Premium
Like (CO) 4 , Do (CS) 4 and (CSe) 4 Have a Triplet Ground State?
Author(s) -
Bao Xiaoguang,
Hrovat David A.,
Borden Weston Thatcher
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201204049
Subject(s) - cyclobutane , ground state , singlet state , molecule , atomic physics , chemistry , triplet state , physics , excited state , ring (chemistry) , organic chemistry
Cyclobutane‐1,2,3,4‐tetraone, (CO) 4 , was computationally predicted and, subsequently, experimentally confirmed to have a triplet ground state, in which a b 2g σ MO and an a 2u π MO were each singly occupied. In contrast, the (U)CCSD(T) calculations reported herein found that cyclobutane‐1,2,3,4‐tetrathione, (CS) 4 , and cyclobutane‐1,2,3,4‐tetraselenone, (CSe) 4 , both had singlet ground states, in which the b 2g σ MO was doubly occupied and the a 2u π MO was empty. Our calculations showed that both the longer CX distances and smaller coefficients on the carbon atoms in the b 2g and a 2u MOs of (CS) 4 and (CSe) 4 contributed to the difference between the ground states of these two molecules and the ground state of (CO) 4 . An experimental test of the prediction of a singlet ground state for (CS) 4 is proposed.