Electronic Effect Promoted Visible-Light-Driven CO-to-CO Conversion in a Water-Containing System.

The design of unsaturated nonprecious metal complexes with high catalytic performance for photochemical CO reduction is still an important challenge. In this paper, four coordinatively unsaturated Co-salen complexes - were explored in situ using -phenylenediamine derivatives and 5-methylsalicylaldehyde as precursors of the ligands in -. It was found that complex , bearing a nitro substituent (-NO) on the aromatic ring of the salen ligand, exhibits the highest photochemical performance for visible-light-driven CO-to-CO conversion in a water-containing system, with TON and CO selectivity values of 5300 and 96%, respectively.

Russian Doll-like 3d-4f Cluster Wheels with Slow Relaxation of Magnetization.

The solvothermal reactions of LnCl·6HO and MCl·6HO (M = Co, Ni) with 2,2'-diphenol (HL) and 5,7-dichloro-8-hydroxyquinoline (HL) gave three 3d-4f heterometallic wheel-like nano-clusters [LnM(L)(L)(-OH)(OCH)Cl(CHCN)]Cl·HO (Ln = Dy, M = Co, = 3 for ; Ln = Dy, M = Ni, = 0 for ; Ln = Tb, M = Ni, = 0 for ) with similar cluster structure. The innermost Ln(III) ion is encapsulated in a planar Ln ring which is further embedded in a chair-conformation M ring, constructing a Russian doll-like 3d-4f cluster wheel Ln(III)⸦Ln⸦M. and show obvious slow magnetic relaxation behavior with negligible opening of the magnetic hysteresis loop.

Electronic effects promoted the catalytic activities of binuclear Co(II) complexes for visible-light-driven CO reduction in a water-containing system.

Under the action of a catalyst, the photoinduced reduction of CO to chemicals and fuels is one of the greenest and environment-friendly approaches for decreasing atmospheric CO emissions. Since the environment was affected by the greenhouse effect, scientists have never stopped exploring efficient photoinduced CO reduction systems, particularly the highly desired non-noble metal complexes. Most of the currently reported complexes based on non-noble metals exhibit low catalytic activity, selectivity, and stability in aqueous systems under the irradiation of visible light.

Highly Efficient Visible-Light-Driven CO-to-CO Conversion by Coordinatively Unsaturated Co-Salen Complexes in a Water-Containing System.

The development of cost-effective catalysts for CO reduction is highly desired but remains a significant challenge. The unsaturated coordination metal center in a catalyst is favorable for the process of catalytic CO reduction. In this paper, two asymmetric salen ligands were used to synthesize two coordinatively unsaturated Co-salen complexes.

Synthesis and antitumor activities of five Cu(II) complexes of bis(5-halosalicylidene)-1,3-propanediamine derivatives.

The development of metal complexes of Schiff base has attracted much attention due to their DNA binding properties and extensive biological activities. We reported here five copper(II) complexes [Cu(L1)] (1), [Cu(L2)] (2), [Cu(L3)] (3), [Cu2(L4)(OAc)] (4), and [Cu2(L5)(HCOO)] (5) bearing the bis-Schiff base ligands of bis(5-chlorosalicylidene)-1,3-propanediamine (H2L1), bis(5-chlorosalicylidene)-2-methyl-1,3-propanediamine (H2L2), bis(5-bromosalicylidene)-2-methyl-1,3-propanediamine (H2L3), bis(5-chlorosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L4), and bis(5-bromosalicylidene)-2-hydroxyl-1,3-propanediamine (H3L5), respectively. The single crystal X-ray diffraction analysis results revealed that complexes 1-3 present mononuclear structures and complexes 4 and 5 show dinuclear structures.

Anticancer activity of four trinuclear cobalt complexes bearing bis(salicylidene)-1,3-propanediamine derivatives.

Schiff base and its complexes are being paid more and more interests for their great prospects in biological applications. We reported here four cobalt(II) complexes [Co(L)(HCOO)] (1), [Co(L)(HCOO)(CHOH)]·2CHOH (2), [Co(HL)(OAc)(DMF)] (3) and [Co(HL)(HCOO)(DMF)]·2HO (4) bearing the bis-Schiff base ligand of bis(5-bromosalicylidene)-1,3-propanediamine (HL), bis(5-bromosalicylidene)-2-methyl-1,3-propanediamine (HL), bis(5-chlorosalicylidene)-2-hydroxyl-1,3-propanediamine (HL) and bis(5-bromosalicylidene)-2-hydroxyl-1,3-propanediamine (HL), respectively. The anti-tumor activities of the four titled complexes were screened on a series of tumor cell lines.

Heterometallic Metal-Organic Framework Based on [CuI] and [HfO] Clusters for Adsorption of Iodine.

Heterometallic metal-organic framework (MOF) as a kind of porous material is very important because of its excellent properties in catalysis, magnetic, sensor, and adsorption fields, but the reasonable design and syntheses of these are still challenging. Herein, we prepared one heterometallic MOF with the formula [Hf( -OH)(OH)][(CuI) (ina)]·22DMF (, ina = isonicotinate). Single-crystal X-ray diffraction analysis revealed that is a three-dimensional network with topology, constructed from 8-connected [Hf( -OH)(OH)] and 4-connected [CuI] clusters as second building units (SBUs).

Two Heterometallic Nanoclusters [DyNi] and [DyMnMn]: Structure, Assembly Mechanism, and Magnetic Properties.

A full understanding of the assembly mechanisms of coordination complexes is of great importance for a directional synthesis under control. We thus explored here the formation mechanisms of the two new heterometallic nanoclusters [DyNi(μ-OH)(L)(OAc)(HO)]·3.25EtOH·4CHCN () and [DyMnMnO(OH)(OAc)(L)(HL)(EtOH)]·2EtOH·2CHCN·2HO () with different cubane-based squarelike ring structures, which were obtained from the reactions of 4-bromo-2-[(2-hydroxypropylimino)methyl]phenol (HL) with Dy(NO)·6HO and the transition metal salt Ni(OAc)·4HO or Mn(OAc)·4HO.

Superb Alkali-Resistant DyNi Single-Molecule Magnet.

A superb alkali-resistant single-molecule-magnet (SMM) material with the molecular formula [DyNi(L)(CHCOO)(NO)] () (HL = 8-hydroxyquinoline) has been structurally and magnetically characterized. Single-crystal X-ray diffraction revealed that possesses a hexanuclear [DyNi] cluster, which is built by two triangular [DyNi] cores double-bridged through two CHCOO ions. Interestingly, can keep its original structure in dilute acid and common basic solutions (e.

Synthesis and anticancer activity of mixed ligand 3d metal complexes.

Our previously reported copper-based complexes of tropolone show nice antitumor effects, but with high cytotoxicity to normal cells, which is presumably caused by copper ions. Here, we managed to achieve this challenge by using other 3D metals to replace copper ions. We thus prepared four mononuclear 3D metal complexes [M(phen)L2] (M = Mn, Co, Ni, and Zn for 1-4, respectively).

Two Decanuclear DyCo ( = 2, 4) Nanoclusters: Structure, Assembly Mechanism, and Magnetic Properties.

The aggregation and formation of heterometallic nanoclusters usually involves a variety of complex self-assembly processes; thus, the exploration of their assembly mechanisms through process tracking is more challenging than that for homometallic nanoclusters. We explored here the effect of solvent on the formation of heterometallic clusters, which gave two heterometallic nanoclusters, [DyCo(μ-OCH)(L)(HL)(OAc)(NO)(CHCN)]·CHCN·HO () and [DyCo(L)(HL)(OAc)(OCHCHOH)(HOCHCHOH)(HO)]·9CHCN (), with the HL ligand formed from the in situ condensation reaction of 3-amino-1,2-propanediol with 2-hydroxy-1-naphthaldehyde in the presence of Co(OAc)·4HO and Dy(NO)·6HO. It is worth noting that the skeleton of cluster has a high stability under high-resolution electrospray ionization mass spectrometry (HRESI-MS) conditions with a gradually increasing energy of the ion source.

Guest-Induced Switching of a Molecule-Based Magnet in a 3d-4f Heterometallic Cluster-Based Chain Structure.

With the motivation of controlling a magnetic switch by external stimuli, we report here an infinite chain structure formed from the secondary building units of CuTb clusters through the linkage of nitrate ions. It behaves as a molecule-based magnet with the highest energy barrier among isolated Tb/Cu-based single-molecule magnets and single-chain magnets, which is close to a dimer of a CuTb cluster unit from a magnetic point as revealed by its correlation length of 2.23 CuTb units.

Synthesis and antitumor activities of transition metal complexes of a bis-Schiff base of 2-hydroxy-1-naphthalenecarboxaldehyde.

The complexes of Schiff base have attracted much attention for their potential biological activities. In this research, five transition metal complexes TML(OAc) (TM = Cu, 1; Ni, 2; Co, 3; Mn, 4; Fe, 5) were prepared using a bis-Schiff base of N,N'-bis[(2-hydroxy-1-naphthalenyl)methylene]-propane-1,3-diamine (HL), which present similar linear trinuclear structures with their three metal ions consolidated by two bis-Schiff base ligands and two acetate ligands. Their antitumor activities in vitro were screened through seven human cancer cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Tuning slow magnetic relaxation behaviour in a {Dy}-based one-dimensional chain crystal field perturbation.

Two novel {Dy}-based one dimensional chain compounds {[Dy(HL)(OAc)]·2MeOH} (1) and {[Dy(HL)(OAc)(NCS)]·2MeOH} (2) (HL = 1,3-bis(2-hydroxynaphthalenemethyleneamino)-propan-2-ol) have been prepared under solvothermal conditions. Crystal structure analyses indicate that 1 and 2 feature similar 1D chain structures bearing dinuclear secondary building units. The difference between these two structures is that one chelated acetate ligand of Dy(iii) ion in 1 is replaced by one monodentate coordinated NCS ion in 2, leading to their different coordination numbers and geometry configurations to Dy(iii) ion.

Two mononuclear dysprosium(iii) complexes with their slow magnetic relaxation behaviors tuned by coordination geometry.

Two mononuclear dysprosium(iii) complexes [Dy(H3NAP)2Cl2]Cl·EtOH (1) and [Dy(H3NAP)2(H2O)Cl2]Cl·-2CH3CN·MeOH·0.5H2O (2) were obtained by coordinating an in situ formed Schiff base ligand of 1,3-bis(2-hydroxynaphthalenemethyleneamino)-propan-2-ol (H3NAP) to the dysprosium(iii) ion. Their Dy(iii) centers are six and seven-coordinated in octahedral and pentagonal-bipyramidal coordination geometries, respectively.

Metal-Organic Frameworks Based on Multicenter-Bonded [M ] (M=Mn, Zn) Clusters with Cubic Aromaticity.

A new concept for constructing metal-organic frameworks (MOFs) based on multicenter-bonded [M ] (M=Mn, Zn) clusters with cubic aromaticity is discussed. In principle, intermolecular/intramolecular hydrogen-bonding, π-π stacking, coordinated covalent bonding and ionic bonding usually account for the structures of MOFs, and multicentered bonds generally exist in cation, anion, neutral and zwitterionic radicals, while rarely appear in MOFs. Meanwhile, aromaticity became one of the most vexing yet fascinating key concepts in chemistry since the proposition of the structure of benzene molecule in 1865.

Stable Zn -Containing MOFs with Large [Zn ] Nanocages from Assembly of Zn Ions and Aromatic [Zn ] Clusters.

Two unique Zn -containing MOFs {[Zn Zn (H O) (HL) ](OH) ⋅13 H O} (x=6, 1; x=2, 2) (HL=tetrazole monoanion) with high-nuclearity Zn-cages were prepared successfully. These Zn-cages are constructed from [Zn ] clusters with multi-centered Zn -Zn bonds and Zn ions. [Zn ] clusters in 1 and 2 display O and D symmetry, respectively.

Metal-Organic Frameworks (MOFs) of a Cubic Metal Cluster with Multicentered Mn(I)-Mn(I) Bonds.

MOFs with both multicentered metal-metal bonds and low-oxidation-state (LOS) metal ions have been underexplored hitherto. Here we report the first cubic [Mn(I) 8 ] cluster-based MOF (1) with multicentered Mn(I)-Mn(I) bonds and +1 oxidation state of manganese (Mn(I) or Mn(I)), as is supported by single-crystal structure determination, XPS analyses, and quantum chemical studies. Compound 1 possesses the shortest Mn(I)-Mn(I) bond of 2.

First tetrazole-bridged d-f heterometallic MOFs with a large magnetic entropy change.

A novel 3D tetrazole-bridged 3d-4f heterometallic MOF {(H3O)3[Gd3Mn2(Trz)4]·12H2O}n (1) with a hexanuclear [Gd6] cluster was obtained via in situ [2+3] cycloaddition reaction and structurally characterized, possessing good solvent and thermal stabilities, as well as a large magnetic entropy change -ΔS(m) = 40.3 J kg(-1) K(-1) for ΔH = 7 T at 2.0 K.

Lanthanide organic framework as a regenerable luminescent probe for Fe(3+).

A unique three-dimensional Tb-BTB framework (1) with two types of one-dimensional channels was obtained and structurally characterized, exhibiting high thermal stability. Luminescent investigations reveal that 1 can detect Fe(3+) with relatively high sensitivity and selectivity. Importantly, 1 as the luminescent probe of Fe(3+) can be simply and quickly regenerated, which represents a rare example in reported luminescent sensors of Fe(3+).

Heterometal-organic frameworks as highly sensitive and highly selective luminescent probes to detect I⁻ ions in aqueous solutions.

Two cationic heterometal-organic frameworks (Eu-Zn (1·NO₃⁻) and Tb-Zn (2·NO₃⁻)) with NO3(-) counter-anions in the channels are structurally and luminously characterized. Both of them can serve as highly sensitive and highly selective luminescent probes for detecting I(-) ions in aqueous solutions. In particular, 2·NO₃⁻ can selectively and reversibly detect I(-) with a fast response time of just 10 s and an extremely low detection limit of 0.

Temperature-controlled chiral and achiral copper tetrazolate metal-organic frameworks: syntheses, structures, and I2 adsorption.

Four tetrazole-based three-dimensional (3D) metal-organic frameworks (MOFs), {[Cu(II)(btz)]·0.5H(2)O}(n) (1), [Cu(II)(btz)](n) (1'), {[Cu(II)(btz)]·0.5I(2)}(n) (1'·0.