Abstract
The basin hopping search algorithm in conjunction with second-order Møller-Plesset perturbation theory is used to determine the lowest energy structures of the radical cation clusters (NH3)n˙(+), (H2O)n˙(+), (HF)n˙(+), (PH3)n˙(+), (H2S)n˙(+) and (HCl)n˙(+), where n = 2-4. The energies of the most stable structures are subsequently evaluated using coupled cluster theory in conjunction with the aug-cc-pVTZ basis set. These cationic clusters can adopt two distinct structural types, with some clusters showing an unusual type of bonding, often referred to as hemibonding, while other clusters undergo proton transfer to give an ion and radical. It is found that proton transfer based structures are preferred by the (NH3)n˙(+), (H2O)n˙(+) and (HF)n˙(+) clusters while hemibonded structures are favoured by (PH3)n˙(+), (H2S)n˙(+) and (HCl)n˙(+). These trends can be attributed to the relative strengths of the molecules and molecular cations as Brønsted bases and acids, respectively, and the strength of the interaction between the ion and radical in the ion-radical clusters.
Highlights
The energies of the most stable structures are subsequently evaluated using coupled cluster theory in conjunction with the aug-cc-pVTZ basis set. These cationic clusters can adopt two distinct structural types, with some clusters showing an unusual type of bonding, often referred to as hemibonding, while other clusters undergo proton transfer to give an ion and radical
It is found that proton transfer bhaesmeidbosntrduecdtusrtersucatruerepsreafreerrfeadvobuyretdheby(N(HPH3)3n).+n,.+(, H(H2O2S)n).n+.,+
The study of (H2O)2.+ has proved to be a challenge for density functional theory (DFT), and many commonly used exchange-correlation functionals wrongly predict the hemibonded structure to be more stable than the proton transfer one
Summary
The properties of ionized clusters can vary significantly from their neutral counterparts and their chemistry has been the subject of many experimental and theoretical studies.[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30] One intriguing phenomenon is the formation of 2-center 3electron bonds between the heavy atoms in cationic clusters of molecules such as water and hydrogen sulphide. The basin hopping search algorithm in conjunction with second-order Møller-Plesset perturbation theory is used to determine the lowest energy structures of the radical cation clusters (NH3)n.+, (H2O)n.+, (HF)n.+, (PH3)n.+, (H2S)n.+ and (HCl)n.+, where n=2-4.
Sign-in/Register to view highlights & summary 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.
