Chiral 鈥淧inwheel鈥?Heterojunctions Self-Assembled from C60 and Pentacene

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• 作者：Joseph A. Smerdon ; Rees B. Rankin ; Jeffrey P. Greeley ; Nathan P. Guisinger ; Jeffrey R. Guest
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：April 23, 2013
• 年：2013
• 卷：7
• 期：4
• 页码：3086-3094
• 全文大小：566K
• 年卷期：v.7,no.4(April 23, 2013)
• ISSN：1936-086X

文摘

We demonstrate the self-assembly of C₆₀ and pentacene (Pn) molecules into acceptor鈥揹onor heterostructures which are well-ordered and鈥攄espite the high degree of symmetry of the constituent molecules鈥?i>chiral. Pn was deposited on Cu(111) to monolayer coverage, producing the random-tiling (R) phase as previously described. Atop R-phase Pn, postdeposited C₆₀ molecules cause rearrangement of the Pn molecules into domains based on chiral supramolecular 鈥減inwheels鈥? These two molecules are the highest-symmetry achiral molecules so far observed to coalesce into chiral heterostructures. Also, the chiral pinwheels (composed of 1 C₆₀ and 6 Pn each) may share Pn molecules in different ways to produce structures with different lattice parameters and degree of chirality. High-resolution scanning tunneling microscopy results and knowledge of adsorption sites allow the determination of these structures to a high degree of confidence. The measurement of chiral angles identical to those predicted is a further demonstration of the accuracy of the models. van der Waals density functional theory calculations reveal that the Pn molecules around each C₆₀ are torsionally flexed around their long molecular axes and that there is charge transfer from C₆₀ to Pn in each pinwheel.

Keywords:

pentacene; carbon-60; scanning tunneling microscopy; chirality; pinwheel