Reactions of Nitro and Halonitro Derivatives of Aluminum(III) and Copper(II) Phthalocyanines with Concentrated Sulfuric Acid

Transformations of the complexes CuPc(4-NO₂)₄, CuPc(4-Br)₄(5-NO₂)₄, (OH)AlRs(4-NO₂)₄, and (OH)AlPc(4-Cl)₄(5-NO₂)₄ in concentrated sulfuric acid were studied by spectrophotometry. One protonated form of CuPc(4-Br)₄(5-NO₂)₄ and (OH)AlPc(4-NO₂)₄ and two protonated forms of CuPc(4-NO₂)₄ and (OH)AlPc(4-Cl)₄(5-NO₂)₄ were detected experimentally and also by ZINDO1 calculations. Step protonation constants of CuPc(4-NO₂)₄ and (OH)AlPc(4-Cl)₄(5-NO₂)₄ were determined by quantum-chemical calculations and acid-base titration; these complexes can be regarded as weak bases with respect to H₂SO₄. The kinetics of dissociation of the complexes at the MÄN bonds were studied. The rate of dissociation of the Cu(II) complexes and (OH)AlPc(4-NO₂)₄ is proportional to [MPc(R) _n ] and [H₃O⁺]². The rate of dissociation of (OH)AlPc(4-Cl)₄(5-NO₂)₄ showed a weak extremal dependence on the composition of the medium, which was explained by change of its structure in 17.0 M H₂SO₄. The electronic effect of substituents on the reaction center was considered with account taken of a complex mechanism of activation and fine details of the molecular structure of macrocyclic complexes.     

Darstellung und Eigenschaften von Kupfer(II)-Hypophosphit

Thermal Behaviour of the Mixtures Na₂S? P₄S₁₀ and Na₄Ge₄S₁₀? P₄S₁₀ of the System Na₂S? GeS₂? P₄S₁₀ The mixtures of Na₂S? P₄S₁₀ and Na₄Ge₄S₁₀? P₄S₁₀ were investigated by DTA and DSC. In the system Na₂S? P₄S₁₀ the congruently melting compounds Na₃PS₄ and (NaPS₃)_x and the peritectic phase Na₄P₂S₇ were found. The IR-spectra are given. Glassy, anhydrous and hydrated Na₄Ge₄S_l0 were prepared and thermochemically characterized. The section Na₄Ge₄S₁₀? P₄S₁₀ is not quasibinary, the mixed cage-anion Ge_4?xP_xS₁₀^(4?x)? thus cannot be prepared by heating and annealing mixtures of Na₄Ge₄S₁₀ and P₄S₁₀.     

A gas electron diffraction study of the molecular structures of methyl allenyl sulphide and methyl vinyl sulphide and their relation to other organic s

The vibrational and electronic spectra as well as the magnetic properties of the ion [Co(NH₃)₄]²⁺are given and discussed. [Co(NH₃)₄](ReO₄)₂ crystallizes cubically and is isostructural with the compounds [Zn(NH₃)₄](ReO₄)₂, [Zn(NH₃)₄](MnO₄)₂, [Cd(NH₃)₄](ReO₄)₂, [Cd(NH₃)₄](MnO₄)₂, [Zn(NH₃)₄]- (OsO₃N)₂ and [Cd(NH₃)₄](OsO₃N)₂.     

Thermal decomposition of some ruthenium carbonyl hydrides

The thermal stability of α-H₄Ru₄(CO)₁₂, H₄Ru₄(CO)₁₀P₂, H₄Ru₄(CO)₉P₃, H₄Ru₄(CO)₈P₄ (where P=triphenylphosphine) has been investigated by differential scanning calorimetry and by thermogravimetric analysis under argon dynamic atmosphere.The TG curves of the triphenylphosphine substituted derivatives of α-H₄Ru₄(CO)₁₂ suggest the release of the carbonyl and of the phenyl groups through a not well-defined pattern and overlapping decomposition reactions up to the retention of phosphorus in the residue, while α-H₄Ru₄(CO)₁₂ decomposes to metallic ruthenium. The decomposition heat of α-H₄Ru₄(CO)₁₂ and the isomerization heat of H₄Ru₄(CO)₈P₄ have been evaluated.     

Stepwise and Self‐Assembly Synthesis of Tetranuclear Iron–Thiolate–Diisocyanide Metallocyclophane Complexes

Treatment of known complex [Cp₂Fe₂ (μ‐SEt )₂(CH₃CN )₂](BF₄ )₂ ( 1 (BF₄ )₂) with 2 equiv of 1,4‐bis(isocyanomethyl)benzene (1,4‐CNCH₂C₆H₄CH₂NC ; L1 ) or 4,4′‐diisocyanophenyl ether (4,4′‐CNC₆H₄OC₆H₄NC ; L2 ) result in the formation of two new‐type diisocyanide complexes [Cp₂Fe₂ (μ‐SEt )₂(1,4‐CNCH₂C₆H₄CH₂NC )₂](BF₄ )₂ ( 2a (BF₄ )₂) or [Cp₂Fe₂ (μ‐SEt )₂(4,4′‐CNC₆H₄OC₆H₄NC )₂](BF₄ )₂ ( 2b (BF₄ )₂), respectively. The new‐type 24‐membered ring tetranuclear iron–thiolate–aryldiisocyanide metallocyclophane complex [Cp₄Fe₄ (μ‐SEt )₄(μ‐1,4‐CNCH₂C₆H₄CH₂NC )₂](BF₄ )₄ ( 3a (BF₄ )₄) has been synthesized by using a self‐assembly reaction between equimolar amounts of 1 (BF₄ )₂ and 1,4‐bis(isocyanomethyl)benzene or by a stepwise route involving mixing a 1:1 molar ratio of complexes 1 (BF₄ )₂ and 2a (BF₄ )₂. A similar approach was used through the application of equal molar ratio of complexes 1 (BF₄ )₂ and 2b (BF₄ )₂ to give a 30‐membered ring tetranuclear iron–thiolate–aryldiisocyanide metallocyclophane complex [Cp₄Fe₄ (μ‐SEt )₄(4,4′‐CNC₆H₄OC₆H₄NC )₂][BF₄ ]₄ ( 3b (BF₄ )₄). The spectroscopic and electrochemical properties of four iron–sulfur core complexes were determined.     

DSC investigation of the thermal behaviour of (NH4)2SO4, NH4HSO4 and NH4NH2SO3

Gaseous products evolved from (NH₄)₂SO₄, NH₄HSO₄ and NH₄NH₂SO₃ during successive heating and cooling cycles were flushed with inert gas into analyzer Dräger tubes hooked tightly to the terminal port of the DSC cell base. This simple procedure allowed the starting temperature of the decomposition to be determined and the amount of the individual gases in the mixture to be identified and even estimated. NH₄NH₂SO₃ at 523 K in humid air produced HNH₂SO₃ initially and, on further cycling, (NH₄)₂SO₄ and NH₄HSO₄ also appeared. The ΔH_f values for NH₄HSO₄ were (kJ mole^?1): in an airtight sample holder 12.67, in a dry argon atmosphere 11.93, and in a static air atmosphere 10.92. Endothermic peaks for (NH₄)₂SO₄ and 498 and 411 K represented the incongruent melting point and the polymorphic transition of (NH₄)₂SO₄·NH₄HSO₄. After the first heating in air to 530 K, (NH₄)₂SO₄ and NH₄HSO₄ exhibited closely similar cyclic DSC curves. The endothermic peaks at about 393–420 K may be assigned to different combinations of (NH₄)₂SO₄ and NH₄HSO₄.     

On precipitation effects of aluminum,lanthanum, iron (III), and thorium phosphates

Summary Typical precipitation curves of various metal phosphates have been obtained using the turbidimetric technique. The following systems have been investigated: Al(NO₃)₃-K₃PO₄, Al(NO₃)₃-KH₂PO₄, Al(NO₃)₃NaH₂PO₄, FeCl₃-K₃PO₄, FeCl₃-(NH₄)₂HPO₄, FeCl₃K₂HPO₄, FeCl₃-KH₂PO₄, FeCl₃-NaH₂PO₄, La(NO₃)₃K₃PO₄,La(NO₃)₃-K₂HPO₄,La(NO₃)₃-KH₂PO₄,La(NO₃)₃NaH₂PO₄ and Th(NO₃)₄-K₂HPO₄. Typical precipitation curves indicated concentration ranges of phosphate precipitation and of complex solubility.

---

Zusammenfassung Typische F?llungskurven verschiedener Metallphosphate, die mittels Trübungsmessungen erhalten wurden, wurden graphisch dargestellt. Die folgenden Systeme wurden untersucht: Al(NO₃)₃-K₃PO₄,Al(NO₃)₃KH₂PO₄, Al(NO₃)₃-NaH₂PO₄, FeCl₃-K₃PO₄, FeCl₃(NH₄)₂HPO₄, FeCl₃-K₂HPO₄, FeCl₃-KH₂PO₄, FeCl₃NaH₂PO₄, La(NO₃)₃-K₃PO₄, La(NO₃)₃-K₂HPO₄, La(NO₃)₃-KH₂PO₄, La(NO₃)₃-NaH₂PO₄ und Th(NO₃)₄K₂HPO₄. Typische F?llungskurven zeigten Konzentrationsgebiete, in welchen die Metallphosphate gef?llt werden, sowie Konzentrationen, die zur Komplexbildung führten.

---

---

Supported in part by the U.S. Army Research Office, Contract No. DA-ORD-10.     

Tetrapnictidotitanate(IV) M4TiX4 (M = Sr,Ba; X = P,As), hierarchische Derivate der KGe-Struktur K4□Ge4

Tetrapnictidotitanates(IV) M₄TiX₄ (M = Sr, Ba; X = P, As), hierarchical Derivatives of the KGe Structure K₄□Ge₄ The four new tetrapnictidotitanates(IV) Sr₄TiP₄, Sr₄TiAs₄, Ba₄TiP₄ and Ba₄TiAs₄ are synthesized from the binary pnictides MX (M = Sr, Ba and X = P, As) and elementary titanium in tantalum ampoules. The compounds are isotypic and isoelectronic with Ba₄SiAs₄ (space group P4 3n (no. 218); cP72; Z = 8; Sr₄TiP₄: a = 1259.0(1) pm; Sr₄TiAs₄: a = 1288.3(4) pm; Ba₄TiP₄: a = 1316.6(2) pm; Ba₄TiAs₄: a = 1346.9(2) pm). The transition metal compounds form cubic, metallic reflecting crystals (Sr₄TiP₄ (green); Sr₄TiAs₄ (silver coloured); Ba₄TiP₄ (silver coloured); Ba₄TiAs₄ (violet). They are semiconducting and very sensitive against air and moisture. The structure is a hierarchical derivative of Cr₃Si (A15) and KGe type: Cr₆Si₂ ? (□Ge₄K₄)₆(□Ge₄K₄)₂ ? (TiX₄M₄)₆(TiX₄M₄)₂, where Ti occupies the positions of the Cr₃Si structure, and the alkaline-earth metal and pnicogen atoms occupy the positions of the KGe structure. Therefore, Ti is surrounded by four X and four more distant M atoms forming a heterocubane. The mean bond lengths are: d (Ti? P) = 238.0(5) pm; 307 ? d(Sr? P) ? 333 pm; d (Ti? As) = 245.9(4); 313 ? d(Sr? As) ? 341 pm; d (Ti? P) = 240.5(5); 324 ? d(Ba? P) ? 348 pm; d (Ti? As) = 248.3(3) pm; 331 ? d(Ba? As) ? 355 pm.     

Oxo-fluoro-aluminates and -gallates

The preparations of (NH₄)₂HAl₂OF₇, (NH₄)H₂AlOF₄, (NH₄)₂HGa₂OF_7^·3.5H₂O and (NH₄)₂HGaOF₄ are described. IR spectra suggest the presence of MOMO chains in these compounds. On isothermal heating at 180°C (NH₄)H₂AlOF₄ decomposes to give (NH₄)HAlOF₃, and at 150°C (NH₄)₂HGaOF₄ yields (NH₄)H₂GaOF₄. At 18°C (NH₄)₂HGa₂OF_7^·3.5H₂O yields the anhydrous compound.     

Vibrational spectra of NH4-Ln(SO4)2·4H2O/D2O (LnLa and Ce)

Infrared and Raman spectra of NH₄Ce(SO₄)₂·4H₂O, NH₄La(SO₄)₂·4H₂O and the deuterated compounds NH₄Ce(SO₄)₂·4D₂O and NH₄La(SO₄)₂·4D₂O have been analysed. Splittings indicating the presence of two types of SO₄ ions are not observed. The SO bond strengths of the different SO₄ units are not significantly different. The SO₄ ion is distorted in these compounds. Deuteration causes changes in the SO₄ bond strength. Three crystallographically distinct water molecules exist in the unit cell.     

Syntheses and Structures of S4N4(OCH3)2 and CH3OS4N4(O)Cl

The reaction of S₄N₄Cl₂ with CH₃OH gives S₄N₄(OCH₃)₂, a simple dimethoxoderivative of S₄N₄. Its overall geometry is analogous to other compounds of the S₄N₄X₂ type. The chlorination of S₄N₄(OCH₃)₂ leads to the oxidation of one sulfur atom to S^VI and CH₃OS₄N₄(O)Cl is formed. The compounds were characterized by ir spectroscopy and their crystal structures were determined from single crystal diffraction data collected at ?153°C. The presence of S^VI in the molecule of CH₃OS₄N₄(O)Cl is manifested by a marked shortening of the bonds formed by this atom as compared with S₄N₄Cl₂ and S₄N₄(OCH₃)₂.     

Aryl-bis(triorganylphosphine)nickel phenoxides

Compounds of general formulatrans-ArNi(PR₃)₂OAr' (R = Et, cyclohexyl; Ar = 2-MeC₆H₄, 2-FC₆H₄; Ar' = 4-FC₆H₄, 4-NO₂C₆H₄) were synthesized by the reaction of Ar'OK with cationic nickel complexes generated by treatment of ArNi(PR₃)₂Cl with TlBF₄. Syntheses of 4-fluorophenoxide complexes, ArNi(PR₃)₂OC₆H₄F-4, additionally give some quantities oftrans-[ArNi(PR₃)₂OC₆H₄F-4][HOC₆H₄F-4] adducts. Exchange reactions MeC₆H₄Ni(PEt₃)₂OC₆H₄F-4 + XC₆H₄OH 2-MeC₆H₄Ni(PEt₃)₂OC₆H₄X + 4-FC₆H₄OH were studied in THF. The equilibrium is shifted to the right as the acidity of ArOH increases. A linear relationship between lgK _eq and pK _a of XC₆H₄OH in DMSO was found. A conclusion concerning the strong polarization of the Ni-O bond was made on the basis of an analysis of the chemical shifts of fluorine atoms in 2-MeC₆H₄Ni(PEt₃)₂OC₆H₄F-4.Translated fromIvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2266–2271, November, 1995.     

Synthesis and Properties of Complexes with Unusual {MnIII4} and {MnII4} Cages

Two types of manganese complexes with [Mn₄] cores featuring the unusual distorted cube topology are presented, the first of which comprises new modifications of the reported complex [Mn^III₄(sao)₄(saoH)₄]·3CHCl₃: [Mn₄(sao)₄(saoH)₄]·1.32(C₄H₁₀O)·0.43(CH₄O) ( 1a ) and [Mn(sao)₄(saoH)₄]·0.5(CH₄O)·0.5(C₂H₃N) ( 1b ) sao = salicylaldoxime. The second, 0.55[Mn₄Cl₄(C₁₂H₉N₂O)₄(CH₃OH)₂(H₂O)₂]·0.45[Mn₄Cl₄(C₁₂H₉N₂O)₄(CH₃OH)₄] ( 2 ), is the first reported case of a {Mn^II₄} core of this topology besides known {Mn^III₄} compounds. Differences between the {Mn^II₄} and {Mn^III₄} situation are discussed, and so far overlooked differences in magnetic properties between different {Mn^III₄} compounds are pointed out.     

Synthese und Röntgenstrukturanalyse von S4N4-Derivaten mit drei- und vierfach koordinierten Schwefelatomen

CF₃SO₂N?SCl₂ reagiert mit (CH₃)₂S[NSi(CH₃)₃]₂, (C₄H₈)S[NSi(CH₃)₃]₂ oder (C₅H₁₀)S[NSi(CH₃)₃]₂ unter Trimethylchlorsilanabspaltung zu den achtgliedrigen S₄N₄-Derivaten S₄N₄(NSO₂CF₃)₂(CH₃)₄ 3 , S₄N₄(NSO₂CF₃)₂(C₄H₈)₂ 4a und S₄N₄(NSO₂CF₃)₂(C₅H_{1 0})₂ 4b . In den achtgliedrigen SN-Ringen haben die Schwefelatome die Koordinationszahl 3 und 4. Die Röntgenstrukturanalyse von 4a ergab eine Sessel-Konformation. 4a kristallisiert orthorhombisch in der Raumgruppe Pna2₁ mit a = 17,641(4), b = 6,406(2), c = 19,130(4) Å, d_x = 1,815 g cm^?3 und Z = 4. Die mittleren S? N-Abstände betragen an den vierfach koordinierten Schwefelatomen 1,597 Å und an den Schwefelatomen mit der Koordinationszahl 3 1,650 Å. CF₃SO₂N? SCl₂ reagiert mit trimethylzinnhaltigen S? N-Verbindungen zum bekannten CF₃SO₂N[Sn(CH₃)₃]S(CH₃)NSO₂CF₃ und Dimethylzinndichlorid. Synthesis and X-Ray Structure Analysis of S₄N₄-Derivatives with Threefold and Fourfold Coordinated Sulfur Atoms CF₃SO₂N?SCl₂ reacts with (CH₃)₂S[NSi(CH₃)₃]₂, (C₄H₈)S[NSi(CH₃)₃]₂ or (C₅H₁₀S[NSi(CH₃)₂]₂ under elimination of (CH₃)₃SiCl to yield the eight-membered S₄N₄ derivatives S₄N₄?NSO₂CF₃)₂(CH₃)₄, 3 , S₄N₄(NSO₂CF₃)₂(C₄H₈)₂ 4a und S₄N₄(NSO₂CF₃)₂(C₅H_{1 0})₂ 4b . In the eight-membered SN-rings the sulfur atoms have the coordination number 3 and 4. The X-ray structure analysis of 4a revealed a chair conformation. 4a crystallizes in the orthorhombic space group Pna2₁ with a = 17.641(4), b = 6.406(2), c = 19.130(4) Å, d_x = 1.815 g cm^?3, and Z = 4. The average S? N distance was found to be 1.597 Å at fourfold coordinated sulfur atoms and 1.650 Å at sulfur with coordination number 3. CF₃SO₂N=SCl₂ reacts with trimethyl tin-containing S? N compounds to the known CF₃SO₂N[Sn(CH₃)₃]S(CH₃)NSO₂CF₃ and dimethyl tin dichloride.     

Schwingungsspektren von β-P4S5 und P4S7

Vibrational Spectra of β-P₄S₅ and P₄S₇ The vibrational spectra of the solid and liquid cage compounds β-P₄S₅ and P₄S₇ have been recorded. The assignments of the frequencies are proposed mainly based on polarization data. β-P₄S₅ decomposes during melting into P₄S₃ α-P₄S₇ and β-P₄S₆. Molten α-P₄S₇ dissociates to some extent into β-P₄S₆ and sulphur. An association of β-P₄S₆ with α-P₄S₇ is discussed for the molten state. All reactions in molten P₄S₇ are reversible.     

Comparison of the crystal structures of sodium orthosilicate,Na4SiO4, and sodium orthogermanate,Na4GeO4

The crystal structures of Na₄SiO₄ and Na₄GeO₄ are isotypic, despite a difference in coordination numbers: in Na₄SiO₄ only one of the four symmetrically independent sodium atoms is four coordinated, in Na₄GeO₄ two of them are.

---

Vergleich der Kristallstrukturen von Natriumorthosilikat, Na₄SiO₄, und Natriumorthogermanat, Na₄GeO₄ (Kurze Mitteilung)

Zusammenfassung Die Kristallstrukturen von Na₄SiO₄ und Na₄GeO₄ sind isotyp, trotz eines Unterschiedes in den Koordinationszahlen: im Na₄SiO₄ ist nur eines der symmetrisch unabhängigen Natriumatome vierfach koordiniert, während es im Na₄GeO₄ derer zwei sind.

     

Beiträge zur Chemie von Phosphorverbindungen mit Adamantanstruktur. XI. Über Darstellung und Eigenschaften von Phosphoroxidsulfiden der allgemeinen Formel P4O10−nSn (n = 2−9)

Contributions to the Chemistry of Phosphorus Compounds with Adamantane-like Structure. XI. Preparation and Properties of Phosphorus Oxide Sulfides of the General Formula P₄S_10?n S_n (n = 2?9) The reaction of P₄O₁₀ with P₄S₁₀ yields a mixture of phosphorus oxide sulfides of the general formula P₄O_10?nS_n. Depending on the molar ratio P₄O₁₀: P₄S₁₀ in the starting product different amounts of the individual phosphorus oxide sulfides occuring in this reorganization product are formed. Besides the well-known P₄O₆S₄ the compounds P₄O₇S₃, P₄O₅S₅, P₄O₄S₆, P₄O₃S₇, P₄O₂S₈, and P₄OS₉ occuring for the first time were obtained by fractional distillation or crystallization. The compound P₄O₈S₂ was identified by N.M.R. spectroscopy.     

Synthesis and Structures of Silver(I) Complexes of 4-Amino-3,5-dipropyl-4H-1,2,4-triazole and 4-Amino-3,5-dibutyl-4H-1,2,4-triazole: A Possible Mechanism of Formation of Ag4tz6 Cluster

Five silver(I) complex of 4-amino-3,5-dipropyl-4H-1,2,4-triazole (4-NH₂-3,5-Pr₂tz) or 4-amino-3,5-dibutyl-4H-1,2,4-triazole (4-NH₂-3,5-Bu₂tz), namely [Ag₂(4-NH₂-3,5-Bu₂tz)₂(NO₃)₂] (1), [Ag₄(4-NH₂-3,5-Pr₂tz)₆(NO₃)₂](NO₃)₂ (2), [Ag₄(4-NH₂-3,5-Pr₂tz)₆](ClO₄)₄ (3), [Ag₄(4-NH₂-3,5-Pr₂tz)₆](CF₃SO₃)₄ (4) and [Ag₄(4-NH₂-3,5-Bu₂tz)₆](BF₄)₄ (5), have been prepared and structurally characterized by X-ray single crystal diffractions. Based on the structural data, a possible mechanism for the formation of Ag₄tz₆ cluster has been proposed, involving the formation of a dimer of dimer—(Ag₂tz₂)₂, followed by the replacement of counterions by two additional triazoles.     

Einstieg in die Chemie einfacher Rhenium-Schwefel-Komplexe und -Cluster. Darstellung und Kristall-Struktur von R[ReS4], R′[ReS9], (NH4)4[Re4S22]·2H2O,R′2[Cl2Fe(MoS4)FeCl2]x [Cl2Fe(ReS4)FeCl2]1-x′ R′2 [(ReS4)Cu3l4] und RR′2[(ReS4)Cu5Br7] (R  NEt4; R′  PPh4; x = 0,3, 0,5)

Entry to the Chemistry of Simple Rhenium Sulfur Complexes and Clusters. Preparation and Crystal Structures of R′[ReS₄], R′[ReS₉], (NH₄)₄[Re₄S₂₂]·2H₂O, R′₂[Cl₂Fe(MoS₄)FeCl₂]_1-x, R′₂[(ReS₄)Cu₃I₄] and RR′₂[(ReS₄)Cu₅Br₇] (R ? NEt₄; R′ ? PPh₄, x = 0.3, 0.5) The compounds R[ReS₄] ( 1 ), R′[ReS₉] ( 2 ), (NH₄)₄[Re₄S₂₂]·2 H₂O ( 3 ), R′₂[Cl₂Fe(MoS₄) FeCl₂]_x[Cl₂Fe(ReS₄)FeCl₂] _1-x (x = 0.3 ( 4 ), 0.5), R′₂[(ReS₄)Cu₃I₄] ( 5 ) and R′₂[(ReS₄)Cu₅Br₇] ( 6 ) (R ? NEt₄; R′ ? PPh₄) have been prepared by reaction of perrhenates or rhenium(VII)oxide with S_x^2? solutions (under different conditions) or by reactions of metal-halides with [ReS₄]^?-ions. All compounds have been characterized by complete X- ray structure analysis. For further details see Inhaltsübersicht.     

Die Reaktionen von Eisen(III)-chlorid mit Trithiazylchlorid. Die Kristallstruktur von [S4N4Cl]+[FeCl4]⊖

Reactions of Iron Trichloride with Trithyazyl Chloride. Crystal Structure of [S₄N₄Cl]⁺[FeCl₄]^? Iron trichloride reacts with (NSCl)₃ yielding S₄N₄[FeCl₄]₂, S₃N₃Cl₂[FeCl₄] or S₄N₄Cl[FeCl₄], depending on the reaction conditions. The i.r. spectra prove the presence of [FeCl₄]^? ions for all three compounds. The ⁵⁷Fe-Mössbauer spectra show a slight quadrupole splitting at 80 K for S₃N₃Cl₂[FeCl₄] (ΔE^Q = 0.42 mm · s^?1) and S₄N₄Cl[FeCl₄] (ΔE^Q = 0.23 mm · s^?1), which indicates a slight deformation of the FeCl₄^? tetrahedra. The crystal structure of S₄N₄Cl[FeCl₄] was determined and refined with X-ray diffraction data (2549 independent reflexions, R = 0.026). S₄N₄Cl[FeCl₄] crystallizes in the triclinic space group P1 with two formula units per unit cell. The lattice constants are a = 712, b = 911, c = 1006 pm, α = 76.5°, β = 83.8° and γ = 80.5°. The structure consists of the so far unknown [S₄N₄Cl]^⊕ cations and slightly deformed FeCl₄^? ions. The [S₄N₄Cl]^⊕ ion consists of a S₄N₄ ring built up of two nearly planar S₃N₂ fragments having a dihedral angle of 136°. The average SN bond length is 157 pm, the SCI bond length 214 pm.