Combination of Magnetic Susceptibility and Electron Paramagnetic Resonance to Monitor the 1D to 2D Solid State Transformation in Flexible Metal–Organic Frameworks of Co(II) and Zn(II) with 1,4-Bis(triazol-1-ylmethyl)benzene

摘要

Two families of coordination polymers, {[M-n(btix)2(OH2)2]·2NO3·2H2O}n [M = Co (1), Zn (2), Co−Zn (3); btix =n1,4-bis(triazol-1-ylmethyl)benzene] and {[M(btix)2(NO3)2]}n [M = Co (4),nZn (5), Co−Zn (6)], have been synthesized and characterized. The twonconformations of the ligand, syn and anti, lead to one-dimensional (1D)ncationic chains or two-dimensional (2D) neutral grids. Extrusion of the waternmolecules of the 1D compounds results in an irreversible transformation intonthe 2D compounds, which involves a change in conformation of the btixnligands and a rearrangement in the metal environment with cleavage andnreformation of covalent bonds. This structural transformation has beennfollowed by electron paramagnetic resonance (EPR) and magneticnsusceptibility measurements to monitor the minor modifications that thenmetal centers suffer.