The ubiquitous paddle-wheel building block in two-dimensional coordination polymers with square grid structure

The strategic use of strongly coordinating base/solvent as blocking ligand to restrict the structure in 2-D space is explored, and the role of organic base on the overall structure formation is further elaborated.

The isostructural [Zn(BDC)(Py)] n ( 1 ) and [Co(BDC(Py)] n ( 2 ) were formed by the use of strong base pyridine (Py) as a blocking ligand whereas reaction using N-methylimidazole (Mim) in place of pyridine gives [Co(BDC)(Mim)] n ( 3 ) with similar topology and coordination environment. The use of weak/non-coordinating base such as 2-chloropyrimidine, pyrazine, and tetramethylammoniumhexafluorophosphate [(CH 3 ) 4 N(PF 6 )] gives the DMF-coordinated 2-D frameworks, [Cu(BDC)(DMF)] n ( 4 ), [Zn(BDC)(DMF)] n ( 5 ), and [Zn(AmBDC)(DMF)] n ( 6 ).