CCL: Trans azo benzene

Dear CCL'ers,
Don't forget about the CCCBDB (http://cccbdb.nist.gov">cccbdb.nist.gov). It contains experimental and computed (quantum mechanics) thermochemical data for a selected set of 1709 gas-phase atoms and small molecules. Molecules less than 9 heavy atoms and 20 or fewer total atoms are present. Azobenzene is too large, but aniline is in there, with geometries and energies computed with about 125 model chemistries. Also both E- and Z-azomethane.
John Keller
University of Alaska Fairbanks


On Sun, Dec 20, 2015 at 8:54 AM, John McKelvey jmmckel^gmail.com <owner-chemistry]~[ccl.net> wrote:
Henry,

Thank for the torsion data in the graphs. Could you provide the color code for the entries in the two graphs?  Info on substituted azobenzenes is also relevant.

For the moment the issue is  constrained to computed geometries in vacuum, XRAY, and neutron diffraction structures.

Best regards,

John

 

On Sun, Dec 20, 2015 at 4:20 AM, Rzepa, Henry S h.rzepa::imperial.ac.uk <owner-chemistry++ccl.net> wrote:
John,

Here is a possible answer: http://www.ch.imperial.ac.uk/rzepa/blog/?p=15141  (Sorry, it contains images which  I would rather not post as attachments here).

Sadly, there is no generally accepted database of computed molecular geometries, only for experimental structures. But  I would add that an organisation called  DataCite collects metadata about computed results that have been published in a data repository supporting  DataCite, and it should be possible to mine such repositories for metadata relating to azobenzene and the computational methods, retrieve the coordinates, and establish the required dihedral.  This is part of the aspects of  RDM (Research data management) about which there will be a two day session at the  ACS meeting in  San Diego in March 2016.  Do come along if you want to contribute suggestions for general solutions to questions such as  John posed here.

On 18 Dec 2015, at 21:06, John McKelvey jmmckel*gmail.com <owner-chemistry a ccl.net> wrote:

Hello,

Could anyone comment on any recent calculated results on the planarity, or lack thereof, of azobenzene?

Thanks!

John
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John McKelvey
545 Legacy Pointe Dr




--
John McKelvey
545 Legacy Pointe Dr