Niobium(V) Saponite Clay for the Catalytic Oxidative Abatement of Chemical Warfare Agents

A Nb^V‐containing saponite clay was designed to selectively transform toxic organosulfur chemical warfare agents (CWAs) under extremely mild conditions into nontoxic products with reduced environmental impact. Thanks to the insertion of Nb^V sites within the saponite framework, a bifunctional catalyst with strong oxidizing and acid properties was obtained. Remarkable activity and high selectivity were observed for the oxidative abatement of (2‐chloroethyl)ethyl sulfide (CEES), a simulant of sulfur mustard, at room temperature with aqueous hydrogen peroxide. This performance was significantly better compared to a conventional commercial decontamination powder.     

Oxidative Neutralization of Mustard‐Gas Simulants in an On‐Board Flow Device with In‐Line NMR Monitoring

The fast and effective neutralization of the mustard‐gas simulant 2‐chloroethyl ethyl sulfide (CEES) using a simple and portable continuous flow device is reported. Neutralization takes place through a fully selective sulfoxidation by a stable source of hydrogen peroxide (alcoholic solution of urea–H₂O₂ adduct/MeSO₃H freshly prepared). The reaction progress can be monitored with an in‐line benchtop NMR spectrometer, allowing a real‐time adjustment of reaction conditions. Inherent features of millireactors, that is, perfect control of mixing, heat and reaction time, allowed the neutralization of 25 g of pure CEES within 46 minutes in a 21.5 mL millireactor (t ^R =3.9 minutes). This device, which relies on affordable and nontoxic reagents, fits into a suitcase, and can be deployed by police/military forces directly on the attack site.     

Selective Photooxidation of a Mustard‐Gas Simulant Catalyzed by a Porphyrinic Metal–Organic Framework

The photooxidation of a mustard‐gas simulant, 2‐chloroethyl ethyl sulfide (CEES), is studied using a porphyrin‐based metal–organic framework (MOF) catalyst. At room temperature and neutral pH value, singlet oxygen is generated by PCN‐222/MOF‐545 using an inexpensive and commercially available light‐emitting diode. The singlet oxygen produced by PCN‐222/MOF‐545 selectively oxidizes CEES to the comparatively nontoxic product 2‐chloroethyl ethyl sulfoxide (CEESO) without formation of the highly toxic sulfone product. In comparison to current methods, which utilize hydrogen peroxide as an oxidizing agent, this is a more realistic, convenient, and effective method for mustard‐gas detoxification.     

Z-Scheme In2S3/NU-1000 Heterojunction for Boosting Photo-Oxidation of Sulfide into Sulfoxide under Ambient Conditions

Photocatalytic oxidation of sulfide into sulfoxide has attracted extensive attention as an environmentally friendly strategy for chemical transformations or toxic chemicals degradation. Herein, we construct a series of In₂S₃/NU-1000 heterojunction photocatalysts, which can efficiently catalyze the oxidation of sulfides to form sulfoxides as the sole product under LED lamp (full-spectrum) illumination in air at room temperature. Especially, the sulfur mustard simulant, 2-chloroethyl ethyl sulfide (CEES), can also be photocatalytically oxidized with In₂S₃/NU-1000 to afford nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) selectively and effectively. In contrast, individual NU-1000 and In₂S₃ show very low catalytic activity on this reaction. The significantly improved photocatalytic activity is ascribed to the constructing of an efficient Z-scheme photocatalysts In₂S₃/NU-1000, which exhibits the enhancement of light harvesting, the promotion of photogenerated electron-hole separation, and the retention of high porosity of the parent MOF. Moreover, mechanism studies in photocatalytic oxidation reveal that the superoxide radical (^.O₂⁻) and singlet oxygen (¹O₂) are the main oxidative species in the oxidation system. This work exploits the opportunities for the construction of porous Z-scheme photocatalysts based on the photoactive MOFs materials and inorganic semiconductors for promoting catalytic organic transformations. More importantly, it provides a route to the rational design of efficient photocatalysts for the detoxification of mustard gas.     

Controlling the Self‐Assembly of a Mixed‐Metal Mo/V–Selenite Family of Polyoxometalates

Five mixed‐metal mixed‐valence Mo/V polyoxoanions, templated by the pyramidal SeO₃^2? heteroanion have been isolated: K₁₀[Mo^VI₁₂V^V₁₀O₅₈(SeO₃)₈]?18 H₂O ( 1 ), K₇[Mo^VI₁₁V^V₅V^IV₂O₅₂(SeO₃)]?31 H₂O ( 2 ), (NH₄)₇K₃[Mo^VI₁₁V^V₅V^IV₂O₅₂(SeO₃)(Mo^V₆V^V‐ O₂₂)]?40 H₂O ( 3 ), (NH₄)₁₉K₃[Mo^VI₂₀V^V₁₂V^IV₄O₉₉(SeO₃)₁₀]?36 H₂O ( 4 ) and [Na₃(H₂O)₅{Mo_18?xV_xO₅₂(SeO₃)} {Mo_9?yV_yO₂₄(SeO₃)₄}] ( 5 ). All five compounds were characterised by single‐crystal X‐ray structure analysis, TGA, UV/Vis and FT‐IR spectroscopy, redox titrations, and elemental and flame atomic absorption spectroscopy (FAAS) analysis. X‐ray studies revealed two novel coordination modes for the selenite anion in compounds 1 and 4 showing η,μ and μ,μ coordination motifs. Compounds 1 and 2 were characterised in solution by using high‐resolution ESI‐MS. The ESI‐MS spectra of these compounds revealed characteristic patterns showing distribution envelopes corresponding to 2? and 3? anionic charge states. Also, the isolation of these compounds shows that it may be possible to direct the self‐assembly process of the mixed‐metal systems by controlling the interplay between the cation “shrink‐wrapping” effect, the non‐conventional geometry of the selenite anion and fine adjustment of the experimental variables. Also a detailed IR spectroscopic analysis unveiled a simple way to identify the type of coordination mode of the selenite anions present in POM‐based architectures.     

Two succinic acid derivatives of 2‐ethyl‐6‐methylpyridin‐3‐ol

Crystals of bis(2‐ethyl‐3‐hydroxy‐6‐methylpyridinium) succinate–succinic acid (1/1), C₈H₁₂NO⁺·0.5C₄H₄O₄²⁻·0.5C₄H₆O₄, (I), and 2‐ethyl‐3‐hydroxy‐6‐methylpyridinium hydrogen succinate, C₈H₁₂NO⁺·C₄H₅O₄⁻, (II), were obtained by reaction of 2‐ethyl‐6‐methylpyridin‐3‐ol with succinic acid. The succinate anion and succinic acid molecule in (I) are located about centres of inversion. Intermolecular O—H...O, N—H...O and C—H...O hydrogen bonds are responsible for the formation of a three‐dimensional network in the crystal structure of (I) and a two‐dimensional network in the crystal structure of (II). Both structures are additionally stabilized by π–π interactions between symmetry‐related pyridine rings, forming a rod‐like cationic arrangement for (I) and cationic dimers for (II).     

Polyoxometalate-Incorporated CuI-Resorcin[4]arene Metal-Organic Complexes as Heterogeneous Catalysts for Catalytic Oxidation of Mustard Gas Simulant

Exploring efficient heterogeneous catalysts for catalytic oxidation of chemical warfare agents (CWAs) is highly desired. As a class of discrete anionic metal oxide clusters, polyoxometalates (POMs) provide abundant catalytic active sites, thus resulting their rich redox properties. Here, a family of known POM-incorporated Cu^I-resorcin[4]arene metal-organic complexes, namely, [Cu₄(TPTR4A)₂][PW₁₂O₄₀](OH) ⋅ 0.5DMA ⋅ 5H₂O ( Cu - PW ), [Cu₄(TPTR4 A)₂][PMo₁₂O₄₀](OH) ⋅ 2DMA ⋅ H₂O ( Cu - PMo ) and [Cu₄(TPTR4A)₂][SiW₁₂O₄₀] ⋅ 2.5DMA ( Cu - SiW ) were utilized as catalysts to promote the oxidation of 2-chloroethyl ethyl sulfide (CEES). Strikingly, compared to the novel compound [Cu₃Cl₆(TPTR4A)(DMA)] ⋅ CH₃CH₂OH (defined as Cu - T ), the three complexes exhibited excellent stability, indicating that the integration of POMs and metal–organic units could improve the stability of the compounds. Moreover, Cu - PMo and Cu - PW showed higher activities for the catalytic oxidation of CEES to CEESO with selectivities both of 99 %.     

Structural comparison of group 7 tricarbonyl complexes of 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate

Two tricarbonyl complexes of rhenium(I) and manganese(I) coordinated by the ligand 2‐{[2‐(1H‐imidazol‐4‐yl)ethyl]iminomethyl}‐5‐methylphenolate are reported, viz. fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)rhenium(I) methanol monosolvate, [Re(C₁₆H₁₄N₃O₄)(CO)₃]·CH₃OH, (I), and fac‐tricarbonyl(2‐{[2‐(1H‐imidazol‐4‐yl‐κN³)ethyl]iminomethyl‐κN}‐5‐methylphenolato‐κO)manganese(I), fac‐[Mn(C₁₆H₁₄N₃O₄)(CO)₃], (II), display facial coordination in a distorted octahedral environment. The crystal structure of (I) is stabilized by O—H...O, N—H...O and C—H...O hydrogen‐bond interactions, while that of (II) is stabilized by N—H...O hydrogen‐bond interactions only. These interactions result in two‐dimensional networks and π–π stacking for both structures.     

A zinc–lithium complex of 4,7‐bis(2‐aminoethyl)‐1,4,7‐triazacyclononane‐1‐acetate

The asymmetric unit of {[4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonan‐1‐yl]acetato}zinc(II) triaqua{μ‐[4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonan‐1‐yl]acetato}lithium(I)zinc(II) chloride diperchlorate, [Zn(C₁₂H₂₆N₅O₂)][LiZn(C₁₂H₂₆N₅O₂)(H₂O)₃]Cl(ClO₄)₂, obtained from the reaction between the lithium salt of 4,7‐bis(2‐amino­ethyl)‐1,4,7‐tri­aza­cyclo­nonane‐1‐acetate and Zn(ClO₄)₂, contains two Zn^II complexes in which each Zn^II ion is six‐coordinated by five N‐atom donors and one O‐­atom donor from the ligand. One carboxyl­ate O‐atom donor is not involved in coordination to a Zn^II atom, but coordinates to an Li⁺ ion, the tetrahedral geometry of Li⁺ being completed by three water mol­ecules. The two complexes are linked via a hydrogen bond between a primary amine N—H group and the carboxyl­ate‐O atom not involved in coordination to a metal.     

Bis[tris(2,2′‐bipyridyl‐κ2N,N′)cobalt(II)] cyclo‐tetravanadate undecahydrate

The title compound, [Co(C₁₀H₈N₂)₃]₂[V₄O₁₂]·11H₂O, is composed of two symmetry‐related cations containing octahedrally coordinated Co^II ions, a centrosymmetric [V₄O₁₂]⁴⁻ anion with an eight‐membered ring structure made up of four VO₄ tetrahedra, and 11 solvent water molecules. The Co^II cations and vanadate anions are isolated and build cation and anion layers, respectively. In addition, the title compound exhibits a three‐dimensional network through intra‐ and intermolecular hydrogen‐bond interactions between water molecules and O atoms of the anions, and the crystal structure is stabilized mainly by hydrogen bonds.     

Characterization of the FeV=O Complex in the Pathway of Water Oxidation

Hypervalent Fe^V=O species are implicated in a multitude of oxidative reactions of organic substrates, as well as in catalytic water oxidation, a reaction crucial for artificial photosynthesis. Spectroscopically characterized Fe^V species are exceedingly rare and, so far, were produced by the oxidation of Fe complexes with peroxy acids or H₂O₂: reactions that entail breaking of the O?O bond to form a Fe^V=O fragment. The key Fe^V=O species proposed to initiate the O?O bond formation in water oxidation reactions remained undetected, presumably due to their high reactivity. Here, we achieved freeze quench trapping of six coordinated [Fe^V=O,(OH)(Pytacn)]²⁺ (Pytacn=1‐(2′‐pyridylmethyl)‐4,7‐dimethyl‐1,4,7‐triazacyclononane) ( 2 ) generated during catalytic water oxidation. X‐ray absorption spectroscopy (XAS) confirmed the Fe^V oxidation state and the presence of a Fe^V=O bond at ≈1.60 Å. Combined EPR and DFT methods indicate that 2 contains a S=3/2 Fe^V center. 2 is the first spectroscopically characterized high spin oxo‐Fe^V complex and constitutes a paradigmatic example of the Fe^V=O(OH) species proposed to be responsible for catalytic water oxidation reactions.     

Synthesis and crystal structure of 2‐amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)vanadate(V) and its conversion to nanostructured V2O5

2‐Amino‐3‐hydroxypyridinium dioxido(pyridine‐2,6‐dicarboxylato‐κ³O²,N,O⁶)vanadate(V), (C₅H₇N₂O)[V(C₇H₃NO₄)O₂] or [H(amino‐3‐OH‐py)][VO₂(dipic)], (I), was prepared by the reaction of VCl₃ with dipicolinic acid (dipicH₂) and 2‐amino‐3‐hydroxypyridine (amino‐3‐OH‐py) in water. The compound was characterized by elemental analysis, IR spectroscopy and X‐ray structure analysis, and consists of an anionic [VO₂(dipic)]⁻ complex and an H(amino‐3‐OH‐py)⁺ counter‐cation. The V^V ion is five‐coordinated by one O,N,O′‐tridentate dipic dianionic ligand and by two oxide ligands. Thermal decomposition of (I) in the presence of polyethylene glycol led to the formation of nanoparticles of V₂O₅. Powder X‐ray diffraction (PXRD) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of the synthesized powder.     

The crystal and molecular structures of three copper‐containing complexes and their activities in mimicking galactose oxidase

The structures of three copper‐containing complexes, namely (benzoato‐κ²O,O′)[(E)‐2‐({[2‐(diethylamino)ethyl]imino}methyl)phenolato‐κ³N,N′,O]copper(II) dihydrate, [Cu(C₇H₅O₂)(C₁₃H₁₉N₂O)]·2H₂O, 1 , [(E)‐2‐({[2‐(diethylamino)ethyl]imino}methyl)phenolato‐κ³N,N′,O](2‐phenylacetato‐κ²O,O′)copper(II), [Cu(C₈H₇O₂)(C₁₃H₁₉N₂O)], 2 , and bis[μ‐(E)‐2‐({[3‐(diethylamino)propyl]imino}methyl)phenolato]‐κ⁴N,N′,O:O;κ⁴O:N,N′,O‐(μ‐2‐methylbenzoato‐κ²O:O′)copper(II) perchlorate, [Cu₂(C₈H₇O₂)(C₁₂H₁₇N₂O)₂]ClO₄, 3 , have been reported and all have been tested for their activity in the oxidation of d ‐galactose. The results suggest that, unlike the enzyme galactose oxidase, due to the precipitation of Cu₂O, this reaction is not catalytic as would have been expected. The structures of 1 and 2 are monomeric, while 3 consists of a dimeric cation and a perchlorate anion [which is disordered over two orientations, with occupancies of 0.64 (4) and 0.36 (4)]. In all three structures, the central Cu atom is five‐coordinated in a distorted square‐pyramidal arrangment (τ parameter of 0.0932 for 1 , 0.0888 for 2 , and 0.142 and 0.248 for the two Cu centers in 3 ). In each species, the environment about the Cu atom is such that the vacant sixth position is open, with very little steric crowding.     

Reactivity and Catalytic Activity of Homobimetallic Vanadium(V) Complex Derived from Bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone Ligand

Homobimetallic vanadium(V) complex of the composition [(CH₃)₂NH₂⁺]₂[(VO₂)₂(sloxCl)].4H₂O was synthesized from the reaction of V₂O₅ with bis(5‐chlorosalicylaldehyde)oxaloyldihydrazone ligand in a 1:1 molar ratio in methanol. The structure of the complex was established by X‐ray crystallography. Reactivity of the complex with H₂O₂ leads to bis (monooxidoperoxidovanadate(V)) [{VO(O₂)}₂(sloxCl)]^2? formation and with HCl, oxidohydroxido complex of composition [(VO (OH)(sloxCl)]^2? was formed. Binding interaction of the complex was also investigated toward protein (BSA) and it was found to be 2.21 x 10⁸ M^?1. The catalytic activity of the complex in the oxidation of alcohols and oxidative bromination of some organic substrates was also studied, and it showed a great potent as a catalyst.     

Syntheses,Structures and Magnetic Behaviours of two Mixed‐Metal Inorganic‐Organic Hybrid Frameworks with N‐(Phosphonomethyl)iminodiacetate

Two mixed‐metal‐center inorganic‐organic hybrid frameworks incorporating N‐(Phosphonomethyl)iminodiacetate(H₄pmida), [Zn₂V₂O₂(pmida)₂(H₂O)₁₀]·H₂O ( 1 ) and [Zn₂V₂O₂(pmida)₂(H₂O)₁₂]·2H₂O ( 2 ), were synthesized by hydrothermal reactions and characterized by elemental analysis, IR spectra, UV‐Vis spectra and single crystal X‐ray analysis. In complex 1 , the centrosymmetric dimeric [V₂O₂(pmida)₂]^4– unit connected to neighboring Zn²⁺ through the phosphonate group, while 2 the [V₂O₂(pmida)₂]^4– unit uncoordinated with the Zn²⁺ in the presence of NaOH. Magnetic measurements in the range 2‐300 K have shown weak antiferromagnetic interaction between the adjacent vanadium ions in complexes.     

Tris(2‐cyanoethyl) isocyanurate

The title compound, 1,3,5‐tris(2‐cyano­ethyl)‐1,3,5‐triazine‐2,4,6(1H,3H,5H)‐trione, C₁₂H₁₂N₆O₃, forms a layered structure stabilized by C—H?O and C—H?N hydrogen bonds.     

CdII and CoII coordination polymers constructed from benzene‐1,4‐dicarboxylic acid and 2‐(pyridin‐3‐yl)‐1H‐benzimidazole ligands

In poly[aqua(μ₃‐benzene‐1,4‐dicarboxylato‐κ⁵O¹,O^1′:O¹:O⁴,O^4′)[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cadmium(II)], [Cd(C₈H₄O₄)(C₁₂H₉N₃)(H₂O)]_n, (I), each Cd^II ion is seven‐coordinated by the pyridine N atom from a 2‐(pyridin‐3‐yl)benzimidazole (3‐PyBIm) ligand, five O atoms from three benzene‐1,4‐dicarboxylate (1,4‐bdc) ligands and one O atom from a coordinated water molecule. The complex forms an extended two‐dimensional carboxylate layer structure, which is further extended into a three‐dimensional network by hydrogen‐bonding interactions. In catena‐poly[[diaquabis[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cobalt(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₉N₃)₂(H₂O)₂]_n, (II), each Co^II ion is six‐coordinated by two pyridine N atoms from two 3‐PyBIm ligands, two O atoms from two 1,4‐bdc ligands and two O atoms from two coordinated water molecules. The complex forms a one‐dimensional chain‐like coordination polymer and is further assembled by hydrogen‐bonding interactions to form a three‐dimensional network.     

Four novel Z-shaped hexanuclear vanadium oxide clusters as efficient heterogeneous catalysts for cycloaddition of CO2 and oxidative desulfurization reactions

Chemical fixation of CO₂ into C1 source, as a general approach, can effectively alleviate the emission of greenhouse gasses. Whereas, the challenge posed by the need for efficient catalysts with high catalytic active sites still exists. In this work, we reported a series of new hexavanadate clusters, [(C₆H₆ON)₂(C₂H₈N₂)₂(CH₃O)₆V^IV₆O₈] (V₆–1), [(C₆H₆ON)₂(C₃H₁₀N₂)₂(CH₃O)₆V^IV₆O₈] (V₆–2), [(C₆H₆ON)₂(C₆H₁₄N₂)₂(CH₃O)₆V^IV₆O₈] (V₆–3) and [(C₆H₆ON)₂(C₄H₁₁N₂O)₂(CH₃O)₄V^IV₆O₈] (V₆–4), assembled by 2-aminophenol and four different kinds of Lewis bases (LB), ethanediamine (en), 1,2-diaminopropane, 1,2-cyclohexanediamine and N-(2-hydroxyethyl)ethylenediamine (ben) together. Among them, the basic unit {V₆} cluster featured Z-shaped configuration represents a brand-new example of hexanuclear vanadium clusters. Remarkably, the catalytic tests demonstrated that V₆–1 as catalyst displays high catalytic activity in the cycloaddition for the CO₂ fixation into cyclic carbonates by virtue of open V sites. As expected, for oxidative desulfurization of sulfides, V₆–1 also exhibits satisfied catalytic effectiveness. Furthermore, the recycling test confirmed that catalyst V₆–1 may be a bifunctional heterogeneous catalyst with great promise for both CO₂ cycloaddition and oxidative desulfurization reactions.     

New Entangled Coordination Networks Based on Charge‐Tunable Keggin‐Type Polyoxometalates

Investigation into a hydrothermal reaction system with transition‐metal (TM) ions, 1,4‐bis(1,2,4‐triazol‐1‐lmethyl)benzene (BBTZ) and various charge‐tunable Keggin‐type polyoxometalates (POMs) led to the preparation of four new entangled coordination networks, [Co^II(HBBTZ)(BBTZ)_2.5][PMo₁₂O₄₀] ( 1 ), [Cu^I(BBTZ)]₅[BW₁₂O₄₀] ? H₂O ( 2 ), [Cu^II(BBTZ)]₃[AsW^V₃W^VI₉O₄₀] ? 10 H₂O ( 3 ), and [Cu^II₅(BBTZ)₇(H₂O)₆][P₂W₂₂Cu₂O₇₇(OH)₂] ? 6 H₂O ( 4 ). All compounds were characterized by using elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. The mixed valence of W centers in compound 3 was further confirmed by using XPS spectroscopy and bond‐valence sum calculations. In the structural analysis, the entangled networks of 1 – 4 demonstrate zipper‐closing packing, 3D polythreading, 3D polycatenation, and 3D self‐penetration, respectively. Moreover, with the enhancement of POM negative charges and the use of different TM types, the number of nodes in the coordination networks of 1 – 4 increased and the basic metal–organic building motifs changed from a 1D zipper‐type chain (in 1 ) to a 2D pseudorotaxane layer (in 2 ) to a 3D diamond‐like framework (in 3 ) and finally to a 3D self‐penetrating framework (in 4 ). The photocatalytic properties of compounds 1 – 4 for the degradation of methylene blue under UV light were also investigated; all compounds showed good catalytic activity and the photocatalytic activity order of Keggin‐type species was initially found to be {XMo₁₂O₄₀}>{XW₁₂O₄₀}>{XW_12?nTM_nO₄₀}.     

Three isotypic polymeric complexes with rare earth cations,but‐2‐enoate anions and 4,4′‐(ethane‐1,2‐diyl)dipyridine and 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligands

Three isotypic rare earth complexes, catena‐poly[[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐bis(μ‐but‐2‐enoato)‐κ³O,O′:O;κ³O:O,O′‐[aquabis(but‐2‐enoato‐κ²O,O′)yttrium(III)]‐μ‐4,4′‐(ethane‐1,2‐diyl)dipyridine‐κ²N:N′], [Y₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], the gadolinium(III) analogue, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₂N₂)(H₂O)₂], and the gadolinium(III) analogue with a 4,4′‐(ethene‐1,2‐diyl)dipyridine bridging ligand, [Gd₂(C₄H₅O₂)₆(C₁₂H₁₀N₂)(H₂O)₂], are one‐dimensional coordination polymers made up of centrosymmetric dinuclear [M(but‐2‐enoato)₃(H₂O)]₂ units (M = rare earth), further bridged by centrosymmetric 4,4′‐(ethane‐1,2‐diyl)dipyridine or 4,4′‐(ethene‐1,2‐diyl)dipyridine spacers into sets of chains parallel to the [20] direction. There are intra‐chain and inter‐chain hydrogen bonds in the structures, the former providing cohesion of the linear arrays and the latter promoting the formation of broad planes parallel to (010).