Thermally Stable Coordination Polymer with Hybrid Functional Groups and Mn–SO₄ Double Chains

Abstract

A coordination polymer constructed from the ligand 2,2Јbipyridine-5,5Ј-carboxylate (Bpydc) with hybrid functional groups and the co-ligand SO 4 2was synthesized and structurally characterized by single-crystal X-ray diffraction. It shows an intriguing structure of parallel infinite Mn-SO 4 double chains resulting from the coordination of SO 4 2groups to central Mn II atoms. Further linkage of the Bpydc ligands with the Mn-SO 4 double chains gave rise to a three-dimensional pillar-layer framework, in which the Mn-SO 4 double chains act as pillars and the Bpydc ligands form the layers.

Copper/Zinc-Directed Heterometallic Uranyl-Organic Polycatenating Frameworks: Synthesis, Characterization, and Anion-Dependent Structural Regulation

“…The decomposition of bpdc ligand was observed in the range of 370–560 °C. The following weight loss above 600 °C could be attributed to the release of SO 2 due to the decomposition of SO 4 2– groups . The expected remaining weight losses observed in these four compounds are close to the calculated values (based on the stoichiometric chemical formula by treating Cu to CuO, Zn to ZnO, and U to 1/3­(U 3 O 8 )) .…”

“…2− groups. 37 The expected remaining weight losses observed in these four compounds are close to the calculated values (based on the stoichiometric chemical formula by treating Cu to CuO, Zn to ZnO, and U to 1/3(U 3 O 8 )). 59 The remaining weight value of these compounds were 39.0% for 1-Cu (calculated: 44.0%), 45.2% for 1′-Zn (calculated: 44.1%), 43.0% for 2-Cu (calculated: 41.2%), and 53.7% for 3-Zn (calculated: 51.8%), respectively.…”

“…Among these O/N mixed ligands, only N-containing monocarboxylic acid ligands, i.e., nicotinic or isonicotinic acid, have been attempted to assemble uranyl organic frameworks, ,,− while N-containing polycarboxylic acids, with more than one carboxylate group, have been rarely concerned. For example, 2,2′-bipyridine-5,5′-dicarboxylic acid ( H 2 bpdc ), which can be considered as an integration of 4,4′-biphenyl dicarboxylic acid and 2,2′-bipyridine, has not been employed to prepare uranyl-organic compounds, though it had been widely used for the construction of mono- and bimetallic coordination polymers. − Compared to the N-containing monocarboxylic acids, the rigid dicarboxylic acid moieties of H 2 bpdc ligand make it more suitable for the construction of MOF-like uranyl-organic frameworks. Meanwhile, two spare nitrogen atoms of pyridine groups can afford an additional cross-linking ability by coordination with other heterometallic ions (i.e., d-block transition metal ions).…”