Nanoprocessability of a one-dimensional oxalato-bridged cobalt(II) complex with 1,2,4-triazole

The polymer {[Co(ox)(Htr)2] · 2H2O}n (ox = oxalate dianion; Htr = 1,2,4-triazole) (1) has been synthesized and characterized by FT-IR spectroscopy, thermal analysis, variable-temperature magnetic measurements and X-ray diffraction methods. The physical analysis allows us to propose a one-dimensional structure in which [Co(Htr)2]2+ units are bridged by bis-bidentate oxalato ligands. Magnetic measurements at variable temperature show an overall antiferromagnetic behavior of the compound. Isolated chains of this polymer have been obtained by sonication of 1 in water and deposition on mica or on mica treated with poly-l-lysine. Circular molecules and nano-fibres have been isolated on Highly Oriented Pyrolitic Graphite (HOPG) by casting deposition of sonicated solutions of 1 in ethanol. The direct reaction on HOPG surface between CoII, H2ox and Htr has proved a useful route to isolate one-dimensional systems on surfaces. The development of new strategies to characterize these types of polymers on surfaces opens the possibility to perform nano-scale studies on their properties and their potential use as nano-materials.