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New chemistry database – organoboron compounds

admin — Thu, 18 Apr 2013 08:39:36 +0000

Organoboron Compounds – chem. database
From website: “Boronic acids and their esters are highly popular synthetic intermediates in organic synthesis for their ease and efficiency of conversion to other functional groups, in metal-catalyzed cross-coupling reactions and for their unique biochemical activity.The palladium-catalyzed cross-coupling reaction of organoboron compounds with organic halides or pseudo-halides – the Suzuki-Miyaura reaction – is a remarkably useful tool in organic synthesis.”
Synthesis references and physical data (melting/boiling point, refractive index, density) for more than 2,000 boronic acids, boronic acid esters and trifluoroborates. You can search for substance by chemical name and CAS number.

Cas Registry Number

admin — Sun, 18 Sep 2011 21:20:01 +0000

CAS Registry Numbers are an important tool for substance searching. These are unique identifiers assigned by the Chemical Abstracts Service (CAS) to specific substances identified by them in the chemical literature.

CAS Numbers are not related to chemistry, are unrelated to any previous systems, and do not readily form phonetic analogs or synonyms. The numbers are simple and regular, convenient for database searches.

The format of CAS number is three blocks of numbers divided by hyphens ie. XXX-XX-X. It should will always be read from right to left:

The first block can be between 2 and 6 digits. The second block has only 2 digits and the last block is always a single digit. Any preceding zeros in the first block need to be discarded. For example, the CAS number for formaldehyde is 50-00-0.

Cas numbers save you from having to think of all the different trivial or semisystematic names, synonyms, brand names, or possible systematic names when you are doing a compound search by linking them all into a single search term.

For example, there are over ten synonyms for methanol, e.g., carbinol, methyl hydroxide, methyl alcohol, wood alcohol. The CAS Registry Number for it, 67-56-1, is specific to all those names for the same substance.

Where to find CAS numbers on the Internet? The following free websites can be used:
1) Chemical Synthesis Database
2) Common Chemistry
3) R&D Chemicals
4) Pubchem
5) ChemIDplus

Chemis3D – Molecular Viewer Applet

admin — Tue, 25 Jan 2011 14:45:53 +0000

Chemis3D is a free Java Applet for the online 3D Visualization of Molecular Models. Small molecules as well as macromolecular structures could be manipulated and rendered in a variety of styles and colors. In addition some useful tools permit the user to label atoms or groups and to measure inter-atomic distances. Chemis3D is a small applet, which is quickly loaded and uses most common chemical file formats (*.xyz, *.mol, *.pdb). Its integration in a Web page is very easy and supports many options.

The Nobel Prize in Chemistry 2010

admin — Thu, 07 Oct 2010 06:15:23 +0000

This year’s Nobel Prize in chemistry was awarded jointly to Richard F. Heck, Ei-ichi Negishi and Akira Suzuki for the development of palladium-catalyzed cross coupling.

Left to Right: Richard F. Heck, Ei-ichi Negishi and Akira Suzuki

General scheme of palladium-catalyzed cross coupling reactions

This chemical tool has vastly improved the possibilities for chemists to create sophisticated chemicals, for example carbon-based molecules as complex as those created by nature itself.

Palladium-catalyzed cross coupling is used in research worldwide, as well as in the commercial production of for example pharmaceuticals and molecules used in the electronics industry.