Metastatic Gastric Mucosal Melanoma: A Rare Case Presenting With Diffuse Gastric Polyposis.

We report a 66-year-old Chinese lady who presented with a three-month history of postprandial vomiting, early satiety, anorexia and weight loss, and significant physical findings of hepatomegaly and ascites. Gastroscopy revealed gastric polyposis with both hyperpigmented and unpigmented lesions over the gastric fundus, body, and proximal antrum, biopsies of which yielded malignant melanoma histologically. Cross-sectional imaging with CT also demonstrated extensive hepatic and bony metastases. No cutaneous or ocular primary was detected. She was treated with a combination of ipilimumab and nivolumab but developed interval progression of hepatic metastases after two cycles of immunotherapy. The patient eventually succumbed two months after diagnosis.

Encapsulating a Ni(II) molecular catalyst in photoactive metal-organic framework for highly efficient photoreduction of CO2.

Photocatalytic reduction of CO2 to CO is a promising strategy for reducing atmospheric CO2 levels and storing solar radiation as chemical energy. Here, we demonstrate that a molecular catalyst [NiII(bpet)(H2O)2] successfully encapsulated into a highly robust and visible-light responsive metal-organic framework (Ru-UiO-67) to fabricate composite catalysts for photocatalytic CO2 reduction. The composite Ni@Ru-UiO-67 photocatalysts show efficient visible-light-driven CO2 reduction to CO with a TON of 581 and a selectivity of 99% after 20-h illumination, because of the facile electron transfer from Ru-photosensitizer to Ni(II) active sites in Ni@Ru-UiO-67 system. The mechanistic insights into photoreduction of CO2 have been studied based on thermodynamical, electrochemical, and spectroscopic investigation, together with density functional theory (DFT) calculations. This work shows that encapsulating molecular catalyst into photoactive MOF highlights opportunities for designing efficient, stable and recyclable photocatalysts.

Integration of Lanthanide-Transition-Metal Clusters onto CdS Surfaces for Photocatalytic Hydrogen Evolution.

Heterometallic lanthanide-transition-metal (4f-3d) clusters with well-defined crystal structures integrate multiple metal centers and provide a platform for achieving synergistic catalytic effects. Herein, we present a strategy for enhanced hydrogen evolution by loading atomically precise 4f-3d clusters Ln52 Ni56 on a CdS photoabsorber surface. Interestingly, some Ni2+ ions in the clusters Ln52 Ni56 were exchanged by the Cd2+ to form Ln52 Ni56-x Cdx /CdS composites. Photocatalytic studies show that the efficient synergistic multipath charge separation and transfer from CdS to the Eu52 Ni56-x Cdx cluster enable high visible-light-driven hydrogen evolution at 25 353 µmol h-1 g-1 . This work provides the strategy to design highly active photocatalytic hydrogen evolution catalysts by assembling heterometallic 4f-3d clusters on semiconductor materials.

Photo-generated dinuclear {Eu(II)}2 active sites for selective CO2 reduction in a photosensitizing metal-organic framework.

Photocatalytic reduction of CO2 is a promising approach to achieve solar-to-chemical energy conversion. However, traditional catalysts usually suffer from low efficiency, poor stability, and selectivity. Here we demonstrate that a large porous and stable metal-organic framework featuring dinuclear Eu(III)2 clusters as connecting nodes and Ru(phen)3-derived ligands as linkers is constructed to catalyze visible-light-driven CO2 reduction. Photo-excitation of the metalloligands initiates electron injection into the nodes to generate dinuclear {Eu(II)}2 active sites, which can selectively reduce CO2 to formate in a two-electron process with a remarkable rate of 321.9 µmol h-1 mmolMOF-1. The electron transfer from Ru metalloligands to Eu(III)2 catalytic centers are studied via transient absorption and theoretical calculations, shedding light on the photocatalytic mechanism. This work highlights opportunities in photo-generation of highly active lanthanide clusters stabilized in MOFs, which not only enables efficient photocatalysis but also facilitates mechanistic investigation of photo-driven charge separation processes.

Anion-Dependent Assembly of Heterometallic 3d-4f Clusters Based on a Lacunary Polyoxometalate.

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 trinuclear [Ln3(CO3)]7+ and one WO42--templated [NiII3(WO4)]+ unit. Compounds 7 and 8 exhibited unique pentameric architectures that featured three 3d-4f cubane clusters of {LnNi3(µ3-OH)3} capped by two {SbW9O33} and three {PW9O34} building blocks. Interestingly, the structural regulation of the heterometallic 3d-4f clusters in the polyoxometalate systems with trimers, tetramers, and pentamers was realized by introducing different anions.

Three Giant Lanthanide Clusters Ln37 (Ln = Gd, Tb, and Eu) Featuring A Double-Cage Structure.

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.

Single-Crystal to Single-Crystal Phase Transition and Segmented Thermochromic Luminescence in a Dynamic 3D Interpenetrated Ag(I) Coordination Network.

A new 3D Ag(I)-based coordination network, [Ag2(pz)(bdc)·H2O]n (1; pz = pyrazine and H2bdc = benzene-1,3-dicarboxylic acid), was constructed by one-pot assembly and structurally established by single-crystal X-ray diffraction at different temperatures. Upon cooling from 298 to 93 K, 1 undergo an interesting single-crystal to single-crystal phase transition from orthorhombic Ibca (Z = 16) to Pccn (Z = 32) at around 148 K. Both phases show a rare 2-fold-interpenetrated 4-connected lvt network but incorporate different [Ag2(COO)2] dimeric secondary building units. It is worth mentioning that complex 1 shows red- and blue-shifted luminescences in the 290-170 and 140-80 K temperature ranges, respectively. The variable-temperature single-crystal X-ray crystallographic studies suggest that the argentophilic interactions and rigidity of the structure dominated the luminescence chromism trends at the respective temperature ranges. Upon being mechanically ground, 1 exhibits a slight mechanoluminescence red shift from 589 to 604 nm at 298 K.

A one-dimensional cadmium metal-organic chain based on a [Cd4(COO)4] secondary building unit and a flexible dicarboxylic acid ligand.

An infinite one-dimensional cadmium metal-organic chain, namely catena-poly[aquabis(µ3-2,2'-{[1,2-phenylenebis(methylene)]bis(sulfanediyl)}dibenzoato)dicadmium(II)], [Cd2(C22H16O4S2)2(H2O)]n, was synthesized by solvothermal reaction of Cd(NO3)2·4H2O and 2,2'-{[1,2-phenylenebis(methylene)]bis(sulfanediyl)}dibenzoic acid (H2L). The Cd(II) centres have six-coordinate CdS2O4 and CdSO5 geometries. Due to the flexible -CH2-S- arms, the L(2-) ligand adopts both syn and anti conformations. Four Cd(II) cations are linked by two syn L(2-) ligands to form a centrosymmetric planar tetranuclear Cd(II) core, which is further extended through bonding to the anti L(2-) ligands to form a one-dimensional metal-organic chain. Adjacent one-dimensional chains are connected by C-H···π interactions and nonclassical C-H···O hydrogen bonds to form the resultant three-dimensional supramolecular framework.

A novel one-dimensional silver cylinder stabilized by mixed 2-mercaptobenzoic acid and ethylenediamine ligands.

A novel infinite one-dimensional silver cylinder, namely poly[µ-ethylenediamine-µ(5)-(2-sulfanidylbenzoato)-µ(4)-(2-sulfanidylbenzoato)-tetrasilver(I)], [Ag(4)(C(7)H(4)O(2)S)(2)(C(2)H(8)N(2))](n), has been synthesized by one-pot reaction of equivalent molar silver nitrate and 2-mercaptobenzoic acid (H(2)mba) in the presence of ethylenediamine (eda). One Ag atom is located in an AgS(2)NO four-coordinated tetrahedral geometry, two other Ag atoms are in an AgS(2)O three-coordinated T-shaped geometry and the fourth Ag atom is in an AgSNO coordination environment. The two mba ligands show two different binding modes. The µ(2)-N:N'-eda ligand, acting as a bridge, combines with mba ligands to extend the Ag(I) ions into a one-dimensional silver cylinder incorporating abundant Ag···Ag interactions ranging from 2.9298 (11) to 3.2165 (13) Å. Interchain N-H···O hydrogen bonds extend the one-dimensional cylinder into an undulating two-dimensional sheet, which is further packed into a three-dimensional supramolecular framework by van der Waals interactions; no π-π interactions were observed in the crystal structure.