A Mn() single ion magnet with tridentate Schiff-base ligands

• Published in: Dalton transactions : an international journal of inorganic chemistry 2016-08, Vol.45 (31), p.1231-1237
• Main Authors: Realista, S, Fitzpatrick, A. J, Santos, G, Ferreira, L. P, Barroso, S, Pereira, L. C. J, Bandeira, N. A. G, Neugebauer, P, Hrubý, J, Morgan, G. G, van Slageren, J, Calhorda, M. J, Martinho, P. N
• Format: Article
• Language: English
• Subjects: Cations; Computation; Crystallography; Electronic structure; Elongation; Ligands; Magnetic measurement; Splitting
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c6dt02538b

Single ion magnet behaviour is reported for a mononuclear Mn( iii ) ion with tridentate Schiff-base ligands which exhibits a tetragonal Jahn-Teller elongation along the N amine -Mn-N amine axis and crystallises with two crystallographically distinct Mn( iii ) cations (unit A and unit B). While magnetic measurements show a large and negative axial zero-field splitting ( D = −4.73 cm −1 ), HF-EPR reveal two distinct large axial D s ( D = −4.60 cm −1 for unit A and D = −4.18 cm −1 for unit B), thus resulting in the largest D known to date for a Mn( iii ) single ion magnet. AC magnetic measurements at 2000 Oe allowed determination of the energy barrier for spin reversal (10.19 K) and spin reversal relaxation time (1.476 × 10 −6 s) for the Mn( iii ) ion. Computational studies were used to characterise the electronic structure and substantiate the zero field splitting in the Mn( iii ) complex. Single ion magnet behaviour is reported for a mononuclear Mn( iii ) ion with tridentate Schiff-base ligands revealing that the size of the axial anisotropy is the highest reported to date.