Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Structures as shown were modified from Sigma-Aldrich (www.sigma.com) and constructed in ChemSketch (ACD/Labs, Toronto, Ontario, Canada).
