Developments of Functional Devices Using Iron Spin Crossover complexes With Large Cooperative Effects

点击翻译按钮获取中文摘要

Substituent-effects on the spin crossover (SCO) property in the Fe(II)-qsal system have been thoroughly investigated. The complex with carboxylic acid [Fe(qsal-5c)2] show SCO phenomenon at 150 K with hysteresis of 21 K due to the 2-d hydrogen-bond network, while [Fe(qsal-4c)2] with it at different position and [Fe(qsal-nOH)2] (n = 3, 4, 5) with a hydroxyl group show no SCO phenomenon. Qnal-series having naphthalene moiety with different substituent positions, qnal-21, qnal-12, and qnal-32 were also investigated and only [Fe(qnal-21)2] shows SCO phenomenon. Single crystal X-ray analyses revealed that the pi-pi interaction is important factor to maintain the planarity of ligands, which strongly affects the ligand-field strength.