for the metal–organic framework (MOF). We show that with
appropriate solvent exchange and activation conditions, Ru-HKUST-1
can display a BET surface area as high as 1439 m2/g. We
utilize a combination of spectroscopic and diffraction techniques
to accurately determine the structure of the MOF, which is most accurately
described here as Ru3(btc)2(OAc)1.07Cl0.43, as prepared under our conditions. Furthermore,
simply treating the sample as air-sensitive upon isolation greatly
improved the adsorption selectivities toward unsaturated molecules.

Ru-HKUST-1（Ru3(btc)2X1.5; btc3– = 1,3,5-苯三甲酸；X– = 氯化物、醋酸盐、三甲酸盐、氢氧化物）由于其独特的结构类型、可调性以及构成金属桨叶单元的氧化还原活性，受到了广泛关注。与其他HKUST-1家族成员相比，其表面积通常报道为预期值的约25%以下。与此形成鲜明对比的是，相关钌基多孔配位笼Ru24(tBu-bdc)24Cl12，在与其他Cr2+和Mo2+类似物相比时，表现出预期的表面积。在本研究中，我们探讨了导致这种金属有机框架（MOF）表面积降低的因素。我们表明，在适当的溶剂交换和活化条件下，Ru-HKUST-1可以显示出高达1439 m2/g的BET表面积。我们利用光谱和衍射技术的结合，精确地确定了MOF的结构，该结构在此条件下最精确地描述为Ru3(btc)2(OAc)1.07Cl0.43。此外，在分离样品时，简单地将样品作为对空气敏感的物质处理，极大地提高了对不饱和分子的吸附选择性。