# Role of Spectator Species for Amine-Surface Chemistry: Reactions of Amines and Alkenes on Pt(111)

## TL;DR

This study shows that ethylidyne actively participates in amine-surface chemistry on platinum, challenging the belief that it is just a passive observer.

## Contribution

The paper reveals that ethylidyne acts as both a reaction partner and a stabilizer in hydroamination on Pt(111).

## Key findings

- Ethylidyne transfers a methyl group to NMA, forming N,N-dimethylaniline.
- Ethylidyne stabilizes reaction intermediates and prevents NMA decomposition.
- Ethylene reacts with NMA decomposition products when coadsorbed.

## Abstract

This study investigates the roles of ethylene and ethylidyne
in
the surface chemistry of N-methylaniline (NMA) on
Pt(111). Using X-ray photoelectron spectroscopy, temperature-programmed
desorption, and density functional theory calculations, we demonstrate
that ethylidyne is not merely a passive spectator species but actively
contributes to hydroamination. It facilitates C–N bond formation
by transferring a methyl group to NMA, leading to the formation of N,N-dimethylaniline. Additionally, it stabilizes
reaction intermediates and suppresses the decomposition of NMA. This
works demonstrates, in contrast to the widely accepted notion, that
ethylidyne is not just an inert spectator species; rather, it plays
a dual role as both an active reaction partner and a stabilizer. In
addition, the coadsorption of ethylene on an NMA-precovered surface
shows a side reaction of ethylene with the decomposition products
of NMA.