title: Electron paramagnetic resonance study of partially oriented clay platelets intercalated with copper(II) 1,4,8,11-tetraazacyclotetradecane.
abstract: Electron paramagnetic resonance (EPR) spectra of powder and oriented films of montmorillonite, hectorite, and saponite intercalated with [Cu(cyclam)](2+) (cyclam = 1,4,8,11-tetraazacyclotetradecane) exhibit three components: an orientation-dependent component without hyperfine features, an orientation-dependent component with hyperfine features, and an orientation-independent component without hyperfine feature. EPR spectra of [Cu(cyclam)](2+)-saponite, which exhibit only two components and the best resolved hyperfine features, were simulated. The spectra indicate that a large portion of the saponite platelets are inclined to the glass surface, although they tend to align with their basal planes parallel to the glass surface. The orientation-dependent spectra could be simulated by introducing a Gaussian distribution with a standard deviation of 20 degrees for the inclination angle. The standard deviation may be used as a disorder parameter for the microcrystals assembled on glass plates. Spectral simulation also shows that the CuN(4) plane of [Cu(cyclam)](2+) is parallel to the clay layers. EPR spectra of some other partially oriented systems are also discussed.
authors.affiliation: Department of Chemistry, Sogang University, Seoul 121-742, Korea. hyunso@sogang.ac.kr
authors.forename: Hyunsoo
authors.initials: H
authors.lastname: So
authors.forename: Hyun
authors.initials: H
authors.lastname: Jung
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choy
authors.forename: R Linn
authors.initials: RL
authors.lastname: Belford
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008280:Magnetics; D016011:Normal Distribution
chemical_list: D000538:Aluminum Silicates; D006571:Heterocyclic Compounds; C024560:cyclam; C099453:saponite; D003300:Copper