Institut für Optik und Atomare Physik, Technische Universität Berlin, EW 3-1, Hardenbergstr. 36, 10623 Berlin, Germany.
J Chem Phys. 2013 Jan 14;138(2):024310. doi: 10.1063/1.4774268.
We investigated the changes in electronic structures induced by chemical functionalization of the five smallest diamondoids using valence photoelectron spectroscopy. Through the variation of three parameters, namely functional group (thiol, hydroxy, and amino), host cluster size (adamantane, diamantane, triamantane, [121]tetramantane, and [1(2,3)4]pentamantane), and functionalization site (apical and medial) we are able to determine to what degree these affect the electronic structures of the overall systems. We show that unlike, for example, in the case of halobenzenes, the ionization potential does not show a linear dependence on the electronegativity of the functional group. Instead, a linear correlation exists between the HOMO-1 ionization potential and the functional group electronegativity. This is due to localization of the HOMO on the functional group and the HOMO-1 on the diamondoid cage. Density functional theory supports our interpretations.
我们通过价带光电子能谱研究了五种最小的类金刚石笼经化学官能化后电子结构的变化。通过改变三个参数，即官能团（巯基、羟基和氨基）、主体团簇大小（金刚烷、二聚金刚烷、三聚金刚烷、[121]四聚金刚烷和[1(2,3)4]五聚金刚烷）和官能化位置（顶端和中心），我们可以确定这些因素在何种程度上影响整个系统的电子结构。我们表明，与例如卤代苯的情况不同，电离势并不随官能团的电负性呈线性变化。相反，HOMO-1 电离势与官能团电负性之间存在线性相关性。这是由于 HOMO 定域在官能团上，而 HOMO-1 定域在类金刚石笼上。密度泛函理论支持我们的解释。
