H-1 and Na-23 nuclear magnetic resonance study of V6 magnetic molecular clusters Jung, JK Jung JK Procissi, D Procissi D Jang, ZH Jang ZH Suh, BJ Suh BJ Borsa, F Borsa F Luban, M Luban M Kögerler, Paul Kögerler Paul Müller, Achim Müller Achim We report H-1 and Na-23 nuclear magnetic resonance (NMR) and relaxation measurements in two variants of the V6 cluster with formula [CH3H6](4)Na-2[H-4{V3L}(2)P4O4].14H(2)O and Na-6[H-4{V3L}(2)P4O4].18H(2)O, respectively. Both the NMR linewidth and the spin-lattice relaxation (NSLR) data can be explained semiquantitatively by assuming a dipolar coupling between the proton (sodium) nuclei and the three V(IV) magnetic moments forming an almost equilateral triangle with nearest neighbor antiferromagnetic exchange interactions. From the temperature dependence of the Na-23 NSLR we obtain the value of the two gaps separating the lower energy total spin states. (C) 2002 American Institute of Physics. 91 10 AMER INST PHYSICS 2002