title: Syntheses and spin-spin exchange interactions of calix[4]arene biradicals.
abstract: Three novel paramagnetic calix[4]arenes (2, 3 and 4) with two opposite nitroxide radicals on the upper rims were synthesized and characterized. The through-space spin-spin exchange interactions of these calixarene biradicals were investigated, and found to be affected by many factors, such as molecular conformational flexibility, steric hindrance, temperature, solvent effect and complexation of silver ion.
authors.affiliation: Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, PR China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Hu
authors.forename: Haijun
authors.initials: H
authors.lastname: Yang
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
mesh_terms: D047250:Calixarenes / Q000138:chemical synthesis* / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008968:Molecular Conformation; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D013696:Temperature; D014050:Toluene / Q000737:chemistry
chemical_list: D010636:Phenols; C121325:calix(4)arene; D047250:Calixarenes; D014050:Toluene; D012834:Silver