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The design of assembling high-nuclearity transition-lanthanide (3d-4f) clusters along with excellent magnetocaloric effect (MCE) is one of the most prominent fields but is extremely challenging. Herein, two heterometallic metal coordination polymers are constructed via the “carbonate-template” method, formulated as {[Gd18Ni24(IDA)22(CO3)7(μ3-OH)32(μ2-OH)3(H2O)5Cl]·Cl8·(H2O)14}n and {[Eu18Ni23.5(IDA)22(CO3)7(μ3-OH)32(H2O)5(IN)(CH3COO)2 (NH2CH2COO)Cl]·Cl6·(H2O)17}n [abbreviated as 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n respectively; H2IDA = iminodiacetic acid; HIN = isonicotinic acid]. Concerning the structures, compounds 1-(Gd18Ni24)n and 2-(Eu18Ni23.5)n both feature the one-dimensional (1D) chain-like structure which is rarely reported in high-nuclearity metal complexes. Meanwhile, the large presences of Gd3+ ions in compound 1-(Gd18Ni24)n are conducive to the fantastic MCE, and the value of −∆Sm is 35.30 J kg−1 K−1 at 3.0 K and ∆H = 7.0 T. And more significantly, compound 1-(Gd18Ni24)n shows the large low-field magnetic entropy change (−∆Sm = 20.95 J kg−1 K−1 at 2.0 K and ∆H = 2.0 T) among the published 3d-4f mixed metal clusters.

Two hourglass-type molybdophosphate hybrids with the formulas [Cd(H2O)2DABT]4[Cd(H7P4Mo6O31)2]·19H2O (1) and (C2H5OH)(C3H5N2)6[Co3(H6P4Mo6O31)2]·H2O (2) (DABT= 3,3′-diamino-5,5′-bis(1H-1,2,4-triazo...

An eight-membered ring petal-shaped cluster [V8ⅣO8(CH3O)16(C2O4)](C6NH16)2(CH3OH)2 (V8) has been successfully designed and synthesized via hydrothermal method. Structure analysis revealed that each vanadium atom was in an octahedral geometrical configuration six-coordinated, two adjacent vanadium atoms were linked by oxygen atoms on oxalic acid to form a ring. The selective sulfur oxidation experiments reveal that V8 had good catalytic activity under mild conditions, and the removal rate of phenyl sulfide was >99% within 4 h at 40 °C. In addition, the open aperture Z-scan test of V8 was carried out and found that V8 also has latent application value as nonlinear optical (NLO) material.

Three novel metal-organic hosts with POM guests coordination polymers, [Co(bim)4][HPMoVI10VIV4O42] (1), {[Co(bim)2(H2O)]2 [PMoVI8VIVVV3O40(VIVO)2]}·2H2O (2), and {[Ni(bim)2(H2O)]2 [PMoVI8VIVVV3O40(VIVO)2]}□8H2O (3) (bim = bis (1-imidazolyl) methane) have been successfully prepared under hydrothermal conditions. Compound 1 shows one dimensional chain with bi-capping Keggin anion [HPMoVI10VIV4O42]2- (abbreviated as PMo10V4) as guest molecule, which forms a three dimensional array by hydrogen bonds. Considering that there are a large number of free coordinating N present on the organic ligand in 1, we increased the ratio of Co2+/bim and got a new polyoxometalate-based complex 2. Compound 2 mainly consists of host two dimensional rigid MOF sheets and guest bi-capping Keggin anion [PMoVI8 VIVVV3O40(VIVO)2]4- (denoted as PMo8V6) cluster, which are covalently-linked together to form a three dimensional array. Compound 3 and 2 are isomorphic, but contains the metal ions Ni2+ instead of Co2+ and the number of free water is different. Magnetothermal studies indicate that compound 1 and 2 all have antiferromagnetic interactions. Interestingly, compound 2 represents the novel 3D host-guest coordination polymer network with a gradual and partial spin-crossover phenomenon.

Based on {e-PMoV8MoVI4O40Zn4} POM units, two novel organic–inorganic hybrids, [TBA]2[H3PMoV8MoVI4O40Zn4]2[4-pyim]6·7H2O (1) (4-pyim = 4-(imidazol-2-yl)pyridine) and [H3PMoV8MoVI4O40Zn4][2-pyim]4·3H2O (2) (2-pyim = 2-(imidazol-2-yl)pyridine), have been triumphantly gained under the hydrothermal conditions via self-assembly method. Compound 1 is made up of two Zn-e-Keggin units jointed by two Zn O bonds, which modified by three 4-pyim ligands, respectively, to form a dimer, while compound 2 consists of a Zn-e-Keggin unit coordinated with four 2-pyim ligands. The coordination mode of the different ligands causes a change in the number of ligands coordinated on each Zn-e-Keggin unit, resulting in the formation of dimers and monomers. What’s more, the third-order non-linear optical (NLO) properties of the two compounds were detected in detail due to the existence of a large number of conjugated organic ligands. Compound 1 has a superiority over compound 2 in NLO performance and the two-photon absorption (TPA) cross section (σ) are 7320 GM for 1 and 1573 GM for 2, which is attributed to the fact that 1 own more conjugated organic ligands. The NLO testing results of compound 1 and 2 show that Zn-e-Keggin unit can provide a good NLO response through combining with conjugated organic ligands, indicating that it is a wally choice for NLO materials. Furthermore, the electrochemistry properties of two compounds were also amply explored.