The complex {[Dy(PDOA)(HO)]·2HO} (1) (HPDOA = 1,2-phenylenedioxydiacetic acid) was prepared from aqueous solution. Its crystal structure, built up of {-Dy-O-C-O-} chains interlinked by PDOA ligands yielding a ladder-like arrangement, was determined at 173 K. 1 exhibits slow magnetic relaxation under a small magnetic field B = 0.2 T with two (LF and HF) relaxation channels. The LF relaxation time at B = 0.2 T and T = 1.85 K is as slow as τ(LF) = 46 ms whereas the HF channel is τ(HF) = 1.4 ms. The mole fraction of the LF species is x = 0.76 at 1.85 K and it escapes progressively on heating. In the dinuclear analogue [Dy(PDOA)(HO)]·3.5HO (2) one PDOA ligand forms a bis(chelate) bridge between the two Dy(iii) atoms yielding a local structure analogous to that in 1; however its AC susceptibility data show slightly different quantitative characteristics of the single-molecule magnetic behaviour.

Preparation, spectroscopic and magnetic characterization of Cu(cyclam)M(CN) 4 complexes exhibiting one-dimensional crystal structures (cyclam 5 1,4,8, M 5 Ni, Pd, Pt) Abstract From the systems Cu(II)-cyclam-[M(CN) 4 ] 2-(cyclam = 1,4,8,11-tetraazacyclotetradecane; M = Ni, Pd, Pt), three cyanidocomplexes Cu(cyclam)M(CN) 4 [M = Ni (1), Pd (2), Pt (3)] were isolated and characterized by chemical analysis, IR and UV-VIS spectroscopy. The three compounds are isostructural, and their crystal structures are formed by quasi-linear chains exhibiting [-Cu(cyclam)-l-NC-M(CN) 2 -l-CN-] n composition. The Cu(II) atoms reside on centres of symmetry and are coordinated in the form of an elongated octahedron with mean equatorial Cu-N bonds of 2.015(12), 2.017(13) and 2.011(11) Å in (1), (2) and (3), respectively, and weakly N-bonded bridging cyanido ligands in the axial positions [2.5321(9) Å in (1), 2.518(2) Å in (2) and 2.549(3) Å in (3)]. Hydrogen bonds of the N-HÁÁÁN cyanido ÁÁÁH-N type link neighbouring chains, and a topologically square network of paramagnetic Cu(II) atoms is formed. The magnetic susceptibilities of all three complexes follow the Curie-Weiss law with a weak antiferromagnetic exchange coupling below 5 K.

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