Iron(II) Spin Crossover Complex with the 1,2,3-Triazole-Containing Linear Pentadentate Schiff-Base Ligand and the MeCN Monodentate Ligand
Iron(II) Spin Crossover Complex with the 1,2,3-Triazole-Containing Linear Pentadentate Schiff-Base Ligand and the MeCN Monodentate Ligand
复制标题
DOI：
10.3390/cryst9060276
复制
发表时间：
2019-05
期刊：
影响因子：
2.7
通讯作者：
Tomoe Matsuyama;Kei Nakata;Hiroaki Hagiwara;T. Udagawa
中科院分区：
文献类型：
--
作者：
Tomoe Matsuyama;Kei Nakata;Hiroaki Hagiwara;T. Udagawa
合成了一个单核铁配合物[FeIIMeCN（L3-Me-3 Ph）]（BPh 4）2·MeCN·H2O（1）（L3-Me-3 Ph =双（N，N′-1-苯基-1H-1，2，3-三唑-4-基-亚甲基氨基丙基）甲胺）。变温磁化率测量显示，在第一次加热时，在约400 K的较高温度下，从室温低自旋（LS，S = 0）状态到LS和高自旋（HS，S = 2）物种的混合物的不完全一步自旋交叉（SCO），这在连续冷却模式下是不可逆的。在400 K左右的磁调制是由晶体到非晶的转变引起的，伴随着晶格MeCN溶剂的损失，这是显而易见的，从粉末X射线衍射（PXRD）研究和热重分析。单晶X射线衍射研究表明，配合物在296 ~ 387 K之间处于LS态（S = 0）。在晶格中，络合阳离子和B（1）Ph 4 −离子通过MeCN配体的甲基和B（1）Ph 4 −离子的苯基之间的分子间CH···π相互作用交替连接，形成一维链状结构。一维链通过P4 AE（parallel fourfold aryl embrace）相互作用进一步连接在两个相邻的配合物阳离子之间，构建了一个二维扩展结构。B（2）Ph 4 −离子和MeCN晶格溶剂存在于2D层的空间中。密度泛函理论计算证实，含1，2，3-三唑的配体L3-Me-3 Ph在铁离子的八面体配位环境周围提供了比类似的含咪唑的配体H2 L2 Me更强的配位场（= bis（N，N′-2-甲基咪唑-4-基-亚甲基氨基丙基）甲胺）的已知化合物[FeIIMeCN（H2 L2 Me）]（BPh 4）1.5·Cl 0.5·0.5MeCN（2）由松本等人报道（Nishi，K.; Fujinami，T.; Kitabayashi，A.;松本，N.咪唑-氯氢键构筑的四聚体自旋交叉铁（II）配合物。无机化学通讯2011，14，1073-1076），导致1的自旋转变温度比2高得多。
A mononuclear iron(II) complex bearing the linear pentadentate N5 Schiff-base ligand containing two 1,2,3-triazole moieties and the MeCN monodentate ligand, [FeIIMeCN(L3-Me-3Ph)](BPh4)2·MeCN·H2O (1), have been prepared (L3-Me-3Ph = bis(N,N′-1-Phenyl-1H-1,2,3-triazol-4-yl-methylideneaminopropyl)methylamine). Variable-temperature magnetic susceptibility measurements revealed an incomplete one-step spin crossover (SCO) from the room-temperature low-spin (LS, S = 0) state to a mixture of the LS and high-spin (HS, S = 2) species at the higher temperature of around 400 K upon first heating, which is irreversible on the consecutive cooling mode. The magnetic modulation at around 400 K was induced by the crystal-to-amorphous transformation accompanied by the loss of lattice MeCN solvent, which was evident from powder X-ray diffraction (PXRD) studies and themogravimetry. The single-crystal X-ray diffraction studies showed that the complex is in the LS state (S = 0) between 296 and 387 K. In the crystal lattice, the complex-cations and B(1)Ph4− ions are alternately connected by intermolecular CH···π interactions between the methyl group of the MeCN ligand and phenyl groups of B(1)Ph4− ions, forming a 1D chain structure. The 1D chains are further connected by P4AE (parallel fourfold aryl embrace) interactions between two neighboring complex-cations, constructing a 2D extended structure. B(2)Ph4− ions and MeCN lattice solvents exist in the spaces of the 2D layer. DFT calculations verified that the 1,2,3-triazole-containing ligand L3-Me-3Ph gives a stronger ligand field around the octahedral coordination environment of the iron(II) ion than the analogous imidazole-containing ligand H2L2Me (= bis(N,N′-2-methylimidazol-4-yl-methylideneaminopropyl)methylamine) of the known compound [FeIIMeCN(H2L2Me)](BPh4)1.5·Cl0.5·0.5MeCN (2) reported by Matsumoto et al. (Nishi, K.; Fujinami, T.; Kitabayashi, A.; Matsumoto, N. Tetrameric spin crossover iron(II) complex constructed by imidazole⋯chloride hydrogen bonds. Inorg. Chem. Commun. 2011, 14, 1073–1076), resulting in the much higher spin transition temperature of 1 than that of 2.