Electron spin-echo envelope modulation and pulse electron nuclear double resonance studies of Cu2+...beta-carotene interactions in Cu-MCM-41 molecular sieves.
Perdeuterated all-trans beta-carotene imbedded in activated Cu-MCM-41 was examined by electron paramagnetic resonance (EPR) and electron spin-echo envelope modulation (ESEEM) spectroscopies. The EPR study showed that complexation and electron transfer between Cu2+ and deuterated beta-carotene occurs. The interaction was confirmed by detecting the spin-echo modulation of deuterium in the ESEEM spectra of Cu2+. Ratio analysis of ESEEM was used to determine the number of deuterons which interact with Cu2+ and the distance between deuteron(s) and Cu2+. The bonding site of beta- carotene determined by ESEEM and pulse electron nuclear double resonance is the C15=C15' double bond.
Gao
Yunlong
Y
Key Lab of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing, 210093, People's Republic of China. gao003@bama.ua.edu
Kispert
Lowell D
LD
van Tol
Johan
J
Brunel
Louis-Claude
LC
D003300:Copper / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D019207:beta Carotene / Q000737:chemistry*
D019207:beta Carotene; D003300:Copper