Abstract
Exploratory crossed molecular beam studies of bimolecular reactions of alkaline earth dihalides with halogen containing compounds are reported. The c.m. product distribution is symmetric about ϑ=90° for the BaI2+Cl2 halogen-exchange reaction indicating formation of a collision complex which persists for a least a few rotational periods. The data are consistent with, but do not establish, formation of a similar complex in the SrI2+Cl2 reaction and with a statistical loose transition state energy partitioning in both reactions. The BaI2+HCl→BaICl+HI reaction is direct, favoring backscattering of the metal atom. Relative total reaction cross sections for the MX2+Cl2 halogen-exchange reactions decrease as 1.0:0.45:<0.007 when M is varied from Ba to Sr to Mg. All of these observations support an ion-pair adduct model which was previously advanced to interpret facile four-center exchange reactions of cesium halides with diatomic halogens. This model, which qualitatively correlated observed trends with reactant electronic structure, pictures these present reactions as (MI)+I−+Cl2→ (MI)+(Cl−I−Cl)−→products and (MI)+I−+HCl→ (MI)+(I−H−Cl)−→MICl+HI.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
