Rotas Georgios, Sandanayaka Atula S D, Tagmatarchis Nikos, Ichihashi Toshinari, Yudasaka Masako, Iijima Sumio, Ito Osamu
Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Ave., Athens 116 35, Greece.
J Am Chem Soc. 2008 Apr 9;130(14):4725-31. doi: 10.1021/ja077090t. Epub 2008 Mar 18.
New metallo-nanostructured materials of carbon nanohorns (CNHs), within the family of elongated carbon nanotubes, have been prepared by the coordination of copper(II)-2,2':6',2' '-terpyridine (Cu(II)tpy) with oxidized carbon nanohorns (CNHs-COOH). The resulted CNHs-COO-Cu(II)tpy metallo-nanocomplexes have been characterized by diverse analytical spectroscopic tools and cyclic and differential pulse voltammetry. Scanning transmission electron microscopy (STEM), dynamic light scattering (DLS), and energy dispersive X-ray spectroscopy (EDX) measurements have been employed to probe the morphological characteristics and particle-size distribution of CNHs-COO-Cu(II)tpy as well as to investigate the elemental composition of the metallo-nanocomplex. Steady-state and time-resolved fluorescence emission studies have shown efficient fluorescence quenching, suggesting that electron transfer occurs from the singlet excited state of Cu(II)tpy to CNHs. Photoexcitation of Cu(II)tpy resulted in the one-electron reduction of nanohorns with a simultaneous one-electron oxidation of the Cu(II)tpy unit (CNHs(-)-COO-(Cu(II)tpy)+) as revealed by transient absorption measurements. The charge-separated state of CNHs(-)-COO-(Cu(II)tpy)+ has been confirmed with the aid of an electron mediator, such as hexyl-viologen dication (HV2+) and an electron-hole shifter in polar solvents.
通过铜（II）-2,2':6',2''-三联吡啶（Cu（II）tpy）与氧化碳纳米角（CNHs-COOH）配位，制备了细长碳纳米管家族中的新型金属纳米结构材料——碳纳米角（CNHs）。所得的CNHs-COO-Cu（II）tpy金属纳米复合物已通过多种分析光谱工具以及循环伏安法和差分脉冲伏安法进行了表征。利用扫描透射电子显微镜（STEM）、动态光散射（DLS）和能量色散X射线光谱（EDX）测量来探测CNHs-COO-Cu（II）tpy的形态特征和粒径分布，并研究金属纳米复合物的元素组成。稳态和时间分辨荧光发射研究表明存在有效的荧光猝灭，这表明电子从Cu（II）tpy的单重激发态转移到CNHs。瞬态吸收测量表明，Cu（II）tpy的光激发导致纳米角的单电子还原，同时Cu（II）tpy单元发生单电子氧化（CNHs（-）-COO-（Cu（II）tpy）+）。借助电子介质，如己基紫精二价阳离子（HV2+）和极性溶剂中的电子-空穴转移剂，证实了CNHs（-）-COO-（Cu（II）tpy）+的电荷分离状态。
