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After touching the history of polyoxometalate (POM) chemistry, the basics of isopolyoxometalates (IPOM) and heteropolyoxometalates (HPOM) are discussed. The main focus is placed on molybdenum- and tungsten-containing IPOM and HPOM. The HPOM are presented based on the coordination of the ‘hetero’atom: tetrahedral (Keggin and Wells–Dawson structures, including their lacunary and mixed anions, Preyssler-Pope-Jeannin polyanion), octahedral (Anderson-Evans structure), square-prismatic (Peacock-Weakley sandwiches) and icosahedral (Dexter-Silverton structure). Subsequently the specifics of polyoxocations (POC) are highlighted, examples of naturally occurring HPOM are given and the nomenclature of POM is discussed. In conclusion, selected applications are presented.

The existence of a dodecamolybdoantimonate(v) anion with the Keggin structure would be a highlight of the heteropolyoxometalate chemistry as a whole. However, we could not confirm the existence of ammonium, potassium, rubidium and cesium dodecamolybdoantimonate as claimed by the authors. As a matter of fact, the authors misinterpreted their presented experimental data. Instead of the dodecamolybdoantimonates, the well-known hexagonal molybdenum oxide was prepared. The given misinformation has to be corrected, even 28 years after its publication.

After a historical excursus, the basic properties of tungsten are summarized, followed by selected classes of inorganic compounds (tungsten halides and oxyhalides, tungsten oxides, Magneli phases and tungsten bronzes, iso- and heteropolyoxotungstates). Subsequently, the specifics of non-sag tungsten wire as well as tungsten carbide and a variety of tungsten alloys, the green bullets and the suppression of tungsten’s leachability are described. In conclusion, tungsten’s medicinal role is discussed.

The basic properties of molybdenum and subsequently the methods of producing metallic molybdenum are described. Selected classes of important inorganic compounds (molybdenum halides, molybdenum oxides, iso- and hetero-polyoxomolybdates) as well as molybdenum hexacarbonyl and hybrid inorganic–organic materials are presented. Thereafter the focus is directed to various applications of metallic molybdenum, its alloys and compounds such as catalysts, lubricants and refractory ceramics. In conclusion, molybdenum’s medicinal role and the antimicrobial activity of MoO3 and solid solutions Mo n W1-n O3 are discussed.

The aim of this work was to describe the vibrations connected with the short hydrogen bonds of differing geometries in 2,4-dinitrobenzoic acid and in 2,4-dinitrobenzoic acid complexed in two ratios with pyridine. All three compounds contain short hydrogen bonds either between two acid molecules (OH ⋯ O bond) or between acid and pyridine (NH ⋯ O bonds) or both. We selectively deuterated the proton of the 2,4-dinitrobenzoic acid molecule involved in the proton transfer to aid in the assignment of the H-bond protonic modes. The compounds have been characterized with single crystal X-ray diffraction, CHN elemental analysis, FT-IR and IINS spectroscopy. We show that our combination of analytical methods with DFT calculations represents a fruitful approach to observe the relationship between the geometries of hydrogen bonds and their dynamics.

In 1906, the preparation of “molybdic acid hydrate” was published by Arthur Rosenheim. Over the past 40 years, a multitude of isostructural compounds, which exist within a wide phase range of the system MoO3−NH3−H2O, have been published. The reported molecular formulas of “hexagonal molybdenum oxide” varied from MoO3 to MoO3·0.33NH3 to MoO3·nH2O (0.09 ≤ n ≤ 0.69) to MoO3·mNH3·nH2O (0.09 ≤ m ≤ 0.20; 0.18 ≤ n ≤ 0.60). Samples, prepared by the acidification route were investigated using thermal analysis coupled online to a mass spectrometer for evolved gas analysis, X-ray powder diffraction, Fourier transform infrared, Raman, magic-angle-spinning 1H- and 15N NMR spectroscopy, and incoherent inelastic neutron scattering. A comprehensive characterization of these samples will lead to a better understanding of their structure and physical properties as well as uncover the underlying relationship between the various compositions. The synthesized polymeric parent samples can be represented by the structural formula (NH4)(x∞)(3)[Mo(y square 1−y)O(3y)(OH)(x)(H2O)(m−n)]·nH2O with 0.10 ≤ x ≤ 0.14, 0.84 ≤ y ≤ 0.88, and m + n ≥ 3 − x − 3y. The X-ray study of a selected monocrystal confirmed the presence of the well-known 3D framework of edge- and corner-sharing MoO6 octahedra. The colorless monocrystal crystallizes in the hexagonal system with space group P6(3)/m, Z = 6, and unit cell parameters of a = 10.527(1) Å, c = 3.7245(7) Å, V = 357.44(8) Å3, and ρ = 3.73 g·cm(−3). The structure of the prepared monocrystal can best be described by the structural formula (NH4)(0.13∞)(3)[Mo(0.86 square 0.14)O2.58(OH)0.13(H2O)(0.29−n)]·nH2O, which is consistent with the existence of one vacancy (square) for six molybdenum sites. The sample MoO3·0.326NH3·0.343H2O, prepared by the ammoniation of a partially dehydrated MoO3·0.170NH3·0.153H2O with dry gaseous ammonia, accommodates NH3 in the hexagonal tunnels, in addition to [NH4]+ cations and H2O. The “chimie douce” reaction of MoO3·0.155NH3·0.440H2O with a 1:1 mixture of NO/NO2 at 100 °C resulted in the synthesis of MoO3·0.539H2O. This material is of great interest as a host of various molecules and cations.

The synthesis and structural characterization of the neutral mixed-valence methoxo-polyoxovanadium cluster [V(6)O(8)(OCH(3))(11)] (1) and its single oxidation product in the hexachloroantimonate salt [V(6)O(8)(OCH(3))(11)][SbCl(6)] (2) are presented here. The cluster comprises a hexauclear polyoxovanadate core of the Lindqvist structure, of which all but one of the mu-bridging oxo ligands are substituted by methoxo. As revealed by cyclic voltammetry, the cluster is highly redox active, displaying several further thermodynamically stable V(IV)/V(V) mixed-valence redox derivatives. Furthermore, valence sum calculations performed on the X-ray structural data as well as results from IR and UV-vis spectrometry characterize them as class II mixed-valence compounds. In the present article, we equally present results from cyclic voltammetry, UV-vis spectrometry, and magnetic measurements obtained for members of the previously reported [V(6)O(7)(OCH(3))(12)] cluster series, which, as opposed to 1 and its derivatives, contain exclusively methoxo ligands as mu-bridging moieties. Magnetic measurements performed on the highly reduced cluster species [V(IV)(5)V(V)(1)O(7)(OCH(3))(12)](-) and [V(IV)(6)O(7)(OCH(3))(12)](2-) reveal net antiferromagnetic exchange interactions between the d-electrons, which at lower temperatures are in part suppressed for reasons attributed to geometric spin frustration. Among the present results, the comparison of the cyclic voltammograms of 1 and [V(6)O(7)(OCH(3))(12)] has proven to be of considerable interest, showing an unexpectedly pronounced discrepancy in all but one of their corresponding redox potentials. In particular, a detailed analysis of the electrochemical conversions indicates that the observed shift is almost entirely the result of a different degree of d-electron spin-spin interactions in corresponding mixed valence species of the cluster series.

The synthesis, crystal structure, and magnetic properties of two trinuclear oxo-centered carboxylate complexes are reported and discussed: [Cr3(μ3-O)(μ2-PhCOO)6(H2O)3]NO3·4H2O·2CH3OH (1) and [Cr3(μ3-O)(μ2-PhCOO)2(μ2-OCH2CH3)2(bpy)2(NCS)3] (2). For both complexes the crystal system is monoclinic, with space group C2/c for 1 and P1/n for 2. The structure of complex 1 consists of discrete trinuclear cations, associated NO3- anions, and lattice methanol and water molecules. The structure of complex 2 is built only by neutral discrete trinuclear entities. The most important feature of 2 is the unusual skeleton of the [Cr3O] core due to the lack of peripheral bridging ligands along one side of the triangular core, which is unique among the structurally characterized (μ3-oxo)trichromium(III) complexes. Magnetic measurements were performed in the 2−300 K temperature range. For complex 1, in the high-temperature region (T > 8 K), experimental data could be satisfactorily reproduced by using an isotropic exchange ...

Methyl 2-trimethylsiloxycyclopropanecarboxylates 1, 2-aminopyridine (2), and isonitriles 3 combine in a one-pot reaction to provide a series of novel δ-amino acids 4 incorporating an imidazo[1,2-a]pyridine backbone. Scope and limitations of this new three-component synthesis were investigated. Several reactions of compounds 4 affording suitably protected derivatives such as 5, 6 and 9 were performed to allow couplings with L-alanine derivatives. The expected peptides 11 and 12 were obtained by standard coupling reactions with excellent or moderate yield. Cyanide-catalyzed reactions converted compounds 4e and 4h into tricyclic δ-lactams 10e and 10h in very good yields.

Alkali-isocyanoacetates. Synthesis and Structure of [K(18-crown-6)](O2CCH2NC) The alkali isocyanoacetates M+[O2CCH2NC]− (M = Li,Na,K,Cs) (1a-d) are synthesized by reaction of ethyl isocyanoacetate with the respective alkali hydroxides in ethanol and characterized by IR, NMR (1H, 13C), and mass spectrometry (FAB). In alcoholic solution as well as in the gas phase ion pairs and higher aggregated species are observed. In contrast, [K(18-crown-6)][O2CCH2NC] (2) which is obtained from 1c and 18-crown-6, turns out to be a 1:1 electrolyte in solution (acetone); in the solid, the isocyanoacetate anion binds to K+ via the two carboxylate oxygen atoms resulting in an O8-coordinated metal atom.

Reaction of acidified (pH ≈ 7) sodium tungstate solutions with transition metal cations (Fe3+, Ni2+, Zn2+, Co2+) leads to the formation of transition-metal-disubstituted Keggin-type heteropolytungs...

The alkoxo-polyoxovanadium clusters [V6O7(OR)12] (R = −CH3, −C2H5) are fully alkylated polyoxometalate derivatives comprising a hexavanadate core with the vanadium ions organized in an octahedral fashion, a classic isopolyoxometalate structure (Lindqvist) which as an entity is not known for vanadium. The clusters are highly redox-active compounds, displaying a large number of thermodynamically stable redox isomers of which the chemical syntheses and structural characterization of the neutral and cationic VIV/VV mixed-valence species [VIV(4-n)VV(2+n)O7(OR)12]n+[SbCl6]n (R = −CH3, n = 0, 1; R = −C2H5, n = 0, 1, 2) are presented here. Neutral and positively charged clusters remain exceptional in the field of polyoxometalate chemistry. Results obtained from cyclic voltammetry, infrared spectroscopy, and from valence sum calculations conducted on X-ray structural data classify these clusters as class II mixed-valence compounds. Their highly symmetrical molecular structures make them particularly interesting as...

The two rhenium(IV)-copper(II) heterometallic complexes [CuL β ][ReCl 4 (ox)].DMF (1) and [(CuL α ) 2 Cl][ReCl 4 (ox)]Cl (2) (Lp = N-dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene and L α = N-dl-5,7,7,12,12,14-hexamethyl-1,4,8,11 -tetraazacyclotetradeca-4,14-diene) were synthesized, and the crystal structures of both compounds were determined at 173(2) K. Complex 1 crystallizes in a monoclinic space group P2 1 , with a = 9.365(2) A, b = 15.150(2) A, c = 10.776(1) A, β = 110.01(1)°, Z = 2, whereas 2 crystallizes in an orthorhombic space group Pca2 1 with a = 16.660(5) A, b = 16.017(5) A, c = 17.066(5) A, and Z = 4. The CuLp macrocycle cation is approximately planar and coordinated from above and below by [ReCl 4 (ox)] 2 - units through the bis(bidentate) oxalato ligands. It features an oxalato-bridged heterometallic Re I V -Cu I I zigzag chain, the shortest intrachain metal-metal distances are Re...Cu = 5.568(2) and 5.870(2) A in the direction of the b axis. The crystal structure of 2 consists of dinuclear complex cations [(CuL α ) 2 Cl] 3 + with [Re-Cl 4 ox] 2 - and isolated Cl - as counter anions. Cu atoms in CuL α are only fivefold coordinated in a square pyramidal surrounding, and the cations (CuL α ) 2 + are connected in pairs by chloride. The intramolecular Cu...Cu separation is 4.885(3) A, the shortest Re...Cu distance is 7.612(3) A. The magnetic behavior of 1 and 2 has been investigated over the temperature range 1.7-300 K. Compound 1 behaves like a ferrimagnetic Cu I I -Re I V dimetallic, one-dimensional chain with intrachain antiferromagnetic coupling. Compound 2 shows weak antiferromgunetic interactions within the Cu I I -Cu I I units.

Reaction of the rhenium(IV) compound, [Bu4N]2ReCl4ox, with the highly unsaturated tetraazabismacrocyclic copper(II) complex cation [CuCuL]4+ (L = 6,13-Bis(dodecylaminomethylidene)-1,4,8,11-tetraazacyclotetradeca-4,7,11,14-tetraene) produced a new kind of heterobimetallic compound: [CuCuL][ReCl4ox]2 · 2DMF in which [ReCl4ox]2− anions and [CuCuL]4+ cations are linked by electrostatic forces. The crystal structure of this compound was determined at 173(2) K. It crystallizes triclinic, space group P 1 ¯ , with a = 9.441(4), b = 11.032(5), c = 15.261(7) A, α = 89.05(1)°, β = 88.93(1)°, γ = 77.09(1)°, Z = 1, R1 = 0.0557, wR2 = 0.1332. The magnetic behavior of this compound has been investigated over the temperature range 1.72–300 K. The compound behaves as a ferrimagnetic CuIIReIV bimetallic, chain with intrachain antiferromagnetic coupling.

The crystal structures of two 1:1 ligand-silver(I) cyanide complexes, [Ag(CN)(en)] (en = ethane-1,2-diamine) (1) and [Ag(CN)(pn)] (pn = propane-1,2-diamine) (2), and of two 2:1 ligand-silver(I) cyanide compounds, [(AgCN)2 · tn] (tn = propane-1,3-diamine) (3) and [(AgCN)2 · bn] (bn = butane-1,4-diamine) (4), were determined from single-crystal X-ray diffraction data, collected at 173 K. In 1 and 2, mononuclear AgCN complexes are formed, in which silver(I) is coordinated by one cyanide and one chelating alkanediamine donor ligand. However, in the dinuclear adducts of 3 and 4, two AgCN units are connected by one alkane-1,n-diamine bridging ligand (n = 3, 4). The resulting molecules of 1–4 are cross-linked via N–H⋯N hydrogen bonds. Apart from these intermolecular contacts, comparatively short Ag(I)–Ag(I) distances of 3.182(1) A (in 1), 3.267(1) A (in 2), 3.023(2) A (in 3) and 3.050(2) A (in 4) occur.

A series of bicyclic alkenyl nonaflates was prepared in good yields by deprotonation of the corresponding 8-oxabicyclo[3.2.1]oct-6-en-3-ones and a sulfur relative with LDA followed by trapping with nonafluorobutanesulfonyl fluoride (NfF). The resulting compounds undergo Heck couplings to methyl acrylate under standard conditions, generally providing bicyclic dienes in satisfactory yields. For nonaflates 2 and 12 a novel base-promoted fragmentation reaction to substituted furan derivatives was observed. Several Diels–Alder reactions of the bicyclic dienes were conducted leading to polycyclic compounds. Whereas the diastereofacial selectivity with respect to the oxygen or sulfur bridge of the dienes is excellent, the exo/endo selectivity strongly depends on the substitution patterns of the bicyclic diene and the dienophile. The results presented demonstrate the potential of bicyclic nonaflates to serve as versatile building blocks in diversity-orientated synthesis.

Addition of lithiated methoxyallene to pivalonitrile afforded after aqueous workup the expected iminoallene 1 in excellent yield. Treatment of this intermediate with silver nitrate accomplished the desired cyclization to the electron-rich pyrrole derivative 2 in moderate yield. Surprisingly, trifluoroacetic acid converted iminoallene 1 to a mixture of enamide 3 and trifluoromethyl-substituted pyridinol 4 (together with its tautomer 5). A plausible mechanism proposed for this intriguing transformation involves addition of trifluoroacetate to the central allene carbon atom of an allenyl iminium intermediate as crucial step. Enamide 3 is converted to pyridinol 4 by an intramolecular aldol-type process. A practical direct synthesis of trifluoromethyl-substituted pyridinols 4, 10, 11, and 12 starting from typical nitriles and methoxyallene was established. Pyridinol 10 shows an interesting crystal packing with three molecules in the elementary cell and a remarkable helical supramolecular arrangement. Trifluoromethyl-substituted pyridinol 4 was converted to the corresponding pyridyl nonaflate 13, which is an excellent precursor for palladium-catalyzed reactions leading to pyridine derivatives 14-16 in good to excellent yields. The new synthesis of trifluoromethyl-substituted pyridines disclosed here demonstrates a novel reactivity pattern of lithiated methoxyallene which is incorporated into the products as the unusual tripolar synthon B.

Die Alkan-1, n-diammonium-hexacyanotetracuprate(I) (n = 2 bis 4) [NH3(CH2)2NH3][Cu4(CN)6]·2H2O (1), [NH3(CH2)3NH3][Cu4(CN)6]·H2O (2) und [NH3(CH2)4NH3][Cu4(CN)6]·2H2O (3) sowie das Pentan-1, 5-diammonium-tetradecacyanooctacuprat(I) [NH3(CH2)5NH3]3[Cu8(CN)14]·3H2O (4) wurden hydrothermal durch Umsetzungen von Ethan-1, 2-diamin, Propan-1, 3-diamin, Butan-1, 4-diamin und Pentan-1, 5-diamin mit CuCN und NaCN in Gegenwart von Ameisensaure erhalten. In den Kristallstrukturen der Verbindungen 1 bis 3 werden anionische Schichten vernetzter (CuCN)6-Ringe unterschiedlicher Konformation durch starre, all-anti α, ω-Alkandiammoniumionen als Gegenkationen und Abstandshalter ubereinander gestapelt. Wassermolekule verbinden die Dikationen uber Wasserstoffbrucken-Bindungen zu Ketten, die Anionenschichten nadelformig durchbohren. Die leichter deformierbaren Dikationen [NH3(CH2)5NH3]2+ in 4 sind dagegen in Hohlraume eines dreidimensional vernetzten Cyanocuprat(I)-Gerustes eingelagert. Kristalldaten s. Abstract. The Structure-directing Influence of α, ω-Alkanediammonium Ions on the Formation of Cyanocuprates(I) The alkane-1, n-diammonium-hexacyanotetracuprates(I) (n = 2 - 4) [NH3(CH2)2NH3][Cu4(CN)6]·2H2O (1), [NH3(CH2)3NH3][Cu4(CN)6]·H2O (2) and [NH3(CH2)4NH3][Cu4(CN)6]·2H2O (3) and the pentane-1, 5-diammonium-tetradecacyanooctacuprate(I) [NH3(CH2)5NH3]3[Cu8(CN)14]·3H2O (4) were obtained by hydrothermal reaction of ethane-1, 2-diamine, propane-1, 3-diamine, butane-1, 4-diamine and pentane-1, 5-diamine with CuCN, NaCN and formic acid. In the crystal structures of compounds 1 - 3 anionic layers of connected (CuCN)6-rings which vary in conformation are piled up containing rigid all-anti α, ω-alkanediammonium ions as spacers. The dications and water molecules are linked to chains by hydrogen bridges, penetrating the anionic layers in a needle-like fashion. In contrast the deformable dications [NH3(CH2)5NH3]2+ in 4 are integrated in cavities of a three-dimensional cyanocuprate(I). Crystal structure data:1, monoclinic, P21/c, a = 6.982(3) A, b = 8.579(4) A, c = 13.054(6) A, β = 92.806(10)°, V = 780.9(6) A3, Z = 2, dc = 2.145 gcm-1, R1 = 0.094; 2, orthorhombic, C2221, a = 8.715(2) A, b = 14.764(3) A, c = 12.411(2) A, V = 1596.7(5) A3, Z = 4, dc = 2.098 gcm-1, R1 = 0.026; 3, orthorhombic, Pnn2, a = 7.276(2) A, b = 8.612(2) A, c = 14.731(3) A, V = 923.1(3) A3, Z = 2, dc = 1.916 gcm-1, R1 = 0.036; 4, triclinic, P1, a = 8.113(5) A, b = 11.068(5) A, c = 13.689(5) A, α = 91.270(5)°, β = 99.718(5)°, γ = 103.994(5)°, V = 1173.1(10) A3, Z = 1, dc = 1.746 gcm-1, R1 = 0.057.

The hexanuclear methoxo-oxovanadium cluster V6O7(OCH3)12 (1) is investigated by electrospray ionization in methanol solution. Collision experiments unravel the fragmentation schemes of the molecular ions 1+ and 1− as well as the H+, Na+, and Cs+ adducts of 1. In general, fragmentation of the hexanuclear cluster ions commences with sequential expulsions of two OV(OCH3)3 units to yield the corresponding V4 clusters. However, when an active proton is present in the cluster ion, e.g., in the protonated molecule [ 1 + H ]+, loss of methanol precedes degradation to V4 clusters. In addition, the experiments suggest that electrospray ionization provides as an alternative method for the generation of metal oxide cluster ions VmOn+/− (m=1–4, n=0–11).

Based on our earlier results employing lithiated methoxyallene 2 as C(3) building block and imines 3 for the synthesis of dihydropyrrole derivatives 5, we have investigated chiral imines 6, 10, and 15 as electrophilic components. Combined with lithiated alkoxyallenes, these imines provide the corresponding primary adducts and finally the dihydropyrrole derivatives 8, 12, 17, 20, and 22 in good yields and with high to excellent syn selectivities. This stereochemical outcome is interpreted as a result of alpha-chelate control. Treatment with hydrochloric acid converted syn-8 and syn-12 into bicyclic compounds 9 and 13, whereas under more mildly acidic conditions adduct syn-17 was transformed into diol syn-18. The total synthesis of the uncommon gamma-amino acid (-)-detoxinine could be achieved by starting from (S)-malic acid, which was converted into imine 15 in four steps. Lithiated benzyloxyallene added to imine 15 and efficiently furnished the crucial dihydropyrrole derivative syn-22. The hydrogenolysis of this compound did not directly provide the protected triol 29 as anticipated, but a stepwise protocol made the triol available in a fairly satisfactory manner. A second crucial step of the synthesis was the selective oxidation of 29, which could be achieved by employing platinum dioxide and oxygen. The resulting bicyclic lactone 30 was smoothly transformed into enantiopure (-)-detoxinine. Thus, a fairly short synthesis of this natural product based on a lithiated alkoxyallene could be performed, demonstrating the potential of these intermediates for syntheses of interesting functionalized heterocyclic compounds.

Durch Umsetzung von ortho-Vanadinsauremethylester [VO(OMe)3] mit Quadratsaure und Kalium- bzw. Caesiumhydroxid konnten unter Solvothermalbedingungen die Verbindungen K4[VIV12O12(OCH3)16(C4O4)6] (2) und Cs10[VIV24O24(OCH3)32(C4O4)12][VIV8O8(OCH3)16(C2O4)] (3) synthetisiert werden. Mit Tetra-n-butyl- bzw. Tetra-n-ethylammoniumfluorid erhalt man [N(nBu)4]2[VIV8O8(OCH3)16(VIVOF4)] (4) und [N(Et)4]2[VIV8O8(OCH3)16(VIVOF4)] (5). In den Verbindungen 2 und 3 sind an den Ecken eines Tetraeders bzw. Wurfels sitzende {(VO)3(OMe)4}-Gruppen entlang der Tetraeder- bzw. Wurfelkanten uber sechs bzw. zwolf Quadratatogruppen miteinander verknupft. Die achtkernigen Anionen in den Verbindungen 3, 4 und 5 kann man sich aus oligomeren, kettenformigen Fragmenten des Vanadinsauremethylesters, die sich um die Anionen C2O42— oder VOF4— zum Ring schliessen, aufgebaut denken. Kristalldaten: 2, tetragonal, P43, a = 18, 166(3)A, c = 29, 165(7)A, V = 9625(3)A3, Z = 4, dc = 1, 469 gcm—3; 3, orthorhombisch, Pbca, a = 29, 493(5)A, b = 25, 564(4)A, c = 31, 076A, V = 23430(6)A3, Z = 4, dc = 1, 892 gcm—3; 4, monoklin, P21/n, a = 9, 528(1)A, b = 23, 021(2)A, c = 19, 303(2)A, β = 92, 570(2)°, V = 4229, 8(5)A3, Z = 2, dc = 1, 391 gcm—3; 5, monoklin, P21/n, a = 16, 451(2)A, b = 8, 806(1)A, c = 23, 812(1)A, β = 102, 423(2)°, V = 3368, 7(6)A3, Z = 2, dc = 1, 534 gcm—3. >From Small Fragments to New Poly-alkoxo-oxo-metalate Derivatives: Syntheses and Crystal Structures of K4[VIV12O12(OCH3)16(C4O4)6], Cs10[VIV24O24(OCH3)32(C4O4)12][VIV8O8(OCH3)16(C2O4)], and M2[VIV8O8(OCH3)16(VIVOF4)] (M = [N(nBu)4] or [NEt4]) By solvothermal reaction of ortho-vanadicacid ester [VO(OMe)3] with squaric acid and potassium or caesium hydroxide the compounds K4[VIV12O12(OCH3)16(C4O4)6] (2) and Cs10[VIV24O24(OCH3)32(C4O4)12][VIV8O8(OCH3)16(C2O4)] (3) could be syntesized. With tetra-n-butyl- or tetra-n-ethylammonium fluoride [N(nBu)4]2[VIV8O8(OCH3)16(VIVOF4)] (4) and [N(Et)4]2[VIV8O8(OCH3)16(VIVOF4)] (5) could be isolated. In 2 and 3 the corners of a tetrahedron or cube resp. are occupied by {(VO)3(OMe)4} groups and connected along the edges of the tetrahedron resp. cube by six or twelve resp. squarato-groups. The octanuclear anions in the compounds 3, 4, and 5 are assumedly built up by fragments of the ortho-vanadicacid ester [VO(OMe)3]. Around the anions C2O42— or VOF4— these oligormeric chains are closed to a ring . Crystal data: 2, tetragonal, P43, a = 18.166(3)A, c = 29.165(7)A, V = 9625(3)A3, Z = 4, dc = 1.469 gcm—3; 3, orthorhombic, Pbca, a = 29.493(5)A, b = 25.564(4)A, c = 31.076A, V = 23430(6)A3, Z = 4, dc = 1.892 gcm—3; 4, monoclinic, P21/n, a = 9.528(1)A, b = 23.021(2)A, c = 19.303(2)A, β = 92.570(2)°, V = 4229.8(5)A3, Z = 2, dc = 1.391 gcm—3; 5, monoclinic, P21/n, a = 16.451(2)A, b = 8.806(1)A, c = 23.812(1)A, β = 102.423(2)°, V = 3368.7(6)A3, Z = 2, dc = 1.534 gcm—3.

Die Verbindungen A8[Ta6O19] · n H2O (A = Rb, Cs; n = 0, 4, 14) enthalten das Isopolyanion [Ta6O19]8–, das aus sechs zu einem grosen Oktaeder kantenverknupften [TaO6]-Oktaedern besteht. Sie gehen – wie u. a. die thermoanalytischen Untersuchungen (TG/DSC) zeigen – durch reversible Hydratations/Dehydratationsprozesse ineinander uber und zeigen auch strukturell enge Bezuge. Cs8[Ta6O19] (tetragonal, I4/m, a = 985.9(1) pm, c = 1403.3(1) pm, Z = 2), die isotypen Phasen A8[Ta6O19] · 14 H2O (A = Rb/Cs; monoklin, P21/n, a = 1031.30(6)/1055.4(1) pm, b = 1590.72(9)/1614.9(6) pm, c = 1150.43(6)/1171.4(1) pm, β = 100.060(1)/ 99.97(2)°, Z = 2) und Rb8[Ta6O19] · 4 H2O (monoklin, C2/c, a = 1216.9(4) pm, b = 1459.2(5) pm, c = 1414.7(4) pm, β = 90.734(6)°, Z = 4) wurden auf der Basis von Einkristalldaten strukturell charakterisiert. Die RAMAN-Spektren erlauben daruberhinaus einen detallierten Vergleich der Hexatantalat-Ionen in den vier Verbindungen. Rubidium und Caesium Compounds with the Isopolyanion [Ta6O19]8– – Synthesis, Crystal Structures, Thermogravimetric and Vibrational Spectrocopic Analysis of the Oxotantalates A8[Ta6O19] · n H2O (A = Rb, Cs; n = 0, 4, 14) The compounds A8[Ta6O19] · n H2O (A = Rb, Cs; n = 0, 4, 14) contain the isopoly anion [Ta6O19]8–, which consists of six [TaO6] octahedra connected via corners to form a large octahedron. They transform into each other by reversible hydratation/dehydratation processes, as shown from thermoanalytic measurements (TG/DSC), and show also structural similarities. Cs8[Ta6O19] (tetragonal, I4/m, a = 985.9(1) pm, c = 1403.3(1) pm, Z = 2), the isotypic phases A8[Ta6O19] · 14 H2O (A = Rb/Cs; monoclinic, P21/n, a = 1031.30(6)/1055.4(1) pm, b = 1590.72(9)/1614.9(6) pm, c = 1150.43(6)/1171.4(1) pm, β = 100.060(1)/99.97(2)°, Z = 2) and Rb8[Ta6O19] · 4 H2O (monoclinic, C2/c, a = 1216.9(4) pm, b = 1459.2(5) pm, c = 1414.7(4) pm, β = 90.734(6)°, Z = 4) have been characterised on the basis of single crystal x-ray data. Furthermore the RAMAN spectra allow a detailled comparison of the hexatantalate ions in the four compounds.

In this paper, the syntheses of a variety of substituted phenyl pyrenes 5a−n by Suzuki cross-coupling and of two decoupled analogues 10 and 17 are reported. These compounds have been investigated by fluorescence spectroscopy. The solvatochromism of their emission bands (Stokes shift) and the quantum yields in methylcyclohexane and acetonitrile have been determined. Furthermore, the crystal structure of a pyrenyl-tris(2,2′-bipyridine)ruthenium(II) complex 19 is presented.

The new compounds [NBu4][Cu(CN)X] (X = Br (1), I (2)) and [NBu4][Cu3(CN)4]·CH3CN (3) have been prepared by reaction of [NBu4]X with CuCN in acetone (1, 2) or acetonitrile (3), and have been characterized by X-ray crystallography and vibrational spectroscopy. Compounds 1 (C34H72Br2Cu2N4, a = 17.4956(11) A, b = 12.1741(8) A, c = 19.2434(12) A, orthorhombic, Pna21, Z = 4) and 2 (C34H72Cu2I2N4, a = 21.683(2) A, b = 12.233(2) A, c = 17.632(3) A, β = 111.710(10)°, monoclinic, P21/c, Z = 4) contain infinite one-dimensional (zigzag) −CuI−CN−CuI−CN− chains which run parallel to the crystallographic a (X = Br) or c (X = I) axis. Each CuI center within these chains is additionally bound to an X = Br or I atom, and the whole network is planar, with successive planar units stacked in the b direction. Bands in the IR and Raman spectra are assigned to ν(CN), ν(CuC/N), δ(CuCN), and δ(NCuC) modes of the CuCN chains. The IR spectra of the products of the reversible reaction of CuCN with aqueous KX (X = Br, I) show ν(CN) an...

The synthesis of four solid solutions (NH4)10–xKx[H2W12O42] · n H2O (x/n: 6.9/9.7, 5.9/9.5, 3.3/8.5, and 2.6/9.0) with the structure of triclinic K10[H2W12O42] · 10 H2O (I) and two solid solutions (x/n: 3.1/4.0, and 2.6/4.0) with the structure of monoclinic (NH4)10[H2W12O42] · 4 H2O (II), was accomplished by a new method from ammoniacal monotungstate solution by adding the appropriate amount of potassium hydroxide and the release of ammonia during evaporative crystallization. The preparation of corresponding single crystals was achieved by slow evaporation of saturated solutions of the corresponding polycrystalline samples according to the method of isothermal evaporation. The study of coordination and space filling behavior of the potassium and ammonium cations, crystal water molecules, and the paratungstate ‘Z' anion revealed that the predominance of the triclinic structure (2.6 ≤ x ≤ 10.0) in the system is effected by the bulkiness of NH4+. The transition area (2.6 ≤ x ≤ 3.1; 4 ≤ n ≤ 8.5) with coexisting triclinic and monoclinic mixed crystals represents the miscibility gap, typical for a heterotypic substitutional solid solution. The ‘resistance' of three specific K+ positions, to be substituted by NH4+, is caused by peculiarities of bond lengths, coordination numbers, and character of coordinated neighbors. Heterotype Substitutionsmischkristallbildung von (NH4)10–xKx[H2W12O42] · n H2O im System Ammoniumparawolframat ,Z‘/Kaliumparawolframat ,Z‘ Mittels neuer Methode wurden vier Mischkristallverbindungen (NH4)10–xKx[H2W12O42] · n H2O (x/n: 6,9/9,7; 5,9/9,5; 3,3/8,5 und 2,6/9,0) mit der Struktur von triklinem K10[H2W12O42] · 10 H2O (I) und zwei (x/n: 3,1/4,0 und 2,6/4,0) mit der Struktur von monoklinem (NH4)10[H2W12O42] · 4 H2O (II) synthetisiert. Die Praparation der Einkristalle gleicher Zusammensetzung gelang aus gesattigten wasrigen Losungen der polykristallinen Proben mit der Methode der isothermalen Verdampfung. Da die Muttersubstanzen I und II in unterschiedlichen Strukturen kristallisieren (P 1 bzw. P21/n), ist die zu beobachtende vollstandige Mischbarkeit als heterotype Substitutionsmischkristallbildung mit der Mischungslucke (2,6 ≤ x ≤ 3,1; 4 ≤ n ≤ 8,5) zu beschreiben. Die monokline ist gegenuber der triklinen Struktur benachteiligt, da NH4+ infolge Wasserstoffbruckenbindung mehr Raum als K+ beansprucht.

We have studied the preparation and isolation of the halogenated alkylidene oxonium salts CH(3)OCHX(+)MF(6)(-) (X = Cl, F; M = As, Sb). Addition of dichloromethylmethylether at -78 degrees C to the superacidic media HF/MF(5) resulted in the formation of the chlorine compounds CH(3)OCHCl(+)MF(6)(-), whereas at -65 degrees C the fluorinated salts CH(3)OCHF(+)MF(6)(-) are formed by a chlorine/fluorine exchange. The salts are characterized by their low-temperature IR and Raman spectra. Additionally, the crystal structures of the hexafluoroantimonates are presented. The structures of the cations turned out to be different in some points. The salt CH(3)OCHF(+)SbF(6)(-) crystallizes in the monoclinic space group P2(1)/c with 4 molecules in the unit cell and a = 9.942(2), b = 7.454(2), and c = 10.297(3) Å; beta = 111.27(2) degrees. The salt CH(3)OCHCl(+)SbF(6)(-) crystallizes in the monoclinic space group P2(1)/c with 4 formula in the unit cell and a = 5.970(3), b = 12.019(5), and c = 10.994(5) Å; beta = 92.59(3) degrees.

The largest isopolyoxotunstate ion known to date, W24 O8424- (structure shown in the picture), isolated as the cesium salt, and a chainlike polyoxotungstate ion made up of planar W4 O16 units, isolated as the sodium salt, hide behind the simple empirical formulas of the title compounds.

Protonated hydrogen peroxide is produced from the reaction of antimony pentafluoride with bis(trimethylsilyl)peroxide in the presence of hydrogen fluoride. Depending on the stoichiometry of the reaction mixture, the compounds H3 O2 SbF6 and H5 O4 SbF6 are formed, which are stable up to room temperature and have been characterized by X-ray crystallography. The structure of the H3 O2+ ion is shown on the right.

The heterobimetallic iron(II)–chromium(>0>) complexes [(OC)2CpFe(µ-η1∶η7-C7H6)Cr(CO)3]+ and [(OC)2CpFe(µ-η1∶η7-C2C7H6)Cr(CO)3]+ containing the bridging carbene ligand cycloheptatrienylidene C7H6 and the cumulogous allenylidene ligand (cycloheptatrienylidene)ethenylidene C2C7H6 have been prepared and their properties studied. The former has been prepared by hydride abstraction from the heterobimetallic µ-η1∶η6-cyclohepta-1,3,5-trien-2-yl complex obtained by lithiation of 2-trimethylstannyl-cyclohepta-1,3,5-triene followed by reaction with [FeCp(CO)2Br] and [Cr(CO)3(NCEt)3]. Treatment of 7-ethynyl-cyclohepta-1,3,5-triene with LiBun and consecutive reaction with [FeCp(CO)2Br] and [Cr(CO)3(NCEt)3] led to the formation of endo-[(OC)2CpFe(µ-η1∶η6-CC–C7H7)Cr(CO)3] which was treated with [Ph3C][BF4] to give [(OC)2CpFe(µ-η1∶η7-C2C7H6)Cr(CO)3][BF4]. The crystal structures of [(OC)2CpFe(µ-η1∶η6-C7H7)Cr(CO)3], [(OC)2CpFe(µ-η1∶η7-C7H6)Cr(CO)3][PF6]·0.25CH2Cl2 and [(OC)2CpFe(µ-η1∶η7-C2C7H6)Cr(CO)3]+[BF4]·CH2Cl2 have been determined.

C15H17BrO5, monoclinic, P121/n1 (no. 14), a = 11.295(2) Å, b = 23.628(5) Å, c = 16.610(3) Å, β = 92.145(5)°, V = 4429.7 Å3, Z = 12, Rgt(F) = 0.038, wRref(F2) = 0.105, T = 173 K.

C28H49NO5Si2, monoclinic, P1211 (no. 4), a = 14.325(3) Å, b = 11.850(2) Å, c = 19.459(4) Å, β = 102.978(5)°, V = 3218.8 Å3, Z = 4, Rgt(F) = 0.046, wRref(F2) = 0.103, T = 173 K.

The reaction of CuI or Lil with Cdl2 in the polar solvent acetonitrile results in the formation of the iodocadmates [Cu(CH3CN)4]4[Cd6I16] · 1.5CH3CN (1) and [Li(CH3CN)4]4[Cd6I16] · 1.5CH3CN (2) with the oligomeric anion [Cd6I16]4-. This new type of halometallate anion, which is found in both isotypic structures, is built up by six alternating corner and edge sharing Cdl4 tetrahedra. 1: Space group P1̄ (No 2), a = 838.5(4), b = 1465.9(9), c = 1929.8(6) pm, α = 93.01(3), β = 99.13(3), γ = 105.11(3)°; 1: Space group P1̄(No 2), a = 841.7(8), b = 1470(9), c = 1945.5(9) pm, α = 93.27(5), β = 99.13(5), γ = 104.83(5)°.

Durch basischen Aufschlus von Ta2O5 mit p. a. KOH erhalt man durchsichtige Einkristalle der Zusammensetzung K8Ta6O19 · 16H2O. Der Einsatz von technischer KOH dagegen fuhrt beim gleichem Synthese-Verfahren zu Einkristallen der Zusammensetzung K7NaTa6O19 · 14H2O, einer Verbindung, die in der Literatur als K8Ta6O19 · 14H2O beschrieben ist. Das Isopolyanion [Ta6O19]8− besteht in beiden Fallen aus sechs kantenverknupften (TaO6)-Oktaedern in der Anordnung eines grosen Oktaeders. Es konnte somit die von Lindqvist et al. angegebene Schweratom-Teilstruktur bestatigt werden. Zusatzlich wurden die kompletten Kristallstrukturen einschlieslich der Positionen der Sauerstoffatome des Isopolyanions sowie der Kationen und Kristallwasser Molekule (ohne Wasserstoffatome) ermittelt. The Crystal Structures of K8Ta6O19 · 16H2O and K7NaTa6O19 · 14H2O By alkaline digestion of Ta2O5 with p.a. KOH transparent single crystals of the composition K8Ta6O19 · 16H2O are formed. When technical grade KOH is used, the same kind of synthesis yields crystals of the composition K7NaTa6O19 · 14H2O. The latter compound has been given the formula K8Ta6O19 · 14H2O until now. In both cases the isopolyoxoanion [Ta6O19]8 consists of six TaO6-octahedra connected by edge sharing. This means that the heavy atom partial structure found by Lindquist et al. is confirmed. Additionally the complete structures including the atomic positions of the oxygen atoms of the polyanions as well as those of the cations and crystal water molecules (without hydrogen positions) are determined.

Umsetzungen von CuSCN und AgSCN mit Tetraethylammoniumiodid in Aceton fuhren zu neuartigen, Iodo-thiocyanato-cupraten(I) bzw. -argentaten(I) mit polymeren Anionengittern, in deren Hohlraumen Kationen und Losungsmittelmolekule Platz finden. [(C2H5)4N+]2[Cu 4I4(SCN)4/22−] · 2(CH3)2CO 1 kristallisiert in der monoklinen Raumgruppe P21; a = 1205,7(1), b = 2489,1(3), c = 1238,0(1) pm; β = 93,04(1)°; V = 3710,1(8) 106 pm3; Z = 2. Die Kristallstruktur ist aus zwei unterschiedlichen, zweifach negativ geladenen Heterocuban-Einheiten [Cu4I4(SCN)4/22−] aufgebaut. Diese sind uber 1,3-μ-Thiocyanat-Liganden dreidimensional vernetzt. Zwischen den eckenverknupften Heterocuban-Einheiten verlaufen schlauchformige Kanale, in denen sich die Kationen und Losungsmittelmolekule (Aceton) befinden. [(C2H5)4N+]2[Ag 4I4(SCN)4/22−] · (CH3)2CO 2 kristallisiert in der orthorhombischen Raumgruppe C2221 mit den Zellparametern a = 1206,7(1), b = 1398,2(1), c = 2318,8(2) pm; V = 3912,4(7)· 106 pm3; Z = 8. In dieser Verbindung bilden 1,3-μ-SCN-verbruckte Heterocuban-Gruppen [Ag4I4(SCN)4/22−] polymere Schichten mit senkrecht dazu angeordneten, kanalformigen Hohlraumen, in denen Kationen und Losungsmittelmolekule (Aceton) Platz finden. Synthesis and Structure Investigations on Iodocuprates(I). XVII. Crystal Structures of Polymeric Iodo-thiocyanato Metallates(I) with Heterocubane-like Structure Units: [(C2H5)4N+]2[Cu4I4(SCN)4/22−] · 2(CH3)2CO and [(C2H5)4N+]2[Ag 4I4(SCN)4/22−] · (CH3)2CO The reaction of CuSCN and AgSCN with (C2H5)4NI in acetone results in the formation of new Iodothiocyanato cuprates(I) or argentates(I) with polymeric anion lattices and areas of holes in which the cations and solvent molecules are inserted. [(C2H5)4N+]2[Cu 4I4(SCN)4/22−] · 2(CH3)2CO 1 crystallizes in the monoclinic space group P21 with a = 1205.7(1), b = 2489.1(3), c = 1238.0(1) pm; β = 93.04(1)°; V = 3710.1(8) 106 pm3; Z = 2. Two different, negatively charged heterocubane units [Cu4I4(SCN)4/22−] are three-dimensionally connected by 1,3-μ-thiocyanato ligands forming a crystal structure with hose-shaped channels where cations and acetone molecules are placed. [(C2H5)4N+]2[Ag 4I4(SCN)4/22−] · (CH3)2CO 2 crystallizes in the orthorhombic space group C2221 with a = 1206.7(1), b = 1398.2(1), c = 2318.8(2) pm; V = 3912.4(7) · 106 pm3; Z = 8. In this compound 1,3-μ-thiocyanato-bridged heterocubane units [Ag4I4(SCN)4/22−] form a layer structure with channel-shaped cavities vertical to them. Within these hollows there is again place for the cations and acetone molecules.

Es wird uber die Darstellung von HC(OH)2+MF6− (M = As, Sb) durch Protonierung von Ameisensaure in den supersauren Systemen HF/MF5 berichtet. Die hydrolyseempfindlichen und thermolabilen Dihydroxycarbeniumsalze werden schwingungs- und NMR-spektroskopisch charakterisiert. Sie sind unter inerten Bedingungen bei −40°C wochenlang haltbar. HC(OH)2+AsF6− kristallisiert in der orthorhombischen Raumgruppe Pbca (Nr. 61) mit den Gitterkonstanten a = 965,8(1), b = 1582,20(16) und c = 766,40(8) pm mit acht Formeleinheiten in der Elementarzelle. Dihydroxycarbeniumhexafluorometallates – Synthesis, Spectroscopic Characterization, and Crystal Structure of HC(OH)2+AsF6− The preparation of HC(OH)2+ MF6− (M = As, Sb) by protonation of HCOOH in the superacid systems HF/MF5 is reported. The very hydrolysable and thermolabile salts are characterized by vibrational and NMR spectroscopic methods. Under inert conditions they are stable at −40°C for some weeks. HC(OH)2+AsF6− crystallizes in the orthorhombic space group Pbca (No. 61) with a = 965.8(1), b = 1582.20(16), c = 766.40(8) pm with eight formula units per unit cell.

Der dreizahnige Ligand 2-(2-Hydroxy-5-methylphenyl)-6-(2-hydroxyphenyl)pyridin 4a wurde synthetisiert und rontgenographisch charakterisiert. Die Verbindung bildet mit Kupfer(II) einen Komplex der Zusammensetzung Cu2L2. Aus Pyridin kristallisiert 2-(2-Hydroxy-5-methylphenyl)-6-(2-hydroxyphenyl)pyridinato(2−)-dipyridin-kupfer(II) 4c mit der Koordinationszahl 5 aus. Kristallstrukturanalyse von 4a: Raumgruppe An, Z = 8, 1994 beobachtete unabhangige Reflexe, R = 0,069, Gitterabmessungen bei 295 K: a = 960,6(2) pm, b = 1678,5(3) pm, c = 1824,5(3) pm, β = 100,89(3)° Kristallstrukturanalyse von 4c: Raumgruppe P21/c, Z = 4, 847 beobachtete unabhangige Reflexe, R = 0,064, Gitterabmessungen bei 295 K: a = 901,8(1) pm, b = 1781,2(3) pm, c = 1494,2(3) pm, β = 104,83(2)° Synthesis and Structure of the Copper Complex 2-(2-Hydroxy-5-methylphenyl)-6-(2-hydroxyphenyl)pyridinato(2−)dipyridin-copper(II) and of the free Ligand The tridentate diacidic ligand 2-(2-hydroxy-5-methyl)-6-phenyl-6-(2-hydroxyphenyl)pyridine 4a was synthesized and characterized by X-ray structural analysis. The compound forms a copper complex, 2-(2-Hydroxy-5-methyl-phenyl)-6-(2-hydroxyphenyl)pyridinato(2−)-dipyridine copper(II), which was crystallized from pyridine solution. The coordination number of the central atom copper ist five.

The syntheses and crystal structures of the following paratungstates-Z with different alkaline cations are reported and discussed: Na10[H2W12O42] · 20H2O (I), Na10[H2W12O42] · 27H2O (II), Na10[H2W12O47] · 28H2O (III), K10[H2W12O42] · 10H2O (IV), K6Na4[H2W12O42] · 13H2O (V), Cs6Na4[H2W12O42] · 16H2O (VI), Cs8Na2[H2W12O42] · 10H2O (VII), Cs8Na2[H2W12O42] · 12H2O (VIII), K3Na7[H2W12O42] · 24H2O (IX) and K5Na2[H2W12O42] · 12H2O (X). Priority has been set on the description of the coordination of the cations with the oxygen ligands H2W12O42 10- and H2O.

Synthesis and Crystal Structure of [N(Hex)4][Cu2(CN)3] [N(Hex)4][Cu2(CN)3] has been prepared by solvothermal reaction of CuCN with Tetra-n-hexylammoniumiodide in acetone. The crystal structure is built up by condensed (CuCN)6 and (CuCN)7 rings, forming a zeolith type cyanocuprate(I) framework [Cu2(CN)3—]. Space group R3; α = 44.482(6), c = 21.283(4) A, V = 36471(9) A3; Z = 9.

Solid 1,2-Se2S5 polymerizes endothermically at 47°C to give a linear polymer which after stretching and extraction consists of helical molecules similar to those of polymeric sulfur. Heating of the polymer results in slow exothermic depolymerization at 84°C to give a mixture of seven cyclic SenS8–n molecules which melts at 111°C. When the polymeric Se2S5 is refluxed with CS2 the initial depolymerization Products are 1,2-Se2S5, SeS5 and 1,2,3-Se3S5 but in addition SeS7 and 1,2-Se2S6 are formed. These results indicate the atomic sequence –SeS5Se– in the polymer. The powder x-ray diffraction pattern and Raman spectrum of the polymer as well as its lattice parameters are reported and the Probable mechanism of its depolymerization is discussed. Schwefelverbindungen. 164. Thermische Polymerisation des cyclischen Selensulfids 1,2-Se2S5 – eine Untersuchung mittels DSC, HPLC, Ramanspektroskopie und Rontgenbeugung Kristallines 1,2-Se2S5 polymerisiert bei 47°C endotherm zu einem kettenformigen Polymer, das nach Streckung und Extraktion aus helicalen Molekulen ahnlich denen im polymeren Schwefel besteht. Beim Erhitzen zersetzt sich das Polymer bei 84°C exotherm zu einer Mischung aus sieben cyclischen SenS8–n-Molekulen; diese Mischung schmilzt bei 111°C. Wenn das polymere Se2S5 mit CS2 gekocht wird, enstehen primar 1,2-Se2S5, SeS5 und 1,2,3-Se3S5, aber zusatzlich werden SeS7 und 1,2-Se2S6 beobachtet. Diese Ergebnisse sprechen fur die Atomfolge –SeS5Se– in dem Polymer, dessen Pulverdiagramm, Gitterkonstanten und Ramanspektrum mitgeteilt werden.