A Q- and X-Band Pulsed Electron Nuclear Double Resonance Study of the Structure and Location of the Vanadyl Ions in the Cs Salt of Heteropolyacid PVMo11O40

作者： Marlen Gutjahr , Joachim Hoentsch , Rolf Böttcher , Oksana Storcheva , Klaus Köhler

关键词: Ion 、 Paramagnetism 、 Vanadium 、 Electron localization function 、 Nuclear chemistry 、 Hyperfine structure 、 Physical chemistry 、 Coordination geometry 、 Electron nuclear double resonance 、 Chemistry 、 Electronic structure 、 Colloid and Surface Chemistry 、 Biochemistry 、 General chemistry 、 Catalysis

摘要: The location and coordination geometry of vanadium(IV) ions in the cesium salt molybdovanadophosphoric heteropolyacid Cs4PVMo11O40 were studied using orientation-selective pulsed ENDOR (electron nuclear double resonance) experiments. To enhance orientation selectivity for paramagnetic vanadyl species, these investigations done at Q-band frequencies. It was possible to resolve interactions (VO2+) with all relevant nuclei, 1H, 31P, 51V, 133Cs. species by determination complete 31P hyperfine tensor. This approach both fresh calcined materials, no differences structures VO2+ complexes found. results give experimental evidence V(IV) ions. For samples, it exclude incorporation Mo sites. are directly attached outer surface heteropolyanion coordin...