Mn-Ln complexes based on azo-salicylaldehyde: Synthesis, structure and magnetic properties

Three Mn-Ln complexes of [MnLn2(TTMSA)4(HTTMSA)2(H2O)6] [Mn(H2O)6]·4H2O (H2TTMSA = 5-azotetrazolyl-3-methoxysalicylaldehyde, Ln = Gd (1), Ho (2), Er (3)) have been synthesized and structurally characterized. The structural characterization reveals that the Mn2+ ion adjusts two mononuclear [LnL3(H2O)2]2 parts into tri-nuclear {[LnL3(H2O)2]2Mn}2− cluster and additional [Mn(H2O)6]2+ just as counter ion to keep electric neutrality of the molecule. The ac susceptibility measurement revels that both complexes of 2 and 3 show slow magnetic relaxation process.