Spin-State Patterning in an Iron(II) Tripodal Spin-Crossover Complex

Li Li; Suzanne M Neville; Alexander R Craze; Jack K Clegg; Natasha F Sciortino; Kasun S Athukorala Arachchige; Outi Mustonen; Christopher E Marjo; Christopher R McRae; Cameron J Kepert; Leonard F Lindoy; Janice R Aldrich-Wright; Feng Li

doi:10.1021/acsomega.7b00630

Spin-State Patterning in an Iron(II) Tripodal Spin-Crossover Complex

ACS Omega. 2017 Jul 10;2(7):3349-3353. doi: 10.1021/acsomega.7b00630. eCollection 2017 Jul 31.

Affiliations

¹ School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, Sydney, NSW 2751, Australia.
² School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia.
³ School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia.
⁴ Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia.
⁵ Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia.

Abstract

A mononuclear iron(II) complex that displays a gradual two-step spin-crossover (SCO) transition is reported. The intermediate plateau (IP) occurs between HS^0.40LS^0.60 and HS^0.30LS^0.70 (HS = high spin; LS = low spin) ratios over the region of ca. 190-170 K. A phase change occurs at the IP, breaking the symmetry, resulting in six independent SCO sites compared to one at the 100% HS and LS plateau regions, respectively. Variable-temperature X-ray photoelectron spectroscopy shows that the SCO behavior is completely reversible among the HS, IP, and LS regions. The results both confirm and extend the related results for the above system described by Halcrow et al. (Kulmaczewski R.; Cespedes O.; Halcrow M. A.Gradual Thermal Spin-Crossover Mediated By a Reentrant Z' = 1 → Z' = 6 → Z' = 1 Phase Transition, Inorg. Chem. 2017, 56, 3144-3148) in a recent report.