Solvent-dependent variations of both structure and catalytic performance in three manganese coordination polymers

Three new manganese 4'-(3,5-dicarboxyphenyl)-2,2':6',2 ''' -terpyridine (H(2)DATP) metal-organic framework materials have been generated through regulating the ratios of a binary solvent mixture (DMA/H2O) under solvothermal conditions. Compound 1 {[Mn-2(DATP)(HDATP)(H2O)(4)](OH)center dot 10H(2)O}(n) displaying a one-dimensional (1D) chainlike structure was crystallized from the (DMA/H2O) mixture with a molar ratio of 1: 1, while the two-dimensional (2D) layer species, ([Mn(DATP)(H2O)]center dot 2H(2)O)(n) (2) was produced by increasing the ratio of DMA/H2O to 5 :1. Interestingly, the crystallization in pure DMA yields a three-dimensional (3D) interpenetrating network {[Mn(DATP)]center dot 4H(2)O}(n) (3), featuring higher solvent stability and pH stability than compounds 1 and 2. It is proved that solvent not only influences the structural transformation process of crystals but also has a significant effect on their properties. These three compounds present different catalytic performances in the CO2 cycloaddition to epoxides with various substituent groups into corresponding cyclic carbonates, and only 3 can serve as an efficient and recyclable catalyst at mild temperature.