Lenka Krešáková, Miroslava Litecká, Itziar Oyarzabal, Ján Titiš, Michaela Červeňáková, Elizabeth A. Hillard, Jerome Robert and Juraj Černák
{"title":"两种基于双室配体的 Ni/Ce 复合物,具有磁场支持的慢磁弛豫†。","authors":"Lenka Krešáková, Miroslava Litecká, Itziar Oyarzabal, Ján Titiš, Michaela Červeňáková, Elizabeth A. Hillard, Jerome Robert and Juraj Černák","doi":"10.1039/D4NJ03545C","DOIUrl":null,"url":null,"abstract":"<p >Dinuclear Ni(<small>II</small>)/Ce(<small>III</small>) complexes, namely [Ni(<em>o-van-dap</em>)Ce(H<small><sub>2</sub></small>O)(NO<small><sub>3</sub></small>)<small><sub>3</sub></small>] (<strong>1</strong>) and [Ni(H<small><sub>2</sub></small>O)<small><sub>2</sub></small>(<em>o-van-dmdap</em>)Ce(NO<small><sub>3</sub></small>)<small><sub>3</sub></small>] (<strong>2</strong>), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both <strong>1</strong> and <strong>2</strong> bicompartmental Schiff base-type ligands (<em>o-van-dap</em>)<small><sup>2−</sup></small> and (<em>o-van-dmdap</em>)<small><sup>2−</sup></small> are present, with neighbouring <em>cis</em>-N<small><sub>2</sub></small>O<small><sub>2</sub></small> and O<small><sub>4</sub></small> donor sets. The smaller N<small><sub>2</sub></small>O<small><sub>2</sub></small> cavity is occupied by the Ni(<small>II</small>) ions while the larger O<small><sub>4</sub></small> cavity contains a Ce(<small>III</small>) ion; both metal ions are linked <em>via</em> a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex <strong>1</strong> the bridging unit within the Schiff base-type ligand is formed from two carbon atoms; consequently the central Ni(<small>II</small>) atom has a square-planar geometry, and is thus diamagnetic. In complex <strong>2</strong> the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(<small>II</small>) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(<small>III</small>) atoms in both <strong>1</strong> and <strong>2</strong> are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in <strong>2</strong>, while another aqua ligand increases the coordination number of the Ce(<small>III</small>) atom in <strong>1</strong> to 11. Variable temperature dc magnetic studies of both <strong>1</strong> and <strong>2</strong> (2–300 K) corroborate the diamagnetism of the Ni(<small>II</small>) atom (<em>S</em> = 0) in <strong>1</strong> and paramagnetism of the Ni(<small>II</small>) atom (<em>S</em> = 1) in <strong>2</strong>. The ac magnetic studies showed that both complexes <strong>1</strong> and <strong>2</strong> exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are <em>Δ</em>/<em>k</em><small><sub>B</sub></small> = 24.1 K with <em>τ</em><small><sub>0</sub></small> = 6.96 × 10<small><sup>−8</sup></small> s for <strong>1</strong>, and <em>Δ</em>/<em>k</em><small><sub>B</sub></small> = 9.88 K with <em>τ</em><small><sub>0</sub></small> = 5.36 × 10<small><sup>−7</sup></small> s for <strong>2</strong>. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(<small>II</small>) central atoms from <em>S</em> = 0 in <strong>1</strong> to <em>S</em> = 1 in <strong>2</strong>, and this change leads to significant differences in the values of the respective <em>Δ</em>/<em>k</em><small><sub>B</sub></small> parameters. Theoretical <em>ab initio</em> calculations for complexes <strong>1</strong> and <strong>2</strong> were performed to investigate their magnetic properties in detail.</p>","PeriodicalId":95,"journal":{"name":"New Journal of Chemistry","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Two Ni/Ce complexes based on bicompartmental ligands with field supported slow magnetic relaxation†\",\"authors\":\"Lenka Krešáková, Miroslava Litecká, Itziar Oyarzabal, Ján Titiš, Michaela Červeňáková, Elizabeth A. Hillard, Jerome Robert and Juraj Černák\",\"doi\":\"10.1039/D4NJ03545C\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Dinuclear Ni(<small>II</small>)/Ce(<small>III</small>) complexes, namely [Ni(<em>o-van-dap</em>)Ce(H<small><sub>2</sub></small>O)(NO<small><sub>3</sub></small>)<small><sub>3</sub></small>] (<strong>1</strong>) and [Ni(H<small><sub>2</sub></small>O)<small><sub>2</sub></small>(<em>o-van-dmdap</em>)Ce(NO<small><sub>3</sub></small>)<small><sub>3</sub></small>] (<strong>2</strong>), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both <strong>1</strong> and <strong>2</strong> bicompartmental Schiff base-type ligands (<em>o-van-dap</em>)<small><sup>2−</sup></small> and (<em>o-van-dmdap</em>)<small><sup>2−</sup></small> are present, with neighbouring <em>cis</em>-N<small><sub>2</sub></small>O<small><sub>2</sub></small> and O<small><sub>4</sub></small> donor sets. The smaller N<small><sub>2</sub></small>O<small><sub>2</sub></small> cavity is occupied by the Ni(<small>II</small>) ions while the larger O<small><sub>4</sub></small> cavity contains a Ce(<small>III</small>) ion; both metal ions are linked <em>via</em> a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex <strong>1</strong> the bridging unit within the Schiff base-type ligand is formed from two carbon atoms; consequently the central Ni(<small>II</small>) atom has a square-planar geometry, and is thus diamagnetic. In complex <strong>2</strong> the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(<small>II</small>) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(<small>III</small>) atoms in both <strong>1</strong> and <strong>2</strong> are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in <strong>2</strong>, while another aqua ligand increases the coordination number of the Ce(<small>III</small>) atom in <strong>1</strong> to 11. Variable temperature dc magnetic studies of both <strong>1</strong> and <strong>2</strong> (2–300 K) corroborate the diamagnetism of the Ni(<small>II</small>) atom (<em>S</em> = 0) in <strong>1</strong> and paramagnetism of the Ni(<small>II</small>) atom (<em>S</em> = 1) in <strong>2</strong>. The ac magnetic studies showed that both complexes <strong>1</strong> and <strong>2</strong> exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are <em>Δ</em>/<em>k</em><small><sub>B</sub></small> = 24.1 K with <em>τ</em><small><sub>0</sub></small> = 6.96 × 10<small><sup>−8</sup></small> s for <strong>1</strong>, and <em>Δ</em>/<em>k</em><small><sub>B</sub></small> = 9.88 K with <em>τ</em><small><sub>0</sub></small> = 5.36 × 10<small><sup>−7</sup></small> s for <strong>2</strong>. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(<small>II</small>) central atoms from <em>S</em> = 0 in <strong>1</strong> to <em>S</em> = 1 in <strong>2</strong>, and this change leads to significant differences in the values of the respective <em>Δ</em>/<em>k</em><small><sub>B</sub></small> parameters. Theoretical <em>ab initio</em> calculations for complexes <strong>1</strong> and <strong>2</strong> were performed to investigate their magnetic properties in detail.</p>\",\"PeriodicalId\":95,\"journal\":{\"name\":\"New Journal of Chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7000,\"publicationDate\":\"2024-10-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"New Journal of Chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj03545c\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"New Journal of Chemistry","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/nj/d4nj03545c","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Two Ni/Ce complexes based on bicompartmental ligands with field supported slow magnetic relaxation†
Dinuclear Ni(II)/Ce(III) complexes, namely [Ni(o-van-dap)Ce(H2O)(NO3)3] (1) and [Ni(H2O)2(o-van-dmdap)Ce(NO3)3] (2), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both 1 and 2 bicompartmental Schiff base-type ligands (o-van-dap)2− and (o-van-dmdap)2− are present, with neighbouring cis-N2O2 and O4 donor sets. The smaller N2O2 cavity is occupied by the Ni(II) ions while the larger O4 cavity contains a Ce(III) ion; both metal ions are linked via a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex 1 the bridging unit within the Schiff base-type ligand is formed from two carbon atoms; consequently the central Ni(II) atom has a square-planar geometry, and is thus diamagnetic. In complex 2 the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(II) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(III) atoms in both 1 and 2 are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in 2, while another aqua ligand increases the coordination number of the Ce(III) atom in 1 to 11. Variable temperature dc magnetic studies of both 1 and 2 (2–300 K) corroborate the diamagnetism of the Ni(II) atom (S = 0) in 1 and paramagnetism of the Ni(II) atom (S = 1) in 2. The ac magnetic studies showed that both complexes 1 and 2 exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are Δ/kB = 24.1 K with τ0 = 6.96 × 10−8 s for 1, and Δ/kB = 9.88 K with τ0 = 5.36 × 10−7 s for 2. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(II) central atoms from S = 0 in 1 to S = 1 in 2, and this change leads to significant differences in the values of the respective Δ/kB parameters. Theoretical ab initio calculations for complexes 1 and 2 were performed to investigate their magnetic properties in detail.