77827-66-8Relevant academic research and scientific papers
N-macrocyclic complexes of ruthenium(II) and ruthenium(III)
Walker, Darrel D.,Taube, Henry
, p. 2828 - 2834 (1981)
The following new macrocycle ligand complexes of ruthenium have been synthesized: [Ru(mac)Cl2]Cl (mac = 2,3-dimethyl-1,4,8,11-tetraazacyclotetradecane (I), 1,4,8,12-tetraazacyclopentadecane (II), and 1,5,9,13-tetraazacyclohexadecane (III)). Compounds II and III, along with the previously reported [Ru([14]aneN4)Cl2]Cl ([14]aneN4 = 1,4,8,11-tetraazacyclotetradecane) comprise a series differing in the ring size of the macrocycle. Changes in ring size do not appreciably affect the charge-transfer electronic spectra or the Ru-Cl infrared stretching vibration. A small cathodic shift in the formal potential of the Ru(mac)Cl2+/0 couple and a decrease in the chloride affinity of the Ru(II) is observed as the ring size is increased. The structure of [Ru([14]aneN4)Cl2]Br was determined from three-dimensional X-ray diffraction analysis, and the trans geometry of the chloro ligands was verified. Revealed in the structure are nonbonded interactions within the cation between the chloro ligands and the nitrogen-bound hydrogen atoms, which affect the charge-transfer spectra of the Ru(III) form.
