The key role of the intermolecular π-π interactions in the presence of spin crossover in neutral [Fe(abpt)2A2] complexes (A = terminal monoanion N ligand)

被引:90
作者
Dupouy, Gaelle [1 ]
Marchivie, Mathieu [1 ]
Triki, Smail [1 ]
Sala-Pala, Jean [1 ]
Salaun, Jean-Yves [1 ]
Gomez-Garcia, Carlos J. [2 ]
Guionneau, Philippe [3 ]
机构
[1] Univ Bretagne Occidentale, UMR CNRS 6521, F-29285 Brest, France
[2] Univ Valencia, Inst Ciencia Mol, Valencia 46980, Spain
[3] ICMCB, UPR CNRS 9048, F-33608 Pessac, France
关键词
D O I
10.1021/ic800955r
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
New iron(II) complexes of formulas [Fe(abpt)(2)(tcm)(2)] (1), [Fe(abpt)(2)(tcnome)(2)] (2), and [Fe(abpt)(2)(tcnoet)(2)] (3) (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole, tcm(-) = [C(CN)(3)](-) = tricyanomethanide anion; tcnome(-) = [(NC)(2)CC(OCH3)C(CN)(2)](-) = 1,1,3,3-tetracyano-2-methoxypropenide anion; tcnoet(-) = [(NC)(2)CC(OC2H5)C(CN)(2)](-) = 1,1,3,3-tetracyano-2-ethoxypropenide anion) have been synthesized and characterized by infrared spectroscopy, magnetic properties and by variable-temperature single-crystal X-ray diffraction. The crystal structure determinations of 1 and 2 reveal in both cases centrosymmetric discrete iron(II) monomeric structures in which two abpt chelating ligands stand in the equatorial plane and two terminal polynitrile ligands complete the distorted octahedral environment in trans positions. For 3, the crystallographic studies revealed two polymorphs, 3-A and 3-B, exhibiting similar discrete molecular structures to those found for 1 and 2 but with different molecular arrangements. In agreement with the variable-temperature single-crystal X-ray diffraction, the magnetic susceptibility measurements, performed in the temperature range 2-400 K, showed a spin-crossover phenomenon above room temperature for complexes 1, 3A and 3-B with a T-1/2 of 336, 377, and 383 K, respectively, while complex 2 remains in the high-spin ground state (S = 2) in the whole temperature range. To understand further the magnetic behaviors of 1, 3-A, and 3-B, single-crystal X-ray diffraction measurements were performed at high temperatures. The crystal structures of both polymorphs could not be obtained above 400 K because the crystals decomposed. However, single-crystal X-ray data have been collected for compound 1, which reaches the full high-spin state at lower temperatures. Its crystal structure, solved at 400 K, showed a strong modification of the iron coordination sphere (average Fe-N = 2.157(3) angstrom vs 1.986(3) angstrom at 293 K). In agreement with the magnetic properties. Such structural behavior is a signature of the spin-state transition from low-spin (LS) to high-spin (HS). On the basis of the intermolecular T stacking observed for the series described in this paper and for related complexes involving similar discrete structures, we have shown that complexes displaying frontal pi stacking present spin transition such as 1, 3-A, and 3-B and those involving sideways T stacking such as complex 2 remain in the HS state.
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页码:8921 / 8931
页数:11
相关论文
共 53 条
[1]   SIR97:: a new tool for crystal structure determination and refinement [J].
Altomare, A ;
Burla, MC ;
Camalli, M ;
Cascarano, GL ;
Giacovazzo, C ;
Guagliardi, A ;
Moliterni, AGG ;
Polidori, G ;
Spagna, R .
JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1999, 32 :115-119
[2]  
[Anonymous], 1999, J. Appl. Crystallogr, DOI [DOI 10.1107/S0021889899006020, 10.1107/S0021889899006020]
[3]   New planar polynitrile dianion and its first coordination polymer with unexpected short M...M contacts (tcno2- = [(NC)2CC(O)C(CN)2]2-) [J].
Atmani, Chahlae ;
Setifi, Fatima ;
Benmansour, Samia ;
Triki, Smail ;
Marchivie, Mathieu ;
Salaun, Jean-Yves ;
Gomez-Garcia, Carlos J. .
INORGANIC CHEMISTRY COMMUNICATIONS, 2008, 11 (08) :921-924
[4]   Structure and magnetism of coordination polymers containing dicyanamide and tricyanomethanide [J].
Batten, SR ;
Murray, KS .
COORDINATION CHEMISTRY REVIEWS, 2003, 246 (1-2) :103-130
[5]   New multidimensional coordination polymers with μ2- and μ3-dcno cyano carbanion ligand {dcno- = [(NC)2CC(O)O(CH2)2OH]-} [J].
Benmansour, Samia ;
Setifi, Fatima ;
Triki, Smail ;
Salaun, Jean-Yves ;
Vandevelde, Fanny ;
Sala-Pala, Jean ;
Gomez-Garcia, Carlos J. ;
Roisnel, Thierry .
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, 2007, (01) :186-194
[6]  
Capes L, 2000, CHEM-EUR J, V6, P2246, DOI 10.1002/1521-3765(20000616)6:12<2246::AID-CHEM2246>3.0.CO
[7]  
2-X
[8]  
Carboni, 1959, ORG SYNTH, V39, P64, DOI [10.1002/0471264180.os039.23, DOI 10.15227/ORGSYN.039.0064]
[9]   SYNTHESIS AND PROPERTIES OF ISOSTRUCTURAL TRANSITION-METAL (COPPER, NICKEL, COBALT, AND IRON) COMPOUNDS WITH 7,7',8,8'-TETRACYANOQUINODIMETHANIDE(1-) IN AN UNUSUAL MONODENTATE COORDINATION MODE - CRYSTAL-STRUCTURE OF BIS(3,5-BIS(PYRIDIN-2-YL)-4-AMINO-1,2,4-TRIAZOLE)BIS(7,7',8,8'-TETRACYANOQUINODIMETHANIDO)COPPER(II) [J].
CORNELISSEN, JP ;
VANDIEMEN, JH ;
GROENEVELD, LR ;
HAASNOOT, JG ;
SPEK, AL ;
REEDIJK, J .
INORGANIC CHEMISTRY, 1992, 31 (02) :198-202
[10]  
DEENEY FA, 1998, DALTON T, P1837