Unexpected electric perturbation effects of simple PEG environments on the optical properties of small cadmium chalcogenide clusters
Unexpected electric perturbation effects of simple PEG environments on the optical properties of small cadmium chalcogenide clusters
复制标题
简单 PEG 环境对小型镉硫族化物团簇光学性质的意外电扰动效应
DOI：
10.1039/c5nr06307h
复制
发表时间：
2015
期刊：
影响因子：
6.7
通讯作者：
Katsuaki Konishi
中科院分区：
文献类型：
--
作者：
Naoto Fukunaga;Katsuaki Konishi
聚乙二醇（PEG）由于其几乎“惰性”的性质已被广泛用于无机纳米物体的表面保护，但很少有人关注其对无机核的固有电子影响。在此，我们通过对一系列PEG修饰的Cd 10 Se 4（SR）10簇的光学性质的研究明确表明，周围的PEG环境可以以电子方式影响无机核心的性质。对于PEG单元直接连接到无机核上的簇合物（R =（CH 2CH 2 O）nOCH 3，1-PEGn，n = 3，CH 27，CH 217，CH 246），与低能跃迁相关的吸收带随着PEG链长的增加而连续蓝移。链长的依赖性也观察到的光致发光性能，特别是在激发光谱分布。通过结合几个PEG 17-改性的簇（2-Cm-PEG 17和3）的PEG和核心单元由各种烷基链为基础的间隔分开的光谱特征，它被证明，足够长的PEG单元，包括PEG 17和PEG 46，导致电子扰动的集群性能时，它们被安排在无机核心附近。长PEG环境的这些独特效应可能与它们的大偶极矩相关，这表明近端化学环境的极性在影响无机簇核心的电子性质时是至关重要的。
Poly(ethylene glycol) (PEG) has been widely used for the surface protection of inorganic nanoobjects because of its virtually ‘inert’ nature, but little attention has been paid to its inherent electronic impacts on inorganic cores. Herein, we definitively show, through studies on optical properties of a series of PEG-modified Cd10Se4(SR)10 clusters, that the surrounding PEG environments can electronically affect the properties of the inorganic core. For the clusters with PEG units directly attached to an inorganic core (R = (CH2CH2O)nOCH3, 1-PEGn, n = 3, ∼7, ∼17, ∼46), the absorption bands, associated with the low-energy transitions, continuously blue-shifted with the increasing PEG chain length. The chain length dependencies were also observed in the photoluminescence properties, particularly in the excitation spectral profiles. By combining the spectral features of several PEG17-modified clusters (2-Cm-PEG17 and 3) whose PEG and core units are separated by various alkyl chain-based spacers, it was demonstrated that sufficiently long PEG units, including PEG17 and PEG46, cause electronic perturbations in the cluster properties when they are arranged near the inorganic core. These unique effects of the long-PEG environments could be correlated with their large dipole moments, suggesting that the polarity of the proximal chemical environment is critical when affecting the electronic properties of the inorganic cluster core.