Subject: posphinic acid parameters

From: Alfonso Garcia Sosa <[email-masked]>
Date: Mon, 27 Jan 2003 15:21:40 +0000 (GMT)

Dear all, would anyone have any information/experience on
forcefield parameters of phosphinic acid derivatives (a phosporous atom
bonded to two oxygens, and to two alifatic carbons which are part of
chains):

   O
-C-P-C-O-C-
   O

or

     |
    -C-
     |
   O=P=O
     |
     O
     |
    -C-
     |

for use in amber (or other forcefields?).

I've had a look in some files and literature but couldn't find the
information. There are some old ab-initio studies on their geometries, but
no charges, or force constants. Could the data be derived from other data
on phosphate or phosphonic data?

Specifically, I was looking for

P-C, P=O distances and energies;
C-P-C, O-P-C, and O-C-P angles;
and related dihedrals.

Any help would be much appreciated. Thanks and have a nice week

--
Alfonso T Garcia-Sosa [email-masked] Tel(44)1223238042, (44)07966465513
http://www.cus.cam.ac.uk/~atg21
Drug Design Group, Dept. of Pharmacology, University of Cambridge
& Wolfson College, Cambridge CB3 9BB, UK
& De Novo Pharmaceuticals, Histon, Cambridge CB4 9ZR, UK