Title of Paper:A Series of Linear {(Fe2FeII)-Fe-III} Complexes with Paramagnetic Building-Block-Modified Spin Crossover Behaviors

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Date of Publication:2017-11-13

Journal:CHEMISTRY-A EUROPEAN JOURNAL

Included Journals:SCIE、EI、PubMed

Volume:23

Issue:63

Page Number:15930-15936

ISSN No.:0947-6539

Key Words:building blocks; light-induced spin crossover; spin crossover; stacking interactions; steric hindrance

Abstract:Tuning of the spin crossover (SCO) behavior through paramagnetic building blocks with different steric hindrance effects is of great interest in terms of the synergy between SCO and magnetic interactions. Herein, the steric effect of specified Fe-III building blocks is modified, from the large Tp* (hydridotris(3,5-dimethylpyrazol-1-yl)borate) analogue to a small Tp (hydrotris(pyrazolyl)borate) derivative; the Fe-II SCO unit and Fe-III paramagnetic ions are incorporated into three well isolated trinuclear complexes featuring thermally induced and light-induced SCO properties. Reanalysis of the structures reveals that - stacking interactions play a key role in the thermal hysteresis and anomalous octahedral distortion parameter sigma around the Fe-II ion. The Tp* ligand showing the largest steric hindrance induces elongated Fe-II-N bond lengths and bending of the C  N-Fe-II angle in 1, as well as having a relatively large electron donor effect, which leads to the lowest thermal transition temperature among the three compounds.