Chemistry

pKa is an acid dissociation constant used to describe the acidity of a particular molecule. Its value is directly related to the structure of the given compound. This website contains various online resources about organic chemistry.

ChemSpider is a free chemical structure database providing fast text and structure search access to over 100 million structures from hundreds of data sources.

Comprehensive one-volume reference resource for science research. It is sometimes nicknamed the "Rubber Bible" or the "Rubber Book", as CRC originally stood for "Chemical Rubber Company"

National Institute of Standards and Technology. Search by formula, name, InChI Key, or CAS Number.

PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.

Organized by the National Institute of Advanced Industrial Science and Technology (AIST) in Japan.

Publication of reliable methods for the preparation of organic compounds

ChemSynthesis is a freely accessible database of chemicals. This website contains substances with their synthesis references and physical properties such as melting point, boiling point and density. There are currently more than 40,000 compounds and more than 45,000 synthesis references in the database.

ChemSpider is a free chemical structure database providing fast text and structure search access to over 100 million structures from hundreds of data sources.

Founded in 1974, EMBL is Europe’s flagship laboratory for the life sciences – an intergovernmental organisation with more than 80 independent research groups covering the spectrum of molecular biology. It operates across six sites: Heidelberg, Barcelona, Hamburg, Grenoble, Monterotondo and EMBL-EBI Hinxton.

PubChem is the world's largest collection of freely accessible chemical information. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical properties, biological activities, safety and toxicity information, patents, literature citations and more.