Spin crossover complex [FeL21](ClO4)(2)center dot H2O (L-1=4-methyl-2,6-bis (1H-pyrazol-1-yl)pyrimidine): Synthesis and properties

Spin crossover complex [FeL21](ClO4)(2)center dot H2O (L-1=4-methyl-2,6-bis (1H-pyrazol-1-yl)pyrimidine): Synthesis and properties Full article

Journal

Polyhedron
ISSN: 0277-5387

Output data

Year: 2012, Volume: 43, Number: 1, Pages: 81-88 Pages count : DOI: 10.1016/j.poly.2012.05.039

Tags

Iron(II); Pyrazolylpyrimidines; N-ligands; Spin crossover; Vacuum adiabatic calorimetry; Spectroscopy (Mossbauer, electronic, IR)

Authors

Bushuev Mark B. ^1,2 , Krivopalov Viktor P. ³ , Nikolaenkova Elena B. ³ , Daletsky Vasiliy A. ¹ , Berezovskii Gleb A. ¹ , Sheludyakova Lilia A. ^1,2 , Varnek Vladimir A. ¹

Affiliations

1	(Данные Web of science) Russian Acad Sci, Siberian Branch, Nikolaev Inst Inorgan Chem, Novosibirsk 630090, Russia
2	(Данные Web of science) Natl Res Univ, Dept Nat Sci, Novosibirsk State Univ, Novosibirsk 630090, Russia
3	(Данные Web of science) Russian Acad Sci, Siberian Branch, NN Vorozhtsov Novosibirsk Inst Organ Chem, Novosibirsk 630090, Russia

The complex [FeL21](ClO4)(2)center dot H2O (1a) (L-1 = 4-methyl-2,6-bis(1H-pyrazol-1-yl)pyrimidine) was synthesized by the reaction of Fe(ClO4)(2)center dot 6H(2)O with new NNN-tridentate pyrazolylpyrimidine ligand L-1 in MeOH/EtOH mixture. It is the first example of iron(II) spin crossover complexes with 2,4(6)-di(1H-pyrazol-1-yl)pyrimidines and manifests gradual spin transition centered around 150 K on the chi T-M versus T curve without hysteresis. A broad heat capacity anomaly with the maximum at 150 K was observed on the C-p(T) dependence, Delta H-trs = 5.50 kJ/mol and Delta S-trs = 42.0 J/(mol K). Surprisingly, the syntheses of iron(II) perchlorate compound with L-1 performed in EtOH and iPrOH afford another modification of the complex, [FeL21](ClO4)(2)center dot H2O (1b), being high spin in the 78-300 K temperature range. The complexes with 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-methylpyrimidine (L-2). [FeL22](ClO4)(2)center dot EtOH (2), [FeL22](CF3SO3)(2) (3), [(FeLCl2)-Cl-2] 0.5H(2)O (9) and [FeL2(NCS)(2)] (5) were synthesized in EtOH solutions. They are in the high spin state within 78-300 K temperature range. (C) 2012 Elsevier Ltd. All rights reserved.

Bushuev M.B. , Krivopalov V.P. , Nikolaenkova E.B. , Daletsky V.A. , Berezovskii G.A. , Sheludyakova L.A. , Varnek V.A.
Spin crossover complex [FeL21](ClO4)(2)center dot H2O (L-1=4-methyl-2,6-bis (1H-pyrazol-1-yl)pyrimidine): Synthesis and properties
Polyhedron. 2012. V.43. N1. P.81-88. DOI: 10.1016/j.poly.2012.05.039 WOS Scopus РИНЦ

Published print:

Aug 1, 2012

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