Fu-Xing Shen , Kun-Hua Zhang , Ao-Na Sun , Jiong Yang , Dong Shao
{"title":"具有五角形双锥体Fe(II)中心的混合氰化物-氧桥接{feii2feii2}配合物的合成、结构和单分子磁性能","authors":"Fu-Xing Shen , Kun-Hua Zhang , Ao-Na Sun , Jiong Yang , Dong Shao","doi":"10.1016/j.molstruc.2025.144209","DOIUrl":null,"url":null,"abstract":"<div><div>The first cyanide-oxo-bridged tetranuclear {Fe<sup>III</sup><sub>2</sub>Fe<sup>II</sup><sub>2</sub>} complex, {[(Tp*)Fe<sup>III</sup>(CN)<sub>3</sub>][Fe<sup>II</sup>(tdmmb)]O}<sub>2</sub>·H<sub>2</sub>O·3MeOH (<strong>Fe<sub>4</sub></strong>) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, tdmmb = 1,3,10,12-tetramethyl-1,2,11,12-tetra-aza[[3](2,6)pyridino[3](2,9)-1,10-phenanthrolinophan-2,10-diene) was prepared and structurally and magnetically characterized. Structural characterization of the tetranuclear molecule reveals an uncommon structure in which a pentagonal bipyramidal iron(II) sites (<em>S</em> = 2) are connected by one single O<sup>2-</sup> bridge and further the Fe(II) dimer are bridged terminally by two tricyanoferrate(III) anions (<em>S</em> = 1/2). Magnetic susceptibility reveals antiferromagnetic coupling between Fe<sup>3+</sup>-CN-Fe<sup>2+</sup> and Fe<sup>2+</sup>-O-Fe<sup>2+</sup> centers, with the coupling constants of <em>J</em><sub>Fe(III)/Fe(II)</sub> = -4.8 cm<sup>−1</sup> and <em>J</em><sub>Fe(II)/Fe(II)</sub> = -11.2 cm<sup>−1</sup>, to give an <em>S</em> = 5 ground state. This <strong>Fe<sub>4</sub></strong> molecule was found to exhibit the single-molecule magnet (SMM) behavior with the effective energy barrier <em>U</em><sub>eff</sub> = 38.2 K. Furthermore, an open magnetic hysteresis loop was observed for the compound. This work provides not only a rare cyanide-oxo mixed bridged complex but also suggest pentagonal bipyramidal Fe(II) building block represents a promising avenue to create high-performance single molecule magnets.</div></div>","PeriodicalId":16414,"journal":{"name":"Journal of Molecular Structure","volume":"1351 ","pages":"Article 144209"},"PeriodicalIF":4.7000,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Synthesis, structure, and single-molecule magnet property of a mixed cyanide-oxo-bridged {FeIII2FeII2} complex featuring pentagonal bipyramidal Fe(II) centers\",\"authors\":\"Fu-Xing Shen , Kun-Hua Zhang , Ao-Na Sun , Jiong Yang , Dong Shao\",\"doi\":\"10.1016/j.molstruc.2025.144209\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The first cyanide-oxo-bridged tetranuclear {Fe<sup>III</sup><sub>2</sub>Fe<sup>II</sup><sub>2</sub>} complex, {[(Tp*)Fe<sup>III</sup>(CN)<sub>3</sub>][Fe<sup>II</sup>(tdmmb)]O}<sub>2</sub>·H<sub>2</sub>O·3MeOH (<strong>Fe<sub>4</sub></strong>) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, tdmmb = 1,3,10,12-tetramethyl-1,2,11,12-tetra-aza[[3](2,6)pyridino[3](2,9)-1,10-phenanthrolinophan-2,10-diene) was prepared and structurally and magnetically characterized. Structural characterization of the tetranuclear molecule reveals an uncommon structure in which a pentagonal bipyramidal iron(II) sites (<em>S</em> = 2) are connected by one single O<sup>2-</sup> bridge and further the Fe(II) dimer are bridged terminally by two tricyanoferrate(III) anions (<em>S</em> = 1/2). Magnetic susceptibility reveals antiferromagnetic coupling between Fe<sup>3+</sup>-CN-Fe<sup>2+</sup> and Fe<sup>2+</sup>-O-Fe<sup>2+</sup> centers, with the coupling constants of <em>J</em><sub>Fe(III)/Fe(II)</sub> = -4.8 cm<sup>−1</sup> and <em>J</em><sub>Fe(II)/Fe(II)</sub> = -11.2 cm<sup>−1</sup>, to give an <em>S</em> = 5 ground state. This <strong>Fe<sub>4</sub></strong> molecule was found to exhibit the single-molecule magnet (SMM) behavior with the effective energy barrier <em>U</em><sub>eff</sub> = 38.2 K. Furthermore, an open magnetic hysteresis loop was observed for the compound. This work provides not only a rare cyanide-oxo mixed bridged complex but also suggest pentagonal bipyramidal Fe(II) building block represents a promising avenue to create high-performance single molecule magnets.</div></div>\",\"PeriodicalId\":16414,\"journal\":{\"name\":\"Journal of Molecular Structure\",\"volume\":\"1351 \",\"pages\":\"Article 144209\"},\"PeriodicalIF\":4.7000,\"publicationDate\":\"2025-09-29\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Molecular Structure\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022286025028510\",\"RegionNum\":2,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Structure","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022286025028510","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Synthesis, structure, and single-molecule magnet property of a mixed cyanide-oxo-bridged {FeIII2FeII2} complex featuring pentagonal bipyramidal Fe(II) centers
The first cyanide-oxo-bridged tetranuclear {FeIII2FeII2} complex, {[(Tp*)FeIII(CN)3][FeII(tdmmb)]O}2·H2O·3MeOH (Fe4) (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate, tdmmb = 1,3,10,12-tetramethyl-1,2,11,12-tetra-aza[[3](2,6)pyridino[3](2,9)-1,10-phenanthrolinophan-2,10-diene) was prepared and structurally and magnetically characterized. Structural characterization of the tetranuclear molecule reveals an uncommon structure in which a pentagonal bipyramidal iron(II) sites (S = 2) are connected by one single O2- bridge and further the Fe(II) dimer are bridged terminally by two tricyanoferrate(III) anions (S = 1/2). Magnetic susceptibility reveals antiferromagnetic coupling between Fe3+-CN-Fe2+ and Fe2+-O-Fe2+ centers, with the coupling constants of JFe(III)/Fe(II) = -4.8 cm−1 and JFe(II)/Fe(II) = -11.2 cm−1, to give an S = 5 ground state. This Fe4 molecule was found to exhibit the single-molecule magnet (SMM) behavior with the effective energy barrier Ueff = 38.2 K. Furthermore, an open magnetic hysteresis loop was observed for the compound. This work provides not only a rare cyanide-oxo mixed bridged complex but also suggest pentagonal bipyramidal Fe(II) building block represents a promising avenue to create high-performance single molecule magnets.
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