One‐, Two‐ and Three‐Dimensional 3d‐4f Heterometal Complexes Constructed from Pyridine‐2,3‐dicarboxylic Acid

Abstract

Abstract The reaction of pyridine‐2,3‐dicarboxylic acid (2,3‐pydcH 2 ) with CuI and Ln 2 O 3 under hydrothermal conditions generated a series of new one‐, two‐, and three‐dimensional coordination polymers, namely, {[Cu 3 Ln 2 (2,3‐pydc) 6 (H 2 O) 12 ] · 12H 2 O} n [Ln = La( 1 ), Nd( 2 )], {[Cu 3 Ln 2 (2,3‐pydc) 6 (H 2 O) 8 ] · 6H 2 O} n [Ln = Sm( 3 ), Gd( 4 )], and {[Cu 3 Ln 2 (2,3‐pydc) 6 (H 2 O) 10 ] · 10H 2 O} n [Ln = Tb( 5 ), Ho( 6 ), Er( 7 ), Yb( 8 ), Lu( 9 )]. The results show that compounds 1 and 2 (type I structure) are 1‐D Cu‐4f rhombic lattice chains that are formed through assembly of two building block units Cu 3 (pydc) 6 and Ln(H 2 O) 6 . Compounds 3 – 4 (type II structure) are 2‐D layers that are constructed from building block units [Cu(pydc) 2 (H 2 O) 2 ] μ 2 ‐bridging adjacent 1‐D rhombic lattice chains –[(Cu 2 (pydc) 4 )‐(La(H 2 O) 4 )] n –. Complexes 5 – 9 (type III structure) are also isomorphous and have the same 3‐D network structures with 1‐D channels along the c axis, and are formed by assembly of building block units Cu 3 (pydc) 6 with Ln(H 2 O) 5 . The progressive structural variation from the 1‐D chains 1 – 2 to 2‐D layers 3 – 4 and to 3‐D frameworks 5 – 9 is attributed to the lanthanide contraction effect and to the different coordination modes of 2,3‐pydc 2– . The N 2 gas adsorption and fluorescent properties of the partial complexes were also investigated.