Related Experiment Video
Updated: Feb 3, 2026
11:00
Determination of the Gas-phase Acidities of Oligopeptides
Published on: June 24, 2013
11.6K
Gas Phase Organic Functionalization of SiO2 with Propanoyl Chloride
Ryan J Gasvoda1, Scott Wang2, Dennis M Hausmann3
1Department of Chemical and Biological Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States.
Langmuir : the ACS Journal of Surfaces and Colloids
|October 31, 2018
Summary
Propanoyl chloride reacts with SiO2 films, forming ester linkages at high temperatures. At lower temperatures, a stable enol tautomer forms, influencing surface functionalization and hydrocarbon coverage on silica surfaces.
Area of Science:
- Surface Chemistry
- Materials Science
- Spectroscopy
Background:
- Surface functionalization of silicon dioxide (SiO2) is crucial for tailoring material properties.
- Understanding reaction mechanisms on SiO2 surfaces informs the development of advanced materials and coatings.
- Propanoyl chloride is a reactive acylating agent used in organic synthesis and surface modification.
Purpose of the Study:
- To investigate the reaction mechanism of propanoyl chloride with hydroxyl-terminated SiO2 films.
- To determine the temperature dependence of the surface functionalization reaction.
- To elucidate the formation and stability of different reaction products on the SiO2 surface.
Main Methods:
- In situ surface infrared spectroscopy was employed to monitor the reaction.
- SiO2 films with surface hydroxyl groups (-SiOH) were exposed to propanoyl chloride (C2H5COCl).
- Reactions were studied at varying temperatures (70 °C and 230 °C).
Main Results:
- Propanoyl chloride reacts with -SiOH groups to form ester linkages at 230 °C.
- At 70 °C, ketone groups transform into a thermally stable enol tautomer.
- The enol form, stabilized by hydrogen bonding, is directly formed at 70 °C and is unreactive with water at this temperature.
- Higher temperatures and water exposure can increase overall hydrocarbon coverage.
Conclusions:
- The surface functionalization of SiO2 with propanoyl chloride is highly temperature-dependent.
- A stable enol tautomer of the reaction product can form and persist on the SiO2 surface.
- Water plays a role in modifying the surface and increasing reactive sites at elevated temperatures, enabling further functionalization.
Related Concept Videos
01:17Gas Chromatography: Types of Columns and Stationary Phases
2.4K
Gas chromatography (GC) relies on stationary phases to separate and analyze components in a sample. There are two main types of stationary phases: liquid and solid. Liquid stationary phases are non-volatile, thermally stable, and chemically inert liquids coated onto the column. Solid stationary phases are particles of adsorbent material, such as silica gel or molecular sieves.
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
For an analyte to remain on the column for a sufficient amount of time, it must exhibit some level of compatibility (or...
2.4K
02:39Phase Diagrams
50.2K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
50.2K
02:31Phase Transitions
23.2K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
23.2K
01:20Gas Exchange and Transport
76.9K
Gas exchange, the intake of molecular oxygen (O2) from the environment and the outflow of carbon dioxide (CO2) into the environment, is necessary for cellular function. Gas exchange during respiration occurs largely via the movement of gas molecules along pressure gradients. Gas travels from areas of higher partial pressure to areas of lower partial pressure. In mammals, gas exchange occurs in the alveoli of the lungs, which are adjacent to capillaries and share a membrane with them.
76.9K
02:34Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules
37.5K
The test of the kinetic molecular theory (KMT) and its postulates is its ability to explain and describe the behavior of a gas. The various gas laws (Boyle’s, Charles’s, Gay-Lussac’s, Avogadro’s, and Dalton’s laws) can be derived from the assumptions of the KMT, which have led chemists to believe that the assumptions of the theory accurately represent the properties of gas molecules.
37.5K
02:33Phase Transitions: Sublimation and Deposition
20.2K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
20.2K