Construction of conducting bimetallic organic metal chalcogenides via selective metal metathesis and oxidation transformation

Abstract

Conducting organic metal chalcogenides (OMCs) have attracted considerable interest for their superior electrical properties and fascinating functions. However, the electronic structural and functional regulation of OMCs are typically limited to the combination of monometallic nodes and graphene-like ligands. Here, we report a family of bimetallic OMCs ([CuAgx(C6S6)]n, x = 4 or 2) synthesized via selective metal metathesis and oxidation transformation. Both OMCs have alternatively stacked one-dimensional (1D) copper-dithiolene chains and 2D Ag-S networks, which can synergistically serve as charge transport pathways, rendering these bimetallic materials highly conductive. The incorporation of heterometallic nodes turned nonmagnetic [Ag5(C6S6)]n into paramagnetic metallic [CuAg4(C6S6)]n, which exhibited a coherence-incoherence crossover in magnetic susceptibility measurements and an unusually large Sommerfeld coefficient, reminiscent of the characteristics of Kondo lattice. This work opens up an avenue for tailoring the electronic structures of OMCs and provides a platform for studying the dichotomy between electronic localization and itinerancy.

Nonporous, conducting bimetallic coordination polymers with an advantageous electronic structure for boosted faradaic capacitance

“…Ag 5 BHT and CuAg 4 BHT were synthesized via coordination assembly and subsequently metal metathesis according to our previous work. 34 As shown in Fig. 1a and b, the experimental powder X-ray diffraction (PXRD) patterns of the attained samples match well with the simulated ones in peak positions, identifying the successful preparation of these two CPs.…”

“…Density functional theory (DFT) calculations revealed that the total energy of Ag 5 BHT (À122.4 eV) is higher than that of CuAg 4 BHT (À125.6 eV), suggesting that this selective metal metathesis reaction is a thermodynamically favorable process. 34 Additionally, the density of state (DOS) near the Fermi level in monometallic Ag 5 BHT mainly originates from the S-p orbitals and Ag-d orbitals, showing that the two-dimensional Ag-S network is the preferred charge transport path. 33,34 However, for CuAg 4 BHT, due to copper incorporation into the framework, the DOS near the Fermi level is dominated by contributions from the d orbitals of Cu and Ag and p orbitals of S. Besides, in terms of the electrically neutral framework, the chemical state of the ligand moiety in CuAg 4 BHT can be proposed to be À6.…”

“…34 Additionally, the density of state (DOS) near the Fermi level in monometallic Ag 5 BHT mainly originates from the S-p orbitals and Ag-d orbitals, showing that the two-dimensional Ag-S network is the preferred charge transport path. 33,34 However, for CuAg 4 BHT, due to copper incorporation into the framework, the DOS near the Fermi level is dominated by contributions from the d orbitals of Cu and Ag and p orbitals of S. Besides, in terms of the electrically neutral framework, the chemical state of the ligand moiety in CuAg 4 BHT can be proposed to be À6. Compared with that of Ag 5 BHT, the charge redistribution induced by metal metathesis could be found in this c-CPs, which is also illustrated by the electron density distribution maps (Fig.…”

“…33 By optimizing the transmetallation reaction conditions, another electrochemically active nonporous c-CP (CuAg 4 BHT) was derived, in which the square-planar Ag ions in Ag 5 BHT were precisely replaced by Cu ions. 34 Herein, two nonporous c-CPs, Ag 5 BHT and CuAg 4 BHT, were synthesized and their electrochemical properties in organic SCs were systematically studied. The results show that Ag 5 BHT and CuAg 4 BHT are battery-type capacitor materials displaying a large potential window of 1.1 V in an aqueous electrolyte, which is much wider than the recently reported c-MOF electrodes (0.5 V, Cu–CAT NWAs; 19 0.5 V, Ni 3 (HIB) 2 ; 22 0.7 V, Cu-DBC; 35 0.7 V, CNF@Ni-HITP) 36 and is essential for enhancing the energy density of asymmetric SC devices.…”