Multifunctional Lanthanide Metal-Organic Frameworks Based on -NH2 Modified Ligand: Fluorescent Ratio Probe, CrO42- Ions Adsorption, and Photocatalytic Property.

In response to the growing concern for environmental pollution, two lanthanide compounds {[Ln(L)(H2O)]·4H2O}n (where Ln = Tb and Gd, H3L = 1-amino-2,4,6-benzene tricarboxylic acid) were synthesized using a -NH2 modified ligand and systematically characterized. Both compounds exhibit remarkable fluorescence response, adsorption of CrO42- ions, and photocatalytic degradation properties, as well as exceptional acid-base and thermal stability. Remarkably, the pH-dependent 1-Tb exhibits exceptional performance as a fluorescent probe for detecting Fe3+ and CrO42-/Cr2O72- ions in aqueous solutions, while also serving as a ratiometric fluorescent probe for the detection of Cr3+, offering rapid response, high sensitivity, selectivity, and recoverability advantages in application. Moreover, 1-Tb exhibits excellent detection capabilities and displays effective adsorption of CrO42- ions, with a maximum adsorption capacity of 230.71 mg/g. On the other hand, 1-Gd exhibits superior performance compared to 1-Tb in the photocatalytic degradation of antibiotics. The degradation mechanism is further elucidated by conducting experiments with DFT theoretical calculations.

Icosidodecahedral Coordination-Saturated Cuprofullerene.

The first coordination-saturated buckyball with a C60 molecule totally encased in an icosidodecahedral Cu30 in a (µ30 -(η2 )30 )-fashion, namely C60 @Cu30 @Cl36 N12 , has been successfully realized by a C60 -templated assembly. The 48 outmost coordinating atoms (36Cl+12N) comprise a new simple polyhedron that is described by a ccf topology. Charge transfer from (CuI , Cl) to C60 explains the expansion of the light absorption up to 700 nm, and accounts for an ultrafast photophysical process that underpins its high photothermal conversion efficiency. This work makes a giant step forward in exohedral metallofullerene (ExMF) chemistry.

A 1D Mixed-Valence Cuprofullerene Pyrazolate Polymer as a Semiconductor Material.

Polymeric {Cu6[(µ3-η2:η2:η2)2-C60](FPz)6Cl·3C6H5Cl}∞ [FPz = 4-(trifluoromethyl)pyrazolate], synthesized solvothermally with chlorobenzene as the solvent, is a doubly-connecting trans bis-adduct hexanuclear cuprofullerene that has copper in mixed valence. The compound is an example of a metallofullerene having semiconductivity character.

Regioisomeric core-shell cuprofullerene C60@Cu24.

The controlled synthesis of high-nuclear regioisomeric core-shell exohedral metallofullerenes (ExMFs) is challenging. Herein, we demonstrated the synthesis of regioisomeric core-shell cuprofullerene C60@CuI24 and its 3-D coordination polymer using heteroleptic ligands, realizing high-nuclear regioisomeric ExMFs and a polymeric ExMF structure.

SHG in a centrosymmetric crystal - can it be possible?

The present report lists selected publications on centrosymmetric compounds that manifest second harmonic generation responses in a laser, along with a few publications that dispute the laser outcomes. Two studies provide a plausible explanation for this apparent contradiction between second-order nonlinear susceptibility and inversion symmetry: the crystals are noncentrosymmetric and are twinned by inversion. If crystal structures of SHG-active compounds are presented in centrosymmetric settings, the authors of the publications may consider stipulating that the true space group is likely to be one of the noncentrosymmetric sub-space groups.

Resolvable polymorphism in an intergrowth of two modifications of tris(diethyldithiocarbamato)antimony.

Tris(diethyldithiocarbamato-κS)antimony(III), [Sb(C5H10NS2)3], is tentatively presumed to comprise a triclinic and a monoclinic polymorph intergrown into each other. The geometry in the triclinic phase is a ψ-capped octahedron and that in the monoclinic phase is a ψ-pentagonal bipyramid. The study also identifies the polyhedral symbols for a reported pair of polymorphs of another SbIII coordination compound, as well as for those of published polymorphic modifications of other BiIII and PbII coordination compounds; the symbols in the pair differ in most of these examples. When differentiating related structures of such classes of coordination compounds, lone-pair stereochemistry may be another informative variable, as stereochemical activity is not always apparent from bond distances and angles only.

Ψ-Polyhedral symbols for coordination geometries of lead(II) with a stereochemically active lone pair.

Because an IUCr/IUPAC-designated set of letters/numbers identifies the configuration of the atoms linked to the PbII atom in its coordination compounds, a Ψ prefix before such as a polyhedral symbol provides useful information when its lone pair is stereochemically active. Such notation is especially relevant when the metal atom is connected to eight or more atoms regardless of whether the lone pair is active or inert. The polyhedral symbols for the crystal structures in some 50 articles published after 2000 are reported here as the original studies did not expressly identify coordination geometries.

Discrete Heteropolynuclear Yb/Er Assemblies: Switching on Molecular Upconversion Under Mild Conditions.

The salts {[Ln2 Ln*(Hhmq)3 (OAc)3 (hfac)2 ]+ [Ln*(hfac)3 (OAc)(MeOH)]- } (Hhmq=2-methanolquinolin-8-oxide, hfac=hexafluoroacetylacetonate; Ln, Ln*=Er, Gd, Yb) feature a discrete heteronuclear cation consisting of two types of lanthanide atoms. The quinolinoxy O-atom serves as a µ2 -bridge to two Ln atoms and as a µ3 -bridge to all three atoms, with metal⋅⋅⋅metal distances being around 3.7 Å. For 1 ([Yb2 Er]+ ), near-infrared downshifted luminescence is switched to competitive upconversion luminescence upon irradiation by a 980 nm laser under an extremely low excitation power (0.288 W cm-2 ) through introduction of fluoride ions. The stability of 1 after addition of fluoride was confirmed by powder X-ray diffraction and multistage mass spectrometry, associated with the 1 H NMR of 6 ([La2 Eu]+ ). More importantly, the at least 20-fold enhancement of the quantum yield in non-deuterated solvents at room temperature under low power densities (2 W cm-2 ) is the highest among the few molecular examples reported.

Synthesis, characterization and multiple targeting with selectivity: Anticancer property of ternary metal phenanthroline-maltol complexes.

The cobalt(II), copper(II) and zinc(II) complexes of 1,10-phenanthroline (phen) and maltol (mal) (complexes 1, 2, 3 respectively) were prepared from their respective metal(II) chlorides and were characterized by FT-IR, elemental analysis, UV spectroscopy, molar conductivity, p-nitrosodimethylaniline assay and mass spectrometry. The X-ray structure of a single crystal of the zinc(II) analogue reveals a square pyramidal structure with distinctly shorter apical chloride bond. All complexes were evaluated for their anticancer property on breast cancer cell lines MCF-7 and MDA-MB-231, and normal cell line MCF-10A, using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and morphological studies. Complex 2 was most potent for 24, 48 and 72 h treatment of cancer cells but it was not selective towards cancer over normal cells. The mechanistic studies of the cobalt(II) complex 1 involved apoptosis assay, cell cycle analysis, dichloro-dihydro-fluorescein diacetate assay, intracellular reactive oxygen species assay and proteasome inhibition assay. Complex 1 induced low apoptosis, generated low level of ROS and did not inhibit proteasome in normal cells. The study of the DNA binding and nucleolytic properties of complexes 1-3 in the absence or presence of H2O2 or sodium ascorbate revealed that only complex 1 was not nucleolytic.

Real-time and visual sensing devices based on pH-control assembled lanthanide-barium nano-cluster.

Real-time and visual monitoring of pollutants in the air is of great importance since they are usually cannot be seen, smelled, or touched. Lanthanide nano-cluster is a kind of luminescent sensor for various species. However, controlling synthesis of lanthanide nano-cluster remains experimentally challenging. In this work, four series of lanthanide-barium (Ln-Ba) nano-clusters of Dy2Ba (1), Tb2Ba2 (2), Ln4Ba3 (Ln = Tb, 3a; Eu, 3b), Tb4Ba4 (4) were assembled through precisely controlling the pH of the reactant solutions. The work features the first example that the number of cluster's nuclei changes regularly with the pH. Moreover, investigation reveals that nano-cluster 3a is a highly selective and sensitive sensor towards acetylacetone (acac) and aniline. Interestingly, easy-to-use sensing devices of test paper, agarose gel, and five kinds of film on CaCO3, polyfoam, coin, mask, and wall that based on 3a were fabricated by facile methods. The seven sensing devices showed remarkable ability to sense aniline and acac vapors with visibility to the naked eyes. This is the first work on multiple real-time and visual sensing devices based on the lanthanide nano-cluster.

Luminescent polymorphic aggregates of trinuclear Cu(I)-pyrazolate tuned by intertrimeric CuNPy weak coordination bonds.

Five luminescent polymorphic aggregates of trinuclear Cu(i)-pyrazolate, namely [anti-Cu3L3]2 (1), [syn-Cu3L3·C2H5OH]2 (2), [anti-Cu3L3·C2H5OH]n (3), [anti-Cu3L3·0.5C7H8]n (4) and [syn-Cu3L3·C8H10]n (5) (HL = 4-(pyridin-4-ylthio)-3,5-dimethyl-1H-pyrazole), were reported. The trimeric Cu3L3 fragments present syn- and anti-conformations dependent on the dangled direction of 4-pyridyl groups on the two sides of the Cu3Pz3 plane (Pz = pyrazolate). Intertrimeric NPyCu weak coordination bonds associate these Cu3L3 fragments together to form dimeric or polymeric structures, which are further stabilized by crystallized solvent molecules or intertrimeric CuCu interactions. The solvated complexes (3-5) may be transformed into the unsolvated complex 1 by evacuation of the crystallized solvents upon heating. All these complexes emit from green to yellow under UV irradiation, which originated from the triplet excited states of metal to ligand charge transfer (3MLCT) mixed with intertrimeric CuCu interactions. This work provides a novel kind of supramolecular aggregate based on Cu3Pz3 beyond the classical π-acidbase adducts and metallophilicity-dependent dimers/oligomers.

Exohedral Cuprofullerene: Sequentially Expanding Metal Olefin Up to a C60@Cu24 Rhombicuboctahedron.

Exohedral cuprofullerenes with 6-, 12-, or 24-nuclearity were obtained by utilizing fluorocarboxylic/dicarboxylic acid under solvothermal conditions. The 24-nuclear molecule presents a C60@Cu24 core-shell structure with a rhombicuboctahedron Cu24 coated on the C60 core, representing the highest nuclearity in metallofullerene. The resultant complexes show an efficient absorption of visible light as opposed to the pristine C60. TD-DFT calculations revealed the charge transfer from Cu(I) and O atoms to the fullerene moiety dominates the photophysical process.

Adducts of triangular silver(i) 3,5-bis(trifluoromethyl)pyrazolate with thiophene derivatives: a weak interaction model of desulfurization.

π-Acidic triangular silver(i) 3,5-bis(trifluoromethyl)pyrazolate (Ag3pz3) can form 1 : 1 adducts with dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (DMDBT), benzothiophene (BT), and 2,5-dimethylthiophene (DMT), which are stabilized by weak AgS and AgC contacts and sometimes by π-π stacking and, therefore, may represent a weak interaction model for some adsorptive desulfurization processes.

A luminescent edge-interlocked prismatic heteroleptic metallocage assembled through a ligand replacement reaction.

A luminescent edge-interlocked heteroleptic metallocage based on Cu3(pyrazolate)3 was prepared through a ligand replacement reaction from a homoleptic metallocage and a new ligand. Its structure was confirmed by XRD and MALDI-TOF mass spectrometry. Theoretical calculations revealed the new ligand was evidently responsible for the bathochromic shift of the optimal excitation. This work provides a heteroleptic strategy to regulate the interlocking fashion and photophysical mechanism of metallocages based on Cu3(pyrazolate)3.

Cd(ii) coordination polymers constructed from bis(pyridyl) ligands with an asymmetric spacer in chelating mode and diverse organic dicarboxylates: syntheses, structural evolutions and properties.

Self-assembly of diverse Cd(ii) metal salts, four organic dicarboxylic acids, and two flexible bis(pyridyl) ligands leads to the formation of thirteen complexes, namely, [Cd(L1)(C4H4O4)]n (1), [Cd(L2)(C4H4O4)0.5]n·nOH·8nH2O (2), [Cd(L1)(C4H2O4)]n (3), [Cd(L1)(C4H2O4)]n (4), [Cd2(L2)(C4H2O4)2(H2O)2]n·nH2O (5), [Cd2(L1)(m-BDC)2(H2O)2]n (6), [Cd2(L2)(m-BDC)2(H2O)2]n (7), [Cd3(L1)2(p-BDC)3(H2O)4]n·2nH2O (8), [Cd(L2)(p-BDC)0.5Cl]n (9), [Cd(L2)(p-BDC)0.5(H2O)]n·n(ClO4)·nH2O (10), [Cd3(L2)2(p-BDC)(SO4)2(H2O)6]n·4nH2O (11), [Cd(L2)(p-BDC)]n·nH2O (12) and [Cd(L2)(p-BDC)]n·nMeOH (13) (L1 = N,N'-bis(pyridin-4-ylmethyl)propane-1,2-diamine, L2 = N,N'-bis(pyridin-3-ylmethyl)propane-1,2-diamine, m-BDC2- = m-benzene dicarboxylate dianion, p-BDC2- = p-benzene dicarboxylate dianion), which have been characterized by elemental analysis, IR, TG, PL, and powder and single-crystal X-ray diffraction. The influence of different Cd(ii) salts on the structure variations and properties has also been investigated. Complexes 1 and 3 present a (4,4) layer motif accomplished by the interconnection of adjacent Cd(ii) cations through L1 molecules and trans-conformational succinates or fumarates. In contrast, the cis-conformational succinates in complex 2 only afford the formation of a chain structure. The L1 and L2 molecules in complexes 4 and 5 adopt the same coordination and join adjacent Cd(ii) cations together with fumarates, giving rise to different 3D networks with vma and irl topologies. The same coordination mode of L1 and L2 in complexes 6-8 joins adjacent Cd(ii) cations together with aromatic dicarboxylates, leading to different (63)(65·8), 2-periodic (6·3) and (4·4) layer motifs. The L2 molecules in complexes 9-13 present different coordination modes and join adjacent Cd(ii) cations together with p-BDC2- dianions to form diverse (6·3) layer motifs, and different 3D networks with cds and eca topologies. Therefore, the diverse coordination modes of the bis(pyridyl) ligand and the feature of different organic dicarboxylate anions can effectively influence the topological structures of these complexes. Luminescence investigation reveals that the emission maximum of these complexes varies from 403 to 433 nm in the solid state at room temperature.

Ultrahigh luminescence quantum yield lanthanide coordination polymer as a multifunctional sensor.

The investigation and development of advanced multifunctional and sensitive sensors with high luminescent quantum yield and the capability of detecting different analytes, such as metal ions, is imperative. Due to its inherent properties the lanthanide coordination complex is one candidate for sensing applications, particularly for multifunctional sensors. Herein, we present two series of alkali ion decorated lanthanide coordination polymers (Ln-CPs), which show ultrahigh luminescence quantum yields (QYs) of 77% (1a) and 92% (2a). To the best of our knowledge, 1a represents the first trifunctional lanthanide complex sensor that can simultaneous detect and discriminate three different analytes, namely H+/Cd2+/Cr3+ through a multimode optical response. Furthermore, the limit of detection (LOD) for Cr3+ is an ultralow value of 2.0 × 10-9 M with a sensing time of 2 h, which is comparable to the most sensitive Cr3+ chemosensor. More interestingly, 92% (2a) is an unprecedented luminescence QY among the reported lanthanide coordination complexes.

Chiroptical Activity from an Achiral Biological Metal-Organic Framework.

Chiroptical activity is observed from an achiral adenine-containing metal-organic framework (MOF) named ZnFDCA. Such a seemingly counterintuitive phenomenon can, in fact, be predicted by the intrinsic crystal symmetry of 4̅2 m point group. Although theoretically allowed, examples of optically active achiral crystals are extremely rare. ZnFDCA is the first reported achiral MOF showing optical activity, as demonstrated by a pair of circular dichroism signals with opposite signs and enhanced intensity. Moreover, simply through adding an amino substituent to adenine, the chiroptical activity, as well as nonlinear optical activity, of the analogous MOF, namely ZnFDCA-NH2, disappears due to diverse packing pattern giving rise to centrosymmetric crystal symmetry.

High Catalytic Performance of a CeO2-Supported Ni Catalyst for Hydrogenation of Nitroarenes, Fabricated via Coordination-Assisted Strategy.

A family of two-dimensional salen-type lanthanide complexes was synthesized through a facile solution diffusion method. The two-dimensional lanthanide complexes were characterized by single-crystal X-ray diffraction (SCXRD) and X-ray photoelectron spectroscopy (XPS) analytical techniques. The SCXRD and XPS analyses reveal that the obtained two-dimensional structures are rich in uncoordinated imine (-CH═N-) groups located on the skeleton of the salen-type organic ligand, which retain strong coordination ability with metal ions. On the basis of this unique feature, a highly dispersed CeO2-supported Ni catalyst (Ni/CeO2-CAS) with highly strong metal-support interaction was first synthesized via a coordination-assisted synthesis (CAS) method, which exhibits a much better catalytic activity in the hydrogenation of nitrobenzene than the traditional Ni/CeO2-IWI catalyst prepared by incipient wetness impregnation (IWI). The origin of the improved catalytic activity of Ni/CeO2-CAS as well as the role of Ni@Ce-H2salen was revealed by using diverse characterizations. On the basis of the comparative characterization results, the superior catalytic performance of Ni/CeO2-CAS to Ni/CeO2-IWI could have resulted from the smaller and highly dispersed Ni nanoparticulates, the intensified Ni-CeO2 interaction, the enhanced NiO reducibility, and the higher concentration of oxygen vacancies, favoring the H2 dissociation and adsorption of the nitrobenzene reactant. The Ni/CeO2-CAS catalyst also exhibits high catalytic performance for reduction of diverse nitroarenes to their corresponding functionalized arylamines. We anticipated that this coordination-assisted strategy may provide a new way for preparing other highly oxide-supported catalysts with potential applications in various catalytic reactions.