Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline)2 building blocks

Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen)2(H2O)(HTST)]·2H2O (1), [Co3(phen)6(H2O)2(TST)2]·7H2O (2), and [Co2Cu(phen)6(H2O)2(TST)2]·10H2O (3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H3TST) with the M2+ (M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen)2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen)2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen)2 in 2 with a trans-Cu(II)(phen)2, which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen)2 and Cu(II)(phen)2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H3TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π–π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1.