Subject: QSARs for molar absorptivity - summary

From: "Manchester, John" <[email-masked]>
Date: Thu, 17 Aug 2000 06:39:42 -0400

Only got 2 responses to this post, pointing to approximate MO methods (ZINDO
and VAMP, now part of Tsar).  Depending on your point of view, maybe these
can be considered QSARs.  Except their accuracy doesn't depend on a logP
calculator  (that's an attempt at humor--it's still quite early here).  Many
thanks to Cikiu Liang and Doug Smith for their replies.

John

RESPONSES:
-----
Zindo should be a good code for calcuating UV/Vis absorption spectra.
Details please refer to http://www.msi.com/materials/cerius2/zindo.html.
Hope this helps.

Best Regards,
Cikui
-----

If you have Tsar or our new Tsar for Windows, along with VAMP (Tim Clark's
semiempirical MO package that comes with the 3D version of Tsar) then you
can perform calculations of UV/vis spectra using standard CI methods.
Because Tsar works using a spreadsheet format, you can set up and calculate
this and other properties for tens of thousands of compounds at once.  You
can also use the Neural Network capability within Tsar to create a model for
molecular absorptivity based on your UV spectra calculations, other
descriptors, and experimental data.

Tsar runs on SGI while Tsar for Windows runs on Intel and Intel-compatible
processors.  The complete Tsar for Windows package, including VAMP, is quite
reasonably priced.

For more information on these products, please contact me via email at
[email-masked] or your local OMG sales representative.

Doug

-----
ORIGINAL POST:

Hi CCLers,

I'm looking for methods to estimate extinction coefficients (seems like
there ought to be some fragment-based models), or at least cheap ways to
calculate the UV absorption spectra for lots of compounds.  I'd be most
grateful for any information, and will summarize for the net.

Thanks in advance,
John

John Manchester
Senior Scientist			Computational Design & Informatics
tel: 781-994-0317			ArQule, Inc.
fax: 781-938-9789			19 Presidential Way
[email-masked]		Woburn, MA 01801
http://www.arqule.com