Synthesis and crystal structure of a layered cobalt phosphate with a racemic 1,2-Diaminopropane template

A novel layered cobalt phosphate with racemic 1,2-diaminopropane as the templating agent, [CH₂(NH₃)-CH(NH₃)CH₃] [CoPO₄]₂, has been synthesized and structurally characterized by single-crystal X-ray diffraction methods. The compound crystallizes in the monoclinic system, space group P2₁/c with a = 10.457(2), b = 7.849(1), c = 6.692(l)?Å, β = 103.30(1)°, V = 534.5(2)?ų, Z = 2. The interaction of cobalt phosphate anionic layers and doubly protonated 1,2-diaminopropane cations is mainly ionic. The crystal structure is stabilized by a hydrogen bonding network between layers and templating cations.     

Synthesis and structures of two cobalt complexes [NaCoII(NTA)(H2O)] n and NH4[CoIII(IDA)2] · 2H2O

Two cobalt complexes [NaCo^II(nta)(H₂O)] _n (H₃nta?=?nitrilotriacetic acid) (1) and NH₄[Co^III(ida)₂]?·?2H₂O (H₂ida?=?iminodiacetic acid) (2) have been synthesized and characterized by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the orthorhombic system, space group P2₁2₁2₁ with a?=?7.9770(12)?Å, b?=?9.7613(15)?Å, c?=?12.1945(18)?Å, V?=?949.5(2)?ų, Z?=?4, and R ₁?=?0.0705 for 1597 observed reflections. Compound 2 crystallizes in the monoclinic system, space group P2(1)/c with a?=?5.1801(3)?Å, b?=?11.2073(6)?Å, c?=?12.2891(7)?Å, V?=?707.09(7)?ų, Z?=?2, and R ₁?=?0.0349 for 1143 observed reflections. In compound 1, the Co is coordinated by a nitrogen and five oxygen atoms in a distorted octahedral geometry {CoNO₅}, and the Na is coordinated by one water molecule and four carboxyl oxygen atoms in slightly distorted square pyramidal geometry. The entire structure shows a three-dimensional network. In compound 2, Co atom is equatorially coordinated by two ida ligands in a distorted octahedral geometry {CoN₂O₄}. The discrete [Co(ida)₂]^2? anions are linked by hydrogen bonding to a three-dimensional supramolecular network.     

Structural effects of lone-pair electrons: a novel three-dimensional,open-framework metal selenite constructed from {CoSeO3}n double helical chains linked via ethylenediamine pillars

A novel three-dimensional, open-framework selenite [H₂N(CH₂)₂NH₂]_0.5·CoSeO₃ (1) has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, XPS spectrum, TG analysis and single crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P2₁/n, with a?=?6.6018(14)?Å, b?=?9.2559(19)?Å, c?=?7.9097(16)?Å, β?=?113.56(3)°, V?=?443.02(16)?ų, and Z?=?4. Compound 1 exhibits an interesting three-dimensional open-framework structure constructed from unique {CoSeO₃}_n layers aggregated from double helical chains pillared by en ligands. Furthermore, the open framework of 1 possesses three types of one-dimensional channels, in which the triangular channel is particularly rare in covalently bonded microporous materials.     

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.     

NMR of enaminones. Part 7 1H-, 13C-, and 17O-NMR and X-ray structure determinations of 1,2-disubstituted conjugated 3-[(tert-Butyl)amino]enones

¹H-, ¹³C-, and ¹⁷O-NMR spectra for the 2-substituted enaminones MeC(O)C(Me)?CHNH(t-Bu) ( 1 ), EtC(O)C(Me)?CHNH(t-Bu) ( 2 ), PhC(O)C(Me)?CHNH(t-Bu) ( 3 ), and MeC(O)C(Me)?CHNH(t-Bu) ( 4 ) are reported. These data show that 3 exists mainly in the (E)-form, 4 in (Z)-form, and 1 and 2 as mixtures of both forms. Polar solvents favour the (E)-form. The (Z)- and (E)-forms exist in the 1,2-syn,3,N-anti and 1,2-anti,1,N-anti conformations A and B , respectively. The structures of the (E)- and (Z)-form are confirmed by X-ray crystal-structure determinations of 3 and 4. The shielding of the carbonyl O-atom in the ¹⁷O-NMR spectrum by intramolecular H-bonding (Δλ_HB) ranging from ?28 to ?41 ppm, depends on the substituents at C(l) and C(2). Crystals of 3 at 90 K are monoclinic. with a = 9.618(2) Å, b = 15.792(3) Å, c = 16.705(3) Å, and β = 94.44(3)°, and the space group is P2₁/c with Z = 8 (refinement to R = 0.0701 on 3387 independent reflections). Crystals of 4 at 101 K are monoclinic, with a = 16.625(8) Å, b = 8.637(6) Å, c = 11.024(7) Å, and β = 101.60(5)°, and the space group is Cc with Z = 4 (refinement to R = 0.0595 on 2106 independent reflections).     

Syntheses,structural determination,and binding studies of nine-coordinate multinuclear (mnH)2[EuIII(egta)]2·6H2O and binuclear (mnH)4[EuIII2(dtpa)2]·6H2O

Two lanthanide complexes, (mnH)₂[Eu^III(egta)]₂·6H₂O (1) (H₄egta = ethyleneglycol-bis-(2aminoethylether)-N,N,N′,N′-tetraacetic acid) and (mnH)₄[Eu^III₂(dtpa)₂]·6H₂O (2) (H₅dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), have been synthesized and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction reveals that 1 is multinuclear nine-coordinate and crystallizes in the monoclinic crystal system with space group C2/c. The obtained cell dimensions are a = 38.513(3)?Å, b = 13.5877(8)?Å, c = 8.7051(5)?Å, β = 99.6780(10)°, and 4490.6(5)?ų. Each methylamine (mnH⁺) cation in 1, through hydrogen bonds, connects three adjacent [Eu^III(egta)]^? anions. The [Eu^III(egta)]^? anions connect one another forming a 1-D multinuclear zigzag chain structure along the c-axis. Complex 2 is nine-coordinate binuclear structure with tricapped trigonal prismatic conformation and crystallizing in the monoclinic crystal system, but with space group P2₁/n. The obtained cell dimensions are a = 9.9132(8)?Å, b = 24.1027(18)?Å, c = 10.7120(10)?Å, β = 109.1220(10)°, and 2418.2(3)?ų. For 2, there are two kinds of methylamine cations (mnH⁺) connecting [Eu^III₂(dtpa)₂]^4? complex anions and lattice waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure.     

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.     

An open-framework cobalt molybdate possessing {Mo2O7} building block: hydrothermal synthesis and structural characterization of [CoMo2O7(4,4′-bipy)1.5]

The hydrothermal reaction of Co(COO)₂?·?4H₂O, MoO₃, H₃PO₄ and 4,4′-bipyridine yields bipyridine-ligated cobalt dimolybdate [CoMo₂O₇(4,4′-bipy)_1.5] (1) (4,4′-bipy?=?4,4′-bipyridine) in the triclinic system with space group of P 1 and cell parameters of a?=?7.1951(8)?Å, b?=?11.1708(17)?Å, c?=?11.4514(11)?Å, α?=?98.545(7)°, β?=?90.315(2)°, γ?=?105.777(5)°, V?=?874.88(19)?ų, and Z?=?2. Its structure consists of Co/Mo/O bimetal oxide layers with {Mo₂O₇} building blocks, linked by the coordination of 4,4′-bipy ligand with Co and Mo atoms, into a 3D porous hybrid framework.     

Hydrothermal syntheses and characterizations of two new hydrogen bond-supported supramolecular compounds based on polyoxometalates

Two new polyoxometalates [HN(C₂H₅)₃]₃[PMo₁₂O₄₀] (1) and [NH₂(C₂H₄NH₃)₂]₂[Mo₅P₂O₂₃] (2) have been hydrothermally synthesized and characterized by IR, UV-Vis, XPS spectra, TG analyses, and single crystal X-ray diffraction. Crystal data for 1: monoclinic, space group C2/c, a = 24.651(5) Å, b = 10.822(2) Å, c = 22.413(5) Å, β = 120.37(3)°, and V = 5158.7(18) ų; for 2: triclinic, space group P-1, a = 9.821(2) Å, b = 9.948(2) Å, c = 14.687(3) Å, α = 95.490(3)°, β = 98.870(3)°, γ = 95.710(3)°, and V = 1401.7(5) ų. The crystal structure analyses reveal complex hydrogen bonds in both 1 and 2 in 3-D supramolecular arrays constructed from different polyoxoanions and organic ligands.     

Synthesis,characterization and luminescence of the tetranuclear gold cluster: [Au4{7,8-(PPh2)2-7,8-C2B9H10}2(PPh3)2]

A tetranuclear gold cluster has been synthesized by the reaction of [Au(PPh₃)NO₃] with the closo carborane diphosphine 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀ in THF, and characterized by elemental analysis, FT-IR, ¹H and ¹³C?NMR spectroscopy and X-ray structure determination. The cluster crystallizes in the triclinic Pī, a?=?15.118(8)?Å, b?=?16.057(9)?Å, c?=?24.284(13)?Å, α?=?80.822(9)°, β?=?79.624(8)°, γ?=?81.938(8)°, Z?=?2, R ₁?=?0.0626, wR ₂?=?0.1894. A single crystal structure determination showed that four gold atoms form a tetrahedral framework. Among these four gold atoms, two were chelated by two nido carborane diphosphine [7,8-(PPh₂)₂-7,8-C₂B₉H₁₀]^? anions coming from the degradation of the initial closo ligand 1,2-(PPh₂)₂-1,2-C₂B₁₀H₁₀, while the other two were ligated to two PPh₃ groups. The luminescence of this cluster was also investigated in dichloromethane solution at room temperature.     

Synthesis,crystal structure and luminescence of a 3-D coordination polymer based on 4-(1H-tetrazol-5-yl) benzoic acid

A cobalt(II) coordination polymer [Co(4-TZBA^2?)(H₂O)₂] (1) was obtained by treatment of Co(ClO₄)₂ · 6H₂O with 4-(1H-tetrazol-5-yl)benzoic acid [H₂(4-TZBA)] under hydrothermal conditions. The X-ray single crystal diffraction analysis reveals that 1 crystallizes in monoclinic P2₁/c, with a = 10.503(2) Å, b = 9.0860(18) Å, c = 10.179(2) Å, β = 96.75(3)° and Z = 4. In 1, adjacent cobalt(II) atoms are bridged by two 4-TZBA^2? ligands to form a dimer, which is linked with six dimers to result in a 3-D structure. 1 exhibits strong luminescence at room temperature in the solid state.     

Synthese und Kristallstruktur der Monoammoniakate von Lithiumhalogeniden: LiBr·NH3 und LiI·NH3

Syntheses and Crystal Structures of the Monoammoniates of Lithium Halides: LiBr·NH₃ and LiI·NH₃ Crystals of LiBr·NH₃ and LiI·NH₃ sufficient in size and quality for X‐ray structure determinations were obtained in autoclaves by the reaction of Li with NH₄Br and LiH with NH₄I at 523 K and 423 K respectively. Lattice constants obtained from X‐ray single crystal data are: LiBr·NH₃: P2₁/n, a = 7, 077(2)Å, b = 7, 026(2)Å, c = 7, 490(2)Å β = 114, 84(3)°, Z = 4 LiI·NH₃: P2₁, a = 4, 493(1)Å, b = 6, 077(1)Å, c = 7, 512(2)Å β = 107, 15(3)°, Z = 2 The ammoniates contain different structural building units. Both of them contain layers of connected tetrahedra Li(NH₃)X_3/3 with X = Br, I. Tetrahedra‐double units with a common Br‐Br edge occur, whilst for the iodide all tetrahedra are exclusively vertex connected to puckered layers. IR‐ and Raman‐spectroscopic measurements show, that only weak H‐bridges N‐H···X are present and that the NH₃‐ligands are in fixed positions at room temperature.     

Synthesis,Spectroscopic and X-ray Structural Study of cis-diazidobis- (ethylenediamine)Cobalt(III) Thiocyanate

Reaction of cis-diazidobis(ethylenediamine)cobalt(III)nitrate with ammonium thiocyanate in a 1?:?2 molar ratio in aqueous medium gave the title cobalt(III) compound, cis-[Co(en)₂(N₃)₂]SCN, as reddish brown crystals in almost quantitative yield. The complex salt was characterized by elemental analysis, IR, electronic, ¹H and ¹³C NMR spectroscopic studies. An X-ray structure determination revealed an ionic structure with the monoclinic space group P2₁/c, having cell dimensions a = 12.1950(6), b = 9.0317(5), c = 12.6017(7)?Å; β = 113.419(1)°, V = 1273.63(12)?ų and Z = 4. The structure was refined by a full-matrix least-square procedures to R ₁ = 0.0297 and wR ₂ = 0.0697.     

Transition-metal complexes with bidentate ligands spanning trans-position. Part XVI. X-ray structural and 31P-NMR solution studies of 2,11-Bis(diethylphosphinomethyl)benzo[c]phenanthrenesilver(I) perchlorate

The preparation of complexes {AgX(1c)} (X ? Cl, Br, I, NO₃ and ClO₄; 1c = 2,11-bis(diethylphosphinomethyl)benzo[c]phenanthrene) is reported. The ³¹P-NMR spectra of the above complexes were recorded and the ¹J(¹⁰⁷Ag, ³¹P) values are compared with the corresponding data for related complexes. The X-ray crystal structure of [Ag(1c)](ClO₄) was determined. There are two crystallographically independent molecules in the unit cell each containing two-coordinate silver, the O-atoms of the perchlorate anions being outside bonding range from the central atom. The two molecules, however, show different bonding parameters: Thus for ‘molecule 1’ P(1)? Ag(1)? P(2) = 167.6(1)°, Ag(1)? P(1) = 2.389(3) and Ag(1)? P(2) = 2.393(3) Å, while for ‘molecule 2’ P(3)? Ag(2)? P(4) = 164.8(1)°, Ag(2)? P(3) = 2.377(3), and Ag(2)? P(4) = 2.378(3) Å. These differences are probably due to packing forces in the crystal lattice.     

Syntheses,structural determination,and binding studies of nine-coordinate mononuclear (mnH)2[DyIII(Httha)]·3H2O and (enH2)3[DyIII(ttha)]2·9H2O

Two dysprosium coordination compounds, (mnH)₂[Dy^III(Httha)]·3H₂O (1) (H₆ttha?=?triethylenetetramine-N,N,N′,N″,N′′′,N′′′-hexaacetic acid and mn?=?methylamine) and (enH₂)₃[Dy^III(ttha)]₂·9H₂O (2) (en?=?ethylenediamine), were synthesized through direct heating and characterized by elemental analysis, FT-IR, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction analysis displays that 1 is a mononuclear nine-coordinate complex with a pseudo-monocapped square antiprismatic conformation (MCSAP) crystallizing in the monoclinic crystal system with P2(1)/c space group. The crystal data are as follows: a?=?16.1363(19)?Å, b?=?13.9336(11)?Å, c?=?13.6619(14)?Å, β?=?102.2490(10)°, and V?=?3001.8(5)?ų. There are two kinds of methylamine cation in 1. They connect [Dy^III(Httha)]^2?and crystal waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure. The polymeric 2 also is a nine-coordinate structure with a pseudo-MCSAP crystallizing in the monoclinic crystal system with P2/c space group. The cell dimensions are: a?=?17.7801(16)?Å, b?=?9.7035(10)?Å, c?=?22.096(2)?Å, β?=?118.874(2)°, and V?=?3338.3(6)?ų. In 2 there are also two types of ethylenediamine cations. One connects three adjacent [Dy^III(ttha)]^3? complex anions through hydrogen bonds and the other is symmetrical forming hydrogen bonds with two neighboring [Dy^III(ttha)]^3? complex anions. These hydrogen bonds result in formation of a 2-D ladder-like layer structure as well.     

The Neutral Complex (NH3)Ag(NCO)

Dissolution of solid AgNCO (silver isocyanate) in aqueous ammonia (25 %) and subsequent crystal growth at T = –9 °C furnished the new ammoniate (NH₃)Ag(NCO) as colorless crystals [P2₁/c (no. 14); a = 4.1817(3) Å, b = 14.445(1) Å, c = 6.1988(5) Å, β = 102.0(4)°, V = 365,6(2) ų; Z = 4]. In the molecular monammine complex, which is only stable at temperatures below T = 0 °C, silver is in a twofold, however, asymmetrical coordination by the isocyanate anion and ammonia. At the reaction conditions applied, AgNCO does not form an ionic diammine species (e.g. [Ag(NH₃)₂]⁺) as known from related silver salts. In this sense, the solvation chemistry of AgNCO exhibits a rarely observed feature.     

Structural Investigations and Thermal Behaviour of Mercury(II) Sulfito Complexes

The crystal structures of (NH₄)[HgSO₃Cl] ( 1 ) and of (NH₄)₂[Hg(SO₃)₂] ( 2 ) were determined from single crystal diffractometer data sets. 1 : 22 °C, Pnma, Z = 4, a = 15.430(3), b = 5.525(1), c = 6.679(1) Å, R(F) = 0.0256, R_w(F²) = 0.0642 (all 1056 unique reflections). 2 : ?108 °C, P2₁2₁2₁, Z = 4, a = 6.2240(4), b = 9.3908(6), c = 13.6110(8) Å, R(F) = 0.0179, R_w(F²) = 0.0493 (all 2699 unique reflections). The structure of 1 contains bent Cl‐Hg‐SO₃ entities (site symmetry m; d(Hg‐Cl) = 2.3403(13) Å, d(Hg‐S) = 2.3636(12) Å, ∠(Cl‐Hg‐S) = 164.51(5)°, d(S‐O) 2×1.458(3) Å, 1.468(4) Å, = 1.461Å) linked to undulated ribbons parallel to the b ‐axis by intermolecular secondary bonds SO···Hg (d(O···Hg) = 2×2.595(3) Å). These ribbons in turn aggregate to layers around the bc ‐plane. The layers are stacked along the a ‐axis with interlayer distances of a /2. The structure of 2 is made up of O₃S‐Hg‐SO₃ moieties (d(Hg‐S) = 2.3935(7), 2.3935(8) Å; ∠(Hg‐S‐Hg) = 174.41(3)°; = 1.474Å), that are linked to ribbons parallel to the a axis by coordination of Hg to three remote O atoms (2.801(4) < d(Hg‐O) < 2.844(3) Å). Adjacent ribbons are joined together by an additional Hg‐O contact of 2.733(3) Å, leading to a three‐dimensional anionic framework. Both crystal structures are stabilised by disordered NH₄⁺ cations, placed between the anionic layers or in the vacancies of the framework, via moderate hydrogen bonding interactions N‐H···O with donor‐acceptor distances ranging from 2.8 to 3.2Å. 1 and 2 were further characterised by thermal analysis (TG, DSC). They start to decompose at temperatures above 130 °C.     

Syntheses and crystal structures of two maleonitriledithiolate complexes containing the 1-(R-benzyl)pyrazinium cation (R = 4′-nitro or 4′-bromo)

The complexes [NO₂BzPz]₂[Ni(mnt)₂] (1) and [BrBzPz]₂[Pd(mnt)₂] (2) have been prepared by reaction of Na₂mnt, NiCl₂·6H₂O or PdCl₂, and the corresponding 1-(R-benzyl)pyrazinium bromide salt (R = 4′-nitro, R = 4′-bromo). Crystallographic data for 1: monoclinic, P2₁/n, a = 7.3494(15), b = 15.223(3), c = 15.054(3)?Å, β = 102.42(3)°, V = 1644.8(6)?ų, Z = 2. Data for 2: monoclinic, P2₁/n, a = 7.399(2), b = 19.024(4), c = 12.224(2)?Å, β = 94.62(3)°, V = 1715.0(7)?ų, Z = 4. In both complexes, the [M(mnt)₂]^2? anion has a centre of symmetry at the metal atom and two cations are related to each other by the symmetry centre. The [M(mnt)₂]^2? anion exhibits a quasi-planar structure in both complexes, which show similar crystal packing.     

Kristallzucht und Strukturverfeinerung von Quecksilber(II)‐amidchlorid – HgClNH2

Crystal Growth and Refinement of the Crystal Structure of Mercury(II) Amide Chloride – HgClNH₂ Single crystals were prepared by recrystallization of HgClNH₂ from aqueous NH₃/NH₄⁺ solution at 160 °C. They were used for a single‐crystal X‐ray structure redetermination. The previously reported [W. N. Lipscomb, Acta. Crystallogr. 1951 , 4, 266.] structural topology determined on basis of X‐ray powder diffraction data is now confirmed. However, a higher symmetry is found: Space group type Pmma (instead of Pmm2), a = 6.709(1) Å, b = 4.351(1) Å, c = 5.154(1) Å, Z = 2. The crystal structure contains zig‐zag‐chains [Hg(NH₂)_2/2]⁺. Four Cl atoms complete the coordination sphere of Hg to a distorted octahedron. These share common faces and edges in layers [HgCl_4/4(NH₂)_2/2]. These layers are connected via hydrogen bonds N–H…Cl.     

Crystal and Molecular Structure of Carbonyl (1,1,4,4-Tetrafluoro-2-tert-Butyl-1,4-Disilabut-2-Ene) (η5-Cyclopentadienyl) Cobalt (II)

(C₃H₅)Co(CO)(Si₂F₄C₄H₁₀) was synthesized by the photochemical reaction between dicarbonyl (η⁵-cyclopentadienyl) cobalt and 1,1,2,2-tetrafluoro-1,2,-disilacyclobutene. Its structure was identified by IR, NMR and mass spectrometry. The single crystal structure was studied for confirmation. The compound crystalized in a monoclinic space group P2₁/n with unit cell a=7.120 (6), b=20.334. (3), c=10.682(1) Å, β=90.97(8)°, Z=4 final R=0.050 for 3667 observed reflections. The molecule has a mirror plane symmetry about the Co atom coordination sphere. The reaction between the cobalt carbonyl and the 1,2-disilacyclobutene produces only silicon-cobalt σ bonds.