Bis(pyrazolato)-Based Metal–Organic FrameworksFabricated with 4,4′-Bis((3,5-dimethyl-1H-pyrazol-4-yl)methyl)biphenyl and Late Transition Metals.

The reaction between the flexible,bis(pyrazolato)-based ligand4,4′-bis((3,5-dimethyl-1H-pyrazol-4-yl)methyl)biphenyl(H2DMPMB) and late transition metal ions allowed the isolationof the two series of thermally stable metal–organic frameworks [M(DMPMB)](M = Co, Zn, Cd) and [M2(DMPMB)](M = Cu, Ag). X-ray powder diffraction(XRPD) structure determinations demonstrated that the anticonformation adopted by the ligand, juxtaposed to its exo-tetradentate coordination mode, induces the formation of a 3-D architecturewith nonpervious 1-D channels in the three isomorphous species [M(DMPMB)]and of corrugated 2-D layers in [Cu2(DMPMB)]. Coupling thermogravimetricanalyses and variable temperature XRPD highlighted that the five materialsare thermally stable at least up to 300 °C, both under nitrogenand in air, the Cd(II) derivative decomposing only at the remarkablyhigh temperature of 500 °C. No thermal event could be detected;all the materials preserve their structural motifs up to decomposition.The adsorption properties of the five compounds were assayed toward N2at77 K: while no adsorption was observed for [Cd(DMPMB)], the other species possess estimated BET and Langmuir specific surfaceareas in the ranges 64(1)–526(3) m2/g and 142(4)–713(27)m2/g, respectively, thus being an example of the interestingphenomenon known as “porosity without pores”. Finally,the luminescence properties of the Zn(II), Cd(II), and Cu(I) derivativeswere investigated. [ABSTRACT FROM AUTHOR]