Icosahedral noble-metal 13-atom nanoclusters (NCs) can form connected structures, which can be regarded as superatomic molecules, by vertex sharing. However, there have been very few reports on the superatomic molecules formed using silver (Ag) as the base element. In this study, we synthesized [Ag23Pd2(PPh3)10Cl7]0 (Pd = palladium, PPh3 = triphenylphosphine, Cl = chloride), in which two icosahedral 13-atom NCs are connected, and elucidated its geometric and electronic structures to clarify what type of superatomic molecules can be synthesized. The results revealed that [Ag23Pd2(PPh3)10Cl7]0 is a synthesizable superatomic molecule. Single crystal x-ray diffraction analysis showed that the metal–metal distances in and between the icosahedral structures of [Ag23Pd2(PPh3)10Cl7]0 are slightly shorter than those of previously reported [Ag23Pt2(PPh3)10Cl7]0, whereas the metal–PPh3 distances are slightly longer. On the basis of several experiments and density functional theory calculations, we concluded that [Ag23Pd2(PPh3)10Cl7]0 and previously reported [Ag23Pt2(PPh3)10Cl7]0 are more stable than [Ag25(PPh3)10Cl7]2+ because of their stronger superatomic frameworks (metal cores). These findings are expected to lead to clear design guidelines for creation of new superatomic molecules.
The unique structural characteristics of threedimensional (3D) covalent organic frameworks (COFs) like high surface areas, interconnected pore system and readily accessible active sites render them promising platforms for a wide set of functional applications. Albeit promising, the reticular construction of 3D COFs with large pores is a very demanding task owing to the formation of interpenetrated frameworks. Herein we report the designed synthesis of a 3D non-interpenetrated stp net COF, namely TUS-64, with the largest pore size of all 3D COFs (47 Å) and record-low density (0.106 g cm À 3 ) by reticulating a 6-connected triptycenebased linker with a 4-connected porphyrin-based linker. Characterized with a highly interconnected mesoporous scaffold and good stability, TUS-64 shows efficient drug loading and controlled release for five different drugs in simulated body fluid environment, demonstrating the competency of TUS-64 as drug nanocarriers.
Three-dimensional (3D) covalent organic frameworks (COFs)
exemplify
a new generation of crystalline extended solids with intriguing structures
and unprecedented porosity. Notwithstanding substantial scope, the
reticular synthesis of 3D COFs from pre-designed building units leading
to new network topologies yet remains a demanding task owing to the
shortage of 3D building units and inadequate reversibility of the
linkages between the building units. In this work, by linking a tetragonal
prism (8-connected) node with a square planar (4-connected) node,
we report the first 3D COF with scu-c topology. The new
COF, namely, TUS-84, features a two-fold interpenetrated structure
with well-defined porosity and a Brunauer–Emmett–Teller
surface area of 679 m2 g–1. In drug delivery
applications, TUS-84 shows efficient drug loading and sustained release
profile.
Silver cluster-assembled materials (SCAMs) are emerging light-emitting materials with molecular-level structural designability and unique photophysical properties. Nevertheless, the widespread application scope of these materials is severly curtailed by their dissimilar...
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