Solvothermal techniques allow the crystallization of high nuclearity products that are otherwise inaccessible by conventional techniques, directly from the reaction mixture. By this method, the reaction of the triangular species [Fe3O(OAc)6(H2O)3]Cl with benzotriazole (BtaH) produces an [Fe14] cluster (depicted) with a very large spin ground state.

We report the synthesis, by solvothermal methods, of the tetradecametallic cluster complexes [M14(L)6O6(OMe)18Cl6] (M=FeIII, CrIII) and [V14(L)6O6(OMe)18Cl6-xOx] (L=anion of 1,2,3-triazole or derivative). Crystal structure data are reported for the {M14} complexes [Fe14(C2H2N3)6O6(OMe)18Cl6], [Cr14(bta)6O6(OMe)18Cl6] (btaH=benzotriazole), [V14O6(Me2bta)6(OMe)18Cl6-xOx] [Me2btaH=5,6-Me2-benzotriazole; eight metal sites are VIII, the remainder are disordered between {VIII-Cl}2+ and {VIV=O}2+] and for the distorted [FeIII14O9(OH)(OMe)8(bta)7(MeOH)5(H2O)Cl8] structure that results from non-solvothermal synthetic methods, highlighting the importance of temperature regime in cluster synthesis. Magnetic studies reveal the {Fe14} complexes to have ground state electronic spins of S

We present the results of muon spin relaxation (µ + SR) studies on low dimensional molecular magnet systems. µ + SR measurements have been carried out on the Cu-based chain compounds CuX 2 (pyz) (where X = Br, Cl, NCS and pyz = pyrazine) as a function of temperature and applied longitudinal magnetic field. Oscillations in the time dependence of the muon polarization, characteristic of magnetic order at two distinct muon sites, are detected in both CuBr 2 (pyz) (below T N = 3.6(1) K) and CuCl 2 (pyz) (below T N = 3.2(2) K). No evidence of magnetic order is observed in Cu(NCS) 2 (pyz) down to 0.35 K. The results are discussed in terms of the estimated Cu-X-Cu and Cu-(pyz)-Cu exchange constants. The theory of µ + SR in high spin molecule (HSM) systems, which are effectively zero-dimensional magnets, is discussed and results are presented on [Ni 12 (chp) 23). Measurements made in applied longitudinal magnetic fields on HSM materials at dilution refrigerator temperatures strongly suggest that dynamic local magnetic field fluctuations are responsible for the relaxation of the muon spin ensemble. Trends in temperature and field dependent behaviour in these systems, as probed by the muon, are discussed.