Ge4Br4[Mn(CO)5]4 and Ge6Br2[Mn(CO)5]6: first germanium cluster compounds containing Mn(CO)5 ligands

Cluster compounds of germanium exhibiting germanium-germanium bonds, where the germanium atoms are additionally bound to transition metal ligands, are rare. Here a synthetic pathway to such cluster compounds is described, starting from metastable Ge I halide solutions leading to the two cluster compounds Ge4Br4[Mn(CO)5]4 and Ge6Br2[Mn(CO)5]6, being the first examples of germanium cluster compounds bearing Mn(CO)5 ligands. The Ge6 compound exhibits a novel arrangement of germanium atoms that has not been previously observed in ligand stabilized cluster compounds of germanium, neither with organic nor with transition metal ligands. The bonding situation inside the cluster compounds is discussed, together with a possible reaction pathway that opens the way to metalloid cluster compounds of germanium exhibiting Mn(CO)5 ligands.     

High-nuclearity Ce/Mn and Th/Mn cluster chemistry: preparation of complexes with [Ce4Mn10O10(OMe)6]18+ and [Th6Mn10O22(OH)2]18+ cores

The syntheses, structures, and magnetic properties are reported of the mixed-metal complexes [Ce4Mn10O10(OMe)6(O2CPh)16(NO3)2(MeOH)2(H2O)2] (1) and [Th6Mn10O22(OH)2(O2CPh)16-(NO3)2(H2O)8] (2), which were both prepared by the reaction of (NBun4)[Mn4O2(O2CPh)9(H2O)] (3) with a source of the heterometal in MeCN/MeOH. Complexes 1 and 2 crystallize in the monoclinic space group C2/c and the triclinic space group P, respectively. Complex 1 consists of 10 MnIII, 2 CeIII, and 2 CeIV atoms and possesses a very unusual tubular [Ce4Mn10O10(OMe)6]18+ core. Complex 2 consists of 10 MnIV and 6 ThIV atoms and possesses a [Th6Mn10O22(OH)2]18+ core with the metal atoms arranged in layers with a 2:3:6:3:2 pattern. Peripheral ligation around the cores is provided by 16 bridging benzoates, 2 chelating nitrates, and either (i) 2 each of terminal H2O and MeOH groups in 1 or (ii) 8 terminal H2O groups in 2. Complex 1 is the largest mixed-metal Ce/Mn cluster and the first 3d/4f cluster with mixed-valency in its lanthanide component, while complex 2 is the first Th/Mn cluster and the largest mixed transition metal/actinide cluster to date. Solid-state dc and ac magnetic susceptibility measurements on 1 and 2 establish that they possess S = 4 and 3 ground states, respectively. Ac susceptibility studies on 1 revealed nonzero frequency-dependent out-of-phase (chiM' ') signals at temperatures below 3 K; complex 2 displays no chiM' ' signals. However, single-crystal magnetization vs dc field scans at variable temperatures and variable sweep-rates down to 0.04 K on 1 revealed no noticeable hysteresis loops, except very minor ones at 0.04 K assignable to weak intermolecular interactions propagated by hydrogen bonds involving CeIII-bound ligands. Complex 1 is thus concluded not to be a single-molecule magnet (SMM), and the combined results thus represent a caveat against taking such ac signals as sufficient proof of a SMM.     

Second-sphere coordination in the complex [Mn(H2O)6]2[thiacalix[4]arene tetrasulfonate]

The title calixarene, dimanganese thiacalix[4]arene tetrasulfonate, was prepared and its crystal structure was determined. [Mn(H₂O)₆]₂[thiacalix[4]arene tetrasulfonate]·0.5H₂O crystallizes in the monoclinic system, P2(1)/m space group, with a=13.014 (6), b=14.146 (9), c=13.184 (7) Å, β=113.307 (10)°, V=2229 (2) Å³ and Dc=1.710 gcm⁻³, Z=2. The title calixarene exists in the solid state as bilayer structure. The hydrophobic organic layer consists of thiacalix[4]arene tetrasulfonate in an up-down fashion, whereas, the hydrophilic inorganic layer consists of hexaaquamanganese (II) which is linked to the former through a second-sphere coordination.     

Tellurium-bridged manganese carbonyl clusters: synthesis and structural transformations of [Te4Mn3(CO10]-, [Te2Mn3(CO)9]2-, [Te2Mn3(CO)9]-, and [Te2Mn4(CO)12]2-

The reactions of appropriate ratios of K2TeO3 and [Mn2(CO)10)] in superheated methanol solutions lead to a series of novel cluster anions [Te4Mn3(CO)10] (1), [Te2Mn3(CO)9]2- (2), [Te2Mn3(CO)9]- (3), and [Te2Mn4(CO)12]2- (4). When cluster 1 is treated with [Mn2(CO)10]/KOH in methanol, paramagnetic cluster 2 is formed in moderate yield. Cluster 2 is oxidized by [Cu(MeCN)4]BF4 to give the closo-cluster [Te2Mn3(CO)9]- (3), while treatment of 2 with [Mn2(CO)10]/KOH affords the closo-cluster 4. IR spectroscopy showed that cluster 1 reacted with [Mn2(CO)10] to give cluster 4 via cluster 2. Clusters 1-4 were structurally characterized by spectroscopic methods or/and X-ray analyses. The core structure of 1 can be described as two [Mn(CO)3] groups doubly bridged by two Te2 fragments in a mu2-eta2 fashion. Both [Mn(CO)3] groups are further coordinated to one [Mn(CO)4] moiety. Cluster 2 is a 49 e- species with a square-pyramidal core geometry. While cluster 3 displays a trigonal-bipyramidal metal core, cluster 4 possesses an octahedral core geometry.     

A family of [Mn6] complexes featuring tripodal ligands

The synthesis and magnetic properties of four new Mn complexes containing tripodal alcohol ligands are reported: [Mn6(OAc)6(H2tea)2(tmp)2].2MeCN (1.2MeCN), [Mn6(acac)4(OAc)2(Htmp)2(H2N-ep)2] (2), [Mn6(OAc)8(tmp)2(py)4].2py (3.2py), and [Mn6(OAc)8(thme)2(py)4].2py (4.2py) [H3tea, triethanolamine; H3tmp, 1,1,1-tris(hydroxymethyl)propane; H2N-H2ep, 2-amino-2-ethyl-1,3-propanediol; H3thme, 1,1,1-tris(hydroxymethyl)ethane]. All complexes are mixed-valent with a [Mn(III)2Mn(II)4] oxidation assignment and are constructed from four edge-sharing triangles but differ slightly in that complexes 1 and 2 display a [Mn(III)2Mn(II)4(mu2-OR)6(mu3-OR)4]4+ core, while complexes 3 and 4 feature [Mn(III)2Mn(II)4(mu2-OR)2(mu3-OR)4]8+ and [Mn(III)2Mn(II)4(mu2-OR)4(mu3-OR)4]6+ cores, respectively. dc and ac magnetic susceptibility studies in the 2-300 K range for complexes 1-4 reveal the presence of dominant antiferromagnetic exchange interactions, leading to ground states of S = 0 for 1 and 2, while complexes 3 and 4 display S = 4 ground states with D = -0.44 and -0.58 cm(-1), respectively. Single-molecule magnetism behavior was confirmed for 3 and 4 by the presence of sweep-rate and temperature-dependent hysteresis loops in single-crystal M vs H studies at temperatures down to 40 mK. Theoretical density functional calculations were used to evaluate the individual pairwise exchange interactions present, confirming the diamagnetic ground states for 1 and 2 and the S = 4 ground states for 3 and 4.     

One-dimensional coordination polymers of antiferromagnetically-coupled [Mn4] single-molecule magnets

Reactions of the rhombic [MnII2 MnIII2 (hmp)6]4+ complex in acetonitrile with simple carboxylate ligands yield (i) three new isolated [Mn4] complexes, namely [Mn4(hmp)6(CH3COO)2(H2O)2](ClO4)2.4H2O (1), [Mn4(hmp)6(CCl3COO)2(H2O)2](ClO4)2 (2) and [Mn4(hmp)6(C6H5COO)2(H2O)2](ClO4)2.4CH3CN.2H2O (3) in the presence of either bulky carboxylate or of an excess of Mn(II) source; and (ii) two 1D arrangements of [Mn4] complexes connected through double syn-syn carboxylate bridges when using acetate and chloroacetate, namely {[Mn4(hmp)6(CH3COO)2](ClO4)2.H2O}n (4) and {[Mn4(hmp)6(ClCH2COO)2](ClO4)2.2H2O}n (5). The assembly of such building blocks can thus be controlled by an adequate choice of the bridging anion. As expected, the isolated [Mn4] complexes behave as Single-Molecule Magnets as shown by the study of their static and dynamic magnetic properties. Detailed magnetic studies both on polycrystalline samples and single crystals show that the chain compounds are isolated antiferromagnetic chains. The slow relaxation of their staggered magnetization has been studied thanks to finite-size effects induced by the intrinsic defects of the material     

Dinuclear Manganese(II) Complexes with Bridging Selenidodiarsenate Anions [As2Se4]4−, [As2Se5]4− and [As2Se6]2−

Solvothermal reaction of [MnCl₂(amine)] (amine = terpy and tren) with elemental As and Se at a 1:1:2 molar ratio in H₂O/tren (10:1) affords the dimanganese(II) complexes [{Mn(terpy)}₂(μ‐As₂Se₄)] ( 1 ) and [{Mn(tren)}₂(μ‐As₂Se₅)] ( 2 ) respectively. The tetradentate [As₂Se₄]^4? bridging ligands in 1 contain a central As–As bond and exhibit approximately C_2h symmetry. Pairs of gauche sited Se atoms participate in five‐membered As₂Se₂Mn chelate rings. In contrast, two AsSe₃ pyramids share a common corner in the [As₂Se₅]^4? ligands of 2 and each coordinates an [Mn(tren)]²⁺ fragment through a single terminal Se atom. Such dinuclear complexes are linked into tetranuclear moieties through weak Se···Mn interactions of length 3.026(3) Å involving one of these terminal Se atoms. At a 1:3:6 molar ratio, solvothermal reaction of [MnCl₂(tren)] with As and Se leads to formation of a second dinuclear complex [{Mn(tren)}₂(μ‐As₂Se₆)₂] ( 3 ), which contains two bridging bidentate [As₂Se₆]^2? ligands. These are cyclic with an As₂Se₄ ring and can be regarded as being derived from [As₂Se₅]^4? anions by formation of two Se‐Se bonds to an additional Se atom.     

Mixed-valent selenidoantimonates(III,V) with transition-metal complexes as counterions: solvothermal syntheses and characterization of [M(dien)2]2Sb4Se9 (M = Mn, Fe), [Co(dien)2]2Sb2Se6, and [Ni(dien)2]2Sb2Se5

Novel selenidoantimonate compounds [M(dien)2]2Sb4Se9 [M = Mn (1), Fe (2)], [Co(dien)2]2Sb2Se6 (3), and [Ni(dien)2]2Sb2Se5 (4) (dien = diethylenetriamine) were solvothermally synthesized and characterized. The unique features of compounds 1-3 are the mixed-valent anionic structures constructed by the Sb(III)Se3 trigonal pyramid and Sb(V)Se4 tetrahedron. Three Sb(III)Se3 pyramids share common corners, forming a heterocyclic Sb3Se6 moiety, and the Sb3Se6 moieties are further connected with Sb(V)Se4 tetrahedra to form the novel one-dimensional [Sb4Se9(4-)]n anionic chain in 1 and 2. The discrete [Sb2Se6]4- anion in 3 is formed by an Sb(III)Se3 trigonal pyramid and an Sb(V)Se4 tetrahedron sharing a common corner. The [Sb2Se5]4- anion in 4 is composed of two Sb(III)Se3 trigonal pyramids connected in the same manner as the [Sb2Se6]4- anion. The mixed-valent [Sb4Se9(4-)]n and [Sb2Se6]4- anions were not observed before. The synthesis and solid-state structural studies of the title compounds show that the transition-metal complexes exhibit different structure-directing effects on the formation of selenidoantimonates in dien. Extensive N-H...Se hydrogen bonds are observed between cations and anions in compounds 1-4, resulting in three-dimensional network structures. Optical and thermal properties of the compounds are reported.     

New valence-sandwich [Mn(II)4Mn(III)4Mn(II)4] aggregate showing single-molecule magnet behavior

The reaction of manganese(II) acetate, 1,1,1-tris(hydroxymethyl)methane (H3thme), and triethylamine in methanol leads to the formation of [Mn12O2(OMe)2(thme)4(OAc)10(H2O)4].2MeOH. The [Mn(III)4Mn(II)8] core consists of a central [Mn(III)4O6] rhombus sandwiched by two [Mn(II)4O7] fragments. Frequency-dependent ac susceptibility and hysteresis loops in the magnetization indicate single-molecule magnet behavior with a pure quantum-tunneling regime of relaxation below 0.2 K.     

New insights into the thermal stability of Mn12 clusters: the case of complex [Mn12O12(O2CC[triple bond]-CH)16(H2O)4] x 3H2O and its thermolysis derived [Mn3(O2CC[triple bond]CH)6(H2O)4] x 2H2O complex

Two novel Mn12 derivatives [Mn12O12(O2CC[triple bond]CH)16(H2O)4] x 3H2O (1) and [Mn12(O2CC[triple bond]CC6H5)16(H2O)4] x 3H2O (2) have been prepared and characterized. Magnetic measurements confirm that both function as single-molecule magnets (SMM), showing frequency-dependent out-of-phase AC susceptibility signals and magnetization hysteresis curves. Thermal stability studies of both complexes were first conducted in the solid state. While complex 1 undergoes a sudden exothermal decomposition at T(onset) = 118 degrees C, complex 2 exhibits a higher stability. Thermolysis reaction of 1 was hence assessed in solution to yield dark red crystals of a two-dimensional Mn(II)-based co-ordination polymer [Mn3(O2CC[triple bond]CH)6(H2O)4] x 2H2O (3), which corresponds to an extended sheet-like structure that crystallizes in the monoclinic space group P2(1)/n; a = 9.2800(2) angstroms, b = 9.4132(2) angstroms, c = 14.9675(3) angstroms, beta = 99.630(1) degrees, and Z = 2. Finally, the magnetic properties of complex 3 have been studied on an oriented single crystal over two different orientations of the reciprocal vector versus the external field.     

The mixed-valent manganese [3 x 3] grid [Mn(III)4Mn(II)5(2poap-2H)6](ClO4)10.10 H2O, a mesoscopic spin-1/2 cluster

The magnetic susceptibility and low-temperature magnetization curve of the [3 x 3] grid [Mn(III)4Mn(II)5(2poap-2H)6](ClO4)10.10 H2O (1) are analyzed within a spin Hamiltonian approach. The Hilbert space is huge (4,860,000 states), but the consequent use of all symmetries and a two-step fitting procedure nevertheless allows the best-fit determination of the magnetic exchange parameters in this system from complete quantum mechanical calculations. The cluster exhibits a total spin S = 1/2 ground state; the implications are discussed.     

A large [Mn10Na]4 loop of four linked Mn10 loops

A large [Mn10Na]4 loop-of-loops aggregate was prepared from the use of 1,3-propanediol (pdH2) in manganese carboxylate chemistry. It is constructed from four [Mn10(mu3-O)2(O2CMe)13(pd)6(py)2]- loops linked through Na+ ions and exhibits a saddlelike topology. Magnetic characterization showed that the Mn10 loop has an S approximately 4 ground-state spin and displays frequency-dependent in-phase and out-of-phase alternating current signals and also hysteresis loops that, however, are not typical of single-molecule magnets because of the existence of intermolecular interactions between the Mn10 units.     

31P solid state NMR studies of metal selenophosphates containing [P2Se6]4-, [P4Se10]4-, [PSe4]3-, [P2Se7]4-, and [P2Se9]4- ligands

31P solid-state nuclear magnetic resonance (NMR) spectra of 12 metal-containing selenophosphates have been examined to distinguish between the [P(2)Se(6)](4-), [PSe(4)](3-), [P(4)Se(10)](4-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions. There is a general correlation between the chemical shifts (CSs) of anions and the presence of a P[bond]P. The [P(2)Se(6)](4-) and [P(4)Se(10)](4-) anions both contain a P[bond]P and resonate between 25 and 95 ppm whereas the [PSe(4)](3-), [P(2)Se(7)](4-), and [P(2)Se(9)](4-) anions do not contain a P[bond]P and resonate between -115 and -30 ppm. The chemical shift anisotropies (CSAs) of compounds containing [PSe(4)](3-) anions are less than 80 ppm, which is significantly smaller than the CSAs of any of the other anions (range: 135-275 ppm). The smaller CSAs of the [PSe(4)](3-) anion are likely due to the unique local tetrahedral symmetry of this anion. Spin-lattice relaxation times (T(1)) have been determined for the solid compounds and vary between 20 and 3000 s. Unlike the CS, T(1) does not appear to correlate with P-P bonding. (31)P NMR is also shown to be a good method for impurity detection and identification in the solid compounds. The results of this study suggest that (31)P NMR will be a useful tool for anion identification and quantitation in high-temperature melts.     

[NEt~4][Mn(salophen)(H~2O)~2]~2[Fe(CN)~6]·H~2O· CH~3OH超分子化合物的 合成和结构

室温下将[NEt~4]~3[Fe(CN)~6]和[Mn(salophen)(H~2O)(CH~3OH)]ClO~4反应,得到了超分子化合物[NEt~4][Mn(salophen)(H~2O)~2]~2[Fe(CN)~6]·H~2O·CH~3OH(salophenH~2=双水杨醛缩邻苯二胺),并对其进行了晶体结构测定。结果表明,该晶体属三斜晶系,空间群P1,晶胞参数a=1.2150(4)nm,b=1.4834(6)nm,c=1.6625(6)nm,α=81.896(7)°,β=76.980(8)°,γ=81.120(6)°,V=2.872(2)nm^3,Z=2,D~c=1.388g·cm^-^3。晶体的各部分间以氢键连接成网状超分子体系。     

[Ge4O6Te4]4—, an Adamantanoid Oxotellurido Germanate(IV) with a Central Ge4O6 Core

[Mn(en)₃]₂[Ge₄O₆Te₄]·1.5en ( 1 ) and (enH)₃[Mn(en)₃]₃[Ge₄O₆Te₄]₂I·4.7en ( 2 ) may be prepared at 150 °C by solvothermal reaction of elemental Ge and Te with Mn(OOCCH₃)₂ ·4H₂O in the presence of [CH₃)₄N]I as a mineralizer in respectively superheated ethylenediamine (en) or an en/CH₃OH (3:2) mixture. Both contain the novel [Ge₄O₆Te₄]^4— anion with a central adamantanoid Ge₄O₆ core and four terminal Te atoms and represent the first examples of such a mixed [M₄E₆E₄′]^4— anion (M = Si‐Sn; E = O‐Te). As a result of their increased polarity, the Ge‐Te bonds of 2 are markedly shorter (2.438 — 2.462Å) than those previously reported for telluridogermanates(IV).     

Electrochemical and chemical formation of [Mn4(IV)O5(terpy)4(H2O)2]6+, in relation with the photosystem II oxygen-evolving center model [Mn2(III,IV)O2(terpy)2(H2O)2]3+

To examine the real ability of the binuclear di-mu-oxo complex [Mn2(III,IV)O2(terpy)2(H2O)2]3+ (2) to act as a catalyst for water oxidation, we have investigated in detail its redox properties and that of its mononuclear precursor complex [Mn(II)(terpy)2]2+ (1) in aqueous solution. It appears that electrochemical oxidation of 1 allows the quantitative formation of 2 and, most importantly, that electrochemical oxidation of 2 quantitatively yields the stable tetranuclear Mn(IV) complex, [Mn4(IV)O5(terpy)4(H2O)2]6+ (4), having a linear mono-mu-oxo{Mn2(mu-oxo)2}2 core. Therefore, these results show that the electrochemical oxidation of 2 in aqueous solution is only a one-electron process leading to 4 via the formation of a mono-mu-oxo bridge between two oxidized [Mn2(IV,IV)O2(terpy)2(H2O)2]4+ species. 4 is also quantitatively formed by dissolution of the binuclear complex [Mn2(IV,IV)O2(terpy)2(SO4)2] (3) in aqueous solutions. Evidence of this work is that 4 is stable in aqueous solutions, and even if it is a good synthetic analogue of the "dimers-of-dimers" model compound of the OEC in PSII, this complex is not able to oxidize water. As a consequence, since 4 results from an one-electron oxidation of 2, 2 cannot act as an efficient homogeneous electrocatalyst for water oxidation. This work demonstrates that a simple oxidation of 2 cannot produce molecular oxygen without the help of an oxygen donor.     

Largest mixed transition metal/actinide cluster: a bimetallic Mn/Th complex with a [Mn10Th6O22(OH)2]18+ core

A high-nuclearity mixed transition metal/actinide complex has been prepared from the reaction of a Mn(III)4 complex with Th(NO3)4 in MeCN/MeOH. The complex [Th6Mn10O22(OH)2(O2CPh)16(NO3)2-(H2O)8] is the largest such complex to date and the first Th/Mn species. It is rich in oxide groups, which stabilize all of the metals in the high Th(IV) and Mn(IV) oxidation levels. Magnetic characterization establishes that the complex has an S = 3 ground-state spin value.     

Chloro- und Polyselenoselenate(II) Darstellung,Struktur und Eigenschaften von [Ph3(C2H4OH)P]2[SeCl4] · MeCN, [Ph4P]2[Se2Cl6] und [Ph4P]2[Se(Se5)2]

Chloro- and Polyselenoselenates(II): Synthesis, Structure, and Properties of [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN, [Ph₄P]₂[Se₂Cl₆], and [Ph₄P]₂[Se(Se₅)₂] By symproportionation of elemental selenium and SeCl₄ in polar protic solvents the novel chloroselenates(+II), [SeCl₄]^2? and [Se₂Cl₆]^2?, could be stabilized; they were crystallized with voluminous organic cations. They were characterized from complete X-ray structure analysis. Yellow-orange [Ph₃(C₂H₄OH)P]₂[SeCl₄] · MeCN (space group P1 , a = 10.535(4), b = 12.204(5), c = 16.845(6) Å, α = 77.09(3)°, β = 76.40(3)°, γ = 82.75(3)° at 140 K) contains in its crystal structure monomeric [SeCl₄]^2? anions with square-planar coordination of Se(+II). The mean Se? Cl bond length is 2.441 Å. In yellow [Ph₄P]₂[Se₂Cl₆] (space group P1 , a = 10.269(3), b = 10.836(4), c = 10.872(3) Å, α = 80.26(3)°, β = 79.84(2)°, γ = 72.21(3)° at 140 K) a dinuclear centrosymmetric [Se₂Cl₆]^2? anion, also with square-planar coordinated Se(+II), is observed. The average terminal and bridging Se? Cl bond distances are 2.273 and 2.680 Å, respectively. From redox reactions of elemental Se with boranate/thiolate in ethanol/DMF the bis(pentaselenido)selenate(+II) anion [Se(Se₅)₂]^2? was prepared as a novel type of a mixed-valent chalcogenide. In dark-red-brown [Ph₄P]₂[Se(Se₅)₂] (space group P2₁/n, a = 12.748(4), b = 14.659(5), c = 14.036(5) Å, β = 108.53(3)° at 140 K) centrosymmetric molecular [Se(Se₅)₂]^2? anions with square-planar coordination of the central Se(+II) by two bidentate pentaselenide ligands is observed (mean Se? Se bond lengths: 2.658 Å at Se(+II), 2.322 Å in [Se₅]_2?). The resulting six-membered chelate rings with chair conformation are spirocyclically linked through the central Se(+II). The vibrational spectra of the new anions are reported.     

Sr11Ge4N6: a new nitride composed of [GeN2Sr7]4+ antiperovskite-type slabs and [Sr4Ge]4+ layers, separated by sheets of bent [Ge(II)N2]4- ions

The layered nitride Sr11Ge4N6 contains Ge4- Zintl anions in both [Sr4Ge]4+ layers and [GeN2Sr7]4+ antiperovskite-type slabs which are separated by sheets of bent [Ge(II)N2]4- ions; the observed range of formal germanium oxidation states in nitrides thus extends between +4 and -4.     

Structural features of Ag[AuF4] and Ag[AuF6] and the stuctural relationship of Ag[AgF4]2 and Au[AuF4]2 to Ag[AuF4]2

Synchrotron radiation X-ray powder diffraction data (SPDD) have been obtained for Ag[AgF4]2, Au[AuF4]2, Ag[AuF4], and Ag[AuF6]. Ag[AgF4]2 and Au[AuF4]2 are isostructural with Ag[AuF4]2, space group (SG) P2(1)/n, Z = 2, with the following: for Ag[AgF4]2 a = 5.04664(8), b = 11.0542(2), c = 5.44914(9) A, beta = 97.170(2) degrees; for Au[AuF4]2 a = 5.203(2), b = 11.186(3), c = 5.531(2) A, beta = 90.55(2) degrees. The structure of Ag[AgF4]2 was refined successfully (SPDD) applying the Rietveld method, yielding the following interatomic distances (A): AgII-F = 2.056(12), 2.200(13), 2.558(13); AgIII-F = two at 1.846(12), others = 1.887(12), 1.909(13), 2.786-(12), 2.796(12), 2.855(12). AgAuF4, like other AA'F4 salts (A = Na-Rb; A' = Ag, Au), crystallizes in the KBrF4 structure type, SG I4/mcm (140), Z = 4 with a = 5.79109(6), c = 10.81676(7) A. SPDD gave (in A) four AuIII-F = 1.89(1) and eight AgI-F = 2.577(7). SPDD for AgAuF6 confirmed that it has the LiSbF6 structure, SG R3, Z = 3, with a = 5.2840(2), c = 15.0451(6) A.