A dimer of a dinuclear dysprosium( iii ) SMM has been successfully isolated by assembling Dy ₂ SMMs. Such structural transformation involves the generation and cleavage of chloride bridges and leads to consecutive transformations of one- and two-step slow relaxation.

By employing an amide-containing multicarboxylate ligand of N,N′′-(3,5-dicarboxylphenyl)benzene-1,4-dicarboxamide (H₄L), a 3D (3,4,4,6)-connected Co(II) coordination polymer, namely, [Co(L)_0.5(tttmb)(H₂O)]_n (LCU-112, LCU = Liaocheng University, tttmb = 1,3,5-tris(1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene) has been constructed through solvothermal synthesis. LCU-112 demonstrates a novel (3,4,4,6)-connected {4².6}₂{4².8³.10}{4².8⁴}{4⁴.6².8⁷.10²} net. Fluorescence measurements reveal that LCU-112 could display a highly sensitive fluorescence response to different pH systems, especially in the pH range from 3.93 to 4.46. It may also be viewed as a recyclable on-off-on vapoluminescent sensor responding to typical acidic and alkaline gases HCl and Et₃N. Remarkably, it exhibits excellent turn-on/ratiometric fluorescence sensing ability toward Pb²⁺ and Al³⁺ with a detection limit as low as 0.075 and 0.759 μM, respectively. LCU-112 also has a good fluorescence recognition function on Tb³⁺ with a detection limit of 0.046 μM. Specially, Pb²⁺ and Al³⁺ ions can be further distinguished in the presence of Tb³⁺. For practical application, luminescent test papers for the detection of the above ions in tap water samples were designed. Furthermore, visualization of the quenching effect on Fe³⁺ could also be improved by replacing LCU-112 with the post-synthesized sample Tb³⁺@LCU-112. As a result, this Co-based coordination polymer could be explored as a multifunctional fluorescent material for environmental monitoring.

By changing the stoichiometric ratios, the one-pot reaction of the glycinehydroxamic acid (H₂glyha) ligand with copper(II) and lanthanide(III) salts in the presence of diamagnetic [Na₂{Fe(CN)₅(NO)}] led to two series of isostructural complexes, which can be designated as heterotrimetallic dimeric clusters [{LnCu₅(glyha)₅}{Fe(CN)₅(NO)}(H₂O)₄]₂·xNO₃·yH₂O (x = 2, y = 11 for La (1), x = 2, y = 11 for Pr (2), and x = 2, y = 11 for Nd (3)) and heterotetrametallic coordination polymers [Na{LnCu₅(glyha)₅}{Fe(CN)₅(NO)}₂(H₂O)_x·yH₂O]_n (x = 6, y = 4 for Sm (4), x = 6, y = 0 for Gd (5), x = 6, y = 4 for Tb (6), x = 5, y = 5 Dy (7), and x = 6, y = 4 for Ho (8)). Each molecular structure contains Ln^III[15-metallacrown-5] nodes and diamagnetic [Fe(CN)₅(NO)]²⁻ linkers. The resulting products demonstrate diversified structural frameworks due to the radius effect of Ln^III ions and different bridging fashions of diamagnetic [Fe(CN)₅(NO)]²⁻ linkers. An analysis of magnetic susceptibilities reveals that 7 exhibits ferromagnetic coupling between Cu^II and Dy^III ions and field-induced SMM behavior.

Four coordination compounds {[Cd(L)_1/2(H₂O)₂]·2H₂O}_n (1), {[Ni₂(L)(bpyBr)₂(H₂O)₂]·H₂O}_n (2), {[Ni(H₂L)(bipy)(H₂O)]·H₂O}_n (3), and [Co(H₂L)(bipy)(H₂O)₂]_n (4) (H₄L = 5,5′-(pentane-1,4-diylbis(oxy))diisophthalic acid, bpyBr = 4,4′-dibromo-2,2′-bipyridyl, bipy = 4,4′-bipyridine) were synthesized and characterized. These four compounds exhibit a 3D open framework with channels, a 2D layer, a 3D supramolecular network constructed from coordination layers and a 3D supramolecular network constructed from coordination chains, respectively. The reaction temperature can influence the coordination modes of the organic multi-carboxylate ligands and the acidity of the compounds. AC impedance spectral studies suggest that the order of proton conductivity of compounds 1–4 is 3 > 4 > 1 > 2. The result reveals that the proton conductivities of low dimensional nonporous CPs 3 and 4 are higher than that of high dimensional porous CP 1. The structure–property studies reveal that the highest proton conductivity of 3 may be explained by its acidic hydrophilic groups and highest water uptake. The dimensionality and channels of the CPs can't influence proton conductivity directly. Meanwhile the amount and orientation of hydrophilic groups can decide the water absorption ability of the CPs, which is an important factor on proton conductivity. The protonation degree of hydrophilic groups, i.e. the acidity of the CPs is the first influencing factor. So, large amounts of hydrophilic groups with high protonation degrees should be considered firstly in the design and synthesis of CPs with good proton conducting performance.