Syntheses, structures and properties of three 4-fold interpenetration coordination polymers based on two different dia interpenetrating modes

Abstract

Three new 4-fold interpenetrated coordination polymers based on two different dia interpenetrating modes have been prepared successfully, namely [Cu0.5(bib)0.5(tftpa)0.5]n (1), {[Zn0.5(bib)0.5(tftpa)0.5]·0.5H2O}n (2) and [Cd(bib)(tftpa)(EtOH)]n (3) (bib=1,4-bis(2-methyl-imidazol-1-yl)butane, H2tftpa=tetrafluoroterephthalic acid). Complexes 1 and 3, with the same octahedral metal center, are obtained as 4-fold interpenetrated dia coordination frameworks; however, complex 2, with a tetrahedral metal center, presents a 4-fold dia network with an uncommon [2+2] mode of interpenetration. All of the polymers contain right- and left-handed helices that are constructed alternatively and each helix is built up from [M2(tftpa)(bib)]n. Additionally, thermogravimetric curves and luminescent emissions of 2 and 3 have been studied.