Solvent-assisted structural conversion involving bimetallic complexes based on the tris(oxalato)ferrate(iii) unit with the green → blue → red crystal color sequence

Abstract

Three Cu(ii)/Fe(ii)-bpy-[Fe(ox)3]3− complexes related by structural conversion were studied by XAS, magnetic methods and theoretical calculations.

On/off porosity switching and post-assembly modifications of Cu4L4 metal–organic polyhedra

“…S8 †). As the crystals of 1c and 1d do not completely dissolve during the transformation, we suggest that the conversion to 1e is solvent assisted, 34,35 although a traditional recrystallisation cannot be ruled out. It is noteworthy that 1e could not be obtained through conventional crystallisation methods or by the conversion of other solvatomorphs ( Fig.…”

Structural conversion of three copper(ii) complexes with snapshot observations based on the different crystal colours and morphology

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] The potential application value brought by the diversity of complex structures has attracted more and more attention. 14 The structural transformation is usually characterized by small changes in the number and order of uncoordinated molecules at the molecular level, such as the addition and removal of solvents or guest molecules. [15][16][17] For the coordination centre of the unstable kinetic products, because the metal coordination bonds easily break and generate new coordination bonds, deeper structural changes can occur, such as the exchange of ligands or metal ions and the change of coordination number or coordination conguration.…”

Sorption and Magnetic Properties of Oxalato-Based Trimetallic Open Framework Stabilized by Charge-Assisted Hydrogen Bonds

“…Iron(III) is found in a trigonally distorted octahedral environment formed by six oxygen atoms from oxalate anions. The Fe-O bonds range from 2.005(2) to 2.023(2) Å and are in the range observed for bridging and terminal oxalate anions [38][39][40]. The cobalt(III) cations coordination sphere consists of two oxygen atoms from bidentately coordinated oxalate anion (mode 4, 1.893(2)-1.900(2) Å) (Figure S2) and four nitrogen atoms coming from bpy (1.947(3)-1.954(3) Å) ligands.…”

“…There are four coordination modes of oxalate anions and hence, several bands corresponding to different vibrations of this fivemembered ring were registered. Intense bands in the region of 1720-1620 cm −1 are related to asymmetric ν CO vibrations, whereas those at 1400-1340 cm -1 come from symmetric ν CO vibrations [38,60]. Another bands occurred at 1274, 1246 (ν(CO) + δ(OCO)) cm The increase in temperature causes a gradual removal of H 2 O from the structureobserved mainly as the decrease in the intensity of ν(OH) band (3700-2800 cm -1 ).…”