Structure sensitive enantioselectivity on surfaces: tartaric acid on all surfaces vicinal to Cu(111)
Structure sensitive enantioselectivity on surfaces: tartaric acid on all surfaces vicinal to Cu(111)
复制标题
表面上的结构敏感对映选择性：与 Cu(111) 邻接的所有表面上都有酒石酸
DOI：
10.1039/d1ma00876e
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发表时间：
2022
影响因子：
5
通讯作者：
Gellman, Andrew J.
中科院分区：
文献类型：
--
作者：
Fernández-Cabán, Carlos;Karagoz, Burcu;Kondratyuk, Petro;Gellman, Andrew J.
对铜（111）附近的铜（hkl）表面的对映体表面反应性与晶体取向进行了全面的映射，使用球形单晶，其表面法向量[hkl]跨越了[111]方向14°的所有可能的取向。这使得在169个不同的Cu（hkl）表面上直接测量两个速率常数，k(hkl)i和k(hkl)e，这两个速率常数决定了空缺介导的酒石酸（TA）的爆炸分解动力学。起始速率常数k(hkl)i量化了在吸附的TA单层中产生空位的起始步骤的动力学。爆炸速率常数k(hkl)e量化了导致TA分解和产物脱附的空位介导爆炸步骤的动力学。TA分解动力学对局部表面取向手性的依赖性揭示了对映体特异性。D-TA在S表面上比L-TA反应性强，而L-TA在R表面上反应性强，证明了非对映异构性。在433 K的等温TA分解过程中，达到一半覆盖的时间t(hkl)1/2，可以确定最对映特异性的表面取向；铜(754)。理想的Cu（754）表面结构由（111）个阶地组成，阶地由（100）和（110）个微面形成的单原子台阶分开。
Comprehensive mapping of enantiospecific surface reactivity versus the crystallographic orientation of Cu(hkl) surfaces vicinal to Cu(111) has been conducted using a spherically shaped single crystal on which the surface normal vectors, [hkl], span all possible orientations lying with 14° of the [111] direction. This has allowed direct measurement on 169 different Cu(hkl) surfaces of the two rate constants, k(hkl)i and k(hkl)e, that determine the kinetics of the vacancy-mediated, explosive decomposition of tartaric acid (TA). The initiation rate constant, k(hkl)i, quantifies the kinetics of an initiation step that creates vacancies in the adsorbed TA monolayer. The explosion rate constant, k(hkl)e, quantifies the kinetics of a vacancy-mediated explosion step that results in TA decomposition and product desorption. Enantiospecificity is revealed by the dependence of TA decomposition kinetics on the chirality of the local surface orientation. Diastereomerism is demonstrated by the fact that D-TA is more reactive than L-TA on S surfaces while L-TA is more reactive on R surfaces. The time to reach half coverage, t(hkl)1/2, during isothermal TA decomposition at 433 K allowed determination of the most enantiospecific surface orientation; Cu(754). The ideal Cu(754) surface structure consists of (111) terraces separated by monoatomic steps formed by the (100) and (110) microfacets.