Die IR-Spektren von NH4UO2AsO4·3H2O und NH4UO2PO4·3H2O

The infrared spectra of the title compounds, as well as that of the structurally related mineral meta-autunite, [Ca(UO₂)₂(PO₄)₂·n H₂O], are reported and discussed using the available crystallographic data. The results can be considered as representative for the full group of the so-called torbernite-minerals.     

Synthese und Kristallstruktur von Mangan(II)‐ und Zinkamid,Mn(NH2)2 und Zn(NH2)2

Synthesis and Crystal Structure of Manganese(II) and Zinc Amides, Mn(NH₂)₂ and Zn(NH₂)₂ Metal powders of manganese resp. zinc react with supercritical ammonia in autoclaves in the presence of a mineralizer Na₂Mn(NH₂)₄ resp. Na₂Zn(NH₂)₄_.0.5NH₃ to well crystallized ruby‐red Mn(NH₂)₂ (p(NH₃) = 100 bar, T = 130°C, 10 d) resp. colourless Zn(NH₂)₂ (p(NH₃) = 3.8 kbar, T = 250°C, 60 d). The structures including all H‐positions were solved by x‐ray single crystal data: Mn(NH₂)₂: I4₁/acd, Z = 32, a = 10.185(6) Å, c = 20.349(7) Å, N(F_o) with F > 3σ (F) = 313, N(parameter) = 45, R/R_w = 0.038/0.043. Zn(NH₂)₂: I4₁/acd, Z = 32, a = 9.973(3) Å, c = 19.644(5) Å, N(F_o) with F > 3σ (F) = 489, N(parameter) = 45, R/R_w = 0.038/0.043. Both compounds crystallize isotypic with Mg(NH₂)₂ [1] resp. Be(NH₂)₂ [2]. Nitrogen of the amide ions is distorted cubic close packed. One quarter of tetrahedral voids is occupied by Mn²⁺‐ resp. Zn²⁺‐ions in such an ordered way that units M₄(NH₂)₆(NH₂)_4/2 occur. The H‐atoms of the anions have such an orientation that the distance to neighboured cations is optimum.     

Hochdrucksynthese von Caesiumamidazid,Cs2(NH2)N3 aus Caesiummetall und Ammoniak

High-pressure Synthesis of Cesium Amide Azide, Cs₂(NH₂)N₃ from Cesium Metal and Ammonia The reaction of cesium and yttrium metal with ammonia at 5–6 kbar and 190–220°C led to a well crystallized cesium amide azide and to YN. The formation of the cesium compound is discussed by volume effects. X-ray investigations gave the atomic arrangement of the compound. The tetragonal unit cell with a = 8.194(3) and c = 4.450(1) Å contains two formula units. The structure determination was successfull in the space group P4/mbm. The azide ion has different coordination and bond length (1.255 Å) as compared with that in the alkali metal azides (1.17 Å). The amide ions carry out a strong libration.     

Aufbau und Abbau von (NH4)[BF4] und H3N‐BF3

Production and Decomposition of (NH₄)[BF₄] and H₃N‐BF₃ (NH₄)[BF₄] is produced as single crystals during the reaction of elemental boron and NH₄HF₂ (B : NH₄HF₂ = 1 : 2) and NH₄F (B : NH₄F = 1 : 4), respectively, in sealed copper ampoules at 300 °C. The crystal structure (baryte type, orthorhombic, Pnma, Z = 4) was redetermined at ambient temperature (a = 909.73(18), b = 569.77(10), c = 729.47(11) pm, R_all = 0.0361) and at 140 K (a = 887.3(2), b = 574.59(12), c = 717.10(12) pm, R_all = 0.0321). Isolated (NH₄)⁺ and [BF₄]^— tetrahedra are the important building units. The thermal behaviour of (NH₄)[BF₄] was investigated under inert (Ar, N₂) and reactive conditions (NH₃) with the aid of DTA/TG and DSC measurements and with in‐situ X‐ray powder diffraction as well. Finally, (NH₄)[BF₄] is decomposed yielding NH₃ and BF₃, BN is not produced under the current conditions. Colourless single crystals of H₃N‐BF₃ were prepared directly from the components NH₃ and BF₃. The crystal structure was determined anew at 293 and 170 K (orthorhombic, Pbca, Z = 8, a = 815.12(10), b = 805.91(14), c = 929.03(12) pm, R_all = 0.0367; a = 807.26(13), b = 800.48(10), c = 924.31(11) pm, R_all = 0.0292, T = 170 K). The crystal structure contains isolated molecules H₃N‐BF₃ in staggered conformation with a B‐N distance of 158 pm. The thermal behaviour of H₃N‐BF₃ was studied likewise.     

Triorganoantimon- und Triorganobismutderivate von 2-Pyridincarbonsäure und 2-Pyridylessigsäure Kristall- und Molekülstrukturen von (C6H5)3Sb(O2C-2-C5H4N)2 und (CH3)3Sb(O2CCH2-2-C5H4N)2

Triorganoantimony and Triorganobismuth Derivatives of 2-Pyridinecarboxylic Acid and 2-Pyridylacetic Acid. Crystal and Molecular Structures of (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂ and (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ Triorganoantimony and triorganobismuth dicarboxylates R₃M(O₂C-2-C₅H₄N)₂ (M = Sb, R = CH₃, C₆H₅, 4-CH₃OC₆H₄; M = Bi, R = C₆H₅, 4-CH₃C₆H₄) and (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ have been prepared from (CH₃)₃Sb(OH)₂, R₃SbO (R = C₆H₅, 4-CH₃OC₆H₄), or R₃BiCO₃ (R = C₆H₅, 4-CH₃C₆H₄) and the appropriate heterocyclic carboxylic acid. Vibrational spectroscopic data indicate a trigonal bipyramidal environment of M the O(? C)-atoms of the carboxylate ligands being in the apical and three C atoms (of R) in the equatorial positions; in addition coordinative interaction occurs in the 2-pyridinecarboxylates between M and O(?C) of one and N of the other carboxylate ligand and in (CH₃)₃)Sb(O₂CCH₂-2-C₅H₄N)₂ between Sb and O(?C) of both carboxylate ligands. (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂/(CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂ crystallize monoclinic [space group P2₁/c/P2₁/n; a = 892.6(9)/1043.4(6), b = 1326.9(6)/3166.2(18), c = 2233.1(9)/1147.5(7) pm, β = 99.74(8)°/97.67(5)° Z = 4/8; d(calc.) = 1.522/1.553 × Mg m^?3; V_cell = 2606.7 × 10⁶/3757.0 × 10⁶pm³, structure determination from 3798/4965 independent reflexions (F ≥ 4.0 σ(F))/(I ≥ 1.96 σ(I), R(unweighted) = 0.024/0.036]. Sb is bonding to three C₆H₅/CH₃ groups in the equatorial plane [mean distances Sb? C: 212.2(3)/208.7(6) pm] and two carboxylate ligands via O in the apical positions [Sb? O distances: 218.5(2), 209.9(2)/212.1(3), 213.2(3) pm]. In (C₆H₅)₃Sb(O₂C-2-C₅H₄N)₂ there is a short Sb? O(?C) and a short Sb? N contact [Sb? O: 272.1(2), Sb? N: 260.2(2) pm] and distoritions of the equatorial angles [C? Sb? C: 99.2(1)°, 158.2(1)°, 102.0(1).] and of the axial angle [O? Sb? O: 169.9(1)°], and in (CH₃)₃Sb(O₂CCH₂-2-C₅H₄N)₂, which contains two different molecules in the asym-metric unit, there are two Sb? O(?C) contacts [Sb? O, mean: 302.2(4), and 310.7(4)pm, respectively] and distortions of the equatorial angles [C? Sb? C: 114.5(2)°, 132.4(3)° 113.1(2)°, and 123.9(3)° 115.5(2)°, 120.6(3)°, respectively] and of the axial angles [O? Sb? O: 174,9(1)°, 177.9(1)°, respectively].     

Coordination of a complete series of N2 reduction intermediates (N2H2, N2H4, and NH3) to an iron phosphine scaffold

The series of dinitrogen reduction intermediates (N(2)H(2), N(2)H(4), and NH(3)) coordinated to the Fe(DMeOPrPE)(2)H(+)(DMeOPrPE = 1,2-[bis(dimethoxypropyl)phosphino]ethane) scaffold has been synthesized or generated. The synthesis of trans-[Fe(DMeOPrPE)(2)(NH(3))H][BPh(4)] and generation of trans-[Fe(DMeOPrPE)(2)(N(2)H(4))H][BPh(4)] were achieved by substitu tion of the dinitrogen ligand on trans-[Fe(DMeOPrPE)(2)(N(2))H][BPh(4)]. The trans-[Fe(DMeOPrPE)(2)(N(2)H(2))H](+) complex and its deprotonated conjugate base, trans-Fe(DMeOPrPE)(2)(N(2)H)H, were observed by (31)P and (1)H NMR from decomposition of trans-[Fe(DMeOPrPE)(2)(N(2)H(4))H](+) in the presence of excess hydrazine. Attempts to chemically oxidize trans-[Fe(DMeOPrPE)(2)(N(2)H(4))H](+) to trans-[Fe(DMeOPrPE)(2)(N(2)H(2))H][BPh(4)] with a variety of oxidizing agents yielded only decomposition products consistent with the intermediate formation of trans-[Fe(DMeOPrPE)(2)(N(2)H(2))H](+) prior to decomposition.     

Bildung von NH4[Hg3(NH)2](NO3)3 und Umwandlung in [Hg2N](NO3)

Formation of NH₄[Hg₃(NH)₂](NO₃)₃ and Transformation to [Hg₂N](NO₃) NH₄[Hg₃(NH)₂](NO₃)₃ ( 1 ) and [Hg₂N](NO₃) ( 2 ) are obtained from conc. aqueous ammonia solutions of Hg(NO₃)₂ at ambient temperature and under hydrothermal conditions at 180 °C, respectively, as colourless and dark yellow to light brown single crystals. The crystal structures {NH₄[Hg₃(NH)₂](NO₃)₃: cubic, P4₁32, a = 1030.4(2) pm, Z = 4, R_all = 0.028; [Hg₂N](NO₃): tetra gonal, P4₃2₁2, a = 1540.4(1), c = 909.8(1) pm, Z = 4, R_all = 0.054} have been determined from single crystal data. Both exhibit network type structures in which [HNHg₃] and [NHg₄] tetrahedra of the partial structures of 1 and 2 are connected via three and four vertices, respectively. 1 transforms at about 270 °C in a straightforward reaction to 2 whereby the decomposition products of NH₄NO₃ are set free. 2 decomposes at about 380 °C forming yellow HgO. Most certainly, 1 is identical with a mineral previously analyzed as “Hg(NH₂)(NO₃)” with the same Hg:N:O ratio.     

Darstellung und Kristallstruktur von Diamminmagnesiumdiazid Mg(NH3)2(N3)2

Preparation and Crystal Structure of Diammin Magnesium Diazide Mg(NH₃)₂(N₃)₂ Diammin magnesium diazide was synthesized from Mg₃N₂ and NH₄N₃ in liquid ammonia and crystallized at 150 °C under autogenous atmosphere of HN₃ and NH₃ using sealed ampoules. Mg(NH₃)₂(N₃)₂ is a colorless, microcrystalline powder which can detonate above 180 °C. Caution, preparation and manipulation of Mg(NH₃)₂(N₃)₂ is very dangerous! The crystal structure was solved from powder data using the Patterson method and a Rietveld refinement was performed (Mg(NH₃)₂(N₃)₂, I 4/m, no. 87; a = 6.3519(1), c = 7.9176(2) Å; Z = 2, R(F²)= 0.1162). The crystal structure of Mg(NH₃)₂(N₃)₂ is related to that of SnF₄. It consists of planes built up from corner sharing Mg(NH₃)₂(N₃)₄ octahedra connected equatorially over their four azide bridges with the ammonia ligands being in trans position. IR data were collected and interpreted in accordance with the structural data.     

Metall-Schwefelstickstoff-Verbindungen. 16. Reaktionsprodukte von Blei- und Zinnsalzen mit S4N4 Die Strukturen von PbN2S2 · NH3, PbN2S2 und SnCl4 · 2S4N4

Metal Sulfur Nitrogen Compounds. 16. Products of the Reaction of Lead- and Tin Salts with S₄N₄. Structures of PbN₂S₂ · NH₃, PbN₂S₂, and SnCl₄ · 2S₄N₄ PbN₂S₂ · NH₃ is monoclinic, P2₁/a, a = 5.671, b = 16.123, c = 6.102 Å, β = 95.12°, Z = 4, PbN₂S₂, however, orthorhombic, P2₁2₁2₁, a = 4.375, b = 7.654, c = 12.274 Å, Z = 4. The planar five-membered PbN₂S₂ rings in both compounds show no remarkable differences. In PbN₂S₂ · NH₃, the NH₃ molecule is bound to Pb perpendicularly to the plane of the ring. The structure of the long known addition compound SnCl₄ · 2S₄N₄ was determined. It is orthorhombic, Pc2₁b, a = 11.467, b = 11.995, c = 12.374 Å, Z = 4. Sn shows sixfold coordination, the two S₄N₄ rings are attached to Sn trans to each other via a N atom.     

Synthese,Kristallstruktur und Magnetismus von [(CH3)2NH2][PrCl4(H2O)2]

Preparation, Crystal Structure, and Magnetism of [(CH₃)₂NH₂][PrCl₄(H₂O)₂] The complex water containing chloride [(CH₃)₂NH₂][PrCl₄(H₂O)₂] has been prepared for the first time and the crystal structure has been determined from single crystal X‐ray diffraction data. The compound crystallizes orthorhombically in the space group Cmca (Z = 8) with a = 1796.6(2) pm, b = 940.7(1) pm, and c = 1238.4(2) pm. The anionic part of the structure is built up by chains of edge‐connected trigondodecahedra [PrCl₆(H₂O)₂]^3– according to [PrCl_4/2Cl₂(H₂O)₂]^–, which are held together by dimethylammonium cations ([(CH₃)₂NH₂]⁺). In order to study the interactions between the praseodymium cation (Pr³⁺) and the ligands magnetic measurements were carried out. The magnetic data were interpreted by ligand field calculations applying the angular overlap model.     

Binding N2, N2H2, N2H4, and NH3 to transition-metal sulfur sites: modeling potential intermediates of biological N2 fixation

In the quest for low-molecular-weight metal sulfur complexes that bind nitrogenase-relevant small molecules and can serve as model complexes for nitrogenase, compounds with the [Ru(PiPr(3))('N(2)Me(2)S(2)')] fragment were found ('N(2)Me(2)S(2)'(2-)=1,2-ethanediamine-N,N'-dimethyl-N,N'-bis(2-benzenethiolate)(2-)). This fragment enabled the synthesis of a first series of chiral metal sulfur complexes, [Ru(L)(PiPr(3))('N(2)Me(2)S(2)')] with L=N(2), N(2)H(2), N(2)H(4), and NH(3), that meet the biological constraint of forming under mild conditions. The reaction of [Ru(NCCH(3))(PiPr(3))('N(2)Me(2)S(2)')] (1) with NH(3) gave the ammonia complex [Ru(NH(3))(PiPr(3))('N(2)Me(2)S(2)')] (4), which readily exchanged NH(3) for N(2) to yield the mononuclear dinitrogen complex [Ru(N(2))(PiPr(3))('N(2)Me(2)S(2)')] (2) in almost quantitative yield. Complex 2, obtained by this new efficient synthesis, was the starting material for the synthesis of dinuclear (R,R)- and (S,S)-[micro-N(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] ((R,R)-/(S,S)-3). (Both 2 and 3 have been reported previously.) The as-yet inexplicable behavior of complex 3 to form also the R,S isomer in solution has been revealed by DFT calculations and (2)D NMR spectroscopy studies. The reaction of 1 or 2 with anhydrous hydrazine yielded the hydrazine complex [Ru(N(2)H(4))(PiPr(3))('N(2)Me(2)S(2)')] (6), which is a highly reactive intermediate. Disproportionation of 6 resulted in the formation of mononuclear diazene complexes, the ammonia complex 4, and finally the dinuclear diazene complex [micro-N(2)H(2)[Ru(PiPr(3))('N(2)Me(2)S(2)')](2)] (5). Dinuclear complex 5 could also be obtained directly in an independent synthesis from 1 and N(2)H(2), which was generated in situ by acidolysis of K(2)N(2)(CO(2))(2). Treatment of 6 with CH(2)Cl(2), however, formed a chloromethylated diazene species [[Ru(PiPr(3))('N(2)Me(2)S(2)')]-micro-N(2)H(2)[Ru(Cl)('N(2)Me(2)S(2)CH(2)Cl')]] (9) ('N(2)Me(2)S(2)CH(2)Cl'(2-) =1,2-ethanediamine-N,N'-dimethyl-N-(2-benzenethiolate)(1-)-N'-(2-benzenechloromethylthioether)(1-)]. The molecular structures of 4, 5, and 9 were determined by X-ray crystal structure analysis, and the labile N(2)H(4) complex 6 was characterized by NMR spectroscopy.     

Azidokomplexe von Mangan(II) und Cobalt(II) Die Kristallstrukturen von (PPh4)2[Mn(N3)4] und (PPh4)2[Co(N3)3Cl]

Azido Complexes of Manganese(II) and Cobalt(II). Crystal Structures of (PPh₄)₂[Mn(N₃)₄] and PPh₄₂[Co(N₃)₃Cl] (PPh₄)₂[Mn(N₃)₄] and (PPh₄)₂[Co(N₃)₃Cl] were obtained as light-brown and green blue, nonexplosive crystalline compounds, respectively. They are only slightly sensitive to moisture and were obtained from the tetrachloro complexes (PPh₄)₂MCl₄ by reactions with silver azide in dichloromethane. The compounds were characterized by thier i.r. spectra and by crystal structure analyses. Both crystallized in the monoclinic space group C2/c, Z = 4, but they are not isotypic. (PPh₄)₂[Mn(N₃)₄]: structure determination with 711 independent reflexions, R = 0.097; a = 2249.1, b = 1499.6, c = 1370.3 pm, β = 104.86°. (PPh₄)₂[Co(N₃)Cl]: 2753 reflexions, R = 0.075; a = 1119.7, b = 1899.2, c = 2115.4 pm, β = 90.47°. The structures consist of PPh₄⁺ ions and of anions that are situated on twofold crystallographic rotation axes. The anions show positional disorder, statistically assuming two different orientations with probabilities of 50% each; in the case of [Co(N₃)₃Cl]^2?, the Cl atom is superimposed statistically with an azido group, whereas the [Mn(N₃)₄]^2? ion is tilted by about 20° from the ideal position to two sides of the crystallographic axis. In both compounds the cation form layers and the anions are located between the layers.     

Synthese,Kristallstruktur und Magnetismus von [(CH3)2NH2][NdCl4(H2O)2]

Preparation, Crystal Structure, and Magnetism of [(CH₃)₂NH₂][NdCl₄(H₂O)₂] The complex water containing chloride [(CH₃)₂NH₂][NdCl₄(H₂O)₂] was prepared for the first time and the crystal structure was determined by X‐ray methods from single crystals. The compound crystallizes in the orthorhombic space group Cmca (Z = 8) with a = 1793.5(2) pm, b = 936.6(2) pm and c = 1232.8(2) pm. The anionic part of the structure is built up by chains of edge connected [NdCl_4/2Cl₂(H₂O)₂]^– trigondodecahedra. In order to study the interactions between the neodymium cation and the ligands magnetic measurements were carried out. The magnetic data were interpreted by ligand field calculations applying the angular overlap model.     

Vergleich der Kristallstrukturen der Tetraammoniakate von Lithiumhalogeniden,LiBr·4NH3 und LiI·4NH3, mit der Struktur von Tetramethylammoniumiodid,N(CH3)4I

A Comparison of the Crystal Structures of the Tetraammoniates of Lithium Halides, LiBr·4NH₃ and LiI·4NH₃, with the Structure of Tetramethylammonium Iodide, N(CH₃)₄I Crystals of the tetraammoniates of LiBr and LiI sufficient in size for X‐ray structure determinations were obtained by slow evaporation of NH₃ at room temperature from a clear solution of the halides in liquid ammonia. The compounds crystallize in the space group Pnma (No. 62) with four formula units in the unit cell: LiBr·4NH₃: a = 11.947(5)Å, b = 7.047(4)Å, c = 9.472(3)Å LiI·4NH₃: a = 12.646(3)Å, b = 7.302 (1)Å, c = 9.790(2)Å For N(CH₃)₄I the structure was now successfully solved including the hydrogen positions of the methyl groups. N(CH₃)₄I: P4/nmm (No. 129), Z = 2, a = 7.948(1)Å, c = 5.738(1)Å The ammoniates of LiBr and LiI crystallize isotypic in a strongly distorted arrangement of the CsCl motif. Even N(CH₃)₄I has an CsCl‐like structure. Both structure types differ mainly in their orientation of the [Li(NH₃)₄]⁺ — resp. [N(CH₃)₄]⁺ — cations with respect to the surrounding “cube” of anions.     

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.