Fang-Xue Xu, Xin-Yu Zhang, Hai-Yan Wei and Xin-Yi Wang
{"title":"Hysteretic spin crossover in a Hofmann-type metal–organic framework constructed from a [MoIII(CN)7]4− unit†","authors":"Fang-Xue Xu, Xin-Yu Zhang, Hai-Yan Wei and Xin-Yi Wang","doi":"10.1039/D4QI01064G","DOIUrl":null,"url":null,"abstract":"<p >Using a self-assembly process involving a [Mo<small><sup>III</sup></small>(CN)<small><sub>7</sub></small>]<small><sup>4−</sup></small> unit, an Fe<small><sup>II</sup></small> ion, and a 1,4-bis(4<em>H</em>-1,2,4-triazol-4-yl)benzene (btb) ligand, we have synthesized a novel coordination polymer, denoted as {K<small><sub>2</sub></small>Fe<small><sup>II</sup></small>(btb)[Mo<small><sup>III</sup></small>(CN)<small><sub>7</sub></small>]·5H<small><sub>2</sub></small>O}<small><sub><em>n</em></sub></small> (<strong>1</strong>). Single-crystal structure analysis revealed a three-dimensional (3D) Hofmann-type framework for compound <strong>1</strong>. The [Mo<small><sup>III</sup></small>(CN)<small><sub>7</sub></small>]<small><sup>4−</sup></small> unit engaged four cyanide groups to coordinate with Fe<small><sup>II</sup></small> ions, creating an anionic two-dimensional (2D) cyano-bridged layer of {Fe<small><sup>II</sup></small>[Mo<small><sup>III</sup></small>(CN)<small><sub>7</sub></small>]}<small><sub><em>n</em></sub></small>. The btb ligands, in turn, coordinated axially with the Fe<small><sup>II</sup></small> ions, bridging adjacent 2D layers and thus constructing a 3D framework. Magnetic studies have shown that compound <strong>1</strong> exhibits a hysteretic one-step spin-crossover behavior. Moreover, a ferrimagnetic ordering with a critical temperature of approximately 65 K was also observed, which may be ascribed to the compound's “core–shell” architecture: the main core is responsible for the SCO behavior, while the shell contributes to the ferrimagnetic characteristics. To the best of our knowledge, this is the first observation of spin-crossover behavior in compounds based on the [Mo<small><sup>III</sup></small>(CN)<small><sub>7</sub></small>]<small><sup>4−</sup></small> unit.</p>","PeriodicalId":79,"journal":{"name":"Inorganic Chemistry Frontiers","volume":null,"pages":null},"PeriodicalIF":6.1000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganic Chemistry Frontiers","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/qi/d4qi01064g","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
Using a self-assembly process involving a [MoIII(CN)7]4− unit, an FeII ion, and a 1,4-bis(4H-1,2,4-triazol-4-yl)benzene (btb) ligand, we have synthesized a novel coordination polymer, denoted as {K2FeII(btb)[MoIII(CN)7]·5H2O}n (1). Single-crystal structure analysis revealed a three-dimensional (3D) Hofmann-type framework for compound 1. The [MoIII(CN)7]4− unit engaged four cyanide groups to coordinate with FeII ions, creating an anionic two-dimensional (2D) cyano-bridged layer of {FeII[MoIII(CN)7]}n. The btb ligands, in turn, coordinated axially with the FeII ions, bridging adjacent 2D layers and thus constructing a 3D framework. Magnetic studies have shown that compound 1 exhibits a hysteretic one-step spin-crossover behavior. Moreover, a ferrimagnetic ordering with a critical temperature of approximately 65 K was also observed, which may be ascribed to the compound's “core–shell” architecture: the main core is responsible for the SCO behavior, while the shell contributes to the ferrimagnetic characteristics. To the best of our knowledge, this is the first observation of spin-crossover behavior in compounds based on the [MoIII(CN)7]4− unit.