Preparation and Structure of Melemium Melem Perchlorate HC6N7(NH2)3ClO4·C6N7(NH2)3

A new perchlorate salt of melem (2,6,10‐triamino‐s‐heptazine, C₆N₇(NH₂)₃) was obtained from an aqueous solution of HClO₄ at lower concentration than the ones reported for the synthesis of melemium perchlorate monohydrate (HC₆N₇(NH₂)₃)ClO₄·H₂O. The new salt was identified as melemium melem perchlorate (HC₆N₇(NH₂)₃)ClO₄·C₆N₇(NH₂)₃ representing a melem adduct of water free melemium perchlorate. The crystal structure was solved by single‐crystal X‐ray methods ( , no. 2, Z = 2, a = 892.1(2), b = 992.7(2), c = 1201.5(2) pm, α = 112.30(3), β = 96.96(3), γ = 95.38(3)°, V = 965.8(4)·10⁶ pm³, 4340 data, 387 parameters, R1 = 0.039). Melemium melem perchlorate crystallizes in a layer‐like structure containing both protonated HC₆N₇(NH₂)₃ and non protonated C₆N₇(NH₂)₃ moieties in the coplanar layers as well as perchlorate ions between them, all of which being interconnected by hydrogen bonds. Vibrational spectroscopic investigations (FTIR and Raman) of the salt were conducted.     

Melamine–Melem Adduct Phases: Investigating the Thermal Condensation of Melamine

By studying the thermal condensation of melamine, we have identified three solid molecular adducts consisting of melamine C₃N₃(NH₂)₃ and melem C₆N₇(NH₂)₃ in differing molar ratios. We solved the crystal structure of 2 C₃N₃(NH₂)₃?C₆N₇(NH₂)₃ ( 1 ; C2/c; a=21.526(4), b=12.595(3), c=6.8483(14) Å; β=94.80(3)°; Z=4; V=1850.2(7) ų), C₃N₃(NH₂)₃?C₆N₇(NH₂)₃ ( 2 ; Pcca; a=7.3280(2), b=7.4842(2), c=24.9167(8) Å; Z=4; V=1366.54(7) ų), and C₃N₃(NH₂)₃?3 C₆N₇(NH₂)₃ ( 3 ; C2/c; a=14.370(3), b=25.809(5), c=8.1560(16) Å; β=94.62(3)°; Z=4; V=3015.0(10) ų) by using single‐crystal XRD. All syntheses were carried out in sealed glass ampoules starting from melamine. By variation of the reaction conditions in terms of temperature, pressure, and the presence of ammonia‐binding metals (europium) we gained a detailed insight into the occurrence of the three adduct phases during the thermal condensation process of melamine leading to melem. A rational bulk synthesis allowed us to realize adduct phases as well as phase separation into melamine and melem under equilibrium conditions. A solid‐state NMR spectroscopic investigation of adduct 1 was conducted.     

Zur Kenntnis der Kristallstruktur von Melem C6N7(NH2)3

On the Crystal Structure of Melem C₆N₇(NH₂)₃ Single crystals of melem ( 1 ) were grown from both DMSO‐solutions and the gas phase. The structure of melem ( 1 ) was solved by single‐crystal X‐ray diffraction (P2₁/c, Z = 4, a = 741.66(15), b = 862.28(17), c = 1335.9(3) pm, β = 99.91(3)° R1 = 0.037 for 1098 reflections). The structure determination by X‐ray powder diffraction, which has been previously conducted, is in agreement with our data. The increased quality of the structural information allows for a more detailed understanding of the hydrogen bonding network.     

Formation of a Hydrogen‐Bonded Heptazine Framework by Self‐Assembly of Melem into a Hexagonal Channel Structure

Self‐assembly of melem C₆N₇(NH₂)₃ in hot aqueous solution leads to the formation of hydrogen‐bonded, hexagonal rosettes of melem units surrounding infinite channels with a diameter of 8.9 Å. The channels are filled with strongly disordered water molecules, which are bound to the melem network through hydrogen bonds. Single‐crystals of melem hydrate C₆N₇(NH₂)₃ ? xH₂O (x≈2.3) were obtained by hydrothermal treatment of melem at 200 °C and the crystal structure (R $\bar 3$ c, a=2879.0(4), c=664.01(13) pm, V=4766.4(13)×10⁶ pm³, Z=18) was elucidated by single‐crystal X‐ray diffraction. With respect to the structural similarity to the well‐known adduct between melamine and cyanuric acid, the composition of the obtained product was further analyzed by solid‐state NMR spectroscopy. Hydrolysis of melem to cyameluric acid during syntheses at elevated temperatures could thus be ruled out. DTA/TG studies revealed that, during heating of melem hydrate, water molecules can be removed from the channels of the structure to a large extent. The solvent‐free framework is stable up to 430 °C without transforming into the denser structure of anhydrous melem. Dehydrated melem hydrate was further characterized by solid‐state NMR spectroscopy, powder X‐ray diffraction, and sorption measurements to investigate structural changes induced by the removal of water from the channels. During dehydration, the hexagonal, layered arrangement of melem units is maintained whereas the formation of additional hydrogen bonds between melem entities requires the stacking mode of hexagonal layers to be altered. It is assumed that layers are shifted perpendicular to the direction of the channels, thereby making them inaccessible for guest molecules.     

Synthese und Kristallstruktur von K2(HSO4)(H2PO4), K4(HSO4)3(H2PO4) und Na(HSO4)(H3PO4)

Synthesis and Crystal Structure of K₂(HSO₄)(H₂PO₄), K₄(HSO₄)₃(H₂PO₄), and Na(HSO₄)(H₃PO₄) Mixed hydrogen sulfate phosphates K₂(HSO₄)(H₂PO₄), K₄(HSO₄)₃(H₂PO₄) and Na(HSO₄)(H₃PO₄) were synthesized and characterized by X‐ray single crystal analysis. In case of K₂(HSO₄)(H₂PO₄) neutron powder diffraction was used additionally. For this compound an unknown supercell was found. According to X‐ray crystal structure analysis, the compounds have the following crystal data: K₂(HSO₄)(H₂PO₄) (T = 298 K), monoclinic, space group P 2₁/c, a = 11.150(4) Å, b = 7.371(2) Å, c = 9.436(3) Å, β = 92.29(3)°, V = 774.9(4) ų, Z = 4, R₁ = 0.039; K₄(HSO₄)₃(H₂PO₄) (T = 298 K), triclinic, space group P 1, a = 7.217(8) Å, b = 7.521(9) Å, c = 7.574(8) Å, α = 71.52(1)°, β = 88.28(1)°, γ = 86.20(1)°, V = 389.1(8)ų, Z = 1, R₁ = 0.031; Na(HSO₄)(H₃PO₄) (T = 298 K), monoclinic, space group P 2₁, a = 5.449(1) Å, b = 6.832(1) Å, c = 8.718(2) Å, β = 95.88(3)°, V = 322.8(1) ų, Z = 2, R₁ = 0,032. The metal atoms are coordinated by 8 or 9 oxygen atoms. The structure of K₂(HSO₄)(H₂PO₄) is characterized by hydrogen bonded chains of mixed H_nS/PO₄^– tetrahedra. In the structure of K₄(HSO₄)₃(H₂PO₄), there are dimers of H_nS/PO₄^– tetrahedra, which are further connected to chains. Additional HSO₄^– tetrahedra are linked to these chains. In the structure of Na(HSO₄)(H₃PO₄) the HSO₄^– tetrahedra and H₃PO₄ molecules form layers by hydrogen bonds.     

Synthese und Kristallstruktur von Hydrogensulfaten einwertiger Metalle – Ag(H3O)(HSO4)2, Ag2(HSO4)2(H2SO4), AgHSO4 und Hg2(HSO4)2

Synthesis and Crystal Structure of Metal(I) Hydrogen Sulfates – Ag(H₃O)(HSO₄)₂, Ag₂(HSO₄)₂(H₂SO₄), AgHSO₄, and Hg₂(HSO₄)₂ Hydrogen sulfates Ag(H₃O)(HSO₄)₂, Ag₂(HSO₄)₂ · (H₂SO₄), and AgHSO₄ have been synthesized from Ag₂SO₄ and sulfuric acid. Hg₂(HSO₄)₂ was obtained from metallic mercury and 96% sulfuric acid as starting materials. The compounds were characterized by X‐ray single crystal structure determination. Ag(H₃O)(HSO₄)₂ belongs to the structure type of Na(H₃O)(HSO₄). The silver atom is coordinated by 6 + 2 oxygen atoms. In the structure, there are dimers and chains of hydrogen bonded HSO₄^– tetrahedra. Dimers and chains are connected by the H₃O⁺ ion to form a three dimensional hydrogen network. Ag₂(HSO₄)₂(H₂SO₄) crystallizes isotypic to Na₂(HSO₄)₂(H₂SO₄). The coordination number of silver is 6 + 1. The structure of Ag₂(HSO₄)₂(H₂SO₄) is characterized by hydrogen bonded trimers of HSO₄^– tetrahedra, which are further connected to chains. For the recently published structure of AgHSO₄ the hydrogen bonding system was discussed. There are tetrameres and chains, connected by bifurcated hydrogen bonds. The structure of Hg₂(HSO₄)₂ contains Hg₂²⁺ cations with Hg–Hg distance of 2.509 Å. Every mercury atom is coordinated by one oxygen atom at shorter distance (2.18 Å) and three ones at longer distances (2.57 to 3.08 Å). The HSO₄^– tetrahedra form zigzag chains by hydrogen bonds.     

Kristallstruktur von Natrium‐Dihydrogencyamelurat‐Tetrahydrat Na[H2(C6N7)O3] · 4 H2O

Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H₂(C₆N₇)O₃] · 4 H₂O Sodium dihydrogencyamelurate‐tetrahydrate Na[H₂(C₆N₇)O₃]·4 H₂O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ( a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) ų, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.     

Synthese und Struktur neuer Natriumhydrogensulfate Na(H3O)(HSO4)2; Na2(HSO4)2(H2SO4) und Na(HSO4)(H2SO4)2

Synthesis and Structure of New Sodium Hydrogen Sulfates Na(H₃O)(HSO₄)₂, Na₂(HSO₄)₂(H₂SO₄), and Na(HSO₄)(H₂SO₄)₂ Three acidic sodium sulfates have been synthesized from the system sodium sulfate/sulfuric acid and have been crystallographically characterized. Na(H₃O)(HSO₄)₂ ( A ) crystallizes in the space group P2₁/c with the unit cell parameters a = 6.974(2), b = 13.086(2), c = 8.080(3) Å, α = 105.90(4)°, V = 709.1 Å3, Z = 4. Na₂(HSO₄)₂(H₂SO₄) ( B ) is orthorhombic (space group Pna2₁) with the unit cell parameters a = 9.970(2), b = 6.951(1), c = 13.949(3) Å, V = 966.7 ų and Z = 4. Na(HSO₄)(H₂SO₄)₂ ( C ) crystallizes in the triclinic space group P1 with the unit cell parameters a = 5.084(1), b = 8.746(1), c = 11.765(3) Å, α = 68.86(2)°, β = 88.44(2)°, γ = 88.97(2)°, V = 487.8 Å3 and Z = 2. All three compounds contain SO₄ tetrahedra as HSO₄^? anions and additionally in B and C in form of H₂SO₄ molecules. The ratio H:SO₄ determines the connectivity degree in the hydrogen bond system. In A , there are zigzag chains and dimers additionally connected via oxonium ions. Complex chains consisting of cyclic trimers (two HSO₄^? and one H₂SO₄) are present in B . In structure C , several parallel chains are connected to columns due to the greater content of H₂SO₄. Sodium cations show a distorted octahedral coordination by oxygen in all three structures, the NaO₆ octahedra being “isolated” (connected via SO₄ tetrahedra only) in A . Pairs of octahedra with common edge form Na₂O₁₀ dimeric units in C . Such double octahedra are connected via common corners forming zigzag chains in B .     

Influence of the Organic Species and Oxoanion in the Synthesis of two Uranyl Sulfate Hydrates, (H3O)2[(UO2)2(SO4)3­(H2O)]·7H2O and (H3O)2[(UO2)2(SO4)3(H2O)]·4H2O,and a Uranyl Selenate‐Selenite [C5H6N][(UO2)(SeO4)(HSeO3)]

Two uranyl sulfate hydrates, (H₃O)₂[(UO₂)₂(SO₄)₃(H₂O)] · 7H₂O (NDUS) and (H₃O)₂[(UO₂)₂(SO₄)₃(H₂O)] · 4H₂O (NDUS1), and one uranyl selenate‐selenite [C₅H₆N][(UO₂)(SeO₄)(HSeO₃)] (NDUSe), were obtained and their crystal structures solved. NDUS and NDUSe result from reactions in highly acidic media in the presence of L ‐cystine at 373 K. NDUS crystallized in a closed vial at 278 K after 5 days and NDUSe in an open beaker at 278 K after 2 weeks. NDUS1 was synthesized from aqueous solution at room temperature over the course of a month. NDUS, NDUS1, and NDUSe crystallize in the monoclinic space group P2₁/n, a = 15.0249(4) Å,b = 9.9320(2) Å, c = 15.6518(4) Å, β = 112.778(1)°, V = 2153.52(9) ų,Z = 4, the tetragonal space group P4₃2₁2, a = 10.6111(2) Å,c = 31.644(1) Å, V = 3563.0(2) ų, Z = 8, and in the monoclinic space group P2₁/n, a = 8.993(3) Å, b = 13.399(5) Å, c = 10.640(4) Å,β = 108.230(4)°, V = 1217.7(8) ų, Z = 4, respectively.The structural units of NDUS and NDUS1 are two‐dimensional uranyl sulfate sheets with a U/S ratio of 2/3. The structural unit of NDUSe is a two‐dimensional uranyl selenate‐selenite sheets with a U/Se ratio of 1/2. In‐situ reaction of the L ‐cystine ligands gives two distinct products for the different acids used here. Where sulfuric acid is used, only H₃O⁺ cations are located in the interlayer space, where they balance the charge of the sheets, whereas where selenic acid is used, interlayer C₅H₆N⁺ cations result from the cyclization of the carboxyl groups of L ‐cystine, balancing the charge of the sheets.     

First Characterization of an Extended Ammonium‐Ammonia Complex [{NH4(NH3)4}+(μ‐NH3)2] in the Crystal Structure of [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3

The compound [NH₄(NH₃)₄][Co(C₂B₉H₁₁)₂] · 2 NH₃ ( 1 ) was prepared by the reaction of Na[Co(C₂B₉H₁₁)₂] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C₂B₉H₁₁)₂]^‐ complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH₄(NH₃)₄}⁺(μ‐NH₃)₂] cationic chain, which is formed by [NH₄(NH₃)₄]⁺ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).     

Crystal Structure of Ni(NH3)Cl2 and Ni(NH3)Br2

Ni(NH₃)Cl₂ and Ni(NH₃)Br₂ were prepared by the reaction of Ni(NH₃)₂X₂ with NiX₂ at 350 °C in a steel autoclave. The crystal structures were determined by X‐ray powder diffraction using synchrotron radiation and refined by Rietveld methods. Ni(NH₃)Cl₂ and Ni(NH₃)Br₂ are isotypic and crystallize in the space group I2/m with Z = 8 and for Ni(NH₃)Cl₂: a = 14.8976(3) Å, b = 3.56251(6) Å, c = 13.9229(3) Å, β = 106.301(1)°; Ni(NH₃)Br₂: a = 15.5764(1) Å, b = 3.74346(3) Å, c = 14.4224(1) Å, β = 105.894(1)°. The crystal structures are built up by two crystallographically distinct but chemically mostly equivalent polymeric octahedra double chains [NiX_3/3X_2/2(NH₃)] (X = Cl, Br) running along the short b‐axis. The octahedra NiX₅NH₃ share common edges therein. The crystal structures of the ammines Ni(NH₃)_mX₂ with m = 1, 2, 6 can be derived from that of the halides NiX₂ (X = Cl, Br) by successive fragmentation of its CdCl₂ like layers by NH₃.     

2,5,8‐Trihydrazino‐s‐heptazine: A Precursor for Heptazine‐based Iminophosphoranes

The title compound  C₆N₇(NHNH₂)₃ ( 1 ) was obtained from melem C₆N₇(NH₂)₃ or melon [C₆N₇(NH₂)NH]_n and hydrazine by an autoclave synthesis. Upon treatment with a 10 % HCl solution it is transformed into the trihydrochloride  [C₆N₇(NHNH₃)₃]Cl₃ ( 2 ). Compounds 1 and 2 were analysed with ¹³C NMR, ¹⁵N NMR, FTIR and Raman spectroscopy. Furthermore, the single‐crystal X‐ray structure of the pentahydrate of 2 is reported (P\bar{1} , a = 674.96(3), b = 1214.17(6), c = 1272.15(6) pm, α = 66.288(2)°, β = 75.153(2)°, γ = 80.420(2)°, V = 920.30(8)·10⁶ pm³, Z = 2, T = 90(2) K). The thermal decomposition of 1 and 2 was investigated with TG/DTA. Reaction of 1 with NaNO₂/HCl yields triazido‐s‐heptazine, C₆N₇(N₃)₃ ( 3 ). Tris(tri‐n‐butylphosphinimino)‐s‐heptazine ( 4 ) was synthesised from 3 and characterised by means of ¹³C, ³¹P, ¹H NMR, FTIR and MALDI‐TOF spectroscopy. Similar to s‐heptazine derivative 3 , compounds 1 and 4 are precursors for graphitic carbon nitrides, which have attracted considerable attention recently, and to various potential applications, such as flame retardants and (photo) catalysis.     

[N,N′‐Bis(3‐aminopropyl)ethylenediamine‐κ4N,N′,N′′,N′′′](trithiocyanurato‐κ2N,S)zinc(II) ethanol solvate

In the crystal structure of the title compound, [N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine‐κ⁴N,N′,N′′,N′′′][1,3,5‐triazine‐2,4,6(1H,3H,5H)‐tri­thionato(2−)‐κ²N,S]­zinc(II) ethanol sol­vate, [Zn(C₈H₂₂N₄)₂(C₃HN₃S₃)]·C₂H₆O, the Zn^II atom is octa­hedrally coordinated by four N atoms [Zn—N = 2.104 (2)–2.203 (2) Å] of a tetradentate N‐donor N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine (bapen) ligand and by two S and N atoms [Zn—S = 2.5700 (7) Å and Zn—N = 2.313 (2) Å] of a tri­thio­cyanurate(2−) (ttcH²⁻) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds.     

Reaction with SO3 in Ionic Liquids: The Example of K2(S2O7)­(H2SO4)

The ionic liquid 1‐butyl‐3‐methylimidazolium hydrogensulfate, [bmim]HSO₄, turned out to be resistant even to strong oxidizers like SO₃. Thus, it should be a suitable solvent for the preparation of polysulfates at low temperatures. As a proof of principle we here present the synthesis and crystal structure of K₂(S₂O₇)(H₂SO₄), which has been obtained from the reaction of K₂SO₄ and SO₃ in [bmim]HSO₄. In the crystal structure of K₂(S₂O₇)(H₂SO₄) (orthorhombic, Pbca, Z = 8, a = 810.64(2) pm, b = 1047.90(2) pm, c = 2328.86(6) pm, V = 1978.30(8) ų) two crystallographically unique potassium cations are coordinated by a different number of monodentate and bidentate‐chelating disulfate anions as well as by sulfuric acid molecules. The crystal structure consists of alternating layers of [K₂(S₂O₇)] slabs and H₂SO₄ molecules. Hydrogen bonds between hydrogen atoms of sulfuric acid molecules and oxygen atoms of the neighboring disulfate anions are observed.     

Synthesis and Crystal Structure of [(1‐(Phenyltriazenido)‐2‐(phenyltriazeno)benzene)(nitrato)mercury(II)], {Hg[PhN3C6H4N3(H)Ph](NO3)}, a Complex with Weak Metal‐Arene π‐Interactions

The reaction of PhN₃(H)C₆H₄N₃(H)Ph with Hg(NO₃)₂ in THF in the presence of triethylamine yields {Hg[PhN₃C₆H₄N₃(H)Ph](NO₃)} as a yellow powder that can be recrystallized from THF/acetone. The crystals belong to the monoclinic system, space group P2₁ with the cell dimensions a = 9.639(2), b = 5.412(1), c = 19.675(4) Å, β= 97.47(3)°, V = 1017.7 (4) ų, Z = 2. The crystal structure determination (2668 unique reflections with [I>2σ(I)], 262 parameters, R₁ = 0.0393) shows that the structure consists of mononuclear complexes. Hg atoms are linearly coordinated by one N_α atom of the triazenide unit of the planar ligand [Hg‐N(1) = 2.101(8) Å] and an O atom of the NO₃^— ion [Hg‐O(1) = 2.11(1) Å]. Additional weak Hg‐N contacts [Hg‐N(4) = 2.662(9) and Hg‐N(3) = 2.851(9) Å] and an intramolecular hydrogen bond between the triazenide hydrogen and an O atom of the nitrate group are observed [N(6)‐H(6)···O(2) = 2.92(2) Å]. The complexes are stacked to infinite chains by metal‐arene π‐interactions. Each Hg atom is coordinated by the terminal phenyl rings of two neighboring complexes [Hg‐C from 3.40(1) to 4.10(1) Å] in a η² fashion.     

Cobalt(II) and cadmium(II) square grids supported with 4,4′‐bipyrazole and accommodating 3‐carboxyadamantane‐1‐carboxylate

In poly[[bis(μ‐4,4′‐bi‐1H‐pyrazole‐κ²N²:N^2′)bis(3‐carboxyadamantane‐1‐carboxylato‐κO¹)cobalt(II)] dihydrate], {[Co(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (I), the Co²⁺ cation lies on an inversion centre and the 4,4′‐bipyrazole (4,4′‐bpz) ligands are also situated across centres of inversion. In its non‐isomorphous cadmium analogue, {[Cd(C₁₂H₁₅O₄)₂(C₆H₆N₄)₂]·2H₂O}_n, (II), the Cd²⁺ cation lies on a twofold axis. In both compounds, the metal cations adopt an octahedral coordination, with four pyrazole N atoms in the equatorial plane [Co—N = 2.156 (2) and 2.162 (2) Å; Cd—N = 2.298 (2) and 2.321 (2) Å] and two axial carboxylate O atoms [Co—O = 2.1547 (18) Å and Cd—O = 2.347 (2) Å]. In both structures, interligand hydrogen bonding [N...O = 2.682 (3)–2.819 (3) Å] is essential for stabilization of the MN₄O₂ environment with its unusually high (for bulky adamantanecarboxylates) number of coordinated N‐donor co‐ligands. The compounds adopt two‐dimensional coordination connectivities and exist as square‐grid [M(4,4′‐bpz)₂]_n networks accommodating monodentate carboxylate ligands. The interlayer linkage is provided by hydrogen bonds from the carboxylic acid groups via the solvent water molecules [O...O = 2.565 (3) and 2.616 (3) Å] to the carboxylate groups in the next layer [O...O = 2.717 (3)–2.841 (3) Å], thereby extending the structures in the third dimension.     

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.     

Two Novel CuII Phenanthroline Adipato Complexes with π‐π Stacking Interactions: [Cu(phen)2(C6H8O4)] · 4.5 H2O and [(Cu2(phen)2Cl2)(C6H8O4)] · 4 H2O

The blue copper complex compounds [Cu(phen)₂(C₆H₈O₄)] · 4.5 H₂O ( 1 ) and [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)] · 4 H₂O ( 2 ) were synthesized from CuCl₂, 1,10‐phenanthroline (phen) and adipic acid in CH₃OH/H₂O solutions. [Cu(phen)₂‐ (C₆H₈O₄)] complexes and hydrogen bonded H₂O molecules form the crystal structure of ( 1 ) (P1 (no. 2), a = 10.086(2) Å, b = 11.470(2) Å, c = 16.523(3) Å, α = 99.80(1)°, β = 115.13(1)°, γ = 115.13(1)°, V = 1617.5(5) ų, Z = 2). The Cu atoms are square‐pyramidally coordinated by four N atoms of the phen ligands and one O atom of the adipate anion (d(Cu–O) = 1.989 Å, d(Cu–N) = 2.032–2.040 Å, axial d(Cu–N) = 2.235 Å). π‐π stacking interactions between phen ligands are responsible for the formation of supramolecular assemblies of [Cu(phen)₂(C₆H₈O₄)] complex molecules into 1 D chains along [111]. The crystal structure of ( 2 ) shows polymeric [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains (P1 (no. 2), a = 7.013(1) Å, b = 10.376(1) Å, c = 11.372(3) Å, α = 73.64(1)°, β = 78.15(2)°, γ = 81.44(1)°, V = 773.5(2) ų, Z = 1). The Cu atoms are fivefold coordinated by two Cl atoms, two N atoms of phen ligands and one O atom of the adipate anion, forming [CuCl₂N₂O] square pyramids with an axial Cl atom (d(Cu–O) = 1.958 Å, d(Cu–N) = 2.017–2.033 Å, d(Cu–Cl) = 2.281 Å; axial d(Cu–Cl) = 2.724 Å). Two square pyramids are condensed via the common Cl–Cl edge to centrosymmetric [Cu₂Cl₂N₄O₂] dimers, which are connected via the adipate anions to form the [(Cu₂(phen)₂Cl₂)(C₆H₈O₄)_2/2] chains. The supramolecular 3 D network results from π‐π stacking interactions between the chains. H₂O molecules are located in tunnels.     

Hydrothermal Synthesis,Structures and Thermal Stability of Two Novel Lanthanide Complexes: [Er4(tp)6(H2O)6], [Lu(tp)1.5(H2O)3]

Two novel lanthanide complexes with the formula [Er₄(tp)₆(H₂O)₆] ( 1 ) and [Lu(tp)_1.5(H₂O)₃] ( 2 ) (tp = terephthalate) were synthesized by treating Er(NO₃)₃, Lu(NO₃)₃ with terephthalic acid under hydrothermal conditions, respectively. The structures were determined by X‐ray crystallography. The crystal 1 is of orthorhombic, space group Pbca(61) with a = 9.6656(2) Å, b = 26.2338(5) Å, c = 37.9022(7) Å, C₄₈H₃₆Er₄O₃₀, M = 1761.81, Z = 8, V = 9610.69(32) ų, F(000) = 6688, R₁ = 0.0326 and ωR = 0.0650. The crystal of 2 is of triclinic, space group with a = 7.8204(1) Å, b = 9.5355(1) Å, c = 10.6348(1) Å, α = 68.869(1)°, β = 71.081(1)°, γ = 75.151(1)°, C₂₄H₂₄Lu₂O₁₈, M = 475.19, Z = 2, V = 690.98(1) ų, F(000) = 454, R₁ = 0.0215 and ωR = 0.0474. Both of the two coordination polymers exhibit sandwich‐like packing structures.     

(C5H14N2)[Zn3(HPO4)4], a New 3D Open‐framework Zincophosphate Synthesized by Hydrothermal Reversible Transformation of (C5H14N2)[Zn2(HPO4)3]·H2O

In the system ZnO/H₃PO₄/H₂O/1,4‐diazacycloheptane (C₅H₁₂N₂), a new zincophosphate (ZnPO), (C₅H₁₄N₂)[Zn₃(HPO₄)₄] ( I ), was prepared by hydrothermal transformation (180 °C) of the known ZnPO hydrate (C₅H₁₄N₂)[Zn₂(HPO₄)₃]·H₂O ( II ). The thermally‐induced transformation is reversible; upon keeping the heterogeneous mixture of I and mother liquor at 80 °C recrystallization of II was observed. Single‐crystal X‐ray crystallography revealed that I possesses a unique three‐dimensional (3D) open‐framework structure built from corner‐linked ZnO₄ and HPO₄ tetrahedra. The (3,4)‐connected framework of I differs considerably from the 3D open‐framework ZnPO structure of II . Crystal data for I : Monoclinic system, space group Cc (No. 9) , Z = 4, a = 9.1389(6), b = 23.627(2), c = 9.3073(6) Å, β = 109.463(7)°, T = 298 K.