Supramolecular self-assembly of 1D and 3D heterometallic coordination polymers with triruthenium building blocks

摘要

Ru3(TSA)6 (1; H2TSA=2-thiosalicylic acid), which bears six peripheral carboxylate groups and was isolated in the form [NEt4]1.5[Ru3(HTSA)2(TSA) 4](OAc)0.5·3.5 H2O, serves as a building block for assembly of heterometallic coordination polymers. Treatment of 1 with [Fe(acac)3] (acac=acetylacetonate) in EG/H2O (EG=ethylene glycol) afforded 1D Ru3-Fe coordination polymer 2 by means of the connection of the building block 1 through iron centers. Treatment of 1 with MnCl2 in EG resulted in the formation of 1D Ru3-Mn 3 coordination polymer 3, which features self-assembled polynuclear linking units Mn3(OCH2CH2O)3, each of which contains a planar Mn3O3 ring. By treating 1 with Gd(NO3)3 and NaHCO3 in EG, a 3D Ru 3-Gd6 coordination polymer 4 was obtained; this 3D coordination polymer features unprecedented Gd6(μ3- CO3)4 units. The magnetic properties of 1-4, along with DFT calculations on the electronic structure of 1, are also described. Building bonus: In the assembly of heterometallic coordination polymers (see scheme), the building block Ru3(TSA)6 (1), which bears six peripheral carboxylate groups, could not only be connected through simple iron centers (in 2), it could also support self-assembly of unusual polynuclear linking units, Mn3(OCH2CH2O)3 (in 3) and Gd 6(μ3-CO3)4 (in 4).