An unusual (4,6)-connected three dimensional framework and a two-dimensional (6,3) network based on flexible and rigid co-ligands

The self-assembly reaction of 1,4-bis(1,2,4-triazol-1-yl)butane (btb), 1,4-benzenedicarboxylate (1,4-bdc) and metal salts gave two coordination polymers {[Mn(btb)(1,4-bdc)(H2O)2][Mn(btb)2(1,4-bdc)]}n (1) and {[Co(btb)0.5(1,4-bdc)(H2O)2]•2H2O}n (2). There are two kinds of Mn(II) atoms (4-connected Mn(II) and 6-connected Mn(II)) in one network of 1. 1 consists of a novel (4,6)-connected three-dimensional network. The Schläfli symbol of the 3D network is (44•62)(412•63). 2 is a neutral two-dimensional (6,3) network. The btb ligands show three conformations (the gauche-anti-gauche, anti-anti-gauche and anti-anti-anti) in 1 and one conformation (the gauche-anti-gauche) in 2. The thermal stabilities of 1 and 2 were investigated.