A variety of spin-crossover behaviors depending on the counter anion: two-dimensional complexes constructed by NH...Cl- hydrogen bonds, [FeIIH3LMe]Cl.X (X = PF6 -, AsF6 -, SbF6 -, CF3SO3 -; H3L(Me) = Tris[2-{[(2-methylimidazol-4-yl)methylidene]amino}ethyl
A variety of spin-crossover behaviors depending on the counter anion: two-dimensional complexes constructed by NH...Cl- hydrogen bonds, [FeIIH3LMe]Cl.X (X = PF6 -, AsF6 -, SbF6 -, CF3SO3 -; H3L(Me) = Tris[2-{[(2-methylimidazol-4-yl)methylidene]amino}ethyl
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DOI：
10.1002/chem.200500972
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
M. Yamada;Hiroaki Hagiwara;Haruna Torigoe;N. Matsumoto;M. Kojima;F. Dahan;J. Tuchagues;N. Re
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文献类型：
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作者：
M. Yamada;Hiroaki Hagiwara;Haruna Torigoe;N. Matsumoto;M. Kojima;F. Dahan;J. Tuchagues;N. Re
合成了一系列自旋交叉（SC）配合物[Fe(II)H(3)L(Me)]Cl.X (X(-) = PF(6) (-), AsF(6) (-), SbF(6) (-), CF(3)SO(3) (-)), 1-4，其中H(3)L(Me)表示六齿N(6)三脚配体三[2-{[(2-甲基咪唑-4-基)亚甲基]氨基}乙基]胺，含有三个咪唑基团，目的是确定抗衡阴离子对SC行为的影响。已发现这些配合物在具有相似晶胞尺寸的相同单斜晶系中结晶。一般晶体结构由一个二维 (2D) 扩展网络组成，该网络由三个相邻 [Fe(II)H(3)L(Me)]2+ 离子的 Cl- 和咪唑 NH 基团之间的 NH...Cl- 氢键构成，而阴离子 X 作为孤立的反阴离子存在并占据二维片之间的空间。磁化率和穆斯堡尔谱揭示了取决于反阴离子的各种 SC 行为，包括一步 HS(HS + LS)/2 (1, X = PF(6) (-))、具有缓慢热弛豫的两步 HS(HS + LS)/2LS (2, X = AsF(6) (-))、渐进一步 HSLS (3, X = SbF(6) (-)) 和具有滞后的陡峭单步 HSLS (4, X = CF(3)SO(3) (-))。这些复合体在 HS 状态下假设空间群为 P2(1)/n，在 HS + LS 状态下假设为 P2(1)，在 LS 状态下假设为 P2(1)/n。 Fe-N 键长和 N-Fe-N 键角表示 HS、HS + LS 和 LS 态。抗衡阴离子的分子体积 V 已通过量子化学计算评估如下：53.4 A(3) (BF(4) (-))、54.4 A(3) (ClO(4) (-))、73.0 A(3) (PF(6) (-))、78.5 A(3) (AsF(6) (-))、88.7 A(3) (SbF(6) (-)) 和 86.9 A(3) (CF(3)SO(3) (-))。抗衡阴离子的大小和形状会影响由氢键构建的灵活的二维网络结构，从而导致 SC 行为的改变。这些估计的抗衡阴离子相对大小与观察到的 SC 行为密切相关。
A family of spin-crossover (SC) complexes, [Fe(II)H(3)L(Me)]Cl.X (X(-) = PF(6) (-), AsF(6) (-), SbF(6) (-), CF(3)SO(3) (-)), 1-4, has been synthesized, in which H(3)L(Me) denotes the hexadentate N(6) tripod-like ligand tris[2-{[(2-methylimidazol-4-yl)methylidene]amino}ethyl]amine, containing three imidazole groups, with a view to establishing the effect of the counter anion on the SC behavior. These complexes have been found to crystallize in the same monoclinic crystal system with similar cell dimensions. The general crystal structure consists of a two-dimensional (2D) extended network constructed by NH...Cl- hydrogen bonds between Cl- and the imidazole NH groups of three neighboring [Fe(II)H(3)L(Me)]2+ ions, while the anion X exists as an isolated counter anion and occupies the space between the 2D sheets. Magnetic susceptibilities and Mössbauer spectra have revealed a variety of SC behaviors depending on the counter anion, including a one-step HS(HS + LS)/2 (1, X = PF(6) (-)), a two-step HS(HS + LS)/2LS with a slow thermal relaxation (2, X = AsF(6) (-)), a gradual one-step HSLS (3, X = SbF(6) (-)), and a steep one-step HSLS with hysteresis (4, X = CF(3)SO(3) (-)). The complexes assume the space group P2(1)/n in the HS state, P2(1) in the HS + LS state, and P2(1)/n in the LS state. The Fe-N bond lengths and the N-Fe-N bond angles are indicative of the HS, HS + LS, and LS states. The molecular volumes, V, of the counter anions have been evaluated by quantum-chemical calculations as follows: 53.4 A(3) (BF(4) (-)), 54.4 A(3) (ClO(4) (-)), 73.0 A(3) (PF(6) (-)), 78.5 A(3) (AsF(6) (-)), 88.7 A(3) (SbF(6) (-)), and 86.9 A(3) (CF(3)SO(3) (-)). The size and shape of the counter anion affects the flexible 2D network structure constructed by the hydrogen bonds, leading to modifications of the SC behavior. These estimated relative sizes of the counter anions correlate well with the observed SC behaviors.