In continuation of previous studies showing promising metal-molecule contact properties a variety of C(60) end-capped "molecular wires" for molecular electronics were prepared by variants of the Prato 1,3-dipolar cycloaddition reaction. Either benzene or fluorene was chosen as the central wire, and synthetic protocols for derivatives terminated with one or two fullero[c]pyrrolidine "electrode anchoring" groups were developed. An aryl-substituted aziridine could in some cases be employed directly as the azomethine ylide precursor for the Prato reaction without the need of having an electron-withdrawing ester group present. The effect of extending the π-system of the central wire from 1,4-phenylenediamine to 2,7-fluorenediamine was investigated by absorption, fluorescence, and electrochemical methods. The central wire and the C(60) end-groups were found not to electronically communicate in the ground state. However, the fluorescence of C(60) was quenched by charge transfer from the wire to C(60). Quantum chemical calculations predict and explain the collapse of coherent electronic transmission through one of the fulleropyrrolidine-terminated molecular wires.

Two novel Re IV compounds of formula (Hbpym) 2 [Re IV Br 6 ]•4H 2 O (1) and (H 4 biim)[Re IV Br 6 ]•4H 2 O (2) [Hbpym + = 2,2′-bipyrimidinium cation and H 4 biim 2+ = 2,2′-biimidazolium dication] have been prepared and magnetostructurally characterized. 1 and 2 exhibit distinct crystal packing, and the presence of weak intermolecular contacts, such as Re−Br•••Br−Re (1 and 2), Re− Br•••(H 2 O)•••Br−Re (1 and 2), and Re−Br•••π•••Br−Re ( 2), lead to different magnetic behaviors. While 1 is antiferromagnetic, 2 is a ferromagnetic compound and indeed the first example of ferromagnetic salt based on the hexabromorhenate(IV) anion. These results suggest a straightforward synthetic route to the preparation of new ferromagnetically coupled Re IV compounds.

Simultaneous retention of SMM behaviour and of optical activity is demonstrated upon surface deposition for a chiral SMM.

Eight coordination compounds of formulae [Fe(L˙)][ReCl] (1a), [Fe(L˙)][ReBr] (1b), [Co(L˙)][ReCl]·CHCN (2a), [Co(L˙)][ReBr] (2b), [Ni(L˙)(CHCN)][ReCl]·CHCN (3a), [Ni(L˙)(CHCN)][ReBr]·3CHCN (3b), [Cu(L˙)][ReCl] (4a) and [Cu(L˙)][ReBr] (4b), where L˙ is the aminoxyl radical chelating ligand, 4,4'-dimethyl-2,2'-di(2-pyridyl)oxazolidine-N-oxide, have been synthesised. Structural and magnetic studies reveal metal-radical intramolecular antiferromagnetic interactions in the [M(L˙)] cations in the iron, cobalt and copper based compounds (1a, 1b, 2a, 2b, 4a and 4b) with the central metal ion low-spin in the case of iron (1a and 1b) and a gradual, cobalt based, spin-crossover transition present in 2a and 2b. The nickel based compounds, 3a and 3b, were analysed in the dried form (3a(dried) and 3b(dried)) and directly in acetonitrile (3a(solvated) and 3b(solvated)). Microanalysis and IR spectroscopy on 3a(dried) and 3b(dried) suggest that the dried samples are best formulated as [Ni(L˙)(HO)][ReX], where X = Cl (3a(dried)) and Br (3b(dried)). All forms of 3a and 3b exhibit cationic metal-radical ferromagnetic interactions resulting in S = 3/2 ground states. In addition, 3a(dried) exhibits spin-canting behaviour with an ordering temperature of 2.7 K, an open hysteresis loop with a coercive field H = 580 Oe, and a remanent magnetisation M = 0.21μ, resulting in a canting angle of ∼1.8°. In contrast, 3b(dried) shows no spin-canting behaviour; a maximum in χvs. T at T = 3 K suggesting long-range antiferromagnetic ordering. 3a(solvated) and 3b(solvated) show no indication of long-range magnetic ordering, unlike 4a and 4b where anomalies are evident in the low-temperature magnetic susceptibility measurements.

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