Synthesis of a Novel Tricyclic Dipeptide Template and Its Incorporation into a Cyclic Peptide Mimetic Containing an NPNA Motif

A novel tricyclic dipeptide template, formally derived by coupling (2S,4S)-4-aminoproline (Pro(NH₂)) and (S)-2-(carboxymethyl)proline (Pro(CH₂COOH)) as a diketopiperazine, has been synthesized in a form suitable for solid-phase peptide synthesis using Fmoc chemistry. This template was incorporated into the cyclic molecule cyclo(-Ala¹-Asn²-Pro³-Asn⁴-Ala⁵-Ala⁶-Temp-) (Temp = template), whose conformation in H₂O was studied by NMR methods. Average solution structures derived by restrained simulated annealing point to a highly populated βI-turn within the Asn-Pro-Asn-Ala motif and also indicate which conformations are likely to be preferred by the template.     

A Tricyclic Template Derived from (2S,4R)-4-Hydroxyproline for the Synthesis of Protein Loop Mimetics

A tricyclic diketopiperazine, formally derived by coupling (2S,4S)-4-aminoproline (Pro(NH₂)) and (2S,4R)-4-(carboxymethyl)proline (Pro(CH₂COOH)), is synthesized starting from readily available (2S,4R)-4-hydroxyproline. The resulting tricyclic template has carboxy and amino groups to which a peptide chain may be attached. The Fmoc-protected template 5 is incorporated into the cyclic molecule cyclo(-Ala¹-Asn²-Pro³-Asn⁴-Ala⁵-) ( 6 ) where Pro(NH₂)⁷ = Pro(CH₂COOH)⁸ represents the template, using solid-phase peptide synthesis with cyclization in solution. The molecule is shown by NMR and dynamic simulated annealing methods to adopt a preferred conformation in aqueous solution, which includes an extended backbone at the residues Asn²-Pro³-Asn⁴, and a type-Iβ-turn at . These studies show that this novel template may be used in the synthesis of cyclic peptide and protein mimetics having defined secondary structure in aqueous environments.     

Crystal structure of [Pd(NH3)4][Rh(NH3)(NO2)5]

An XRD analysis is used to study the single crystal of [Pd(NH₃)₄][Rh(NH₃)(NO₂)₅] double complex salt at T = 150(2) K. Crystallographic characteristics are as follows: a = 7.6458(5) ?, b = 9.8813(6) ?, c = 9.5788(7) ?, β = 109.469(2)°, V = 682.30(8) ?³, P2₁/m space group, Z = 2, d _x = 2.553 g/cm³. The geometry of the complex [Rh(NH₃)(NO₂)₅]²⁻ anion is described for the first time: Rh-N(NO₂) distances are 2.020(4)–2.060(3) ?, Rh-N(NH₃) 2.074(4) ?, N(NO₂)-Rh-N(NH₃) trans-angle is 178.8(2)°.     

Intramolekularer Antiferromagnetismus in [Cr2(μ-NH2)3(NH3)6]I3

Intramolecular Antiferromagnetism in [Cr₂(μ-NH₂)₃(NH₃)₆]I₃ The magnetism of [Cr₂(μ-NH₂)₃(NH₃)₆]I₃ which consists of binuclear cations with NH₂^?-bridged face-sharing octahedral coordination polyhedra and a metal-metal separation of 264.9 pm can be explained by antiferromagnetically exchange-coupled Cr^III-3d³ pairs. The magnetochemical analysis in the temperature range 5 K – 295 K on the basis of the isotropic Heisenberg model (spin Hamiltonian ? = ?2 J?₁ · ?₂) leads to the parameter value J = ?98(3) cm^?1. Compared to the exchange coupling in corresponding binuclear chromium compounds with OH^? bridges and identical metal-metal separation the strength of the coupling is significantly enhanced (J_NH2/J_OH ≈? 1.6).     

Darstellung und Kristallstrukturen von [P(C6H5)4][1-(NH3)B10H9] und Cs[(NH3)B12H11] · 2CH3OH

Synthesis and Crystal Structures of [P(C₆H₅)₄][1-(NH₃)B₁₀H₉] and Cs[(NH₃)B₁₂H₁₁] · 2CH₃OH The reduction of [1-(NO₂)B₁₀H₉]^2? with aluminum in alkaline solution yields [1-(NH₃)B₁₀H₉]^? and by treatment of [B₁₂H₁₂]^2? with hydroxylamine-O-sulfonic acid [(NH₃)B₁₂H₁₁]^? is formed. The crystal structures of [P(C₆H₅)₄][1-(NH₃)B₁₀H₉] (triclinic, space group P1 , a = 7.491(2), b = 13.341(2), c = 14.235(1) Å, α = 68.127(9), β = 81.85(2), γ = 86.860(3)°, Z = 2) and Cs[(NH₃)B₁₂H₁₁] · 2CH₃OH (monoclinic, space group P2₁/n, a = 14.570(2), b = 7.796(1), c = 15.076(2) Å, β = 111.801(8)°, Z = 4) reveal for both compounds the bonding of an ammine substituent to the cluster anion.     

Synthese und Charakterisierung von [Zn{Si(NMe2)2(NHCMe3)(NCMe3)}‐(μ‐NC5H4)]2, einem molekularen Einkomponentenvorläufer zur Darstellung von ZnSiN2

Synthesis and Characterization of [Zn{Si(NMe₂)₂(NHCMe₃)(NCMe₃)}(μ‐NC₅H₄)]₂, a Molecular Single Source Precursor for ZnSiN₂ For an application as single source precursor for ZnSiN₂ the siladiazazinca cyclo butane [Zn{Si(NMe₂)₂(NHCMe₃)(NCMe₃)}(μ‐NC₅H₄)]₂has been synthesised for the first time from Si(NMe₂)₂(NLi t‐Butyl)₂ and ZnCl₂(NC₅H₅)₂. It has been characterized by single crystal structure analysis (P1, a = 870.5(3) pm, b = 903.8(3) pm, c = 1530.6(4) pm, α = 96.982(5)°, β = 106.501(5)°, γ = 104.729(5)°). The CP‐MAS‐NMR data for the nuclei ¹³C, ¹⁵N and ²⁹Si are reported. ZnSiN₂ was prepared by thermal decomposition of the precursor molecule and characterized by elemental analysis, EDX, IR spectroscopy and thermal analysis. The crystal structure was determined (X‐ray powder diffraction data, profile matching: P6₃mc, a = 315.33(1) pm, c = 508.07(2) pm, R_B = 4.87). The thermal behaviour of the precursor molecule, the preparation of polymers by linking with NH₃ and the decomposition of the polymers in an argon or NH₃ stream were investigated.     

Synthese und Kristallstrukturen von NH4[Si(NH3)F5] und [Si(NH3)2F4]

Synthesis and Crystal Structures of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] Single crystals of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] are obtained by reaction of silicon powder with NH₄HF₂ in sealed Monel ampoules at 400°C. NH₄[Si(NH₃)F₅] crystallizes with the tetragonal space group P4/n (no. 85) with a = 614.91(7) pm, c = 721.01(8) pm, Z = 2. Characteristic for the structure is the anionic octahedron [Si(NH₃)F₅]^?. Si(NH₃)₂F₄ crystallizes with the monoclinic space group P2₁/c (no. 14) with a = 506.9(1) pm, b = 728.0(1) pm, c = 675.9(1), β = 93,21(2)°, Z = 2. Trans-[Si(NH₃)₂F₄] molecules are characteristic for this structure.     

Die Ammonolyse von (NH4)2GeF6. Darstellung und Struktur von NH4[Ge(NH3)F5]

Ammonolysis Reaction of (NH₄)₂GeF₆. Synthesis and Structure of NH₄[Ge(NH₃)F₅] (NH₄)₂GeF₆ reacts with ammonia to yield NH₄[Ge(NH₃)F₅] at 280°C. The reaction path was elucidated by in situ time and temperature resolved X-ray powder diffraction. NH₄[Ge(NH₃)F₅] crystallizes isostructurally to NH₄[Si(NH₃)F₅] in the tetragonal space group P4/n (No. 85) with lattice constants a = 619.41(1) pm and c = 724.70(1) pm. The germanium atom is coordinated by five fluorine atoms and the nitrogen atom of the ammonia molecule. The ammonium cation is located on the Wyckoff position (2 a) in P4/n. The crystal structure is stabilized by extensive hydrogen bonding.     

Mehrkernige Kobaltkomplexe. II. Herstellung und Struktur von [(tren) (NH3)Co(O2)Co(NH3) (tren)](SCN)4 · 2H2O

Polynuclear Cobalt Complexes. II. Preparation and Structure of [(tren) (NH₃)Co(O₂)Co(NH₃) (tren)](SCN)₄ · 2H₂O The title compound is obtained on oxygenation of [Co(tren)(H₂O)₂]²⁺ in 6M aqueous ammonia or by ligand exchange starting from [(NH₃)₅Co(O₂)Co(NH₃)₅]-(NO₃)₄. An X-ray structure determination was made. The substance forms monoclinic crystals, space group P2₁/c, lattice constants a=10,135, b=8,473, c=19,484 Å, β=108,58°, with two formula units in the cell. The final R is 0,066. The binuclear cation has a center of symmetry, so the Co? O? O? Co unit is planar; the Co? O? O angle is 111,5°. The tertiary nitrogen atoms of both chelate groups are cis to the O₂ bridge, as found in doubly bridged [(tren)Co(O₂,OH)Co(tren)](ClO₄)₃ · 3H₂O. On acidification in solution, the singly bridged cation [(tren) (NH₃)CoO₂Co(NH₃)(tren)]⁴⁺ (a) loses the bound O₂ completely. But unlike the doubly bridged cation b , the rate of dissociation of a is independent of pH (Fig. 5). At higher pH (8–10) bridging a→b (Fig. 2) occurs. Both reactions must have the same rate determining step, the first order rate constants being of the order of 2 · 10^?3 s^?1 (25°, 0,35M KCl).     

Crystal structures of new double complex salts [M(NH3)5Br][AuBr4]2·H2O, where M = Ir, Rh and complex salt [Ir(NH3)5Br]Br2

The crystal structures of double complex salts [M(NH₃)₅Br][AuBr₄]₂·H₂O (M = Ir, Rh) are determined by single crystal XRD. The compounds crystallize in the triclinic system, P-1 space group, Z = 4. Crystallographic characteristics: [Ir(NH₃)₅Br][AuBr₄]₂·H₂O: a = 8.2982(3) ?, b = 15.3045(4) ?, c = 17.4378(6) ?, α = 73.064(1)°, β = 88.938(1)°, γ = 86.221(1)°, V = 2113.95(12) ?³, d _x = 4.419 g/cm³, R = 0.0469; [Rh(NH₃)₅Br][AuBr₄]₂·H₂O: a = 8.2855(2) ?, b = 15.2881(3) ?, c = 17.4053(4) ?, α = 73.015(1)°, β = 88.913(1)°, γ = 86.267(1)°, V = 2104.08(8) ?³, d _x = 4.165 g/sm³, R = 0.0480. The crystal structure of [Ir(NH₃)₅Br]Br₂ is determined. The compound crystallizes in the orthorhombic system, Pnma space group, Z = 4. Crystallographic characteristics: a = 13.8521(3) ?, b = 10.8570(2) ?, c = 6.9908(1) ?, V = 1049.31(3) ?³, d _x = 3.273 g/cm³, R = 0.0127.     

Synthesis and crystal structure of the octahedral cyano-bridged cluster complex β-[{Ni(NH3)5}2{Re6Te8(CN)6}]·4H2O

The rhenium cyano-bridged cluster complex with a composition of β-[{Ni(NH₃)₅}₂{Re₆Te₈(CN)₆}]−4H₂O is obtained and structurally characterized. The compound pound crystallizes in the P $ P\bar 1 $ P\bar 1 triclinic space group with the unit cell parameters: a = 9.997(2) ?, b = 10.423(2) ?, c = 11.714(2) ?, α = 100.92(3)°, β = 111.87(3)°, γ = 98.05(3)°, V = 1082.1(4) ?³, Z = 1, d _calc = 4.072 g/cm³. The rhenium atoms of the {Re₆Te₈} cluster core are coordinated by CN ligands to form the [Re₆Te₈(CN)₆]⁴⁻ cluster; two nitrogen atoms of CN ligands trans-positioned with respect to each other are coordinated to Ni atoms in the {Ni(NH₃)₅}²⁺ fragments to form the molecular complexes of [{Ni(NH₃)₅}₂}Re₆Te₈(CN)₆}]. The crystal structure is the H-bonded packing of these molecular complexes and crystallization water molecules.     

Der strukturdirigierende Einfluß von α, ω-Alkandiammoniumionen auf die Bildung von Cyanocupraten(I)

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) Å, b = 8.579(4) Å, c = 13.054(6) Å, β = 92.806(10)°, V = 780.9(6) ų, Z = 2, d_c = 2.145 gcm^-1, R₁ = 0.094; 2 , orthorhombic, C222₁, a = 8.715(2) Å, b = 14.764(3) Å, c = 12.411(2) Å, V = 1596.7(5) ų, Z = 4, d_c = 2.098 gcm^-1, R₁ = 0.026; 3 , orthorhombic, Pnn2, a = 7.276(2) Å, b = 8.612(2) Å, c = 14.731(3) Å, V = 923.1(3) ų, Z = 2, d_c = 1.916 gcm^-1, R₁ = 0.036; 4 , triclinic, P1, a = 8.113(5) Å, b = 11.068(5) Å, c = 13.689(5) Å, α = 91.270(5)°, β = 99.718(5)°, γ = 103.994(5)°, V = 1173.1(10) ų, Z = 1, d_c = 1.746 gcm^-1, R₁ = 0.057.     

Factors Affecting DNA–DNA Interstrand Cross‐Links in the Antiparallel 3′–3′ Sense: A Comparison with the 5′–5′ Directional Isomer

Reported herein is a study of the unusual 3′–3′ 1,4‐GG interstrand cross‐link (IXL) formation in duplex DNA by a series of polynuclear platinum anticancer complexes. To examine the effect of possible preassociation through charge and hydrogen‐bonding effects the closely related compounds [{trans‐PtCl(NH₃)₂}₂(μ‐trans‐Pt(NH₃)₂{NH₂(CH₂)₆NH₂}₂)]⁴⁺ (BBR3464, 1 ), [{trans‐PtCl(NH₃)₂}₂(μ‐NH₂(CH₂)₆NH₂)]²⁺ (BBR3005, 2 ), [{trans‐PtCl(NH₃)₂}₂(μ‐H₂N(CH₂)₃NH₂(CH₂)₄)]³⁺ (BBR3571, 3 ) and [{trans‐PtCl(NH₃)₂}₂{μ‐H₂N(CH₂)₃‐N(COCF₃)(CH₂)₄}]²⁺ (BBR3571‐COCF₃, 4 ) were studied. Two different molecular biology approaches were used to investigate the effect of DNA template upon IXL formation in synthetic 20‐base‐pair duplexes. In the “hybridisation directed” method the monofunctionally adducted top strands were hybridised with their complementary 5′‐end labelled strands; after 24 h the efficiency of interstrand cross‐linking in the 5′–5′ direction was slightly higher than in the 3′–3′ direction. The second method involved “postsynthetic modification” of the intact duplex; significantly less cross‐linking was observed, but again a slight preference for the 5′–5′ duplex was present. 2D [¹H, ¹⁵N] HSQC NMR spectroscopy studies of the reaction of [¹⁵N]‐ 1 with the sequence 5′‐d{TATACATGTATA}₂ allowed direct comparison of the stepwise formation of the 3′–3′ IXL with the previously studied 5′–5′ IXL on the analogous sequence 5′‐d(ATATGTACATAT)₂. Whereas the preassociation and aquation steps were similar, differences were evident at the monofunctional binding step. The reaction did not yield a single distinct 3′–3′ 1,4‐GG IXL, but numerous cross‐linked adducts formed. Similar results were found for the reaction with the dinuclear [¹⁵N]‐ 2 . Molecular dynamics simulations for the 3′–3′ IXLs formed by both 1 and 2 showed a highly distorted structure with evident fraying of the end base pairs and considerable widening of the minor groove.     

Singlet-Oxygen Ene Reactions of (E)-4-Propyl[1,1,-2H3]oct-4-ene. Short Communication

Rose bengal-sensitized photooxygenation of 4-propyl-4-octene ( 1 ) in MeOH/Me₂CHOH 1:1 (v/v) and MeOH/H₂O 95:5 followed by reduction gave (E)-4-propyl-5-octen-4-ol ( 4 ), its (Z)-isomer 5 , (E)-5-propyl-5-octen-4-ol ( 6 ), and its (Z)-isomer 7 . Analogously, (E)-4-propyl[1,1,1-²H₃]oct-4-ene ( 2 ) gave (E)-4-propyl[1,1,1-²H₃]oct-5-en-4-ol ( 14 ), its (Z)-isomer 15 , (E)-5-[3′,3′,3′-²H₃]propyl-5-octen-4-ol ( 16 ), its (Z)-isomer 17 , and the corresponding [8,8,8-²H₃]-isomers 18 and 19 (see Scheme 1). The proportions of 4–7 were carefully determined by GC between 10% and 85% conversion of 1 and were constant within this range. The labeled substrate 2 was photooxygenated in two high-conversion experiments, and after reduction, the ratios 16/18 and 17/19 were determined by NMR. Isotope effects in 2 were neglected and the proportions of corresponding products from 1 and 2 assumed to be similar (% 4 ≈? % 14 ; % 5 ≈? % 15 ; % 6 ≈? % ( 16 + 18 ): % 7 ≈? % ( 17 + 19 )). Combination of these proportions with the ratios 16/18 and 17/19 led to an estimate of the proportions of hydroperoxides formed from 2 . Accordingly, singlet oxygen ene additions at the disubstituted side of 2 are preferred (ca. 90%). The previously studied trisubstituted olefins 20–25 exhibited the same preference, but had both CH₃ and higher alkyl substituents on the double bond. In these substrates, CH₃ groups syn to the lone alkyl or CH₃ group appear to be more reactive than CH₂ groups at that site beyond a statistical bias.     

Calculation of Some Thermodynamic Properties and Detonation Parameters of 1‐Ethyl‐3‐Methyl‐H‐Imidazolium Perchlorate, [Emim][ClO4], on the Basis of CBS‐4M and CHEETAH Computations Supplemented by VBT Estimates

This paper estimates some thermochemical (in kcal mol^–1) and detonation parameters for the ionic liquid, [emim][ClO₄] and its associated solid in view of its investigation as an energetic material. The thermochemical values estimated, employing CBS‐4M computational methodology and volume‐based thermodynamics (VBT) include: lattice energy, U_POT([emim][ClO₄]) ≈? 123 ± 16 kcal · mol^–1; enthalpy of formation of the gaseous cation, Δ_fH°([emim]⁺, g) = 144.2 kcal · mol^–1 and anion, Δ_fH°([ClO₄]^–, g) = –66.1 kcal · mol^–1; the enthalpy of formation of the solid salt, Δ_fH°([emim][ClO₄],s) ≈? –55 ± 16 kcal · mol^–1 and for the associated ionic liquid, Δ_fH^o([emim][ClO₄],l) = –52 ± 16 kcal · mol^–1 as well as the corresponding Gibbs energy terms: Δ_fG°([emim][ClO₄],s) ≈? +29 ± 16 kcal · mol^–1 and Δ_fG^o([emim][ClO₄],l) = +24 ± 16 kcal · mol^–1 and the associated standard absolute entropies, of the solid [emim][ClO₄], S°₂₉₈([emim][ClO₄],s) = 83 ± 4 cal · K^–1 · mol^–1. The following combustion and detonation parameters are assigned to [emim][ClO₄] in its (ionic) liquid form: specific impulse (I_sp) = 228 s (monopropellant), detonation velocity (V_oD) = 5466 m · s^–1, detonation pressure (p_C–J) = 99 kbar, explosion temperature (T_ex) = 2842 K.     

Cyclic RGD Peptides Containing Azabicycloalkane Reverse‐Turn Mimics

The Fmoc‐protected lactams 3 and 4 were used to prepare cyclo(Arg‐Gly‐Asp‐lactam) 1 and cyclo(Arg‐Gly‐Asp‐Phe‐lactam) 2 , which contain the Arg‐Gly‐Asp (RGD) recognition motif. Their solid‐phase synthesis, conformational analysis, and binding to purified α_Vβ₃ and α_Vβ₅ integrins are reported. Compound 1 was found to act as an active and selective inhibitor of the α_Vβ₅ integrin.     

REACTION OF α-CHLOROTOLUENE WITH ELEMENTAL SULFUR IN LIQUID AMMONIA

Abstract

α-Chlorotoluene (1) reacts with elemental sulfur in liquid ammonia affording dibenzyl disulfide (2), dibenzyl trisulfide (3), dibenzyl tetrasulfide (4), dibenzyl pentasulfide (5) and benzylidene benzylimide (6) at a low temperature such as 20°C. This reaction is presumed to be initiated by the nucleophilic attack of ammonium thioaminohydroxylate, “H₂NS^-NH₄ ⁺,” or dithioaminohydroxylate, “H₂NSS^-NH₄,” formed upon treating elemental sulfur in liquid ammonia, on α-chlorotoluene (1). Benzylidene benzylimide (6) is presumed to be formed from benzylamine, which can be formed by treatment of α-chlorotoluene (1) with ammonia.     

Heteronukleare Komplexverbindungen mit Metall—Metall-Bindungen. IX [1]. Amin-kupfer(I)-carbonylmetallate mit Cobalt,Eisen oder Mangan

Heteronuclear Coordination Compounds with Metal—Metal Bonds. IX. Amine Copper(I) Carbonyl Metalates with Cobalt, Iron, or Manganese Colourless crystals of the carbonyl copper complex [(NH₃)₃(CO)Cu][Co(CO)₄] ( 1 a ) are formed in the reaction of [Cu(NH₃)₄]Cl and Na[Co(CO)₄] (T < ? 8°C, p_CO = 1 bar); above ?5°C and under N₂-atmosphere 1 a converts to [(NH₃)₂CuCo(CO)₄] ( C ), which serves as a starting material for the synthesis of new copper cobaltates: the amines N-amino piperidine, N,N-dimethyl ethylenediamine (dmed) and N-benzyl N,N′-dimethyl ethylenediamine (bn-dmed) replace NH₃ to form [(C₅H₁₀N? NH₂)₃CuCo(CO)₄] ( 1 b ), [(dmed)CuCo(CO)₄] ( 1 c ), [(bn-dmed)CuCo(CO)₄] ( 1 d ) the Cu? Co-bond remaining intact. [(NH₃)₂CuFe(CO)₃NO] ( 2 a ) is isosteric with C ; it is synthesized from [Cu(NH₃)₄]Cl and Na[Fe(CO)₃NO] in aqueous solution; 2 a reacts with N,N,N′,N′-tetramethyl ethylenediamine (tmed) to form [(tmed)(NH₃)CuFe(CO)₃NO] ( 2b ). The [Mn(CO)₅]^? ion reacts with ammine copper ions to form the tetranuclear cluster [{(NH₃)CuMn(CO)₅}₂] ( 3 ). All new compounds have been investigated by X-ray structure analysis.     

Low‐Temperature Synthesis of Diamminesodium(1+) Triamminesodium(1+) Trithioantimonate(3−) Ammoniate (1 : 2 : 1 : 2) ([Na(NH3)3]2[Na(NH3)2]SbS3⋅2 NH3), A Solvated Neutral Sodium Trithioantimonate(3−) (3 : 1) Na3SbS3) Ion Complex

A solution of sodium in liquid ammonia reacts with Sb₂S₃ to form large colorless crystals of the composition Na₃SbS₃⋅10 NH₃. The trigonal‐pyramidal SbS₃³⁻ anion is ion‐paired with three Na⁺ counter ions, the coordination spheres of which are completed by eight ammine ligands. The resulting neutral [Na(NH₃)₃]₂[Na(NH₃)₂]SbS₃ molecules crystallize together with two ammonia molecules of solvation in the space group P2₁/c (a=9.828(2), b=6.0702(4), c=33.4377(6) Å, β=91.362(7)°, V=1994.2(5) ų, Z=4).     

Crystal structure of a tetrahedral cluster complex [Zn2(NH3)6(μ-OH)][Zn(NH3)4]0.5[Re4Te4(CN)12]·5H2O

A cluster complex of the composition [Zn₂(NH₃)₆(μ-OH)][Zn(NH₃)₄]_0.5[Re₄Te₄(CN)₁₂]·5H₂O is obtained by the interaction of an aqueous solution of K₄[Re₄Te₄(CN)₁₂]·5H₂O with an aqueous ammonia solution of ZnCl₂. The compound crystallizes in the C2/m (12) monoclinic space group with unit cell parameters a = 23.233(2) ?, b = 14.5906(16) ?, c = 14.3825(15) ?, β = 125.169(1)°, V = 3985.5(7) ?³, Z = 4, d _x = 3.290 g/cm³. The structure is built from cluster [Re₄Te₄(CN)₁₂]⁴⁻ anions and complex [Zn₂(NH₃)₆(μ-OH)]³⁺ and [Zn(NH₃)₄]²⁺ cations; the latter is disordered over two positions.