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Hybrid organic-inorganic halide perovskites (HOIPs) have received continued interest for their structure diversity and potential application in optoelectronic, solar cells, nonlinear optics (NLO), and ferroelectrics. Structural symmetry breaking induced by water molecules in single-crystal-to-single-crystal (SCSC) transformations is beneficial to develop ferroelectrics or second-harmonic generation (SHG) materials. Along this line, a water-containing two-dimensional (2D) double perovskite, (C

Lanthanide-iron clusters usually display interesting structures and outstanding magnetic properties. However, due to the high reactivity (acidity) of the Fe

Accurately controlling the hydrolysis of metal ions can not only yield the desired structure of metal hydroxide clusters but also provide a deeper understanding of the formation process of natural hydroxide minerals. However, the capture of hydrolysis intermediates remains a significant challenge, and metal hydroxide clusters are mainly obtained by employing adventitious hydrolysis. In this study, we realized a hierarchical building block assembly from Y3+ ions to large Y12, Y34, and Y60 clusters by controlling the hydrolysis process of lanthanide ions under different pH conditions. Single-crystal structural analysis showed that the Y12 wheel, Y34 ship, and Y60 sodalite cage contain 4, 12, and 24 cubane-like [Y4(µ3-OH)4]8+ units, respectively. The structure of the Y60 cluster can be attributed to two Y34 clusters or six Y12 clusters linked by vertices. These clusters can be synthesized through the hydrolysis of Y3+ under different pH conditions, and Y60 can be prepared from the obtained Y12 or Y34 crystals by the simple addition of Y3+ ions. The capture and conversion of the intermediates of lanthanide series hydroxide clusters, Y12 or Y34, during the assembly from Y3+ ions to Y60 can facilitate an understanding of the formation process of high-nuclearity lanthanide clusters.

A high-nuclearity 3d-4f cluster of [Gd30CoII6CoIII6(OH)56(NO3)12(CH3COO)30(H2O)30]·(NO3)22·(en)3·(H2O)3 (1) was synthesized through the reaction of Gd(NO3)3·6H2O, Co(NO3)2·6H2O, and sodium acetate in a mixture of ethanediamine (en), ethanol, and deionized water. The cluster core in 1 features a double-shell structure with a Co12 icosahedron encapsulating a Gd30 icosidodecahedron. A magnetic study reveals that separating Co2+ ions with Gd3+ ions can effectively reduce the magnetic interaction of 3d-4f clusters. Significantly, the magnetocaloric effect (MCE) of 1 at 2 K and 7 T is up to 44.7 J kg-1 K-1, the largest MCE reported to date in the 3d-4f metal clusters.

A 3D coordination polymer, [Gd(HCOO)(C2O4)]n was prepared. Its magnetocaloric effect (MCE) (32.7 J K-1 kg-1 at 2 K and 2 T) is significantly larger than that of commercial Gd3Ga5O12 (GGG) (14.6 J kg-1 K-1 at 2 K and 2 T), while its thermal conductivity (9.9 W m-1 K-1 at 3 K) is comparable to that of the commercial GGG (about 10 W m-1 K-1 at 3 K).

Four pairs of chiral 3D coordination polymers (CPs), [Zn2(BDC)(lac)(DMF)]·guest (2) (H2BDC = benzene dicarboxylic acid; H2lac = lactic acid; guest = 1.5DMF + i-PrOH), [Co2(BDC)(lac)(DMF)]·guest (3) (guest = DMF + 2H2O), [Fe4(BDC)3(lac)2(DMF)2](CO3)·guest (4) (guest = DMF + 2H2O), and {Zn11(BPDC)6(lac)6[NH2(CH3)2]2}·guest (H2BPDC = 3,3'-biphenyldicarboxylic acid; guest = 6DMF + 18H2O) (5), are prepared through the reactions of racemic lactic acid (rac-H2lac) with different metal ions and auxiliary ligands. Structural analyses and DFT calculations reveal that forming more and stronger coordination bonds between the auxiliary ligand and metal ions is more conducive to the spontaneous resolution of enantiomers in 3D CPs than simply increasing the entropy of the auxiliary ligand itself.

A pure inorganic uranyl phosphate-polyoxometalate of Na17{Na@[(SbW9O33)2(UO2)6(PO3OH)6]}·xH2O (abbreviated as Na@U6P6, with x ≈ 46) featuring a sandwich-type structure was prepared using Keggin-type trilacunary [α-B-SbW9O33]9- units as building blocks, which were formed in situ by SbCl3 and Na2WO4·2H2O. Crystal structural analysis showed that six UO22+ cations and six PO3OH2- anions generated a wheel-like cluster unit with a Na+ center ([Na@(UO2)6(PO3OH)6]+) that is stabilized by two [α-B-SbW9O33]9- units. Na@U6P6 displayed a solid-state photoluminescence quantum yield of 33% at 300 K. The temperature-dependent fluorescence emission spectra showed that Na@U6P6 has temperature-sensitive fluorescence in which its emission intensity decreased by 77% as the temperature increased from 200 to 300 K. These results suggest that such uranyl phosphate-polyoxometalate clusters could serve as potential temperature-sensitive molecular materials.

Cocrystallization of different metal nanoclusters facilitates the preparation of cluster-based nanomaterials with enhanced properties. Herein, two pairs of enantiomeric 3d-4f cocrystallization structures of clusters R/S-[Mn10Ln6] and R/S-[Mn6Ln2] (Ln = Dy for 1R and 1S, Y for 2R and 2S) have been reported. Compounds R/S-[Mn10Ln6][Mn6Ln2] exhibit a large optical activity and magneto-optic effect as verified by natural circular dichroism (NCD) and magnetic circular dichroism (MCD). In addition, alternating current (ac) magnetic measurements show that the chiral R/S-[Mn10Dy6][Mn6Dy2] cocrystallization structure displays slow magnetic relaxation with Ueff = 25.1 K.

The magnetodielectric effect is closely related to multiferroic or magnetoelectric coupling; thus, it can be used to predict magnetoelectric coupling, especially in compounds with special magnetic properties. The magnetodielectric response can often be used to predict many interesting and meaningful physical coupling mechanisms. Therefore, fabricating magnetodielectric materials is an effective step toward the development of magnetoelectric materials. Herein, we synthesize the mixed-valence layered ferrimagnetic molecular compound (C

Reported herein are the synthesis and structures of two high-nuclearity AuAg nanoclusters, namely, [Au78Ag66(C≡CPh)48Cl8]q− and [Au74Ag60(C≡CPh)40Br12]2–. Both clusters possess a three-concentric-s...

Generally, compared to conjugated chain molecules, aromaticity provides additional stability for the cyclic, planar, and conjugated molecules. Thus, the concept of aromaticity was undeniably utilized to explain the unique stability for extensive cyclic molecules (notably for benzene, recently reported boron rings, and all-metal multiply aromatic Al42- salts) to guide chemical syntheses. However, can aromaticity alone describe the stability for all of those cyclic and planar clusters or molecules? In this regard, we observed the four-membered prototypical rings: c-M2O2-/0 clusters (M = B, Al, Ga, and In) possessing unique rhombic (four-center, four-electron) π and σ o-bonds, which are considered to have 3-fold aromaticity. Moreover, we not only elucidated the key role of ring strain energy (RSE) to determine the stability of these rings but also unexpectedly revealed that the electrostatic interaction (ionicity) plays a fundamental role in the stability of Al2O2-/0 clusters through systematically experimental and theoretical investigations into the isolated M2O2-/0 clusters (M = B, Al, Ga, and In). Detailed geometries, molecular orbital, and chemical bonding nature were analyzed to unravel those influences. This work provides a clue in which RSE and the electrostatic effect should be carefully taken into account for the stability of diverse cyclic clusters or molecules compared to the expected stability factor from aromaticity.

Metal clusters with well-defined crystal structures are extremely useful for studying the synergistic catalytic effects and associated catalytic mechanisms. In this study, two pairs of chiral lanthanide-transition metal clusters

Two high-nuclearity lanthanide-transition metal clusters with the general formula [Ln18CoIICoIII6(OH)14(CO3)9(CH3CH2COO)6(dea)12(H2O)30]·(NO3)8·Cl4·(CH3CH2OH)6·(H2O)12 (Ln18Co7, Ln = Gd (1) and Dy ...

Polar crystal structures have attracted more and more attention, due to their unique characteristics, such as ferroelectricity, piezoelectricity, and nonlinear optical property, etc. However, the construction of polar materials is always accidental, and finding an effective synthesis strategy to construct polar materials remains a challenge. Herein, inorganic-organic hybrid compounds of [C7H14N][FeCl4] (1) ([C7H14N] = quinuclidinium cation) and [C7H14N][GeCl3] (2) were prepared, respectively, to verify the beneficial effect of polar anions on the construction of polar crystals. Compound 1 crystallized in the Pbca space group, while 2 belongs to the P43 space group at room temperature. Investigation into the structure of 2 reveals that the polarity of 2 derives from the triangular pyramid structure of [GeX3]- with lone pair electrons. Meanwhile, 2 undergoes a phase transition from the P43 space group to the center Pm3m at 385 K, leading to the optic-electric switching property. Thus, the present work exhibits the advantage of [GeX3]- as the inorganic constituent component in the hybrid polar materials and provides an effective approach for the construction of a polar molecule-based crystal with a switchable property.

Two pairs of enantiomeric 3d–4f metal clusters, [Co2Ln[(R)/(S)-L]4]·Cl5·(H2O)2·CH3OH·CH3CH2OH [Co2Ln; Ln = Gd (1S and 1R), Dy (2S and 2R)], were synthesized by the reaction of chiral Schiff-base li...

Accurately controlling the hydrolysis of metal ions can not only yield the desired structure of metal hydroxide clusters but also provide a deeper understanding of the formation process of natural hydroxide minerals. However, the capture of hydrolysis intermediates remains a significant challenge, and metal hydroxide clusters are mainly obtained by employing adventitious hydrolysis. In this study, we realized a hierarchical building block assembly from Y

A high-nuclearity 3d-4f cluster of [Gd

A 3D coordination polymer, [Gd(HCOO)(C

A mixed-valent hexadecanuclear manganese cluster, [MnII2MnIII14(trz)14(thetach)4(μ3-O)8(H2O)10](ClO4)6 (Mn16), containing two MnII and 14 MnIII ions, is constructed from mixed in situ generated ligands, 1,2,3-triazole (Htrz) and 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (H3thetach). Remarkably, both ligands were not initially added into the reaction system, and their formations involve the in situ ligand decomposition and subsequent condensation reactions. The core of Mn16 is an elongated torus comprised of eight Mn atoms and four [Mn2O2] subunits bridged by oxo or alkoxide. The high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) of Mn16 dissolved in CH3CN indicates its structure remains intact as +3 and +4 species. Temperature and field dependent magnetization revealed predominantly antiferromagnetic exchange interactions within the cluster. The work provides one-pot synthesis of high-nuclearity manganese clusters using the ligands generated by in situ reactions in a tandem fashion.

Two lanthanide-titanium oxo clusters (LTOCs), formulated as [Eu3Ti3(μ3-O)2(μ3-OH)(CH3O)2(Ac)2(CH3OH)(tbba)12]·CH3OH (1) and [Eu6Ti8(μ3-O)13(μ2-OH)(μ3-OCH3)2(μ2-OCH3)2(H2O)(CH3OH)2(tbba)19]·Htbba·10H2O (2), were synthesized through the solvothermal reaction of 4-tert-butylbenzoate ligand, Eu(Ac)3·3H2O, and Ti(OiPr)4 in methanol. Single-crystal structural analysis reveals that 1 crystallized in the orthorhombic space group Pnn2, and 2 crystallized in the triclinic space group P1. Structurally, the core of 1 can be viewed as a coplanar unit of [Eu3Ti3(μ3-O)2(μ3-OH)]16+ formed through each μ3-O2- and μ3-OH- bridging one Ti4+ and two Eu3+ ions, while that of 2 can be viewed as two units of [Eu3Ti3(μ3-O)3(μ2-O)4(μ2-OCH3)2(CH3OH)]5+ and [Eu3Ti5(μ3-O)6(μ2-OH)(μ3-OCH3)2(H2O)(CH3OH)]14+ connected through four μ2-O units from the [Eu3Ti3(μ3-O)3(μ2-O)4(μ2-OCH3)2(CH3OH)]5+ unit to respectively coordinate two Eu3+ and two Ti4+ ions from the [Eu3Ti5(μ3-O)6(μ2-OH)(μ3-OCH3)2(H2O)(CH3OH)]14+ unit. Measurement of their luminescence properties shows that the luminescence lifetime and quantum yield are 1212 μs and 69.6% for 1 and 857 μs and 56.2% for 2. When F- was introduced into 1 in a molar ratio of F- to 1 of 1:3, its quantum yield was increased 1.3 times, and the lifetime increased from 1.2 to 1.4 ms. However, no obvious enhancement in the emission intensity was observed in 2; even the molar ratio of F- to 2 is in the range from 2 to 1/4. Investigation on the structures of 1 and 2 reveals that the luminescence lifetime and quantum yield in 1 is significantly larger than that in 2 are attributed to the vibration of the nonradiative O-H vibration groups in 1 being significantly smaller than that in 2.

Based on the anion template and chiral ligand inducting role, two series of high-nuclearity 3 d-4 f heterometallic clusters with formulas [NO3@Ln6Cu24(μ3-OH)30(μ2-OH)3(OAc)6( R/ S-L)12(H2O)24](NO3)14· x(H2O) (Ln = Dy, x = 30 for 1a( R-L) and 1b( S-L); Ln = Tb, x = 40 for 2a( R-L) and 2b( S-L)) and (Et3NH)4[Ln6Cu12(μ3-OH)14(μ2-Cl)6Cl12( R/ S-L)12]Cl2· x(H2O) (Ln = Dy, x = 28 for 3a( R-L) and 3b( S-L); Ln = Tb, x = 33 for 4a ( R-L) and 4b( S-L); HL = ( R/ S)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid), have been synthesized and characterized. Structural analysis reveals that the metal skeleton of compounds 1 and 2 display a Ln6Cu12 octahedral inner core encapsulated by six outer Cu2 units. In the Ln6Cu12 octahedron, 6 Ln3+ ions located at the six vertices and 12 inner Cu2+ ions located at the 12 edges of octahedron, and one NO3- locates in the center of the octahedron. The metal core of compounds 3 and 4 can be viewed as a Ln6 octahedron encapsulated by six Cu2 units. It is interesting that the different inorganic anions involved in the reaction result in the difference in the structures of 1 to 2 and 3 to 4. Circular dichroism spectra of 1-4 display obvious mirror symmetry effect at 600-800 nm of d-d transition of Cu2+, suggesting that the chirality transferred from chiral R- and S-ligand to Cu2+ ions in this system. Notably, the CD peak at the Cu2+ d-d transition position of Ln6Cu12 cluster is obviously blue-shifted compared with that of Ln6Cu24 due to the different coordinated environments of Cu2+. Magnetic studies indicate that 1a and 2a show weak ferromagnetic interactions, while 3a and 4a display antiferromagnetic interactions.

An ab initio one-pot synthesis of the bimetallic clusters [AunAg44–n(SC6H3F2)30]4– (abbreviated (AuAg)44; n ≤ 12) is reported. The mixed-metal (AuAg)44 clusters, synthesized with different reactant...

Driven by the rapidly increasing demand for technological applications, multifunctional materials have been one important research area, which are expected to enhance the capacity and versatility of materials in various applications. Nevertheless, combining more than three functions in one molecular compound is still a challenge. Molecular solid-solid phase transition materials could exhibit switchable properties, which could have potential applications such as switches, sensors, and memory devices. However, these switchable molecular materials are rarely researched as thermal energy storage materials. In this work, we report the coexistence of thermal energy storage and magnetic-optic-electric triple switching in a plastic crystal, trimethylchloromethyl ammonium tetrachloroferrate(III), ([(CH3)3NCH2Cl][FeCl4], referred to as 1). 1 undergoes plastic phase transition at near room temperature (326 K) induced by the order-disorder of the ions. The magnetic-optic-electric triple switching in 1 could be triggered by temperature stimuli near room temperature. Meanwhile, with utilization of large latent heat during the phase transition process and sensible heat, the energy storage in 1 is up to 107 J g-1 from 293 to 343 K, demonstrating its thermal energy storage application in solar energy systems and industrial sectors. This work particularly exhibits the advantages of plastic molecular materials as thermal energy storage materials and introduces the thermal energy storage into the multi-switchable plastic phase transition molecular materials, which will give extra flexibility for the design of new types of multifunctional materials.

Multifunctional lanthanide coordination polymers (CPs) have the advantages of acting in two or more fields simultaneously. Herein, two single lanthanide CPs, formulated as LnL(D/L-Hlac)(H2O)2·0.5H2O (Ln = Eu (1), Tb (2); H2L = 4,4'-(pyridine-3,5-diyl)dibenzoic acid) and their doped lanthanide analogue Tb0.9373Eu0.0627L(D/L-Hlac)(H2O)2·0.5H2O (3) were prepared through hydrothermal methods. Luminescence measurements reveal that 1 displays red photoluminescence and its Commission International ed'Eclairage (CIE) coordinates are almost invariant in the temperature range from 80 to 300 K, while the emission color of 2 changes from yellow to green and its CIE coordinates change from (0.36132, 0.56365) at 80 K to (0.30448, 0.45566) at 300 K. Significantly, 3 not only displays white-light emission with CIE coordinates of (0.32999, 0.33406) but also exhibits a thermal sensitivity of 2.27% K-1 at 230-300 K. The obviously larger thermal sensitivity in 3 in comparison to that of 1.07% K-1 for 2 demonstrates that lanthanide CPs with both a heat-sensitive fluorescent thermometer and high-efficiency white-light emission can be expected by doping Eu(III) ions into Tb(III)-based CPs.

Cocrystallization of different metal nanoclusters facilitates the preparation of cluster-based nanomaterials with enhanced properties. Herein, two pairs of enantiomeric 3d-4f cocrystallization structures of clusters

A luminescent lanthanide-titanium oxo cluster of Eu2Ti4(μ2-O)2(μ3-O)4(phen)2(tbza)10·4CH3CN (1, Eu2Ti4-phen-tbza, phen = 1,10-phenanthroline, Htbza = 4-tert-butylbenzoic acid) was prepared through ...

Two pairs of enantiomeric 3d-4f metal clusters, [Co

A series of lanthanide–titanium oxo clusters (LnTOCs), Ln2Ti8-Ac, Ln2Ti8-p-Toluic, and Ln2Ti8-Anthra (Ln = Eu and Tb), were prepared based on acetic acid (HAc), p-toluic acid (Hp-Toluic), and anthr...

A series of heterometallic 3d–4f clusters, formulated as Na17[Ln3(H2O)5NiII(H2O)3(Sb4O4)(SbW9O33)3(NiIIW6O24)(WO2)3(CH3COO)]·(H2O)65 [abbreviated as Ln3Ni2, where Ln = La3+ (1), Pr3+ (2), and Nd3+ (3)], K5Na11[Ln3(H2O)3NiII3(H2O)6(SbW9O33)3(WO4)(CO3)]·(H2O)40 [abbreviated as Ln3Ni3, where Ln = La3+ (4), Pr3+ (5), and Nd3+ (6)], and K3Na27[Ln3NiII9(μ3-OH)9(SbW9O33)2(PW9O34)3(CH3COO)3]·(H2O)80 [abbreviated as Ln3Ni9, where Ln = Dy3+ (7) and Er3+ (8)], were obtained through the reaction of the lacunary {SbW9O33} precursor with Ln(NO3)3·6H2O and NiCl2·6H2O in a NaAc/HAc buffer in the presence of different anions. Single-crystal X-ray structure analysis revealed that compounds 1–3 possessed tetrameric architectures featuring three Keggin-type {SbW9O33} and one Anderson-type {NiIIW6O24} building blocks encapsulating one {Sb4O4} cluster, three WO2 units, three Ln3+ metal ions, and two Ni2+ metal ions. Compounds 4–6 displayed cyclic trimeric aggregates of three {SbW9O33} units enveloping one CO32–-templated trinu...

Two novel POM-based inorganic–organic hybrids, [Cu6II(2,2′-bipy)6(Mo6O22)(SiW12O40)]n (1), and {[Cu6II(ppz)6(H2O)5(MoO4)(SiW12O40)]·4H2O}n (2) (2,2′-bipy = 2,2′-bipyridine, Hppz = 3-(pyrid-2-yl)pyrazole), have been constructed from heteropolytungstates and molybdates. Two compounds have been identified by single crystal X-ray diffraction, elemental analysis, and FT-IR. Compound 1 shows a 1D (one-dimensional) chain structure constructed from classical Keggin heteropolytungstate [SiW12O40]4– clusters and [Cu6(2,2′-bipy)6] modified isopolymolybdates [Mo6O22]8–. Compound 2 also represents a 1D chain-like motif built from classical Keggin heteropolytungstate [SiW12O40]4– clusters and [Cu8(ppz)6(H2O)5] modified molybdates MoO42–. Compound 1 represents the first example of POM-based inorganic–organic hybrid with mixed heteropolytungstates and isopolymolybdates. ESI-MS (electrospray ionization mass spectrometry) technique was employed to reveal the species and their evolutions in the hydrothermal reaction, whereb...

Three homometallic high-nuclearity clusters, formulated as [(CO3)2@Ln37(LH3)8(CH3COO)21(CO3)12(μ3-OH)41(μ2-H2O)5(H2O)40]·(ClO4)21·(H2O)100 (abbreviated as Ln37, Ln = Gd (1); Tb (2); Eu (3), LH3 = 1,2,3-cyclohexanetriol) and featuring a double cage-like structure, were obtained through the reaction of 1,2,3-cyclohexanetriol, acetate ligand, and Ln(ClO4)3. The largest odd-numbered lanthanide cluster Gd37 exhibits an entropy change (−ΔSm) of 38.7 J kg–1 K–1.

We report two nonanuclear lanthanide complexes, [Ln9(μ4-O)(μ3-OH)8(LH)4(OAc)4(H2O)12]·5ClO4·24H2O (Ln = Gd, 1; Dy, 2), where LH2– is the doubly deprotonated chiral ligand Chromogen I (2-acetamido-2,3-dideoxy-D-erythro-hex-2-enofuranose), one of the many products from the dehydration of N-acetyl-D-glucosamine (GlcNAc). Mass spectroscopic studies established the solution stability of these clusters. Through hydrogen bonding, the cluster complex self-organizes into a nanostructured 54-metal cagelike assembly featuring six of its units occupying the vertices of an octahedron. Free Chromogen I can be obtained in pure form and high yield by a straightforward workup of the cluster complex. This is the first report of dehydrating GlcNAc without the need of a catalyst or forcing conditions.

A mixed-valent hexadecanuclear manganese cluster, [Mn

In recent years, molecular ferroelectrics have received more and more attention. Nevertheless, the study of multiaxial molecular ferroelectrics is relatively rare, which significantly restricts the development of their applications in thin films and other potential fields. Here we demonstrate the characteristics of a room-temperature lead-free multiaxial inorganic–organic hybrid ferroelectric material [(CH3)2NH2] [C6H5CH2NH3]2BiBr6 (1), which goes through a distinctly reversible phase transition around 386 K and possesses six equivalent ferroelectric directions. At 330 K, the remnant polarization (Pr) of 1 is ∼1.0 μC·cm–2, and the coercive field (Ec) of 1 is 20 kV·cm–1. The multiaxial and switching polarization behaviors of 1 were declared with piezoresponse force microscopy (PFM). Notably, the emergence of six equivalent ferroelectric directions is induced by the easily disordered cations and highly geometrically symmetrical anions, because they usually lead to a large symmetry change in the order–disord...

Based on the anion template and chiral ligand inducting role, two series of high-nuclearity 3 d-4 f heterometallic clusters with formulas [NO

Filiació URV: SI As a bridge to connect medium-sized fullerenes, fused-pentagon C74 is still missing heretofore. Of 14-246 possible isomers, the first fused-pentagon C74 with the Fowler-Manolopoulos code of 14-049 was stabilized as C74Cl10 in the chlorine-involving carbon arc. The structure of C74Cl10 was identified by X-ray crystallography. The stabilization of pristine fused-pentagon C74 by stepwise chlorination was clarified in both theoretical simulation with density functional theory calculations and experimental fragmentation with multistage mass spectrometry.

The self-assemblies of 1,4-bis(pyrid-4-yl)benzene (bpb) and Fe(NCX)2 (X = S, Se, BH3) afforded six coordination polymers with the general formula of [Fe(bpb)2(NCX)2]·Y (X = S and Y = 3C2H5OH·2.5H2O for complex 4, X = S and Y = 2C2H5OH for 5, X = Se and Y = 2C2H5OH·H2O for 6, X = Se and Y = 0.67CH2Cl2·1.33C2H5OH·0.67H2O for 7, X = BH3 and Y = 3C2H5OH·2H2O for 8, X = BH3 and Y = 2CH2Cl2·2C2H5OH for 9). The frameworks of complexes 4 and 5 with the NCS(-) anion as coligand are supramolecular isomers, of which complex 4 features a threefold self-interpenetrated three-dimensional (3D) CdSO4-type topological structure with a Schläfli symbol of 6(5)·8, and complex 5 is a two-dimensional (2D) 4(4) rhombic grid network. These two complexes are purely high-spin systems. Complexes 6 and 7 with the NCSe(-) anion as coligand, both having the 3D 6(5)·8 CdSO4-type framework, show gradual and incomplete spin-crossover behaviors with transition temperature T1/2 being equal to 86 and 96 K, respectively. The usage of NCBH3(-) anion as coligand leads to the formation of 2D 4(4) rhombic grid networks for both complexes 8 and 9, which undergo relatively abrupt, complete spin crossover with T1/2 being equal to 247 and 189 K, respectively. The structural divergences are attributed to the coligands NCX(-) (X = S, Se, BH3) and solvent molecules. Meanwhile, a significant coligand effect is observed on the spin-crossover behaviors of these complexes, and the completeness and transition temperature of spin-state conversion depends on the nature of the coligand, that is, T1/2(NCS(-))T1/2(NCSe(-))T1/2(NCBH3(-)). These results further facilitate the design and synthesis of spin-crossover complexes with spin-state conversion.

Three heterometallic lanthanide–titanium oxo clusters (LnTOCs) formulated as Eu2Ti4(μ3-O)4(tbba)12(acac)2 (Eu2Ti4, 1, Hacac = acetylacetone), Eu5Ti4(μ3-O)6(tbba)20(Htbba)(THF)2 (Eu5Ti4, 2), and Eu8Ti10(μ3-O)14(Ac)2(tbba)34(H2O)4(THF)2(Htbba)2 (Eu8Ti10, 3) were prepared through the reactions of 4-tert-butylbenzoate (Htbba), rare-earth salts, and Ti(OiPr)4. The solution luminescence investigation discovered a size-dependent quantum yield phenomenon in solution. A solid-state luminescence study showed that these three LnTOCs display temperature-dependent photoluminescent properties. Interestingly, the Eu5Ti4 cluster exhibited the highest quantum yield of 94.9% in the solid state among the reported 3d–4f clusters.

Decoding the principles of cluster-based framework assembly at the molecular level remains a persistent challenge. Herein, we isolated and characterized a novel water-stable three-dimensional (3D) metal-organic open framework [Cl@Ag

Three homometallic high-nuclearity clusters, formulated as [(CO

We report the synthesis and photoelectrochemical activity of three lanthanide–titanium oxo clusters (LTOCs), formulated as [Ln8Ti10(μ3-O)14(tbba)34(Ac)2(H2O)4(THF)2]·2Htbba [Ln = Eu (1), Sm (2), and Gd (3); Htbba = 4-tert-butylbenzoic acid; Ac– = acetate]. These stable compounds are efficient catalysts of photoelectrochemical water oxidation with high turnover numbers (7581.0 for 1, 5172.4 for 2, and 5413.0 for 3) and high turnover frequencies (2527.0 for 1, 1724.1 for 2, and 1804.0 for 3). The differences in the photoelectrochemical activity among these three compounds may be related to the differences in their band gaps. This work shows that the heterometallic LTOCs provide a tunable platform for the design of highly effective water oxidation catalysts.

Four 3D POM-based silver coordination polymers, namely, [Ag17(ptz)11(PW12O40)2]n (1), [Ag17(ptz)11(PMo12O40)2]n (2), [Ag12(ptz)6(CN)2(SiW12O40)]n (3), and [Ag19(ptz)8(H2ptz)(H3ptz)(AgP5W30O110)·7H2O]n (4), have been obtained by solvothermal reaction of AgNO3 and 5-phenyl-1H-tetrazole (Hptz) ligand in the presence of four types of polyoxometalates. Structural analysis shows that four types of Ag(I)···π interactions, m-η(1), m/p-η(2), o/m-η(2), and o/m/p-η(3), were observed in compounds 1-4, depending on the polyoxometalates used. The in situ generated CN(-) ion in compound 3 shows unprecedented mixed σ and π bonding modes, similar to the C2(2-) ion in well-studied silver acetylides. For 4, the Na(+) ion in the Preyssler heteropolyoxoanion, [NaP5W30O110](14-), was exchanged by Ag(I) under solvothermal conditions, generating a novel [AgP5W30O110](14-) anion. In addition, the photoluminescence behavior of 1-4 was also investigated.

Four 3D coordination polymers, [Co7(OH)4(H2O)2(ina)4(ip)3]·10H2O (1·10H2O, ina = isonicotinate, ip = isophthalate), [Ni7(OH)4(H2O)2(ina)4(ip)3]·10H2O (2·10H2O), [Co7(OH)4(H2O)2(ina)4(pip)3]·5H2O (3·5H2O, pip = 5-phenyl-isophthalate), and [Ni7(OH)4(H2O)2(ina)4(pip)3]·5H2O (4·5H2O), respectively, were hydrothermally synthesized. They crystallized in the orthorhombic space group Pba2 for 1·10H2O and 2·10H2O and monoclinic space group P2/n for 3·5H2O and 4·5H2O, respectively, and were constructed with the identical 8-connected heptanuclear {M7(OH)4} (M = Co(II) or Ni(II)) clusters, possessing uninodal hexagonal primitive net with the point symbol {3(6)·4(18)·5(3)·6}. The four coordination polymers showed dominant antiferromangetic properties, in which 1·10H2O shows spin-canted behavior and 2·10H2O exhibits the coexistence of spin canting and spin glass. Meanwhile, the activated polymers 1 and 2 possessed permanent porosity, displaying relatively large H2 uptake capacity (77 K, 1 atm) of 114 and 133 cm(3) g(-1), and CO2 uptake capacity (273 K, 1 atm) of 65.8 and 73.3 cm(3) g(-1), for 1 and 2, respectively.