Crystal structures and magnetic properties of one-dimensional compounds constructed from Mn2(salen)2 building blocks and organic selenite acid ligands

Abstract

Two new compounds composed of Mn^III salen building blocks and organic selenite acid with ClO₄⁻ counter anions, namely [Mn₂(salen)₂(C₆H₅SeO₂)](ClO₄)(1) and [Mn₂(salen)₂(C₆H₄FSeO₂)](ClO₄)(2) [salen = N,N′-bis(salicylidene)-ethylenediamine], were synthesized through a one-pot reaction and characterized structurally and magnetically. The structures of both compounds were found to be one-dimensional with the Mn₂(salen)₂ dimers linked by O–Se–O bridges via syn–anti and syn–syn coordination modes in 1 and 2, respectively. Direct current (dc) magnetic measurements revealed ferromagnetic interactions between the Mn(III) ions through the double phenoxido bridge and antiferromagnetic interactions through the O–Se–O bridges. Both the static and dynamic magnetic data indicated that spin canting in the 1D compounds results in single-chain magnetic behaviour with effective energy barrier U_eff = 37.1 K for 1 and U_eff = 37.9 K for 2, respectively. To the best of our knowledge, these compounds are rare examples of organic selenite acid bridged Mn(III) based SCMs.