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A d10 Cu(I) two‐dimensional (2D) metal–organic framework (MOF) with chemical formulas, {[Cd(L)(tcm)(H2O)]⋅2H2O}n (1) (L = 1,3,5‐tris(4‐pyridylethynyl)benzene; tcm−1 = tricyanomethanide) was synthesized and structurally characterized by single crystal X‐ray diffraction method. In 1, the coordination geometry of Cu(I) ion is distorted tetrahedral coordinated to four N atoms from three L and one tcm− ligands. A 2D puckered honeycomb‐like layer is formed via the bridges of Cu(I) ions and L ligands with tris‐monodentate coordination mode. Two 2D layers are mutually interpenetrated via the π–π stacking interaction between benzene ring of L ligand and pyridyl ring of neighboring L ligand to form a two‐fold interpenetrated 2D net and then arranged orderly to construct its 3D supramolecular network. Thermal stability and in‐situ temperature‐dependent structural variations of 1 are performed by TG analysis associated with temperature‐dependent PXRD measurement. The water vapor ad‐/de‐sorption isotherm and CO2 adsorption isotherm of 1 are measured and discussed. [ABSTRACT FROM AUTHOR]

A 3Fe4S cluster related to M‐cluster of Mo‐nitrogenase is reported. [K(THF)5][Fe3(μ‐bdt)2(μ‐PPh2)(CO)5] (1) is synthesized from photo‐assisted structural rearrangement of [K(THF)2][(μ,κ2‐bdt)Fe2(μ‐PPh2)(CO)5] under visible light irradiation. The molecular structure of 1 consists of a Fe3 core bearing one dithiolate bridge and the second dithiolate group capping onto the metallic plane. The structural motif of 1 is analogous to that of Mo‐participated 3Fe4S unit in M‐cluster of Mo‐nitrogenase, with the similar Fe‐Fe and Fe‐S bond distances. Upon protonation in 193 K, a Fe‐hydride species (1H) is generated and characterized to possess the bridging hydride group (δ = −12.57 ppm) by 1H‐NMR spectroscopy and DFT calculation. In CH3CN solution, complex 1 exhibits a reversible reduction and oxidation process at E1/2red = −1.94 V and E1/2ox = −0.18 V, respectively, at 273 K. The reduction behavior of 1 in CH2Cl2 solution at 243 K displays a slight modification in the presence of trifluoroacetic acid, revealing a moderate anodic potential shift (~50 mV). The current amplitude of the reduction wave is linearly increased with the increasement of acid added, indicative of the catalytic event. [ABSTRACT FROM AUTHOR]

Two d10 M(II) (M = Cd and Zn) coordination polymers (CPs) with chemical formulas, {[Cd(L1)(NCS)2(H2O)]⋅C2H5OH}n(1), and {[Zn(L1)(NCS)2]⋅C2H5OH⋅0.5H2O}n(2) (L1 = 1,3,5‐tris(4‐pyridylsulfanylmethyl)‐2,4,6‐trimethylbenzene) were synthesized and structurally characterized by single‐crystal x‐ray diffraction method. In compound 1, the coordination environment of Cd(II) ion is distorted octahedral bonded to three nitrogen donors from three L1 ligands located in a facial‐position, two nitrogen donors from NCS− and one water molecule. The L1 acts as a bridge ligand with tris‐monodentate coordination mode in a cis‐cis‐cis structural conformation, connecting the Cd(II) to form a two‐dimensional (2D) zigzag‐like layered metal‐organic frameworks. Adjacent 2D layers are then arranged orderly in an ABAB manner to complete its three‐dimensional (3D) supramolecular architecture. In compound 2, the coordination environment of Zn(II) ion is distorted tetrahedral bonded to two nitrogen donors from two L1 ligands and two nitrogen donors from two NCS− ligands. The L1 acts as a bridge ligand with bis‐monodentate coordination mode in a cis‐cis‐cis structural conformation, connecting the Zn(II) ions to form a one‐dimensional (1D) zigzag‐like polymeric chain. Adjacent chains are arranged orderly in an alternate ABAB manner to generate a 2D framework and then further arranged in an AAA manner to complete its 3D supramolecular architecture. The structural characterization as well as thermal‐stability and solvents de‐/ad‐sorption behavior of 1 and 2 are studied and discussed in details. [ABSTRACT FROM AUTHOR]

Four low‐spin {FeNO}6 complexes, [Fe(NO)(PS2)(PS2H)] (1, PS2H2 = bis(2‐dimercaptophenyl)phenylphosphine) with a pendant thiol, [Fe(NO)(PS2)(PS2CH3)] (2) bearing a pendant thioether, and [Fe(NO)(PS2)(RPS)] (RH, 4a; RTMS, 4b) without the noncovalent thiol/thioether group are spectroscopically and structurally characterized. In comparisons of the νNO, absorption energy in UV/vis spectra and structural parameters from single X‐ray diffraction studies, the four iron‐nitrosyl‐thiolato compounds share similarity in electronic structure. Complex 1 with a pendant thiol leads to NO and HNO production upon exposure to the light. Photolysis of 2 bearing a pendant thioether only affords NO. Effective detection of HNO or NO from 1 or 2 is achieved by the employment of [MnIII(TMSPS3)(DABCO)]. In contrast, 4a and 4b show inertness toward visible‐light stimulus. Photolysis and having pendant thiol/thioether group play key roles in NO production from these iron‐nitrosyl‐thiolato complexes, that is, the Fe‐NO bond is weakened by exposure to light and the noncovalent SH of 1 or SCH3 of 2 can serve as an incoming ligand to interact with Fe atom, resulting in a transient with intramolecular [RS⋅⋅⋅Fe⋅⋅⋅NO] interaction (RH and CH3) which could facilitate NO dissociation. [ABSTRACT FROM AUTHOR]

The chemical screening of a cultured soft coral, Briareum violaceum, led to the isolation of eight natural, briarane-related diterpenoids, including three unreported metabolites, briavioids E–G (1–3), and five known briaranes, briacavatolides B (4) and C (5), briaexcavatin L (6), briaexcavatolide U (7) and briarenol K (8). The structures of briaranes 1–8 were established using spectroscopic methods. The absolute configuration of briavioid A (9), obtained in a previous study, was reported for the first time in this study by a single-crystal X-ray diffraction analysis using a copper radiation source. The anti-inflammatory activity of briaranes 1 and 2 and briaranes 4–8 was evaluated by screening their inhibitory ability against the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells. [ABSTRACT FROM AUTHOR]

The reaction of potassium (aza-15-crown-5)dithiocarbamate (KO4NCS2) and (Me2S)AuCl gave the dinuclear complex [Au(O4NCS2)]2, which underwent structural transformation upon heating to rearrange into the hexanuclear complex [Au(O4NCS2)]6. Under similar reaction conditions, KO4NCS2 reacted with AgNO3 or [Cu(CH3CN)4]ClO4 to give the 1-D coordination polymer [Ag(O4NCS2)]n (1) and the tetranuclear complex [Cu(O4NCS2)]4 (2), respectively. It is noted that upon heating a similar structural transformation process occurs from tetranuclear complex 2 to the octanuclear complex [Cu(O4NCS2)]8 (2′), connected by a weak Cu⋯S contact of 2.846 Å, and it has been isolated and corroborated by powder and single-crystal X-ray diffraction studies as well. Moreover, a variety of MO4NCS2 salts (M = Li+, Na+, K+ and Rb+) were used to react with AgNO3 to construct a series of coordination architectures: [LiAg(O4NCS2)2(μ-H2O)0.5]2 (3), {Na[Ag(O4NCS2)2]}n (4), {K[Ag(O4NCS2)2]}n (5) and {Rb[Ag(O4NCS2)2]}n (6). The smallest Li+ ion only coordinates with four oxygen atoms from the same azacrown ether ring and one H2O molecule, leading to a 1-D hydrogen-bonded chain with another azacrown ether ring for complex 3. The larger Na+ ion coordinates with seven oxygen atoms from two different crown ether rings, leading to a 1-D chain for complex 4. However, the largest K+ and Rb+ ions constitute a 1-D framework, except that each metal ion coordinates with eight oxygen atoms from two different crown ether rings, featuring a 1-D helical chain for complexes 5 and 6. Hence, the different sizes of alkaline metal ions exert a dramatic effect on the structural motifs of complexes 3–6. Remarkably, the dithiocarbamate moieties adopt μ2-bridging ([Au(O4NCS2)]2 and [Au(O4NCS2)]6), μ3- and μ4-bridging (1–2) and chelate forms (3–6) in the structural backbones. [ABSTRACT FROM AUTHOR]

Molybdenum trioxide (MoO3) with a theoretical specific capacity of 1117 mA h g−1 is widely considered a promising anode material for lithium-ion batteries. However, the irreversible conversion reactions, low electrical conductivity, and detrimental volume expansion upon Li intercalation between the one-dimensional layered structures of MoO3 hinder its practical implementation. Herein, we report a facile synthetic protocol that allows surficial modification by replacing the terminal and bridging oxo groups of molybdenum oxide clusters. Successful organoimido functionalization resulted in a large cathodic shift in Mo(VI / V) reduction by 0.6 V, pronounced electronic communication between the organic moiety and the metal–oxide unit, and significant increase in electrical conductivity (80–100 Ω interfacial charge-transfer resistance). Combined with the enlarged active surface area due to the structural hindrance induced by the organic functionality, the steady specific capacity of the organoimido-modified molybdenum oxide clusters was greater than 1200 mA h g−1 at 900 mA g−1 at the end of 360 cycles, where the best value of 1653 mA h g−1 was achieved for the nitroaniline-substituted species. The steady capacity of 480 mA h g−1 was achieved in the fast charge–discharge process (3000 mA g−1) over 1400 cycles. The results indicate that the surficial modification of metal oxides with organo moieties using our facile synthetic method has broad application potential for metal oxides to be used as high-capacity electrode materials in the future. [ABSTRACT FROM AUTHOR]

It is well known that phonon-induced relaxation processes play a significant role in accelerating magnetization relaxation in the low-temperature regime. Unfortunately, many SIMs (single-ion magnets) suffer from being quenched by these mechanisms such that neither out-of-phase signals nor magnetization hysteresis can be readily observed. Nevertheless, because it involves molecular motions at low-frequency (low-energy) levels, methods for synthetically controlling this factor have not yet been addressed by chemists. In this study, we prepared a series of three compounds in which one contains a rigid chelating ligand, and the other two contain analogous ligands that can coordinate more liberally. To our surprise, compound 1, with a rigid chelating ligand, displayed promising SIM behavior with out-of-phase signals up to 11 K in a zero d.c. magnetic field at an a.c. frequency of 1000 Hz. The other two (2 and 3) with dangling ligands failed to show significant out-of-phase signals until an extra d.c. field was applied. The results of magnetization relaxation studies suggest that the phonon-induced relaxation processes play an essential role in 2 and 3, even at very low temperatures. Nevertheless, the rigid chelating ligand in 1 prevents the molecule from being involved in phonon-induced relaxation processes that seriously interfere with the magnetization relaxation up to 5.6 K. Therefore, we concluded that the presence of a rigid chelating ligand can efficiently change the phonon-induced relaxation processes at low temperatures. [ABSTRACT FROM AUTHOR]

Chemical investigation of the octocoral Briareum stechei, collected in the Ie Island, Okinawa, Japan, resulted in the isolation of a new briarane-type diterpenoid, briastecholide A (1), as well as the previously reported metabolites, solenolide C (2) and briarenolide S (3). The structures of briaranes 1–3 were characterized through spectroscopic analysis, and the absolute configuration of 2 was corroborated by a single-crystal X-ray diffraction analysis. Briarane 3 exhibited bioactivity against the protein expression of inducible nitric oxide synthase (iNOS). [ABSTRACT FROM AUTHOR]