Related Experiment Video
Updated: Aug 16, 2026

Hierarchical and Programmable One-Pot Oligosaccharide Synthesis
Published on: September 6, 2019
Atomistic view of the recombinative desorption of H2 from H/Si(100)
1Institute of Physics, National Chiao-Tung University, Hsinchu, Taiwan.
Abstract:
Scanning tunneling microscopy is employed to investigate the recombinative desorption of H2 from hydrogenated Si(100) surfaces consisting of dihydride (SiH2) and monohydride (SiH) surface species organized in (1 x 1), (3 x 1), and (2 x 1) configurations. The results show that desorption from dihydrides involves a pair of neighboring dihydrides linked along the tetrahedral bond direction. Dihydrides in (3 x 1) domains are separated in the same direction by monohydrides, and desorption from a pair is geometrically impossible. The same desorption mechanism nevertheless applies via first a position switching of dihydrides with neighboring monohydrides.
More Related Videos
Related Concept Videos
Acid Halides to Alcohols: LiAlH4 Reduction
The mechanism proceeds in three steps. First, the nucleophilic hydride ion attacks the carbonyl carbon of the acid halide to form a tetrahedral intermediate. Next, the carbonyl group is re-formed, and the halide ion departs as a leaving group, generating an aldehyde. A second nucleophilic attack by the hydride yields an alkoxide ion, which, upon protonation, gives a primary alcohol as...
Hydrolysis
Hydrolysis is a chemical reaction in which the addition of water breaks down a polymer into its simpler monomer units. For example, peptides break into amino acids, carbohydrates into simple sugars, and DNA into nucleotides. Enzymes often facilitate these processes.
Hydrolysis Reverses Dehydration Synthesis
Complex carbohydrates can be broken down by breaking the bonds between individual sugar units. The reaction breaks a glycosidic bond as water is added to the compound. The...
Carboxylic Acids to Primary Alcohols: Hydride Reduction
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Electrophilic 1,2- and 1,4-Addition of HX to 1,3-Butadiene
Acid Halides to Carboxylic Acids: Hydrolysis
As shown below, the mechanism involves a nucleophilic attack by water at the carbonyl carbon to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen π bond along with the departure of a halide ion. A final proton transfer step yields carboxylic acid...

