{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T05:30:05Z","timestamp":1779082205168,"version":"3.51.4"},"reference-count":66,"publisher":"Wiley","issue":"17","license":[{"start":{"date-parts":[[2008,5,9]],"date-time":"2008-05-09T00:00:00Z","timestamp":1210291200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Chemistry A European J"],"published-print":{"date-parts":[[2008,6,9]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:p>We report the synthesis and structural characterisation of a family of finite molecular chains, specifically [{[R<jats:sub>2<\/jats:sub>NH<jats:sub>2<\/jats:sub>]<jats:sub>3<\/jats:sub>[Cr<jats:sub>6<\/jats:sub>F<jats:sub>11<\/jats:sub>(O<jats:sub>2<\/jats:sub>CCMe<jats:sub>3<\/jats:sub>)<jats:sub>10<\/jats:sub>]}<jats:sub>2<\/jats:sub>] (in which R=<jats:italic>n<\/jats:italic>Pr <jats:bold>1<\/jats:bold>, Et <jats:bold>2<\/jats:bold>, <jats:italic>n<\/jats:italic>Bu <jats:bold>3<\/jats:bold>), [{Et<jats:sub>2<\/jats:sub>NH}<jats:sub>2<\/jats:sub>{[Et<jats:sub>2<\/jats:sub>NH<jats:sub>2<\/jats:sub>]<jats:sub>3<\/jats:sub>[Cr<jats:sub>7<\/jats:sub>F<jats:sub>12<\/jats:sub>(O<jats:sub>2<\/jats:sub>CCMe<jats:sub>3<\/jats:sub>)<jats:sub>12<\/jats:sub>][HO<jats:sub>2<\/jats:sub>CCMe<jats:sub>3<\/jats:sub>]<jats:sub>2<\/jats:sub>}<jats:sub>2<\/jats:sub>] (<jats:bold>4<\/jats:bold>), [{[Me<jats:sub>2<\/jats:sub>NH<jats:sub>2<\/jats:sub>]<jats:sub>3<\/jats:sub>[Cr<jats:sub>6<\/jats:sub>F<jats:sub>11<\/jats:sub>(O<jats:sub>2<\/jats:sub>CCMe<jats:sub>3<\/jats:sub>)<jats:sub>10<\/jats:sub>]\u22c52.5\u2009H<jats:sub>2<\/jats:sub>O}<jats:sub>4<\/jats:sub>] (<jats:bold>5<\/jats:bold>) and [{[<jats:italic>i<\/jats:italic>Pr<jats:sub>2<\/jats:sub>NH<jats:sub>2<\/jats:sub>]<jats:sub>3<\/jats:sub>[Cr<jats:sub>7<\/jats:sub>F<jats:sub>12<\/jats:sub>(O<jats:sub>2<\/jats:sub>CCMe<jats:sub>3<\/jats:sub>)<jats:sub>12<\/jats:sub>]}<jats:sub>2<\/jats:sub>] (<jats:bold>6<\/jats:bold>). The structures all contain horseshoes of chromium centres, with each Cr\u22c5\u22c5\u22c5Cr contact within the horseshoe bridged by a fluoride and two pivalates. The horseshoes are linked through hydrogen bonds to the secondary ammonium cations in the structure, leading to di\u2010 and tetra\u2010horseshoe structures. Through magnetic measurements and inelastic neutron scattering studies we have determined the exchange coupling constants in <jats:bold>1<\/jats:bold> and <jats:bold>6<\/jats:bold>. In <jats:bold>1<\/jats:bold> it is possible to distinguish two exchange interactions, <jats:italic>J<\/jats:italic><jats:sub>A<\/jats:sub>=\u22121.1\u2005meV and <jats:italic>J<\/jats:italic><jats:sub>B<\/jats:sub>=\u22121.4\u2005meV; <jats:italic>J<\/jats:italic><jats:sub>A<\/jats:sub> is the exchange interactions at the tips of the horseshoe and <jats:italic>J<\/jats:italic><jats:sub>B<\/jats:sub> is the exchange within the body of the horseshoe (1\u2005meV=8.066\u2005cm<jats:sup>\u22121<\/jats:sup>). For <jats:bold>6<\/jats:bold> only one interaction was needed to model the data: <jats:italic>J<\/jats:italic>=\u22121.18\u2005meV. The single\u2010ion anisotropy parameters for Cr<jats:sup>III<\/jats:sup> were also derived for the two compounds as: for <jats:bold>1<\/jats:bold>, <jats:italic>D<\/jats:italic><jats:sub>Cr<\/jats:sub>=\u22120.028\u2005meV and |<jats:italic>E<\/jats:italic><jats:sub>Cr<\/jats:sub>|=0.005\u2005meV; for <jats:bold>6<\/jats:bold>, <jats:italic>D<\/jats:italic><jats:sub>Cr<\/jats:sub>=\u22120.031\u2005meV. Magnetic\u2010field\u2010dependent inelastic neutron scattering experiments on <jats:bold>1<\/jats:bold> allowed the Zeeman splitting of the first two excited states and level crossings to be observed. For the tetramer of horseshoes (<jats:bold>5<\/jats:bold>), quantum Monte Carlo calculations were used to fit the magnetic susceptibility behaviour, giving two exchange interactions within the horseshoe (\u22121.32 and \u22121.65\u2005meV) and a weak inter\u2010horseshoe coupling of +0.12\u2005meV. Multi\u2010frequency variable\u2010temperature EPR studies on <jats:bold>1<\/jats:bold>, <jats:bold>2<\/jats:bold> and <jats:bold>6<\/jats:bold> have also been performed, allowing further characterisation of the spin Hamiltonian parameters of these chains.<\/jats:p>","DOI":"10.1002\/chem.200800227","type":"journal-article","created":{"date-parts":[[2008,5,9]],"date-time":"2008-05-09T10:17:05Z","timestamp":1210328225000},"page":"5144-5158","source":"Crossref","is-referenced-by-count":43,"title":["Studies of Finite Molecular Chains: Synthesis, Structural, Magnetic and Inelastic Neutron Scattering Studies of Hexa\u2010 and Heptanuclear Chromium Horseshoes"],"prefix":"10.1002","volume":"14","author":[{"given":"Stefan\u2005T.","family":"Ochsenbein","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Floriana","family":"Tuna","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marzio","family":"Rancan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rachel\u2005S.\u2005G.","family":"Davies","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Christopher\u2005A.","family":"Muryn","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Oliver","family":"Waldmann","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Roland","family":"Bircher","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Sieber","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Graham","family":"Carver","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hannu","family":"Mutka","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Felix","family":"Fernandez\u2010Alonso","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andrew","family":"Podlesnyak","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Larry\u2005P.","family":"Engelhardt","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Grigore\u2005A.","family":"Timco","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans\u2005U.","family":"G\u00fcdel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Richard\u2005E.\u2005P.","family":"Winpenny","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[2008,5,29]]},"reference":[{"key":"e_1_2_7_1_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jmmm.2003.12.004"},{"key":"e_1_2_7_2_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.200390067"},{"key":"e_1_2_7_2_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.200390099"},{"key":"e_1_2_7_3_2","doi-asserted-by":"publisher","DOI":"10.1007\/430_022"},{"key":"e_1_2_7_4_2","doi-asserted-by":"publisher","DOI":"10.1002\/adfm.200500244"},{"key":"e_1_2_7_5_2","doi-asserted-by":"publisher","DOI":"10.1021\/ja00082a001"},{"key":"e_1_2_7_6_2","doi-asserted-by":"publisher","DOI":"10.1021\/ic00324a003"},{"key":"e_1_2_7_7_2","doi-asserted-by":"publisher","DOI":"10.1002\/9780470166468.ch2"},{"key":"e_1_2_7_8_2","doi-asserted-by":"publisher","DOI":"10.1002\/ange.19971092225"},{"key":"e_1_2_7_8_3","doi-asserted-by":"publisher","DOI":"10.1002\/anie.199724821"},{"key":"e_1_2_7_9_2","doi-asserted-by":"publisher","DOI":"10.1039\/b615543j"},{"key":"e_1_2_7_10_2","doi-asserted-by":"publisher","DOI":"10.1002\/1521-3765(20020104)8:1<277::AID-CHEM277>3.0.CO;2-D"},{"key":"e_1_2_7_11_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200305641"},{"key":"e_1_2_7_12_2","doi-asserted-by":"publisher","DOI":"10.1002\/chem.200501041"},{"key":"e_1_2_7_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccr.2004.12.019"},{"key":"e_1_2_7_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.ccr.2005.02.003"},{"key":"e_1_2_7_15_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.91.237202"},{"key":"e_1_2_7_16_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.95.057202"},{"key":"e_1_2_7_17_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.98.167401"},{"key":"e_1_2_7_18_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.90.047901"},{"key":"e_1_2_7_19_2","doi-asserted-by":"publisher","DOI":"10.1103\/PhysRevLett.94.207208"},{"key":"e_1_2_7_20_2","first-page":"2007","author":"Ardavan A.","journal-title":"Phys. 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Fitting it independently yielded a FWHM below 50\u2005\u03bceV while the FWHM is 70\u2005\u03bceV for the elastic line and around 90\u2005\u03bceV for the other peaks. 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