Spin-Crossover in Iron(II) Complexes of N,N′-Disubstituted 2,6-Bis(Pyrazol-3-yl)Pyridines: An Effect of a Distal Substituent in the 2,6-Dibromophenyl Group

Crystals

Eva Rentschler¹  Luca M. Carrella¹  Valentin V. Novikov²  Rinat R. Aysin²  Elizaveta K. Melnikova²  Yulia V. Nelyubina²  Igor A. Nikovskiy²  Dmitry Yu. Aleshin²  Alexander V. Polezhaev² 

[1] Johannes Gutenberg-Universität Mainz, Duesbergweg 10–14, 55128 Mainz, Germany;Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia;

关键词: distal substituent;    iron(II) complexes;    molecular design;    paramagnetic NMR spectroscopy;    spin-crossover;    X-ray diffraction;   

DOI  :  10.3390/cryst11080922

来源: DOAJ

【 摘 要 】

A series of new bis(pyrazol-3-yl)pyridines (L^R) N,N′-disubstituted by 4-functionalized 2,6-dibromophenyl groups have been synthesized to study the effect of a distal substituent on the spin-crossover (SCO) behaviour of the iron(II) complexes [Fe(L^R)₂](ClO₄)₂ by variable-temperature magnetometry, NMR spectroscopy, and X-ray diffraction. The SCO-assisting tendency of the substituents with different electronic and steric properties (i.e., the bromine atom and the methyl group) in the para-position of the 2,6-dibromophenyl group is discussed. Together with earlier reported SCO-active iron(II) complexes with N,N′-disubstituted bis(pyrazol-3-yl)pyridines, these new complexes open the way for this family of SCO compounds to emerge as an effective ‘tool’ in revealing structure–function relations, a prerequisite for successful molecular design of switchable materials for future breakthrough applications in sensing, switching, and memory devices.

【 授权许可】

Unknown