Imparting hysteretic behavior to spin transition in neutral mononuclear complexes

• Published in: RSC advances Vol. 6; no. 46; pp. 39627 - 39635
• Main Authors: Seredyuk, Maksym, Znovjyak, Kateryna, Muñoz, M. Carmen, Galyametdinov, Yurii, Fritsky, Igor O., Real, Jose A.
• Format: Journal Article
• Language: English
• Published: 01.01.2016
• Subjects: Atomic beam spectroscopy; Calorimetry; Carbon; Crystal structure; Hysteresis; Magnetic permeability; Phase transformations; Spin transition
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA05342D

A series of spin transition neutral compounds [FeL(NCS) 2 ] has been synthesized and characterized by means of magnetic susceptibility studies, X-ray diffraction, IR and Mössbauer spectroscopic, and calorimetric measurements (L = N , N -bis((3-alkoxypyridin-2-yl)methylene)-propane-1,3-diamine, number of carbon atoms in chains ( n ) = 4, 12, 14, 16, 18, 20). The shortest chain compound is crystalline and displays a gradual spin transition above ambient temperature. Growing the aliphatic substituent up to n = 12 and 14 leads to loss of crystalline order and deterioration of magnetic properties. At the critical chain length n = 16 and above, the compounds undergo a phase transition reflected by a spin transition and resulting in the appearance of susceptibility hysteresis initially not observed for the short chain congener. For the compound with n = 20, hysteresis becomes the most pronounced. The study shows the importance of chain length optimization for effective feedback between phase and spin transitions.