Markus Albrecht from Aachen University and co-workers from other German Institutes and Peking University, China have reported the synthesis of a ligand that can cleanly form heterodinuclear helicates, as long as the resulting species is neutral. Albrecht presents a facile way to forming such complexes, in a cheap and easy manner, resulting in large (kilogram) quantities of the compounds. Albrecht explains 'for the basic investigation of interactions between metal centers it is important to find easy ways to make heterodinuclear coordination compounds readily available.' 

The beauty of the obtained complexes is their versatility, as different combinations of metal ions can be introduced. This makes them interesting because of their photophysical or due to their magnetic properties. Also, the organic ligand can be easily varied (by different substituents at the acylhydrazone or at the catechol) and this therefore allows a fine tuning of the properties of the compound in respect to chirality, solubility, its role as an antenna for light emitting lanthanide ions, and for many other aspects. 

The versatility of the complexes paves the way to some interesting chemistry with the vision to obtain novel materials with new properties in the future. Albrecht explains 'at the moment we are designing and preparing related dinuclear (and multinuclear) compounds in order to introduce properties as mentioned above.' 

'Metal ions possess special features, which are important for chemical processes (e.g. catalysis) or physical properties (e.g. photophysics, magnetism). The latter is especially true for lanthanide metal ions that are used in light emitting devices. They are, for example, applied in TV sets. The properties of metal containing materials can be altered by introducing two different metal centers, which act in concert and thus lead to novel features,' says Albrecht. 

Emma Shiells