Tuning of Adsorption and Magnetic Properties in a Series of Self-Templated Isostructural Ni(II) Metal?Organic Frameworks
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- 作者：Miguel Cortijo ; Santiago Herrero ; Reyes Jiménez-Aparicio ; Josefina Perles ; José L. Priego ; Javier Torroba
- 刊名：Crystal Growth & Design
- 出版年：2014
- 出版时间：February 5, 2014
- 年：2014
- 卷：14
- 期：2
- 页码：716-722
- 全文大小：408K
- ISSN：1528-7505
文摘
An isomorphous series of five metal鈥搊rganic frameworks of formula [Ni4(O2CR)(OH)2(4-pyc)5] [4-pyc = 4-pyridinecarboxylate or isonicotinate; R = C6H5 (1), 4-OMe-C6H4 (2), 2,6-(OMe)2-C6H3 (3), 3,5-(OMe)2-C6H3 (4), 3,4,5-(OMe)3-C6H2 (5)] were obtained by solvothermal reactions. These compounds display a three-dimensional framework where the nickel atoms are coordinated to the hydroxyde anions and two different organic ligands: isonicotinate and phenylcarboxylate. Both hydroxyde (渭3-OH) and phenylcarboxylate (渭3-1魏O,2魏O,3魏O鈥? ligands are coordinated to nickel atoms of the same secondary building unit (SBU). The SBU consists of four edge-sharing NiA6 octahedra (A = O, N). The isonicotinate ligands, however, act as linkers between SBUs displaying three different coordination modes: 渭-1魏N,2魏O; 渭3-1魏N,2魏O,3魏O鈥? and 渭4-1魏N,2:3魏2O,4魏O鈥? Nitrogen adsorption measurements were done to obtain textural parameters of these microporous networks. Micropore size distributions indicate cylindrical pores with diameters of approximately 0.80 nm. The values of Brunauer鈥揈mmett鈥揟eller surface areas (SBET) obtained are in the range of 382鈥?88 m2/g, and the micropore volumes are between 0.13 cm3/g and 0.19 cm3/g. Both parameters are influenced by the substitution grade and position of the methoxy groups of the phenylcarboxylate ligand. The magnetic properties, which also depend on the arylcarboxylate ligands, vary from compound 1 (with only antiferromagnetic interactions) to compound 5, which shows a spin glass behavior (Tg = 15 K).