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Well-defined 3d–4f heterometallic supramolecular architectures have attracted attention because of their applications in the field of luminescence and magnetism. However, covalent metallo-supramolecular discrete complexes, decorated with hetero-metallic vertices, have never been reported because of the difficulties in design and control. Herein, we report a series of covalent metallo-supramolecular discrete complexes with 3d–4f vertices synthesized by hierarchical subcomponent self-assembly of tris(2-aminoethyl)amine, 2,6-diformyl-p-cresol, and lanthanide ions (Ln) with different amines and transition metal ions. The programmable self-assembly process results in the formation of triple-stranded hetero-metallic covalent organic discrete complexes, namely 3a–3c-(Ln, Zn) (Ln = SmIII, EuIII, DyIII, YbIII and LuIII) and 3a′-(Dy, Co), which are characterized by nuclear magnetic resonance (NMR) analysis, electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and single-crystal X-ray analysis. Photophysical investigations disclose that the organic skeleton of 3a-(Ln, Zn) exhibits an excellent sensitizing ability toward SmIII, EuIII, and YbIII ions, displaying characteristic luminescence emission in both the visible and near-infrared (NIR) regions. AC susceptibility measurements of 3a′-(Dy, Co) reveal the frequency-independent performance under zero dc field, suggesting the absence of slow relaxation of magnetization. This work offers a new approach for the fabrication of discrete metallic covalent architectures with 3d–4f vertices. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Understanding the kinetic process during the self‐assembly and chiral amplification of metal‐organic polyhedra (MOPs) is critical for the rational preparation of chiral MOPs. Herein, we report the ionic radius dependent kinetic processes for the self‐assembly and chiral amplification of Ln4L4‐type (Ln, Lanthanides; L, ligand) lanthanide tetrahedral cages. The chiral Eu4(LR)4 tetrahedral cage is structurally characterized by nuclear magnetic resonance (NMR), electrospray ionization time‐of‐flight mass spectrometry (ESI‐TOF‐MS), and single crystal X‐ray diffraction. Kinetic study on the stereo‐controlled self‐assembly of circularly polarized luminescence (CPL)‐active Ln4(LR)4 (Ln = LaIII, PrIII and EuIII) tetrahedra manifests that the larger ionic radius of Ln leads to faster assembly rates. Mixed‐ligand cage assembly experiments with chiral LR/S, achiral Lac and Ln (1 : 3 : 4 molar ratio) reveal that the self‐assembly and chiral amplification occur synchronously for the LaIII and PrIII cages, while two distinct steps, i.e., first self‐assembly and then chiral amplification, are observed for the EuIII cage. Such distinct kinetic behavior is attributed to different ligands exchange rates among the mixed‐ligand Ln4L4 cages. This work provides fundamental guidance for fabrication and property‐optimization of chiral lanthanide‐based molecular materials. [ABSTRACT FROM AUTHOR]

Spin-crossover (SCO) active compounds have received much attention due to their potential application in molecular devices. Herein, a family of solvent-free FeII compounds, formulated as (A)2[FeL2], (H2L = pyridine-2,6-bi-tetrazolate, A = (Me)4N+1, Et2NH2+2, iPr2NH2+3 and iPrNH3+4), were synthesized and characterized. Single-crystal X-ray diffraction studies reveal that 1–4 are all supramolecular frameworks containing the same [FeL2]2− center, which is arranged into two packing modes via inter-molecular interactions, that is, a 3D architecture in 1 and 1D chain in 2–4. The spin states of 1–4 at different temperatures are assigned on the basis of the single-crystal X-ray diffraction data. Solid state magnetic investigations indicate that 1 and 4 exhibit a low spin state (below 350 K) and high spin state (2–400 K), respectively. 2 and 3 display clear SCO behavior in the measured temperature, but with different profiles and critical temperatures. 2 undergoes a complete gradual SCO with a critical temperature of T1/2 = 260 K. 3 has an abrupt near room temperature transition between T1/2 cooling = 278 K and T1/2 warming = 286, centered at 282 K (9 °C). This study reveals the importance of organic cations in the modulation of SCO behavior and offers a new insight for the design of SCO compounds with near room temperature spin transitions. [ABSTRACT FROM AUTHOR]

Molecular cages have attracted great attention because of their fascinating topological structures and well‐defined functional cavities. These discrete cages were usually fabricated by coordination assembly approach, a process employing directional metal‐ligand coordination bonds due to the nature of the divinable coordination geometry and the required lability to encode dynamic equilibrium/error‐correction. Compared to these coordination molecular cages with mononulcear metal‐nodes, an increasing number of molecular cages featuring dinuclear and then polynuclear metal‐cluster nodes have been synthesized. These metal‐cluster‐based coordination cages (MCCCs) combine the merits of both metal clusters and the cage structure, and exhibit excellent performances in catalysis, separation, host‐guest chemistry and so on. In this review, we highlight the syntheses of MCCCs and their potential functions that is donated by the metal‐cluster nodes. [ABSTRACT FROM AUTHOR]

By introduction of a new Fe(L1)2 spin-crossover (SCO) unit into the polynuclear system, a nano-scale Fe4(L2)4 molecular square architecture is designed through coordination-directed self-assembly strategy. Both the mononuclear Fe(L1)2 and tetranuclear Fe4(L2)4 complexes have been structurally confirmed by 1H nuclear magnetic resonance (NMR), electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and temperature-dependent single crystal X-ray diffraction studies. Variable-temperature magnetic susceptibility measurements reveal the presence of an abrupt SCO behavior with a thermal hysteresis width of 4 K for Fe(L1)2. By clear contrast, Fe4(L2)4 undergoes a gradual spin transition behavior with enlarged thermal hysteresis width and higher spin transition temperature. [ABSTRACT FROM AUTHOR]

By introduction of a new Fe(L1)2 spin-crossover (SCO) unit into the polynuclear system, a nano-scale Fe4(L2)4 molecular square architecture is designed through coordination-directed self-assembly strategy. Both the mononuclear Fe(L1)2 and tetranuclear Fe4(L2)4 complexes have been structurally confirmed by 1H nuclear magnetic resonance (NMR), electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS), and temperature-dependent single crystal X-ray diffraction studies. Variable-temperature magnetic susceptibility measurements reveal the presence of an abrupt SCO behavior with a thermal hysteresis width of 4 K for Fe(L1)2. By clear contrast, Fe4(L2)4 undergoes a gradual spin transition behavior with enlarged thermal hysteresis width and higher spin transition temperature. [ABSTRACT FROM AUTHOR]

Organic pollutants have attracted increasing attention due to their strong persistence and extensive diffusivity. Plasticizers (PAEs) and organophosphorus pesticides (OPs), as the vital part of organic pollutants, have made extensive damage to the environment with the rapid development of modern agriculture and industry. Therefore, we have, for the first time, carried out a quantitative analysis of the PAEs and OPs by fluorescence recognition. A series of isostructural lanthanide organic frameworks, [Ln(tftpa)1.5(2,2′-bpy)(H2O)] (Ln = Gd 1, Eu 2 and Tb 3, H2tftpa = tetrafluoroterephthalic acid), were hydrothermally synthesized, of which 3 exhibited excellent hydrolytic resistance to both boiling acidic and basic aqueous solutions. Moreover, luminescence investigations show that 3 can be used as a highly sensitive and recyclable luminescence sensor for the detection of DBP (di-n-butyl phthalate) in simulated seawater and chlorpyrifos in ethanol with the detection limits of 2.07 and 0.14 ppb, respectively. [ABSTRACT FROM AUTHOR]

The introduction of heterometal ions into coordination polymers (CPs) could yield novel structural types and thus unprecedented properties. This work reports on the syntheses, characterizations and magnetic properties of a series of heterometallic CPs (HCPs), namely Mg1−xCoxLi2(3,5-pdcH)2(DMF)2 (x = 0 (1), 0.285 (2), 0.575 (3) and 1 (4); 3,5-pdcH3 = pyrazole-3,5-dicarboxylic). The CPs are isostructural to each other with a three dimensional neutral framework of apo type topology, which is constructed by 3,5-pdcH2− ligands interconnecting infinite chain-like SBUs of [MLi2(COO)4(DMF)2]n (M = Mg (1), Mg0.715Co0.285 (2), Mg0.425Co0.575 (3) and Co (4)). Compound 1 represents a rare example of an s–s block HCP based on lightweight Mg2+ and Li+ ions. Compound 1 is magnetically inactive, while the successful doping of Co2+ ions into Mg2+ sites endows the resulting heterometallic compounds with antiferromagnetic behaviour. The magnetic behaviour of compounds 2–4 was analyzed and was shown to come from the zero field split or the spin–orbit coupling of the high-spin mononuclear Co2+ ions. Compounds 2 and 3 represent a rare type of HCP which simultaneously contains independent metal ions (Li+) and co-occupied ones (Mg2+ and Co2+) in different crystallographic sites. [ABSTRACT FROM AUTHOR]

A new 3D MOF [MnLi2(ip)2(H2O)2] (1) with a 1D heterometallic inorganic Mn(ii)–Li(i) chain is reported. With the assistance of diamagnetic {LiO4} connectors, which separate the paramagnetic Mn(ii) ions and act as magnetic spacers, very weak magnetic interactions were obtained. Remarkably, 1 showed a significant magnetocaloric effect (MCE) with a large entropy change value of 30.4 J kg−1 K−1 for ΔH = 8 T at 2 K. [ABSTRACT FROM AUTHOR]

An iodoplumbate-based organic–inorganic hybrid ferromagnetic semiconductor, [Pb3Cu2I10(phen)4]n, has been solvothermally synthesized. The ferromagnetic exchange interaction is resulting from the multiple aromatic π–π stacking interactions between the adjacent phen molecules. [ABSTRACT FROM AUTHOR]

With the aid of a bifunctional 6-mercaptonicotinic acid ligand, a novel {Ni12Gd24} cage-based (6, 12)-c alb–MROF that is assembled from a {Gd4(OH)4(COO)6} trigonal-prism building unit and a {Ni6S12} hexagonal-prism molecular building block has been synthesized for the first time. It exhibits a large MCE value of 29.86 J kg−1 K−1 for ΔH = 8 T at 2 K. [ABSTRACT FROM AUTHOR]

An anionic CoII-MOF, (Me2NH2)[Co3(Me2NH)3(OH)(SDBA)3] ( 1) (H2SDBA=4,4′-sulfonyldibenzoic acid) consisting of highly symmetric CoII3(μ3-OH) triangles exhibits spin-canting, spin-flop, and easy-plane magnetic anisotropy. Measurement on a single crystal shows that the ab plane of 1 is the easy magnetization plane. After structural modification through simultaneous removal of the coordinated dimethylamine (DMA) molecule at the Co center and the ionic groups DMA+ and OH−, the resulting neutral amorphous framework 2 displays an enhanced spin frustration effect. The deionization of 1 does not result in the collapse of the framework, showing the high stability of the backbone structure. [ABSTRACT FROM AUTHOR]