Structure characterization of the non-crystalline complexes of copper salts with native cyclodextrins.
The characterization of non-crystalline complexes is particularly difficult when techniques like X-ray diffraction or NMR cannot be used. We propose a simple procedure to characterize the physicochemical properties of amorphous new coordination compounds between cyclodextrins (CD) and Cu(2+) salts, by means of the integration of the information provided by several techniques including elemental analysis, flame atomic absorption, TGA, UV-Vis diffuse reflectance, colorimetry, FT-IR and EPR. On the basis of these procedures, we suggest geometrical and structural approximations resulting in an octahedral or distorted octahedral geometry with diverse positions for the metallic centre. According to the EPR spectrum, only one of the complexes may have rhombic symmetry. We also analyzed enthalpy-entropy compensation and the isokinetic effect. In addition, general trends in thermal stability, spectroscopic properties and inclusion in the cavity were analysed. This complete characterization methodology becomes essential for their future application as catalysts.
Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) - CONICET, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina. mvelasco@fcq.unc.edu.ar ckrapacher@fcq.unc.edu.ar ritah@fcq.unc.edu.ar lauraros@fcq.unc.edu.ar.
Manuel I
MI
Velasco
Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) - CONICET, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina. mvelasco@fcq.unc.edu.ar ckrapacher@fcq.unc.edu.ar ritah@fcq.unc.edu.ar lauraros@fcq.unc.edu.ar.
Claudio R
CR
Krapacher
Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) - CONICET, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina. mvelasco@fcq.unc.edu.ar ckrapacher@fcq.unc.edu.ar ritah@fcq.unc.edu.ar lauraros@fcq.unc.edu.ar.
Rita H
RH
de Rossi
Instituto de Investigaciones en Físico Química de Córdoba (INFIQC) - CONICET, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina. mvelasco@fcq.unc.edu.ar ckrapacher@fcq.unc.edu.ar ritah@fcq.unc.edu.ar lauraros@fcq.unc.edu.ar.
Laura I
LI
Rossi
D056831:Coordination Complexes / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D003460:Crystallization; D003505:Cyclodextrins / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D012492:Salts / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D013818:Thermogravimetry
D056831:Coordination Complexes; D003505:Cyclodextrins; D012492:Salts; D003300:Copper