Two-Dimensional Nanosheets from Redox-Active Superatoms

Abstract

We describe a new approach to synthesize two-dimensional (2D) nanosheets from the bottom-up. We functionalize redox-active superatoms with groups that can direct their assembly into multidimensional solids. We synthesized Co6Se8[PEt2(4-C6H4COOH)]6 and found that it forms a crystalline assembly. The solid-state structure is a three-dimensional (3D) network in which the carboxylic acids form intercluster hydrogen bonds. We modify the self-assembly by replacing the reversible hydrogen bonds that hold the superatoms together with zinc carboxylate bonds via the solvothermal reaction of Co6Se8[PEt2(4-C6H4COOH)]6 with Zn(NO3)2. We obtain two types of crystalline materials using this approach: one is a 3D solid and the other consists of stacked layers of 2D sheets. The dimensionality is controlled by subtle changes in reaction conditions. These 2D sheets can be chemically exfoliated, and the exfoliated, ultrathin 2D layers are soluble. After they are deposited on a substrate, they can be imaged. We cast them onto an electrode surface and show that they retain the redox activity of the superatom building blocks due to the porosity in the sheets.

Selective Synthesis of Site-Differentiated Fe4S4 and Fe6S6 Clusters

“…Synthetic metal-chalcogenide clusters have been actively studied for decades owing to their applications in a number of diverse settings. For example, they serve as models for the active sites of Fe-S proteins, [1][2][3] as building blocks in nanomaterials, [4][5][6][7] and as catalysts in their own right. [8][9][10][11][12][13][14][15][16][17] Their broad utility in both biological and abiological contexts derives in part from the diversity of their geometric and electronic structures.…”

Heavy chalcogenide-transition metal clusters as coordination polymer nodes

“…11A) or a tetragonal 2D crystalline solid (Tet 2D) if additional HCl is added during the synthesis. 53 While the structure of Trig 3D is a complicated network in which each {Co 6 Se 8 [-PEt 2 (4-C 6 H 4 COO)] 6 } 6À cluster is coordinated to six unusual trinuclear Zn nodes (Fig. 11B), Tet 2D is a stacked 2D material in which each layer is a square of Co 6 Se 8 clusters bonded to four Zn-carboxylate paddlewheels in the plane (Fig.…”

Dimensional Control of Assembling Metal Chalcogenide Clusters

“…Along with previously described 1D‐, and 2D‐materials, 3D‐crystalline materials were obtained via solvothermal reaction of a [Co 6 Se 8 PEt 2 (4‐C 6 H 4 COOH)] 6 building block with a divalent zinc source . The carboxylic acid functionalized cluster forms two types of materials upon reaction with Zn(NO 3 ) 2 in which the dimensionality is controlled by small alterations in the solvent system from DMF/methanol to DMF/ethanol.…”