Nanocluster growth via graft-onto: effects on geometric structures and optical properties

Atomically precise engineering on the nanocluster surface remains highly desirable for the fundamental understanding of how surface structures of a nanocluster contribute to its overall properties. In this paper, the concept of graft-onto has been exploited to facilitate nanocluster growth on surface structures. Specifically, the Ag-2(DPPM)Cl-2 complex is used for re-constructing the surface structure of Pt1Ag28(SR)(18)(PPh3)(4) (Pt1Ag28, SR = 1-adamantanethiolate) and producing a size-growth nanocluster - Pt1Ag31(SR)(16)(DPPM)(3)Cl-3 (Pt1Ag31). The grafting effect of Ag-2(DPPM)Cl-2 induces both direct changes on the surface structure (e.g., size growth, structural transformation, and surface rotation) and indirect changes on the kernel structure (from a fcc configuration to an icosahedral configuration). Remarkable differences have been observed by comparing optical properties between Pt1Ag28 and Pt1Ag31. Significantly, Pt1Ag31 exhibits high photo-luminescent intensity with a quantum yield of 29.3%, which is six times that of the Pt1Ag28. Overall, this work presents a new approach (i.e., graft-onto) for the precise dictation of nanocluster surface structures at the atomic level.