Water-halogen interactions in chlorine and bromine clathrate hydrates: An example of multidirectional halogen bonding

Download
  1. Get@NRC: Water-halogen interactions in chlorine and bromine clathrate hydrates: An example of multidirectional halogen bonding (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1021/jp402399r
AuthorSearch for: ; Search for: ; Search for:
TypeArticle
Journal titleThe Journal of Physical Chemistry C
ISSN1932-7447
Volume117
Issue27
Pages1417614182; # of pages: 7
SubjectEffective diameter; Hydrate structures; Multi-directional; Structural details; Tetragonal structure; Van der Waals radius; Water oxygen atoms; X-ray structural determination; Chlorine; Crystal structure; Hydration; Molecules; X rays; Hydrates
AbstractThere are unresolved questions in our understanding of the clathrate hydrates with halogen molecule guests. In this work, we describe the synthesis and single crystal X-ray structural determination of cubic structure I (sI) Cl2, tetragonal structure III (sIII) Br2, and mixed cubic sI Cl2-Br2 clathrate hydrate phases. Unlike the previous X-ray structural determination of the pure chlorine clathrate hydrate by Pauling and Marsh (Proc. Nat. Acad. Sci. USA1952, 38, 112), we report that 32.5% of the clathrate small cages are occupied by Cl2 molecules. Pure Br 2 produces the unique tetragonal sIII clathrate hydrate whose structure is refined from single-crystal measurements, identifying disordered Br2 guest positions in cages and giving structural details not previously identified. In mixed sI clathrate hydrate of Cl2 and Br2, we observed that Br2 guests fit into the large sI cages. The introduction of Br2 in the Cl2 hydrate lattice causes severe distortions because of strong Br⋯OH2 interactions. In these three hydrate structures, based on accepted van der Waals radii, the effective diameters of the clathrate hydrate cages are smaller than the size of the Cl2 and Br2 guest molecules. The accommodation of these guests in the cages and the short O⋯Cl and O⋯Br contact distances reveal halogen bonding between the water oxygen atoms and the dihalogen guests. The X-ray structural determinations of the length of the Cl-Cl and Br-Br bonds of the Cl2 and Br2 guests show significant librational shortening compared to free Cl2 and Br2 molecules.
Publication date
LanguageEnglish
AffiliationSecurity and Disruptive Technologies; National Research Council Canada
Peer reviewedYes
NPARC number21270509
Export citationExport as RIS
Report a correctionReport a correction
Record identifier208ce3b3-f37b-4132-8d17-b1b19fb07a8d
Record created2014-02-14
Record modified2017-03-23
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)