Preparation and thermal stability of trioxalatocobaltates of bivalent metals KM2+ [Co(C2O4)3]·xH2O

Trioxalatocobaltates of bivalent metals KM²⁺[Co(C₂O₄)₃]·x H₂O, with M²⁺ = Ba, Sr, Ca and Pb, have been prepared, characterized and their thermal behaviour studied. The compounds decompose to yield potassium carbonate, bivalent metal carbonate or oxide and cobalt oxide as final products. The formation of the final products of decomposition is influenced by the surrounding atmosphere. Bivalent metal cobaltites of the types KM²⁺CoO₃ and M²⁺CoO_3—x are not identified among the final products of decomposition. The study brings out the importance of the decomposition mode of the precursor in producing the desired end products.     

Cyanohydrazonothioformiate – Darstellung und Reaktionen

Cyanohydrazonothioformate — Preparation and Reactions Sodiumcyanohydrazonothioformate-monohydrate NaSC(CN)NNH₂ · H₂O is obtained by reaction of sodiumcyanodithioformate with hydrazine. The new compound forms S-organosubstituted derivatives. Reaction with bivalent metal cations lead to coordination compounds M^II(SC(CN)NNH₂)₂ · 2H₂O, which subjected the facile reaction with carbonyl compounds yield alkylidenehydrazonocyanothioformates M^II(SC(CN)NNCRR¹)₂. The results of i.r. spectroscopic and thermogravimetric measurements are reported.     

Theoretical study on structures and vibrational spectra of M+(H2O)Ar (M = Cu,Ag, Au)

A theoretical study on the structures and vibrational spectra of M⁺(H₂O)Ar_0‐1 (M = Cu, Ag, Au) complexes was performed using ab initio method. Geometrical structures, binding energies (BEs), OH stretching vibrational frequencies, and infrared (IR) absorption intensities are investigated in detail for various isomers with Ar atom bound to different binding sites of M⁺(H₂O). CCSD(T) calculations predict that BEs are 14.5, 7.5, and 14.4 kcal/mol for Ar atom bound to the noble metal ion in M⁺(H₂O)Ar (M = Cu, Ag, Au) complexes, respectively, and the corresponding values have been computed to be 1.5, 1.3, and 2.1 kcal/mol when Ar atom attaches to a H atom of water molecule. The former structure is predicted to be more stable than the latter structure. Moreover, when compared with the M⁺(H₂O) species, tagging Ar atom to metal cation yields a minor perturbation on the IR spectra, whereas binding Ar atom to an OH site leads to a large redshift in OH stretching vibrations. The relationships between isomers and vibrational spectra are discussed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011     

Preparation and Thermal behaviour of Transition Metal Complexes of 4,5-Imidazoledicarboxylic Acid

Some new transition metal imidazolehydrogendicarboxylate hydrates of empirical formula M(Himdc)2·nH₂O (H ₂ imdc=4,5-imidazoledicarboxylic acid), where n=2 for M=Mn, Ni, Zn, Cd and n=3 for M=Co, have been prepared in aqueous solution. The compounds have been characterized by analytical, electronic and IR spectroscopic, thermal analysis and X-ray powder diffraction studies. Electronic spectroscopic data suggest that the Co and Ni compounds are of spin free (high spin) type with octahedral geometry. For these compounds, the IR bands in the region 1750-1710 cm^-1 has been assigned to stretching vibrations of the non-ionized carboxylic group, confirming that the ligand is monoionized. IR spectra also suggest the unidentate co-ordination behaviour of carboxylate (v_asy =1570 and v_sym=1390 cm^-1) groups of the imidazoledicarboxylate monoanion. The thermal behaviour of these compounds has been studied by simultaneous TG-DTA techniques. All of these compounds are dihydrates except cobalt which is a trihydrate. Thermal decomposition studies show that they lose two water molecules endothermally in the range 200-270°C to give their anhydrous compounds, indicating that these water molecules are coordinated to the metal. The anhydrous compounds further decompose exothermally in the range 300-620°C to leave the respective metal oxides via the metal oxalate intermediates. Whereas the manganese compound undergoes pyrolytic cleavage in a single step to give the manganese carbonate as the final residue. Isomorphic nature of these compounds is evident from XRD data. Six-coordination for the metal atoms has been proposed based on the thermal analysis, visible and IR spectroscopic results. This revised version was published online in August 2006 with corrections to the Cover Date.     

Über die Struktur vonM(BF4)2·6H2O fürM=Mg2+, Zn2+, Cd2+

The IR and Raman spectra ofM(BF₄)₂·6H₂O forM=Mg²⁺, Zn²⁺ and Cd²⁺ in the range 4000–140 cm^?1 were recorded, as were theirDTA andTG curves up to 500°C. The data obtained confirm the presence of the water complex [M(H₂O)₆]²⁺ and of the complex anion BF₄ ^? in these compounds. It was also established that the six water molecules in Mg(BF₄)₂·6H₂O and in Zn(BF₄)₂·6H₂O are not crystallographically equivalent, and that hydrogen bonds of the type H₂O...H₂O...F₄B and H₂O...H₂O...H₂O participate in the structure. The energy of the hydrogen bonds H₂O...F₄B for the three crystal hydrates was also calculated. The thermal and thermogravimetric data are in agreement with and confirm the spectroscopic data.     

Mononuclear nickel(II) and zinc(II) complexes with deprotonated forms of the tripodal hexadentate ligand 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine

In the crystal structures of both title compounds, [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]nickel(II) [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]nickel(II) chloride methanol disolvate, [Ni(C₂₆H_25.5N₃O₃)]₂Cl·2CH₄O, and [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]zinc(II) perchlorate [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]zinc(II) methanol trisolvate, [Zn(C₂₆H₂₅N₃O₃)]ClO₄·[Zn(C₂₆H₂₆N₃O₃)]·3CH₄O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol–phenolate O—H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one‐half of a chloride anion and a methanol solvent molecule. In the O—H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The Ni^II compound is thus formulated as [Ni(H_1.5L)]₂Cl·2CH₃OH [H₃L is 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine]. In the analogous Zn^II compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H₂L)]ClO₄·[Zn(HL)]·3CH₃OH. In both compounds, each mononuclear unit is chiral with either a Δ or a Λ configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Δ–Δ and Λ–Λ pairs co‐exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M—O(phenol) and M—O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M—O and M—N bond distances decrease.     

Bis(μ‐benzene‐1,2‐dicarboxylato)bis{aqua[2‐(2‐chloro‐6‐fluorophenyl)‐1H‐imidazo[4,5‐f][1,10]phenanthroline]cadmium(II)} and its zinc(II) analogue

In the isomorphous title compounds, [Cd₂(C₈H₄O₄)₂(C₁₉H₁₀ClFN₄)₂(H₂O)₂] and [Zn₂(C₈H₄O₄)₂(C₁₉H₁₀ClFN₄)₂(H₂O)₂], the Cd^II centre is seven‐coordinated by two N atoms from one [2‐(2‐chloro‐6‐fluorophenyl)‐1H‐imidazo[4,5‐f][1,10]phenanthroline (L) ligand, one water O atom and four carboxylate O atoms from two different benzene‐1,2‐dicarboxylate (1,2‐bdc) ligands in a distorted pentagonal–bipyramidal coordination, while the Zn^II centre is six‐coordinated by two N atoms from one L ligand, one water O atom and three carboxylate O atoms from two different 1,2‐bdc ligands in a distorted octahedral coordination. Each pair of adjacent metal centres is bridged by two 1,2‐bdc ligands to form a dimeric structure. In the dimer, each L ligand coordinates one metal centre. The dimer is centrosymmetric, with a crystallographic inversion centre midway between the two metal centres. The aromatic interactions lead the dimers to form a two‐dimensional supramolecular architecture. Finally, O—H...O and N—H...O hydrogen bonds reinforce the two‐dimensional structures of the two compounds.     

Mechanism of Metal Ion Catalysis in the dissociation of cis-diaquobisoxalatochromate(III) ion

The metal ion (M²⁺) catalysed dissociation of cis-diaquobisoxalatochromate into the tetraaquomonooxalato complex in aqueous perchloric acid medium which follows the rate law — d(complex)/dt = {k_H[H⁺] + k_M[M²⁺]}[complex] has been studied. Based on k_M values the order of catalysing effect of the different metal ions studied is Cu²⁺ > Ni²⁺ > Co²⁺ > Mn²⁺, which is also the order of stabilities (K_MOx) of the monooxalato complexes of these metal ions; in fact the plot of log k_M vs. log K_MOx is linear. This together with the relative values of ΔH^≠ and ΔS^≠ for the H⁺ catalysed and M²⁺ catalysed paths is in agreement with a mechanism involving chelation of the catalysing cation through the free carbonyl oxygens of the oxalate ligand bound to Cr(III), followed by the dissociation of the Cr(III)? O bonds with simultaneous entry of two water molecules into the coordination sphere of Cr(III).     

Zweidimensionale Polymere mit hydrophober Umhüllung: Kristallstrukturen der isostrukturellen Metallkomplexe [M{C6H4(SO2)2N}(H2O)] (M = K,Rb) und des strukturverwandten Ammoniumsalzes [(NH4){C6H4(SO2)2N}(H2O)]

Metal Salts of Benzene‐1,2‐di(sulfonyl)amine. 4. Hydrophobically Wrapped Two‐Dimensional Polymers: Crystal Structures of the Isostructural Metal Complexes [M{C₆H₄(SO₂)₂N}(H₂O)] (M = K, Rb) and of the Structurally Related Ammonium Salt [(NH₄){C₆H₄(SO₂)₂N}(H₂O)] The previously unreported compounds KZ · H₂O ( 1 ), RbZ · H₂O ( 2 ) and NH₄Z · H₂O ( 3 ), where Z^– is Ndeprotonated ortho‐benzenedisulfonimide, are examples of layered inorgano‐organic solids, in which the inorganic component is comprised of metal or ammonium cations, N(SO₂)₂ groups and water molecules and the outer regions are formed by the planar benzo rings of the anions. The metal complexes 1 and 2 were found to be strictly isostructural, whereas 3 is structurally related to them by a non‐crystallographic mirror plane ( 1 – 3 : monoclinic, space group P2₁/c, Z = 4; single crystal X‐ray diffraction at low temperatures). In each structure, the five‐membered 1,3,2‐dithiazolide heterocycle possesses an envelope conformation, the N atom lying about 40 pm outside the mean plane of the S–C–C–S moiety. The metal complexes feature two‐dimensional coordination networks interwoven with O–H…O hydrogen bonds originating from the water molecules. The metal centres adopt an irregular nonacoordination formed by five sulfonyl O atoms, two N atoms and two μ₂‐bridging water molecules; each M⁺ is connected to four different anions. When NH₄⁺ is substituted for M⁺, the metal–ligand bonds are replaced by N⁺–H…O hydrogen bonds, but the general topology of the lamella is not affected. In the three structures, the lipophilic benzo groups protrude obliquely from the surfaces of the polar lamellae and display marked interlocking between adjacent layers.     

Poly[(μ4‐2,5‐dimethoxybenzene‐1,4‐dicarboxylato)manganese(II)] and its zinc(II) analogue: three‐dimensional coordination polymers containing unusually coordinated metal centres

The title compounds, [Mn(C₁₀H₈O₆)]_n and [Zn(C₁₀H₈O₆)]_n, are isomorphous coordination polymers prepared from 2,5‐dimethoxyterephthalic acid (H₂dmt) and the respective metal(II) salts. Both complexes form three‐dimensional metal–organic frameworks with each M^II centre bridged by four 2,5‐dimethoxyterephthalate (dmt²⁻) anions, resulting in the same type of network topology. The asymmetric unit consists of one M^II cation on a twofold axis and one half of a dmt²⁻ anion (located on a centre of inversion). In the crystal structure, the M^II centres are coordinated in a rather unusual way, as there is a distorted tetrahedral inner coordination sphere formed by four carboxylate O atoms of four different dmt²⁻ anions, and an additional outer coordination sphere formed by two methoxy and two carboxylate O atoms, with each of the O atoms belonging to one of the four different dmt²⁻ anions forming the inner coordination sphere. Consideration of both coordination spheres results in a super‐dodecahedral coordination geometry for the M^II centres. Besides the numerous M^II...O interactions, both structures are further stabilized by weak C—H...O contacts.     

Model calculations of the vibrations of bonded water molecules

Model calculations have been made of the vibrational frequencies and normal modes of a water molecule vibrating in a combined internal and external field. A constant internal force field has been used together with an external central force field from four or three nearest-neighbour atoms to the water molecule. These neighbour atoms have been arranged either tetrahedrally or trigonally around the water molecule. The external force field has been further restricted by the use of five possible site symmetries for the water molecule, C_2v, C₂, C_s(σ_xz, C_s(σ_yz) and C₁. A series of calculations have been made where the external force constants have been varied within the range 1—80 Nm^?1.The nine calculated normal modes can be divided into three groups: intra-molecular, rotational and translational vibrations. Among the rotational vibrations it is found that, in the tetrahedral environment, the rocking mode occurs at lower frequencies than the twisting and wagging modes, whereas the opposite occurs for the trigonal environment. Frequency ratios have been calculated using the isotopic species H₂O, D₂O, HDO and H,¹⁸O. The twisting and wagging modes have the vH₂O/vD₂O ratio in the range 1.35-3-1.41 and the rocking mode in the range 1.26—1.41.     

Influence of the chain and layer structure of Fe(III) and In(III) aqua-pentachloro-complexes on the bending vibrations of water molecules

Studies of IR and Raman spectra of monohydrates M^I₂[M^IIICl₅(H₂O)] (where M^I=K⁺, Rb⁺, Cs⁺ and M^III=Fe³⁺, In³⁺) at 1400-1900 cm⁻¹ have been carried out. The medium intensity band, detected in the region 1580-1595 cm⁻¹ was assigned to bending vibrations of water molecules (δHOH). The shift of the δHOH band towards low wavenumbers (1580-1595 cm⁻¹) is a main sign of the water molecule interactions in the chain hydrates. Additionally in the IR and Raman spectra of these salts, the appearance of the low intensity band between 1750 and 1810 cm⁻¹ (ν_x(H₂O)) was observed. In the presented paper we also discuss the influence of M^I and M^III cations on the position and splitting of these bands.     

Mercury(II) oxide as a ligand. III. Far Infrared Spectra of the Addition Compounds of the transition metal sulphates and selenates

A study of the far infrared spectra (700—10 cm^?1) of the divalent transition metal HgO complexes has confirmed the earlier conclusion that the compounds with formula M^IIS(e)O₄ · 2 HgO · (H₂O) resemble HgSO₄ · 2 HgO closely in structure, whereas a lower HgO content indicates a breaking of the HgO framework and coordination of the M²⁺-ions to the oxo anions.     

Synthesis and crystal structures of 3D supramolecular compounds: [ M (4,4′-bipy)2(H2O)4] · (4,4′-bipy)2 · (3,5-daba)2 · 8H2O ( M =Zn,Mn)

Two new supramolecular compounds [M(4,4′-bipy)₂ (H₂O)₄] ·?(4,4′-bipy)₂ ·?(3,5-daba)₂ ·?8H₂O (M=Zn(1) or Mn(2), 4,4′-bipy =?4,4′-bipyridine, 3,5-daba =?3,5-diaminobenzoic acid anion) were synthesized and characterized by elemental analysis and X-ray crystal diffraction. In [M(4,4′-bipy)₂(H₂O)₄]²⁺, the M(II) is coordinated by two nitrogen atoms from two 4,4′-bipy molecules and four oxygen atoms from four waters to form an octahedral configuration. There exist uncoordinated 4,4′-bipy molecules, 3,5-diaminobenzolate counterions and water guests in the compounds. The 3D structures of the title supramolecular compounds are constructed by rich hydrogen bonds among [M(4,4′-bipy)₂(H₂O)₄]²⁺, uncoordinated 4,4′-bipy molecules, water molecules and 3,5-daba, containing a diverting hexa-member water ring.     

1‐[(4‐Chloro­benzoyl)­methyl]‐4‐(N,N‐di­methyl­amino)­pyridinium bromide sesquihydrate and 1‐[(4‐bromo­benzoyl)­methyl]‐4‐(N,N‐di­methyl­amino)­pyridinium bromide sesquihydrate

The title compounds, C₁₅H₁₆ClN₂O⁺·Br⁻·1.5H₂O and C₁₅H₁₆BrN₂O⁺·Br⁻·1.5H₂O, are isomorphous. The benzene ring is oriented nearly normal to the pyridine ring in both compounds. The molecular packing is mainly influenced by intermolecular O—H⋯O and O—H⋯Br interactions, as well as weak intramolecular C—H⋯O interactions. The H₂OBr⁻ units form an extended water–bromide chain, with a bridging water mol­ecule on a twofold axis.     

Preparation,characterization, reactivities and electrochemistry of some homo- and heterodinuclear complexes of 2-hydroxy-5- methylbenzene-1,3-dicarbaldehyde and 1,3-diacetyl- 2-hydroxy-5-methylbenzene

Homo- and heterodinuclear complexes of composition [M₂L₂](ClO₄)₂·4H₂O, [CuML₂](ClO₄)₂·nH₂O (M = Ni, Co or Mn; L = L¹ or L²) and [CuML²Cl₂]·2H₂O (M = Ni or Co) have been synthesized with the dinucleating ligands 2-hydroxy-5-methyl- benzene-1,3-dicarbaldehyde (HL¹) and 1,3-diacetyl-2-hydroxy-5-methylbenzene (HL₂). These compounds have been characterized and their chemical reactivities investigated. The electrochemical behaviour of [M₂L₂²](ClO₄)₂·4H₂O and [CuML₂²](ClO₄)₂·nH₂O complexes have been examined in acetonitrile and dimethyl sulfoxide using Hg and Pt electrodes. The cyclic voltammograms obtained with a Hg electrode show quasi-reversible electron transfers for both metal centres that often get complicated due to decomplexation of metal ions and adsorption phenomena. On a Pt electrode irreversible electron transfers occur at more negative potentials.     

Alkali metal (Na and K)-mediated supramolecular assembly of oxovanadium(V) complexes: Synthesis and structural characterization

The syntheses and characterization of alkali metal complexes [{VO₂L}M(H₂O}_n] (1 and 2) [M = Na⁺ (1), K⁺ (2)] of anionic cis-dioxovanadium(V) species (LVO₂⁻) of the Schiff base 2-hydroxybenzoylhydrazone of 2-hydroxybenzaldehyde have been reported. The number of coordinated water molecules in [{VO₂L}M(H₂O}_n] decreases as the charge density of the alkali metal ion decreases (n = 5 for Na⁺ and 1 for K⁺). These compounds represented M⁺-mediated supramolecular assembly [{VO₂L}M(H₂O}_n]_∝ with an infinite polymeric structure containing an alternating array of cis-dioxo vanadium(V), [VO₂L]⁻, units and aquated metal ion centres, as confirmed by X-ray crystallographic investigation of both. All the compounds are characterized by elemental analysis, IR, UV–Vis and NMR spectroscopy.     

Cobalt(II) and cadmium(II) square grids supported with 4,4′‐bipyrazole and accommodating 3‐carboxyadamantane‐1‐carboxylate

In poly[[bis(μ‐4,4′‐bi‐1H‐pyrazole‐κ²N²:N^2′)bis(3‐carboxyadamantane‐1‐carboxylato‐κO¹)cobalt(II)] dihydrate], {[Co(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (I), the Co²⁺ cation lies on an inversion centre and the 4,4′‐bipyrazole (4,4′‐bpz) ligands are also situated across centres of inversion. In its non‐isomorphous cadmium analogue, {[Cd(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (II), the Cd²⁺ cation lies on a twofold axis. In both compounds, the metal cations adopt an octahedral coordination, with four pyrazole N atoms in the equatorial plane [Co—N = 2.156 (2) and 2.162 (2) Å; Cd—N = 2.298 (2) and 2.321 (2) Å] and two axial carboxylate O atoms [Co—O = 2.1547 (18) Å and Cd—O = 2.347 (2) Å]. In both structures, interligand hydrogen bonding [N...O = 2.682 (3)–2.819 (3) Å] is essential for stabilization of the MN₄O₂ environment with its unusually high (for bulky adamantanecarboxylates) number of coordinated N‐donor co‐ligands. The compounds adopt two‐dimensional coordination connectivities and exist as square‐grid [M(4,4′‐bpz)₂]_n networks accommodating monodentate carboxylate ligands. The interlayer linkage is provided by hydrogen bonds from the carboxylic acid groups via the solvent water molecules [O...O = 2.565 (3) and 2.616 (3) Å] to the carboxylate groups in the next layer [O...O = 2.717 (3)–2.841 (3) Å], thereby extending the structures in the third dimension.     

On the relationship between the structures of Cu(II) complexes and their chemical transformations

The experimental activation energies (E ^*) of dehydration of Cu(NH₃)₄(H₂O)SO₄, Cu(en)₂(H₂O)X₂ (X=Cl^?, Br^?), Cu(en)(H₂O)₂SO₄, Cu(py)₂(H₂O)₂SO₄, CuCl₂ · 2H₂O and M ₂ ^I CuCl₄ · 2H₂O (M ^I =NH₄, K, Rb) were obtained from their non-isothermal thermogravimetric curves using the Coats-Redfern method. TheseE ^* values were compared with known data on the structures of the Cu(II) coordination polyhedra in the above complexes. No dependence of theE ^* values was found on either the central atom — released ligand bond length, or the number and lengths of the hydrogen bonds formed by the released water molecules. However, it was found that it is justified to seek some relationship between theE ^* values and the anisotropic temperature factors of the donor atoms of the ligands split off.     

Polysulfonylamine. CLIV [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 7 [2] Ein dreidimensionales Koordinationspolymer aus Schichten und Pfeilern: Kristallstruktur von Ba[(CH3SO2)2N]2·2H2O

Polysulfonylamines. CLIV. Crystal Structures of Metal Di(methanesulfonyl)amides. 7. A Three‐Dimensional Coordination Polymer Built up from Layers and Pillars: Crystal Structure of Ba[(CH₃SO₂)₂N]₂·2H₂O The barium compound BaA₂·2H₂O, derived from HA = di(methanesulfonyl)amine, has been characterized by single crystal X‐ray diffraction at —95 °C (monoclinic, space group P2₁/n, Z = 4). Despite numerous metal‐ligand bonds, the independent anions A^— and A′^— retain the pseudo‐C₂ symmetric conformation that commonly occurs in organic onium salts BH⁺A^—. The large cation attains ninefold coordination via interactions with one (O, N)‐chelating A^—, three κ¹O‐bonding A^—, two κ¹O‐bonding A′^— and two monodentate water molecules; if a distinctly longer barium‐water distance is included, the coordination number may alternatively be viewed as 9 + 1 and one water molecule regarded as an asymmetrically μ₂‐bridging ligand. In contrast to the previously reported layer structures of SrA₂ and PbA₂, the present crystal displays a three‐dimensional coordination assembly consisting of layers formed by the cations, the water molecules and the pentadentate A^— ligands, and of interlayer pillars provided by the bidentate A′^— ligands; however, the Ba²⁺/A^— substructure turns out to be topologically and crystallographically congruent with the corresponding M²⁺/A^— substructures in SrA₂ and PbA₂. The crystal cohesion of the barium complex is reinforced by four O(W)—H···O=S hydrogen bonds and several non‐classical C—H···O=S hydrogen bonds.