Effect of Intermolecular Distance on Surface-Plasmon-Assisted Catalysis

Abstract

4-Aminothiophenol (PATP) and 4-aminophenyl disulfide (APDS) in contact with silver will form HN-CH-S-Ag (PATP-Ag), and under the conditions of surface-enhanced Raman spectroscopy (SERS), a coupling reaction will generate 4,4-dimercaptoazobenzene (DMAB). DMAB is strongly Raman-active, showing strong peaks at ν ≈ 1140, 1390, and 1432 cm, and is widely used in surface-plasmon-assisted catalysis. Using APDS, PATP, p-nitrothiophenol (PNTP), and p-nitrodiphenyl disulfide (NPDS) as probe molecules, Raman spectroscopy and imaging techniques have been used to study the effect of intermolecular distance on surface-plasmon-assisted catalysis. Theoretically, PATP-Ag formed from APDS will be bound at proximal Ag atoms on the Ag surface due to S-S bond cleavage. The results show that APDS is more prone to surface-plasmon-assisted catalytic coupling due to the smaller distance between surface PATP-Ag moieties than those derived from PATP. Therefore, APDS has a higher reaction efficiency, better Raman activity, and better Raman imaging than does PATP. Analogous experiments with PNTP and NPDS gave similar results. Thus, this technique has great application prospects in the fields of surface chemistry and materials chemistry.

Isomerization of p,p′-Diiodoazobenzene Controlled by the Surface Plasmon-Assisted Reaction

“…22,23 Also, it has been proven that the outstanding SERS performance exhibits high sensitivity with the limit of detection as low as 10 –9 M. 24 Most importantly, the mapping technique in SERS detection can be used to sweep multiple points in a randomly selected region, which avoids the contingency of the experiment, improves the experimental reproducibility, and provides an intuitive image in monitoring this isomerization reaction process. 25,26…”

“…SERS has been recognized to be an effective method in investigating the intermolecular interactions and monitoring plasmon-assisted reactions. − Since the discovery of plasma-driven chemical reactions, there have been numerous reports on its mechanism and influencing factors. − Note that characterization of the isomerized structure of azobenzene derivatives using the SERS technique has the advantages of fast response time − and 10 5 –10 8 times enhanced Raman signal intensity. , Also, it has been proven that the outstanding SERS performance exhibits high sensitivity with the limit of detection as low as 10 –9 M . Most importantly, the mapping technique in SERS detection can be used to sweep multiple points in a randomly selected region, which avoids the contingency of the experiment, improves the experimental reproducibility, and provides an intuitive image in monitoring this isomerization reaction process. , …”

Plasmon-Assisted Transfer Hydrogenation: Kinetic Control of Reaction Chemoselectivity through a Light Illumination Mode

“…29 Actually, the plasmon-assisted reaction selectivity was realized through the tuning of the light excitation wavelength, the distance between the reacting molecules and plasmon-active nanostructures, or the utilization of bimetallic heterostructures. 30,31 Generally, one extraordinary point should be taken into account in plasmon (photo)catalysis: the fact that the plasmon triggering of chemical transformation combines the photoinitiation with the heterogeneous process. 32 acts like photocatalyst molecules in solution, a number of additional processes occurring at the solid/liquid interface during the chemical transformation should be considered.…”

“…The realization of particular mechanisms depends on the formation of metal–molecular complexes and the related overlapping of molecular orbitals with the noble metal surface, energy distribution of plasmon-excited hot carriers, and many others related factors. − It could be expected that different plasmon-assistance mechanisms lead to the excitation of particular molecular bonds and the formation of different intermediates with subsequent selective chemical transformation . Actually, the plasmon-assisted reaction selectivity was realized through the tuning of the light excitation wavelength, the distance between the reacting molecules and plasmon-active nanostructures, or the utilization of bimetallic heterostructures. , …”

Distance-regulating surface plasmon catalyzed coupling reaction of p-nitrophenyl disulfide

“…In the past decade, the development of surface-enhanced Raman spectroscopy (SERS) has provided an effective means to study single-molecule behavior. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Researchers in plasma chemistry have also applied the average enhancement effect of SERS to the theoretical analysis of hot particles with particle enhancement and particle coupling hotspots. Plasma excitation not only drives chemical reactions, but also cleaves specic chemical bonds using hot electrons as nanometer scissors.…”