Accurate Single-Molecule Indicator of Solvent Effects

Abstract

The study of the microscopic structure of solvents is of significant importance for deciphering the essential solvation in chemical reactions and biological processes. Yet conventional technologies, such as neutron diffraction, have an inherent averaging effect as they analyze a group of molecules. In this study, we report a method to analyze the microstructure and interaction in solvents from a single-molecule perspective. A single-molecule electrical nanocircuit is used to directly analyze the dynamic microscopic structure of solvents. Through a single-molecule model reaction, the heterogeneity or homogeneity of solvents is precisely detected at the molecular level. Both the thermodynamics and the kinetics of the model reaction demonstrate the microscopic heterogeneity of alcohol–water and alcohol– n -hexane solutions and the microscopic homogeneity of alcohol–carbon tetrachloride solutions. In addition, a real-time event spectroscopy has been developed to study the dynamic characteristics of the segregated phase and the internal intermolecular interaction in microheterogeneous solvents. The development of such a unique high-resolution indicator with single-molecule and single-event accuracy provides infinite opportunities to decipher solvent effects in-depth and optimizes chemical reactions and biological processes in solution.

Nanoarchitectonics of molecular self assembled monolayers by transition metal ion intercalation for enhancement of molecular junction conductivity

“…A key advantage of molecular electronics lies in the vast array of structural and electronic functionalities available, which vary based on the synthesis method employed. [6][7][8][9][10] The operational characteristics of molecular devices can be ne-tuned by modifying either the molecular backbone or the edge groups that connect to the electrodes, see ref. [11][12][13] for further details.…”

Monitoring Molecular Dynamics with Single‐Molecule Electronic Devices and Fluorescence Techniques†

“…(b) Schematic diagram of a single‐molecule model reaction to detect solvent effects. Reprinted with permission, [ 40 ] Copyright 2021, American Chemical Society. (c) Schematic diagram of the resistance switching via single‐molecule Fries rearrangement.…”

“…For example, a single‐molecule electrical nanocircuit was used to directly detect the microscopic heterogeneity of the solution and compare interactions in solvent networks (Figure 2b). [ 40 ] Experimental results showed that RS and intermediate (IM) have opposite solvent polarity preference, with IM tending to be stable in high‐polarity solvents while RS tends to be stable in low‐polarity solvents. As solvent polarity increased, the dwell time τ (kinetics) of IM gradually increased and contributed a major proportion of the conductance states (thermodynamics).…”

Tunable Interferometric Effects between Single-Molecule Suzuki–Miyaura Cross-Couplings

“…However, to further guide the macroscopic synthesis and industrial production, the gap between single molecule and ensemble should be bridged. Following the above train of thought, SMD can be regarded as the starting point to investigate the emergent complexity from bottom to top . One unique example is to measure the polymerization dynamics of one chain, demonstrating the emergent anomalous behaviors accompanied by increased molecular numbers .…”

“…Following the above train of thought, SMD can be regarded as the starting point to investigate the emergent complexity from bottom to top. 20 One unique example is to measure the polymerization dynamics of one chain, demonstrating the emergent anomalous behaviors accompanied by increased molecular numbers. 13 However, the universal method of measuring the cross-correlation among single-molecule organic reactions and especially the contained elementary step remains a nontrivial task.…”