I’m late to the party here, but there are (at least) 59 instances of a C-S-I fragment in the CCDC.
Flipping through the first third of the list, GIGBED (triphenylmethyl-iodo-sulfane) seems somewhat close. The S-I bond is 2.41Å and the C-S-I bond angle is 105.4 degrees. There may be better ones deeper in the list, but that’s someone else’s project to find. (R.Minkwitz, H.Preut, J.Sawatzki, Zeitschrift fur Naturforschung,B:Chemical Sciences, 1988, 43, 399) From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Paul Emsley <pems...@mrc-lmb.cam.ac.uk> Date: Friday, March 18, 2022 at 3:05 AM To: CCP4BB@JISCMAIL.AC.UK <CCP4BB@JISCMAIL.AC.UK> Subject: Re: [ccp4bb] Cysteine-S-Iodine interaction On 17/03/2022 17:37, Mohd Syed Ahangar wrote: > > > I have been doing some protein crystal soaking with some covalently > binding fragments and in one structure I have got an extra density on > Cysteine but that density doesn't match with the expected fragment. > The fragment was in the form of iodide salt. when I fit the Iodine in > the density, it fitted fairly well than any other possible chemical > entity. From the density map it looks like something is covalently > bound to Cysteine. > Now my question is, can a sulphur atom of Cysteine have such an > interaction with Iodine. No, they are both electronegative, C-S-I is not a thing. > The distance between S and Iodine is 2.76A in this case as shown in > the attached figure. > I would be grateful if someone can shed some light on this. > Your map (this figure) is a textbook example of a covalently linked atom incorrectly refined with a non-bonded contact. Paul. ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB<http://www.jiscmail.ac.uk/CCP4BB>, a mailing list hosted by www.jiscmail.ac.uk<http://www.jiscmail.ac.uk>, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/ ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
