Solvothermal synthesis of uranium(VI) phases with aromatic carboxylate ligands: A dinuclear complex with 4-hydroxybenzoic acid and a 3D framework with terephthalic acid

Structural Consequences of 1,4-Cyclohexanedicarboxylate Cis/Trans Isomerism in Uranyl Ion Complexes: From Molecular Species to 2D and 3D Entangled Nets

“…9 Obviously, even if a general trend appears here, within a family of complexes all involving carboxylate ligands, it is nevertheless important to stress that the coordination number is only one factor at play, the ligand strength in particular exerting an influence. 74,75 Some carboxylate complexes studied by other groups fit well in the present series, 15,16,18,19,26,[86][87][88] but a different evolution of peak positions with respect to number of donors has been found in a family of pyrazine-or pyridine-containing carboxylates. 89 It is known that a red-shift of uranyl emission peaks positions is related to an increase of donor strength in the equatorial plane, inducing a decrease in uranyl oxo bond order, 74,90 which would suggest that the reduced crowding in the equatorial plane, and the associated shorter bond lengths, in O5 species with respect to O6 ones must result in an overall donor strength increase in the former.…”

“…with no change in dimensionality) and polycatenated (with dimensionality increase), and the dimensionality notation proposed by Batten is used for the latter. 21 The divergent, ditopic nature of 1,4-chdc 2-, and the elongated shape of the trans isomer in particular, are favorable to the formation of large rings, these in their turn promoting entanglement, as in the parent aromatic terephthalate ligand, for which several cases of interpenetration are known, 8,16 and 2D → 3D polycatenated species were recently reported. 19 The three interpenetration cases reported here are threefold 2D or 3D, and twofold 3D, the two former involving the H2NMe2 + cation, and the latter [Cu(bipy)2] + (several other cases of uranyl-containing coordination polymers with [M(bipy/phen)n] +/2+ (n = 2 or 3) counterions have been found which display interpenetration 34 or polycatenation 32,35 ).…”

“…4,5 Although our studies of complexes of cis-1,2-cyclohexanedicarboxylate have to date been limited, they do indicate significant differences to be associated with this isomeric form, providing reason for an extension to examination of the complexes of cis-and trans-1,4-cyclohexanedicarboxylic acid, for which but a single uranyl molecular complex of the trans isomer is known. 6 This acid is the alicyclic counterpart of terephthalic acid, which has been used in the synthesis of several coordination polymers, [7][8][9][10][11][12][13][14][15][16][17][18][19] most often one-or two-dimensional (1D or 2D), with only two cases of threedimensional (3D) frameworks, 12,16 and also some examples of interpenetrated nets. 8,14,19 Some of these complexes are heterometallic, 7,11,13,18 and display photocatalytic activity.…”

Tetrahydrofurantetracarboxylic Acid: An Isomerizable Framework-Forming Ligand in Homo- and Heterometallic Complexes with UO22+, Ag+, and Pb2+

“…and 482 nm in the spectra of 2 and 4, respectively, correspond to a shoulder of the first intense band in the spectrum of 1. The positions of the main maxima are very close to those recently measured in an 8-coordinate uranium(VI) complex with 2,5-thiophenedicarboxylate ligands and Ag(bipy)2 + counterions, 66 and also to those in several 7-coordinate complexes, with 4,4'-(1,1,1,3,3,3-hexafluoroisopropylidene)diphthalate, 67 1,1′-biphenyl-2,2′,6,6′-tetracarboxylate, 68 terephthalate, 69,70 and 2,5-thiophenedicarboxylate, 70 irrespective of the different uranium coordination numbers present here (8 in 1, 7 in 4 and a mixture of both in 2), and they are all redshifted, by 10-20 nm, with respect to the values, measured under identical experimental conditions, generally reported for 8-coordinate uranium(VI) carboxylate complexes. 25,40,[70][71][72][73][74][75][76] Spectra that are nearly identical for 7-and 8-coordinate complexes have also been reported in 4,4′biphenyldicarboxylate complexes, with maxima positions blue-shifted by 6 nm with respect to those for 1.…”

Detection and identification of solids, surfaces, and solutions of uranium using vibrational spectroscopy

“…Spectral features from chelating ligands were specifically noted for the citrate [16], malate [133], pyromellitate [134], benzenedicarboxylate [135], and hydrobenzoate [136] systems. Similarly, uranyl peroxide spectra contain overlapping modes from uranyl and peroxide stretches.…”