metallic nanostructures can be used 
 to manipulate light on the subwavelength scale to create tailored 
 optical material properties . 
 next to electric responses , artificial 
 optical magnetism is of particular interest but difficult to achieve 
 at visible wavelengths . 
 dna - self - assembly has proved to serve as a 
 viable method to template plasmonic materials with nanometer precision 
 and to produce large quantities of metallic objects with high yields . 
 we present here the fabrication of self - assembled ring - shaped plasmonic 
 metamolecules that are composed of four to eight single metal nanoparticles 
 with full stoichiometric and geometric control . 
 scattering spectra 
 of single rings as well as absorption spectra of solutions containing 
 the metamolecules are used to examine the unique plasmonic features , 
 which are compared to computational simulations . 
 we demonstrate that 
 the electric and magnetic plasmon resonance modes strongly correlate 
 with the exact shape of the structures . in particular , our computations 
 reveal the magnetic plasmons only for particle rings of broken symmetries , 
 which is consistent with our experimental data . 
 we stress the feasibility 
 of dna self - assembly as a method to create bulk plasmonic materials 
 and metamolecules that may be applied as building blocks in plasmonic 
 devices .