Interlayer Interaction of Two-Dimensional Layered Spin Crossover Complexes [FeIIH3LMe][FeIILMe]X (X- = ClO4-, BF
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- 作者：Masahiro Yamada ; Makoto Ooidemizu ; Yuichi Ikuta ; Shutaro Osa ; Naohide Matsumoto ; Seiichiro Iijima ; Masaaki Kojima ; Franç ; oise Dahan ; and Jean-Pierre Tuchagues
- 刊名：Inorganic Chemistry
- 出版年：2003
- 出版时间：December 15, 2003
- 年：2003
- 卷：42
- 期：25
- 页码：8406 - 8416
- 全文大小：256K
- 年卷期：v.42,no.25(December 15, 2003)
- ISSN：1520-510X
文摘
A series of two-dimensional (2D) spin crossover complexes, [FeIIH3LMe][FeIILMe]X (X- = ClO4-, BF4-, PF6-, AsF6-,SbF6-) 1-5, have been synthesized, where H3LMe denotes an hexadentate N6 tripodlike ligand containing threeimidazole groups, tris[2-(((2-methylimidazol-4-yl)methylidene)amino)ethyl]amine. Compounds 1-5 exhibit a two-step (HS-[FeIIH3LMe]2+ + HS-[FeIILMe]-) 
(HS-[FeIIH3LMe]2+ + LS-[FeIILMe]-) (LS-[FeIIH3LMe]2+ + LS-[FeIILMe]-)spin-transition. The crystal structure of [FeIIH3LMe][FeIILMe]PF6 (3) was determined at 295, 200, and 100 K. Thestructure consists of homochiral extended 2D puckered sheets, in which the complementary [FeIIH3LMe]2+ and [FeIILMe]-capped tripodlike components, linked together by imidazole-imidazolate hydrogen bonds, are alternately arrayedin an up-and-down mode. The Fe-N bond distances and angles revealed that the FeII sites of both constitutingunits are in the high-spin (HS) state at 295 K; at 200 K, the FeII sites of [FeIIH3LMe]2+ and [FeIILMe]- are in the HSand low-spin (LS) states, respectively. The FeII sites of both constituting units are in the LS state at 100 K. Thesize of the counteranion affects significantly the intra- and interlayer interactions leading to modifications of thespin crossover behavior. The onset of the second spin-transition of the ClO4- (1) and BF4- (2) salts adjoins thefirst spin-transition, while a mixed (HS-[FeIIH3LMe]2+ + LS-[FeIILMe]-) spin-state spans a temperature range as wideas 70 K for salts 3-5 with larger counteranions, PF6-, AsF6-, and SbF6-, respectively. Compounds 1 and 2showed remarkable LIESST (light induced excited spin state trapping) and reverse-LIESST effects, whereas 3-5showed no remarkable LIESST effect. The interlayer interaction due to the size of the counteranion is an importantfactor governing the spin crossover behavior and LIESST effect.
(HS-[FeIIH3LMe]2+ + LS-[FeIILMe]-) (LS-[FeIIH3LMe]2+ + LS-[FeIILMe]-)spin-transition. The crystal structure of [FeIIH3LMe][FeIILMe]PF6 (3) was determined at 295, 200, and 100 K. Thestructure consists of homochiral extended 2D puckered sheets, in which the complementary [FeIIH3LMe]2+ and [FeIILMe]-capped tripodlike components, linked together by imidazole-imidazolate hydrogen bonds, are alternately arrayedin an up-and-down mode. The Fe-N bond distances and angles revealed that the FeII sites of both constitutingunits are in the high-spin (HS) state at 295 K; at 200 K, the FeII sites of [FeIIH3LMe]2+ and [FeIILMe]- are in the HSand low-spin (LS) states, respectively. The FeII sites of both constituting units are in the LS state at 100 K. Thesize of the counteranion affects significantly the intra- and interlayer interactions leading to modifications of thespin crossover behavior. The onset of the second spin-transition of the ClO4- (1) and BF4- (2) salts adjoins thefirst spin-transition, while a mixed (HS-[FeIIH3LMe]2+ + LS-[FeIILMe]-) spin-state spans a temperature range as wideas 70 K for salts 3-5 with larger counteranions, PF6-, AsF6-, and SbF6-, respectively. Compounds 1 and 2showed remarkable LIESST (light induced excited spin state trapping) and reverse-LIESST effects, whereas 3-5showed no remarkable LIESST effect. The interlayer interaction due to the size of the counteranion is an importantfactor governing the spin crossover behavior and LIESST effect.