~1H, ~(13)C, ~(15)N NMR coordination shifts in Fe(II), Ru(II) and Os(II) cationic complexes with 2,2~′:6~′,2~″- terpyridine

摘要

~1H, ~(13)C and ~(15)N NMR studies of iron(II), ruthenium(II) and osmium(II) bis-chelated cationic complexes with 2,2~′:6~′,2~″-terpyridine ([M(terpy)_2]~(2+); M = Fe, Ru, Os) were performed. Significant shielding of nitrogen-adjacent H(6) and deshielding of H(3~′), H(4~′) protons were observed, both effects being mostly expressed for Fe(II) compounds. The metal-bonded nitrogens were shielded, this effect being much larger for the outer N(1), N(1~″) than the inner N(1~′) atoms, and enhanced in the Fe(II) → Ru(II) → Os(II) series.