Center for Functional Nanomaterials Seminar

Since the discovery of the prototypical fullerene “Buckminsterfullerene” C60 by Kroto, Heath, O’Brien, Curl and Smalley,1 fullerene chemistry has been developed into a mature field. Isolation of IPR fullerenes up to C96 has been reported in the past 20 years.2 Recently, increasing experimental efforts have been devoted to the isolation of larger IPR fullerenes as well as non-IPR isomers of lower fullerenes (smaller than C80).3 For such a purpose, we have studied the complete set of non-IPR fullerenes C38 - C80 and large IPR fullerene C82 - C120. The best candidates with the lowest electronic energy at density functional theory (DFT) level were predicted for the first time. Theoretical challenge associated with the global search of low-energy structures of large-sized fullerenes stems mainly from the rapid increase of the number of isomers with the fullerene size. For example, the total number of fullerene isomers for C110 is 713,319. For solving the problem, the semiempirical density functional tight binding (DFTB) method was applied as a pre-screening tool efficiently.
Ligand-protected gold nanoparticles (AuNP) have attracted considerable interest because of their promising applications in nanocatalysis, medicine, and optical devices. Two major breakthroughs were made in total structure determination of thiolate-protected gold clusters, namely, Au102(p-MBA)44 and Au25(SR)18.4,5 Significantly, the notion of “staple motif” is firmly established based on these two clusters. This talk will present a theoretical prediction of the most viable structure of the newly synthesized “magic cluster” Au20(SR)16 (R = CH2CH2Ph).6 A related finding is the possible existence of a new type of extended staple motif, namely, -RS-Au-RS-Au-RS-Au-RS-. Homoleptic gold thiolate clusters (AuSR)N (N = 6-12) were also studied theoretically.