Formation of the ionic gold(III) complex [Au3{S2CN(CH2)4O}6][Au2Cl8][AuCl4] in chemisorption systems [M{S2CN(CH2)4O}2] n -[AuCl4]−/2 M HCl (M = Cd, Zn): Supramolecular structure and thermal behavior

The interaction of freshly precipitated cadmium and zinc morpholinedithiocarbamates with solutions of AuCl₃ in 2 M HCl is studied. In both cases, the heterogeneous reactions of gold(III) binding from solutions lead to the formation of the ionic gold(III) complex [Au₃{S₂CN(CH₂)₄O}₆][Au₂Cl₈][AuCl₄] (I), whose molecular and supramolecular structures are determined by X-ray diffraction analysis. Compound I includes centrosymmetric and noncentrosymmetric cations [Au{S₂CN(CH₂)₄O}₂]⁺ in a ratio of 1: 2. According to the manifested structural differences, the complex cations are related as conformers (cations A are Au(1) and cations B are Au(2)). At the supramolecular level, the isomeric cations form linear trinuclear structural fragments [Au₃{S₂CN(CH₂)₄O}₆]³⁺ [A...B...A] due to secondary bonds Au...S of 3.6364 Å. The anionic part of compound I is presented by [AuCl₄]^? and centrosymmetric binuclear [Au₂Cl₈]^2?, whose formation involved secondary bonds Au...Cl of 3.486 and 3.985 Å. The ultimate chemisorption capacity of cadmium and zinc morpholinedithiocarbamates calculated from the binding of gold(III) is 901.7 and 1010.4 mg of Au³⁺ per 1 g of the sorbent, respectively (i.e., each miononuclear fragment of the chemisorption complexes [M{S₂CN(CH₂)₄O}₂] participates in binding of two gold atoms). To establish the conditions for the isolation of bound gold, the thermal properties of compound I are studied by simultaneous thermal analysis. The thermal destruction process includes the thermolysis of the dithiocarbamate part of the complex and anions [AuCl₄]^? and [Au₂Cl₈]^2? with the reduction of gold to the metal, being the only final product of the thermal transformations of compound I.     

A fixation mode of gold(III) in the [Zn2{S2CN(iso-C3H7)2}4]-[AuCl4]−/2 M HCl chemisorption system: Supramolecular structure and thermal behavior of the heteropolynuclear complex ([H3O][Au3{S2CN(iso-C3H7)2}6][ZnCl4]2 · H2O) n

The interaction of freshly precipitated binuclear zinc dithiocarbamate [Zn₂{S₂CN(iso-C₃H₇)₂}₄] with solutions of AuCl₃ in 2 M HCl is studied. The heterogeneous reaction includes the chemisorption of gold(III) and the partial ion exchange to form a polynuclear ionic gold(III)-zinc complex. The molecular and supramolecular structures of the individual fixation mode of gold(III), coordination compound (H₃O[Au₃{S₂CN(iso-C₃H₇)₂}₆][ZnCl₄]₂ · H₂O) _n (I), are determined by X-ray diffraction analysis. Compound I includes three complex cations [Au{S₂CN(iso-C₃H₇)₂}₂]⁺, two of which (noncentrosymmetric, A) are structurally nonequivalent with respect to the third cation (centrosymmetric, B). The structural self-organization of compound I includes the formation of linear trinuclear fragments [Au₃{S₂CN(iso-C₃H₇)₂}₆]³⁺ by three cations (2A and B) due to nonsymmetric secondary Au…S bonds. The interaction between the [Au₃{S₂CN(iso-C₃H₇)₂}₆]³⁺ fragments results in the formation of zigzag polymer chains ([Au₃{S₂CN(iso-C₃H₇)₂}₆]³⁺) _n . The outer-sphere water molecule and the hydronium ion are involved in the pairwise linkage of the [ZnCl₄]₂-anions due to hydrogen bonds Cl…O. The chemisorption capacity of the zinc dithiocarbamate complex calculated from the reaction of gold(III) fixation is 471.2 mg of gold per 1 g of the sorbent. The conditions for the isolation of chemisorbed gold are determined by the simultaneous thermal analysis of the thermal behavior of compound I. The multistage thermal destruction includes two steps of dehydration of the complex, the thermolysis of the dithiocarbamate moiety and [ZnCl₄]^2? (with the release of metallic gold and zinc chloride and the partial formation of ZnS), and the evaporation of ZnCl₂. The final products of the thermal transformations are metallic gold and ZnS.     

Chemisorption of the [AuCl4]− anion by cadmium cyclo-pentamethylenedithiocarbamate and the resulting bound-gold(III) species: The supramolecular structure and thermal behavior of the polynuclear complexes ([Au{S2CN(CH2)5}2]2[CdCl4]) n and ([Au{S2CN(CH2)5}Cl2]) n

The interaction between cadmium cyclo-pentamethylenedithiocarbamate (chemisorbent Ia) and the [AuCl₄]^? anion in 2 M HCl has been investigated. The state of the chemisorbent in contact with AuCl₃ solutions has been probed by ¹¹³Cd MAS NMR spectroscopy. The heterogeneous reactions in the system, including gold(III) chemisorption from the solution and partial ion exchange, yield the gold(III)-cadmium heteropolynuclear complex ([Au{S₂CN(CH₂)₅}₂]₂[CdCl₄]) _n (I) and the polynuclear mixed-ligand complex ([Au{S₂CN(CH₂)₅}Cl₂]) _n (II). The crystal and molecular structures of these compounds have been determined by X-ray crystallography. The main structural units of the compounds are the complex cation [Au{S₂CN(CH₂)₅}₂]⁺, [CdCl₄]^2? anion (in I), and Au{S₂CN(CH₂)₅}Cl₂ molecule (in II). The further structural self-organization of the complexes at the supramolecular level is due to secondary Au...S and Au...Au bonds. [Au₂{S₂CN(CH₂)₅}₄]²⁺ dinuclear cations form in the structure of I, which then polymerize into ([Au₂{S₂CN(CH₂)₅}₄]²⁺) _n chains. In the structure of II, adjacent Au{S₂CN(CH₂)₅}Cl₂ molecules join by forming pairs of asymmetric secondary Au...S bonds, producing polymer chains with alternating antiparallel monomer units. The chemisorption capacity values calculated for cadmium cyclo-pentamethylenedithiocarbamate from gold(III) binding reactions are 455 and 910 mg of gold per gram of sorbent. The gold recovery conditions have been determined by investigating the thermal behavior of I and II by synchronous thermal analysis. The multistep thermal destruction of ionic complex I includes the thermolysis of its carbamate moiety and [CdCl₄]_2? (which liberates gold metal and cadmium chloride and yield some amount of CdS) and CdCl₂ and CdS evaporation. The thermolysis of II proceeds via the formation of Au₂S and AuCl as intermediate compounds. In both cases, the ultimate pyrolysis product is elemental gold.     

A fixation mode of gold(III) in the course of the chemisorption interaction with cadmium cyclo-hexamethylene dithiocarbamate: Structural organization and thermal behavior of the heteropolynuclear complex ([Au{S2CN(CH2)6}2]2[CdCl4] · 3/4H2O) n (an example of the complicated supramolecular structure)

The chemisorption interaction of binuclear cadmium cyclo-hexamethylene dithiocarbamate with H[AuCl₄] in a solution of 2 M HCl is studied. The state of the chemisorbent is monitored by ¹¹³Cd and ¹³C MAS NMR spectroscopy. The result of the heterogeneous reaction, including the chemisorption of gold(III) from a solution and partial ion exchange, is the formation of the heteropolynuclear gold(III)-cadmium complex. The crystal, molecular, and supramolecular structures of the hydrated form of the synthesized coordination compound ([Au{S₂CN(CH₂)₆}₂]₂[CdCl₄] · 3/4H₂O) _n (I) are determined by X-ray diffraction analysis. Compound I includes three structurally nonequivalent complex cations [Au{S₂CN(CH₂)₆}₂]⁺. The character of structural differences between them indicate that they correlate as conformers: cations (A), (B), and (C) are present in the ratio 2: 1: 1. The isomeric cations perform different functions in the self-organization of the chemical system into unusually complicated supramolecular structure I. Cations (A) form centrosymmetric dimers [Au₂{S₂CN(CH₂)₆}]²⁺, which are involved together with cations (B) in the formation of polymeric chains ([Au₂{S₂CN(CH₂)₆}]²⁺ · [Au{S₂CN(CH₂)₆}₂]⁺) _n alternating along the chain length. Cations (C) are structurally isolated, as well as anions [CdCl₄]^2?. The chemisorption capacity of the cadmium cyclo-hexamethylene dithiocarbamate complex calculated from the reaction of Au(III) binding is 427.2 mg of gold per 1 g of the sorbent. To establish the optimum conditions for the regeneration of bound gold, the thermal behavior of I is studied by simultaneous thermal analysis (STA). The multistage process of chemical destruction includes the desorption of hydrate water, the thermolysis of the dithiocarbamate part of the complex and [CdCl₄]^2? (with the release of metallic gold and cadmium chloride and the partial formation of CdS), and the evaporation of CdCl₂ and CdS. The final product of thermal transformations is reduced metallic gold.     

Gold(III) preconcentration from acid solutions by cadmium diisopropyldithiocarbamate: Gold(III)-binding species, supramolecular structure, and thermal properties of the heteropolynuclear complex ([Au{S2CN(iso-C3H7)2}2]2[CdCl4] · 1/2C3H6O) n

The reaction of binuclear cadmium diisopropyldithiocarbamate with a solution of AuCl₃ in 2 M HCl was studied. The heterogeneous reaction of gold(III) binding follows a chemisorption scenario (in combination with partial ion exchange) and yields a heteropolynuclear gold(III)-cadmium complex. The molecular and crystal structure of a solvated species of the compound, namely ([Au{S₂CN(iso-C₃H₇)₂}₂]₂[CdCl₄] · 1/2C₃H₆O) _n (I), was solved by X-ray crystallography. The structure of complex I contains (in the ratio 1: 1) structurally nonequivalent molecular cations [Au{S₂CN(iso-C₃H₇)₂}₂]⁺; the differences between these cations allow them to be classified as conformational isomers (cations A and B). The specifics of the supramolecular organization of complex I consist of the alternation of layers of [Au₂{S₂CN(iso-C₃H₇)₂}₄]²⁺ binuclear cations (formed by cations A), ([Au{S₂CN(iso-C₃H₇)₂}₂]⁺) _n polymer chains (formed by cations B), and [CdCl₄]^2? anions. The chemisorption capacity of the precursor cadmium diisopropyldithiocarbamate as calculated from the gold(III) binding reaction is 423.5 mg Au³⁺ per gram of sorbent. The thermal properties of complex I were studied by simultaneous thermal analysis (STA) in order for the parameters of sorbed gold recovery to be determined. The multistep thermal destruction process involves desorption of solvating acetone molecules, thermolysis of the dithiocarbamate part of the complex and [CdCl₄]^2? with release of metallic gold and cadmium chloride and formation of CdS, as well as vaporization of CdCl₂ and CdS. The only final product of thermal conversions is reduced metallic gold.     

Synthesis,Molecular Structure,and Thermal Properties of the Supramolecular Complex [Zn{NH(CH2)4O}{S2CN(C2H5)2}2]2 · CH2N(CH2)4O}2

The supramolecular complex [Zn{NH(CH₂)₄O}{S₂CN(C₂H₅)₂}₂]₂ · CH₂N(CH₂)₄O}₂ (I) has been synthesized and studied by X-ray crystallography and thermal analysis. The noncentrosymmetric complex is composed of two structurally nonequivalent molecules of the adduct of bis(diethyldithiocarbamato)zinc with morpholine, which are linked with the outer-sphere N,N’-dimorpholinomethane molecule through two hydrogen bonds N-H?O. The major differences between the adduct molecules are related to the strength of Zn-N bonds, spatial orientation of the coordinated morpholine heterocyclic rings, and the proportion between the contributions of the trigonal bipyramidal (TBP) and tetragonal pyramidal (TP) components to the geometry of zinc polyhedra. Calculations show that the geometry of the zinc polyhedra is almost halfway between TBP and TP. The thermal destruction of supramolecular compound I is accompanied by desorption of the outer-sphere and coordinated organic molecules. At the final stage, defragmentation of the “dithiocarbamate part” of the complex leads to the formation of ZnS.     

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}的晶体和分子结构

[(C2H5)4N]2{Fe4S4[S2CN(C2H5)2]4}单晶样品在Nicolet-R3四圆衍射仪上收集X射线衍射数据. 分析结果给出其晶胞参数: a=22.125(6), b=11.313(3),c=25.053A; β=118.05(2)°; V=5534.19A^3, Z=4, 空间群Cc. 衍射数据经过Lρ因子和经验吸收效应校正. 分子中铁原子的位置从三维Patterson图上得到. 接着经过若干轮Fourier和差Fourier电子云密度合成, 发现全部其余非氢原子的坐标.氢原子位置根据理论模型计算. 结构修正最后收敛至R=0.073, Rw=0.069. 标题化合物是由[(C2H5)4N]^+和{FeS4[S2CN(C2H5)2]}^2^-组成的离子型化合物. 结构的主要特点表现在阴离子上, 而在阴离子中含有类立方烷型簇核Fe4S4. 该簇核中每个铁原子与五个硫原子配位, 其配位多面体构型均为畸变的四方锥.     

Rearrangement of the {Mo6S8}cluster fragment to {Mo4S4} and a New {Mo6S6} Cluster Nucleus: Crystal Structure of K6[Mo4S4(CN)12]·10H2O and (18-Crown-6K)8[Mo6S6(CN)16]·17.5H2O

Two new compounds containing molybdenum thiocyanide cluster anions, K₆[Mo₄S₄(CN)₁₂]·10H₂O (1) and (18-crown-6K)₈[Mo₆S₆(CN)₁₆]·17.5H₂O (2), were synthesized and investigated by X-ray structure analysis. Crystal data: a=11.8430(17), b=11.8430(17), c=35.170(7) , V=4932.8(14) ³, space group I4₁/a, Z=4, d_calc=1.563 g/cm³ for 1; a=28.7513(5), b=18.4190(3), c=20.7586(4) , =118.5982(7)°, V=9651.9(3) ³, space group C2/m, Z=4, d_calc =1.563 g/cm³ for 2. The [Mo₄S₄(CN)₁₂]^6- cluster anion in 1 has an ordinary structure typical of cubane transition metal complexes. In the structure of the [Mo₆S₆(CN)₁₆]^8- anion of 2, two crystallographically independent molybdenum atoms form a Mo₆ metallocluster, represented as two edge-sharing tetrahedra.     

Synthesis and crystal structure of a three-dimensional 3d-4f heterometallic supramolecular complex {Eu(DMF)4(H2O)2Cr(CN)6·;H2O} n

A lanthanide-transition heterometallic supramolecular complex {Eu(DMF)₄(H₂O)₂Cr(CN)₆·H₂O} _n (1) has been synthesized based on the reaction of K₃[Cr(CN)₆], N,N-dimethylformamide (DMF) and Eu(NO₃)₃·6H₂O. 1 crystallizes in the monoclinic space group P2(1)/c with a=13.130(6)Å, b=12.923(7)Å, c=19.184(9)Å and Z=4. In 1 each Eu(III) is eight-coordinate with six oxygen atoms from four DMF molecules and two H₂O molecules and two nitrogen atoms from two cis-bridging CN ligands to form a distorted dodecahedron. 1 has a three-dimensional network created by the incorporation of coordinative linkage, three inter-molecular and an intrachain hydrogen bond.     

From an {Fe4S4}-cluster to {Fe2S2}- and {Fe3S}-carbonyls. Crystal structure of [Fe3S(CO)9]2−

We report the electrochemical and chemical synthesis of the first isolable iron carbonyls obtained directly from an {Fe₄S₄}-cluster and carbon monoxide: the structure of one product of chemical reduction, [Fe₃S(CO)₉]²⁻, had been determined by X-ray crystallography.     

Organoselenium(II) complexes containing organophosphorus ligands. Crystal and molecular structure of PhSeSP(S)Ph2, [2-{MeN(CH2CH2)2NCH2}C6H4]SeSP(S)R′2 (R′ = Ph,OPri) and [2-{O(CH2CH2)2NCH2}C6H4]SeSP(S)(OPri)2

Arylselenium(II) derivatives of dithiophosphorus ligands of type ArSeSP(S)R₂ [Ar = Ph, R = Ph (1), OPrⁱ (2); 2-[MeN(CH₂CH₂)₂NCH₂]C₆H₄, R = Ph (3), OPrⁱ (4); 2-[O(CH₂CH₂)₂NCH₂]C₆H₄, R = OPrⁱ (6)] were prepared by redistribution reactions between Ar₂Se₂ and [R₂P(S)S]₂. The derivative [2-{O(CH₂CH₂)₂NCH₂}C₆H₄]SeSP(S)Ph₂ (5) was obtained by the salt metathesis reaction between [2-{O(CH₂CH₂)₂NCH₂}C₆H₄]SeCl and NH₄S₂PPh₂. The compounds were investigated by multinuclear (¹H, ¹³C, ³¹P, ⁷⁷Se) NMR and infrared spectroscopy. The crystal and molecular structures of 1, 3, 4 and 6 were determined by single-crystal X-ray diffraction. In compounds 3, 4 and 6 the N(1) atom is intramolecularly coordinated to the selenium center, resulting in a T-shaped geometry (hypervalent 10-Se-3 species). The dithiophosphorus ligands act as anisobidentate in 1 and monodentate in 3, 4 and 6. Supramolecular architectures based on intermolecular S?H and N?H contacts between molecular units are formed in the hypervalent derivatives 3 and 4, while in the compounds 1 and 6 the molecules are associated into polymeric chains through either Se?S or O?H contacts, with no further inter-chain interactions.     

Platinum(II) cyclo-hexamethylenedithiocarbamate complex, [Pt{S2CN(CH2)6}2] and its solvated form, [Pt{S2CN(CH2)6}2] · CHCl3: Crystal and molecular structures, 13C CP/MAS NMR data, and thermal behavior

Platinum(II) cyclo-hexamethylenedithiocarbamate (HmDtc) complex, [Pt{S₂CN(CH₂)₆}₂] (I), and its solvated form, Pt{S₂CN(CH₂)₆}₂] · CHCl₃ (II), are synthesized and characterized by the ¹³C MAS NMR data. The HmDtc ligands in structure I are not equivalent, whereas the solvation of the complex is accompanied by the structural unification of the initially nonequivalent HmDtc ligands. In addition, the spectra are characterized by the ¹³C-¹⁹⁵Pt spin-spin coupling. The noncentrosymmetric molecular structure of compound I determined by X-ray diffraction analysis includes two nonequivalent dithiocarbamate ligands coordinated by the metal in the S,S′-bidentate mode. The central atom forming the [PtS₄] chromophore (intraorbital dsp ²-hybrid state of platinum) shifts from the plane of four sulfur atoms by 0.07 Å in the vertex of the flattened tetragonal pyramid. The seven-membered heterocycles ?N(CH₂)₆ of the HmDtc ligands are oppositely directed in space relative to the [S₄] plane (trans orientation). The thermal behavior of compounds I and II are studied by simultaneous thermal analysis. In both cases, the final product of the multistage thermal destruction of the complexes is reduced metallic platinum.     

从固相反应产物[NEt4]4[Mo2O2S6Cu6I4Br2]合成原子簇[MoOS3Cu3I(3,5-diMePy)4]·CH3CN和(EtN)4[Mo4Cu8O4S12{(Ph2PS)2}4](英文)

Treatment of iodide-bridged dimer [NEt4] 4[Mo2O2S6Cu6I4Br2] 1 with 3, 5-bimethylpyridine or with K[(Ph2PS) 2N] in CH3CN afforded the tetranuclear cluster [MoOS3Cu3I(3,5-diMePy)4]·CH3CN 2 and dodecanuclear cluster (Et4N)4[Mo4Cu8O4S12{(Ph2PS)2N}4] 3. Monomeric 2 possess a nest-shaped skeleton.The structure of oligomeric 3 can be regarded as a tetramer of nest-shaped MoCu3OS3[(Ph2PS)aN]groups co-polymerized by sharing the limbic Cu atoms.     

Pseudo-Polymeric Mercury(II) Morpholinedithiocarbamate [Hg{S2CN(CH2)4O}2]n: Supramolecular Structure (a Role of Secondary Hg···S Bonds), 13C and 15N CP-MAS NMR Spectra,and Thermal Behavior

Russian Journal of Coordination Chemistry - A new representative of mercury(II) dithiocarbamate complexes, crystalline bis(morpholinedithiocarbamato-S,S')mercury(II) with the...     

Structure of a new binuclear complex of tungsten [W2S4Cl2(dppe)2]·2CH3CN

Journal of Structural Chemistry - In the reaction of (Et4N)2[W2S4Cl4] with 1,2-bis(diphenylphosphino)ethane in acetonitrile a new binuclear complex of tungsten(V) [W2S4Cl2(dppe)2]·2CH3CN is...     

Cluster cyanide-bridged heterometallic coordination polymers: synthesis and crystal structures of compounds [{Cu2(dien)2(CN)}2{Mo4Te4(CN)12}]·14.5H2O and (H3O)3K[{Mn(H2O)2}2{Mn(H2O)2(NO3)}4{W4Te4(CN)12}2]·8H2O

The reactions of anionic molybdenum and tungsten cyanide cuboidal clusters with Cu^II and Mn^II salts afforded two new cyanide-bridged heterometallic coordination polymers with the composition [{Cu₂(dien)₂(CN)}₂{Mo₄Te₄(CN)₁₂}]?14.5H₂O (1) and (H₃O)₃K[{Mn(H₂O)₂}₂{Mn(H₂O)₂(NO₃)}₄{W₄Te₄(CN)₁₂}₂]·8H₂O (2). The structures of these compounds were established by X-ray diffraction analysis. Compound 1 has a layered structure, in which the cuboidal cluster fragments {Mo₄Te₄(CN)₁₂}^6? are linked to the copper atoms of the dinuclear fragments {(H₂O)(dien)Cu(μ-CN)Cu(dien)(H₂O)} through the bridging CN groups. Coordination polymer 2 has a framework structure, in which the cluster fragments {W₄Te₄(CN)₁₂}^6? are linked to the manganese(II) aqua complexes of two types, viz., the dinuclear fragment {Mn(μ₂-H₂O)₂Mn} and the tetranuclear cyclic fragment {(H₂O)₂Mn(μ₂-NO₃)}₄, through the bridging CN groups.     

Synthesis,crystal structure and magnetic properties of the cyano-bridged heteropolynuclear complex [{(Cu(dien))2Co(CN)6}n][Cu(dien)(H2O)Co(CN)6]n·5nH2O

The reaction of [Cu(dien)(H₂O)](NO₃)₂ with K₃[Co(CN)₆] leads to the cyano-bridged heteropolynuclear complex, [{(Cu(dien))₂Co(CN)₆}_n][Cu(dien)(H₂O)Co(CN)₆]_n·5nH₂O, {Cu₃Co₂}, whose crystal structure has been solved. The structure consists of two distinct ionic units, namely one-dimensional cationic chains [{(Cu(dien))₂Co(CN)₆}_n]ⁿ⁺, and discrete binuclear anionic entities [(H₂O)(dien)Cu–NC–Co(CN)₅]⁻. The cryomagnetic investigation of the title compound reveals a very weak antiferromagnetic coupling between the Cu(II) ions within the cationic chain (J=−1.02 cm⁻¹, g=2.14). The complete elimination of the water molecules from the isomorphous {Cu₃Co₂}, {Cu₃Fe₂} and {Cu₃Cr₂} complexes causes the modification of the magnetic properties. The most dramatic one is observed with the Cu(II)–Fe(III) system, where the magnetic behavior changes from ferro- to antiferromagnetic. The dehydrated chromium derivative preserves the ferromagnetic coupling, which is observed at lower temperatures (below 30 K) in comparison with the parent compound (below 150 K).     

{Mo[S_2CN(C_2H_5)_2]_4}~ {MoCl_6}~-的合成及其晶体结构与分子结构

我们合成了化合物{Mo[S_2CN(C_2H_5)_2]_4}~ {MoCl_6}~-,确定了其所属晶系、空间群及晶胞参数,并确定了重原子与其它全部非氢原子坐标等.     

Synthesis and Structure of Trinuclear Iron Acetate [Fe3O(CH3COO)6(H2O)3][AuCl4]·6H2O

Iron acetate of composition [Fe₃O(CH₃COO)₆(H₂O)₃][AuCl₄]·6H₂O (I) was synthesized and investigated by X-ray diffraction analysis and Mössbauer spectroscopy. The [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ complex cation has a structure typical for ₃-O bridged trinuclear ferric compounds with iron atoms lying at the vertices of a regular triangle with an oxygen atom at the center. The iron atoms are each coordinated by 4 oxygen atoms of the four bridging carboxylic groups, the ₃-O bridging atom, and the coordinated water molecule in the trans-position to the latter. In the trinuclear cation, the Fe(III) ions are coupled by antiferromagnetic exchange interactions with the exchange parameter J = -29.0 cm ^–1 (HDVV model for D _3h symmetry). The specific role of the solvate water molecules in structure formation is discussed.