Premium
Breaking the Semi‐Quinoid Structure: Spin‐Switching from Strongly Coupled Singlet to Polarized Triplet State
Author(s) -
Ravat Prince,
Teki Yoshio,
Ito Yoshikazu,
Gorelik Elena,
Baumgarten Martin
Publication year - 2014
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.201403338
Subject(s) - photoexcitation , singlet state , intramolecular force , triplet state , chemistry , molecule , spin states , spectroscopy , hamiltonian (control theory) , spin (aerodynamics) , molecular physics , atomic physics , excited state , physics , stereochemistry , quantum mechanics , inorganic chemistry , mathematical optimization , mathematics , organic chemistry , thermodynamics
2,7‐TMPNO (4,5,9,10‐tetramethoxypyrene‐2,7‐bis( tert ‐butylnitroxide)) was found to exist in semi‐quinoid form with unprecedented strong intramolecular magnetic exchange interaction of 2 J/k B =1185 K operating over a distance of 10 Å. Structural transformations with the activation energy of Δ E eq =949 K were observed by varying the temperature, from more quinoid structure at low temperature to more biradicaloid structure at higher temperature. Moreover, this molecule undergoes a transient spin transition from singlet to polarized triplet state upon photoexcitation revealed by TREPR spectroscopy. The spin Hamiltonian parameters were determined to be S =1, g =2.0065, D =−0.0112 cm −1 , and E =−0.0014 cm −1 by spectral simulation with the hybrid Eigenfield/exact diagonalization method.
Accelerating Research
Robert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom
Address
John Eccles HouseRobert Robinson Avenue,
Oxford Science Park, Oxford
OX4 4GP, United Kingdom