ChemRxiv.org
The Preprint Server for Chemistry, operated by the American Chemical Society

Chem.de
FIZ Chemie Berlin, GDCh, TIB Hannover

Chemie.DE
Deutsches Forschungsnetz, Fachbereich Chemie der FU Berlin

organische-chemie.ch
B. Bart, R. Müller

ATSDR
AGENCY FOR TOXIC SUBSTANCES AND DISEASE REGISTRY

ChemView
U.S. Environmental Protection Agency

GESTIS Stoffdatenbank
Gefahrstoffinformationssystem der gewerblichen Berufsgenossenschaften

Lebensmittelzusatzstoffe (E-Nummern)
Die Verbraucher Initiative, Bonn

NIOSH DATABASES
u.a. "International Chemical Safety Cards"

TOXNET
Toxicology Data Network

The Cambridge Structural Database (CSD)
The Cambridge Crystallographic Data Centre (CCDC)

CHEMnetBASE
Suchfunktion zu "CRC Handbook of Chemistry and Physics" und anderen Nachschlagewerken

ChemSpider
Access to millions of chemical structures - RSC

Crystallography Open Database
Including data and software from CrystalEye

eMolecules
Search over 6 million unique structures for technical and supplier

IUPAC Compendium of Chemical Terminology
"Gold Book" This online version corresponds to the second edition, compiled by Alan D. McNaught and Andrew Wilkinson.

IUPAC Nomenclature of Organic Chemistry
Published with permission of the IUPAC by ACD

molMall
Partner of the MDPI Sustainability Foundation

NIST Physical Reference Data
National Institute of Standards and Technology, USA (Physikalische Konstanten und Daten)

Sigma-Aldrich
Zugang zu den Katalogen verschiedener Chemikalien-Hersteller

Synthesis Reviews
Database of 20'000 review articles of interest to synthetic organic chemists, University of Leeds

WebElements
Anklickbares Periodensystem, Mark Winter, University of Sheffield, England