Synthesis and Structures of Infinite Coordination Polymers from 1,3‐Bis(4‐pyridyl)propane Ligand and Zinc Salts

The reaction of Zn(NO₃)₂‐6H₂O, NH₄SCN and bpp (bpp = 1,3‐bis(4‐pyridyl)propane) in CH₃OH afforded the complex [Zn(NCS)₂(bpp)]_n, 1 , while the reaction of Zn(ClO₄)₂‐6H₂O and bpp in CH₃OH afforded the complex [Zn(ClO₄)₂(bpp)₂]_n, 2 . Both complexes have been characterized by spectroscopic methods and their structures have been determined by X‐ray crystallography. Crystal data for 1 : Orthorhombic, space group P2₁2₁2, a= 12.857(6), b = 14.822(7), c = 4.820(2) Å, β = 90°, V = 918.5(8) ų, Z = 2 with final residuals R1 = 0.0747 and wR2 = 0.1657. Crystal data for 2 : Tetragonal, space group I4/mcm, a = 11.612(1), b = 11.612(1), c = 23.247(9) Å, β = 90°, V = 3135(1) ų, Z = 4 with final residuals R1 = 0.0523 and wR2 = 0.1064. The coordination polymers display a variety of structural architectures, ranging from zigzag chains ( 1 ) and one‐dimensional channel‐type architectures ( 2 ). The effects of the orientation of the nitrogen atom in the pyridine rings on the resultant structures are discussed.     

α, ω-Alkan-bis-dimethylarsansulfide und -selenide,eine neue Klasse von Liganden

α ω-Alkane-bis-dimethylarsine Sulfides and Selenides, a Novel Class of Ligands The reaction of α,ω-alkane-bis-dimethylarsanes (CH₃)₂As? (CH₂)_n? As (CH₃)₂ with sulfur and selenium results in formation of the sulfides and selenides, respectively, (CH₃)₂As(X)? (CH₂)_n? As(CH₃)₂ or (CH₃)₂As(X)? (CH₂)_n? As(X)(CH₃)₂ (X = S, Se), which form chelat-complexes with the salts CoX₂ · 6 H₂O (X = Cl^?, Br^?, I^?, NO₃^?). The UV-spectra of the complexes are presented and discussed.     

Crystal structure refinement for trans-[Pd(NO3)2(H2O)2]

Single crystals of trans-[Pd(NO₃)₂(H₂O)₂] were obtained, and the crystal structure of this complex, previously obtained for polycrystals, was refined. Crystal data (BRUKER X8APEX diffractometer): a = 4.9973(7) Å, b = 10.5982(14) Å, c = 11.7008(17) Å, V = 619.70(15) ų, space group Pbca, Z = 4, d _calc = 2.856 g/cm³. The structure is composed of neutral complexes with a trans configuration. The square plane environment of the Pd atom is formed by four oxygen atoms (Pd-O(NO₃) 1.999(5) Å, Pd-O(H₂O) 2.030(5) Å) and completed to a distorted bipyramid by two intramolecular contacts (Pd…O(NO₃) 2.926 Å). The shortest hydrogen bonds are O…H 2.72 Å.     

Synthesis and crystal structure of New Amminecopper(II) Nitrates: [Cu(NH3)2](NO3)2 and [Cu(NH3)](NO3)2

[Cu(NH₃)₂](NO₃)₂ ( I ) and [Cu(NH₃](NO₃)₂ ( II ) were synthesized by interaction of molten NH₄NO₃ with [Cu(NH₃)₄](NO₃)₂ and Cu(NO₃)₂ · 3 H₂O, respectively, at 180 to 195°C for 24 hr. According to X-Ray single crystal analysis, I is orthorhombic (sp. gr. Pbca) with a = 5.678(1), b = 9.765(2), c = 11.596(2) Å, Z = 4, R = 0.060; II is monoclinic (sp. gr. P2₁/c) with a = 6.670(1), b = 8.658(2), c = 9.661(2) Å, β = 101.78(2)°, Z = 4, R = 0.027. In both structures, the nearest coordination environment of Cu is a slightly distorted square formed by N (from NH₃) and O atoms (from NO₃ groups). The structure of I consists of centrosymmetrical [Cu(NH₃)₂](NO₃)₂ molecules linked by hydrogen bonds. The Cu? N and Cu? O distances are 1.98 and 2.01 Å, respectively. In II , the Cu? N distance is 1.95 Å, the Cu? O distances are 1.96, 2.02, and 2.03 Å. The [CuO₃NH₃] squares are connected by NO₃ bridges into zigzag chains, which are linked into layers by longer Cu? O interactions (2.31 Å). Obviously, the layers are additionally strengthened and held together by hydrogen bonds.     

Synthesis of Heteroleptic Cerium(IV) Complexes Using a Heptadentate (N4O3) Tripodale Schiff‐base Ligand

The Cerium(IV) complexes [{N[CH₂CH₂N=CH(2‐O‐3,5‐^tBu₂C₆H₂)]₃}CeCl] ( 1 ) and [{N[CH₂CH₂N=CH(2‐O‐3,5‐^tBu₂C₆H₂)]₃}Ce(NO₃)] ( 2 ) were derived from the condensation of tris(2‐aminoethyl)amine and 3,5‐di‐tert‐butylsalicylaldehyde and the appropriate Ce starting material CeCl₃(H₂O)₆ and (NH₄)₂[Ce(NO₃)₆], respectively. Single crystal X‐ray diffraction studies reveal monomeric complexes.     

Syntheses,Structures and Spectroscopic Studies of Quadruply Bonded Complexes Containing Bridging Acetate and η3-etp Ligands (etp = Ph2PCH2CH2P(Ph)CH2CH2PPh2)

The quadruply bonded complexes containing bridging acetate and polydentate phosphine ligands of the type Mo₂(O₂CCR₃)X_J(η³-etp) (R = H, X = Br, 1; R = F, X = CI, 2; R = F, X = Br, 3; etp = Ph₂PCH₂CH₂P(Ph)CH₂CH₂PPh₂) were prepared by reactions of Mo₂(O₂CCR₃)X₂(PPh₃)₂ with etp in CH₂X₂. Their UV-vis and ³¹P{¹H}-NMR spectra have been recorded, and the structure of 1 has been determined by X-ray crystallography. Crystal data for 1·2CH₂Br₂: space group P2₁/c, a = 13.924(7) Å, b = 21.157(4) Å, c = 14.427(5) Å, β = 101.82(3)°, V = 4159(2) ų, Z = 4, with final residuals R = 0.0797 and Rw = 0.0793. The absorption wavelengths of the δ → δ* transitions and the chemical shifts and the coupling constants of the ³¹P{¹H}-NMR spectra of these complexes are dependent on the natures of the halogen atoms and the acetate ligands.     

Structural dependencies of pyramidal inversion at sulphur and selenium in thio- and seleno- ether complexes of palladium(II) and platinum(II): A nuclear magnetic resonance study

Total NMR band shape fitting methods have provided accurate energy data for inversion barriers at sulphur and selenium in complexes of types cis-[MX₂L] (M = Pd^II, Pt^II; X = Cl, Br, I; L = MeS(CH₂)₂SMe, MeS(CH₂)₃SMe, o-(SMe)₂C₆H₃Me, cis-MeSCH=CHSMe) and [PtXMe{MeE(CH₂)₂E′Me}] (E= E′= S or Se and E = S, E′= Se; X = Cl, Br, I). Barrier energies were found to decrease by 10–12 kJ mol^?1 in going from aliphatic through aromatic to olefinic ligand back-bone. This can be explained in terms of (3p - 2p) π conjugation between the inverting centre and the ligand back-bone. The effects of ligand ring size, nature of halogen atom and the metal oxidation state on the barrier energies are discussed.     

Novel Hydrogen‐bond Three Dimensional Networks Generated from the Reaction of Metal Nitrate Hydrate (M = Co,Ni) with Ammonium Thiocynate and Bidentate Ligand Piperazine

The reaction of Co(NO₃)₂·6H₂O with two equivalents of PPz (PPz = piperazine hexahydrate) and two equivalents of NH₄SCN in CH₃OH afforded the complex [Co(NCS)₂(PPz)₂(CH₃OH)₂]. The reaction of Ni(NO₃)₂·6H₂O with two equivalents of PPz and four equivalents of NH₄SCN in CH₃OH afforded the complex [Ni(NCS)₄(PPz)₂]. Their IR spectra have been recorded and the structures have been determined. Crystal data for 1 : space group P&1bar;, a = 6.7208(6) Å, b = 8.4310(8) Å, c = 8.5923(8) Å, a = 77.881(2)°, β = 76.342(2)°, γ = 83.936(2)°, V = 461.75(1) ų, Z = 1 with final residuals R1 = 0.0650 and wR2 = 0.1725. Crystal data for 2 : space group P2(1)/n, a = 7.4209(6) Å, b = 11.0231(9) Å, c = 12.317(1) Å, β = 96.642(9)°, V = 1000.9(2) ų, Z = 2 with final residuals R1 = 0.0378 and wR2 = 0.0809. Important NCS—H‐N and O‐H—N(PPz) hydrogen‐bonding interactions in compound 1 and NCS···H‐N hydrogen‐bonding interactions and NCS—SCN interactions in compound 2 play a significant role in aligning the polymer strands in crystalline solids.     

Dimolybdenum Complexes Containing Pairs of Bridging Diphosphine and Carboxylate Ligands. Synthesis and Structures of trans-Mo2(O2CCH3)2(μ-dppa)2(BF4)2 and trans-Mo2X2(O2C(CH2)nCH3)2(μ-dppa)2 (n = 2, 10 or 12; X = Cl or Br; dppa = N,N-Bis(diphenylphosphino)amine)

The red complex trans-Mo₂(O₂CCH₃)₂(μ-dppa)₂(BF₄)₂, 1 , was prepared by reaction of [Mo₂(O₂CCH₃)₂(CH₃CN)₆][BF₄]₂ with dppa (dppa = Ph₂PN(H)PPh₂) in THF. The reactions of Mo₂(O₂C(CH₂)_nCH₃)₄ with dppa and (CH₃)₃SiX (X = Cl or Br) afforded the complexes trans-Mo₂X₂(O₂C(CH₂)_nCH₃)₂(μ-dppa)₂ (X = Cl, n = 2, 2; X = Br, n = 2, 3; X = Cl, n = 10, 4 ; X = Cl, n = 12, 5 ). Their UV-vis, IR and ³¹P{¹H}-NMR spectra have been recorded and the structures of 1, 2 and 3 have been determined. Crystal data for 1 : space group P2₁/n, a = 12.243(1) Å, b = 17.222(1) Å, c = 13.266(1) Å, β = 95.529(1)°, V = 2784.1(6) ų, Z = 2, with final residuals R = 0.0509 and Rw = 0.0582. Crystal data for 24CH₃Cl₂: space group P2₁/n, a = 13.438(1) Å, b = 19.276(1) Å, c = 14.182(1) Å, β = 111.464(1)°, V = 3418.9(6) ų, Z = 2, with final residuals R = 0.0492 and Rw = 0.0695. Crystal data for 3·4CH₂Cl₂: space group P2₁/n, a= 13.579(1) Å, b = 19.425(1) Å, c = 14.199(1) Å, β = 111.881(2)°, V = 3475.6(7) ų, Z = 2, with final residuals R = 0.0703 and Rw = 0.0851. Comparison of the structural data shows that the effect of the axial ligand on weakening the Mo-Mo bond strength is X^? > CH₃CN > BF₄^?. The T_m values are 121.7 °C for 2 , 111.1 °C for 3 and 91.5 °C for 5 , respectively.     

Syntheses,Structures and Spectroscopic Studies of Dimolybdenum Complexes Containing Bridging Butyrate and Phosphine Ligands

By reactions of Mo₂(O₂CPrⁿ)X₂(PPh₃)₂ (X = Cl, 1 ; X = Br, 2 ) with Ph₂PCH₂CH₂P(Ph)CH₂CH₂PPh₂ (etp) in CH₂X₂, the quadruply bonded complexes containing bridging butyrate and tridentate phosphine ligands of the type Mo₂(O₂CPrⁿ)X₃(η³‐etp) (X = Cl, 3 ; X = Br, 4 ) were prepared. Their UV‐vis and³¹P{¹H}‐NMR spectra have been recorded and the structures of 1 and 2 have been determined by X‐ray crystallography. Crystal data for 1 : space group P2₁/c, a = 9.708 (2)Å, b = 18.491 (4)Å, c= 12.688 (3)Å, β = 110.76 (3)°, V = 2130 ų, Z = 2, with final residuals R = 0.0441 and Rw = 0.0519. Crystal data for 2 : space group P2₁/c, a = 9.737 (1)Å, b = 18.632(1)Å, c = 12.680(1)Å, β= 110.27 (1)°,V = 2158.2 (3) ų, Z = 2, with final residuals R = 0.0322 and Rw = 0.0481. The δ → δ* transition energies, ³¹P{¹H}‐NMR chemical shifts and the coupling constants are dependent on the natures of the halogen atoms and the carboxylate ligands. The through metal‐metal couplings |³J_{P‐Mo‐Mo‐P}| for complexes of the type Mo₂(O₂CR)X₃(η³‐P₃), which contain η³‐polydentate phosphine ligands are about 20 ± 2 Hz.     

On Mixed-Valence Dinuclear PtII,PtIII Nucleobase Complexes Derived from cis-Diamineplatinum(II): Effect of steric bulk of amine ligands on the Pt-oxidation state

A series of closely related dinuclear (head-head) Pt^II complexes of general composition cis-[a₂PtL₂Pta′₂]²⁺ with a,a′ = NH₃ or CH₃NH₂ and L = 1-methyluracilate-N3,O4 (1-MeU) or 1-methylthyminate-N3,O4 (1-MeT) has been prepared and the solution behavior toward Ce^IV oxidation studied. The X-ray crystal structure of a representative example cis-[(CH₃NH₂)₂Pt(1-MeU)₂Pt(CH₃NH₂)₂](ClO₄)₂ · 0.5 H₂O ( 1b ), has been determined: Monoclinic, space group P2₁/c, a = 11.907(7) Å, b = 19.087(14) Å, c = 12.525(7) Å, β = 90.49(4)°, Z = 4. Oxidation of these diplatinum(II) complexes ([Pt^2.0]₂) with Ce^IV in aqueous solution to the corresponding diplatinum(III) species ([Pt^3.0]₂) proceeds via tetranuclear [Pt^2.25]₄ or dinuclear [Pt^2.5]₂ mixed-valence state compounds, depending on the nature of the a′ ligands: with a′ = NH₃, blue green [Pt^2.25]₄ forms, whereas with a′ = CH₃NH₂, purple [Pt^2.5]₂ represents the intermediate. This difference is interpreted in terms of differences in bulk between NH₃ and CH₃NH₂ ligands trans to the O(4) positions of the bridging nucleobases which influence the ability of dinuclear species to associate via the O(4)₂ Pt a₂′ faces.     

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.     

Synthesis Characterization,X‐ray Structures,and Solution Studies of Dinuclear Zinc(II) Complexes of Acyclic Schiff Base Ligands

Dizinc(II) complexes of two acyclic Schiff‐base ligands L1 ^– and L2 ^– were synthesized by Schiff base condensation of 2‐[3‐(2‐formylphenoxy)‐2‐hydroxypropoxy]benzaldehyde ( PL ) with 1,2‐diaminopropane and 1,2‐diaminoethane, respectively, in the presence of zinc(II) salts. The isolation of a selection of 2:1 (metal:ligand) complexes of zinc(II) was carried out and conductance measurements, IR, UV/Vis absorption, and fluorescence emission spectroscopy, as well as X‐ray diffraction were employed to probe the nature of the respective complexes in both solid and solution states. The molecular structure of [Zn₂ L1 (NO₃)₃] ( 1 ) complex consists of two six‐coordinate atoms, which are bridged by the deprotonated hydroxy group and one 1,3‐bridging nitrate anion. The structure of [Zn₂ L2 (NO₃)(H₂O)₂](NO₃)₂ · CH₃OH ( 3 ) consists of a dizinc cation and two nitrate anions as counterions. In compound 3 , each zinc atom is bound to water instead of a terminal nitrate anion in a distorted octahedral arrangement. The intermetallic separation distance of Zn ··· Zn in 3 (3.376 Å) is slightly smaller than 1 (3.403 Å) and is similar to that found in zinc phosphotriesterase (3.5 Å). The π–π interactions between the benzene rings of adjacent molecules in 3 are stronger than in 1 .     

Synthesis and structure of Pt(II) acetamidate complexes containing <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethyl-substituted ethylenediamine and trimethylenediamine

Reactions of acetamide with platinum(II) diamines [Pt(N,N-DimeEn)Cl₂], [Pt(Tm)Cl₂], and [Pt(N,N-DimeTm)Cl₂] (N,N-DimeEn = (CH₃)₂N(CH₂)₂NH₂, Tm = NH₂(CH₂)₃NH₂, N,N-DimeTm = (CH₃)₂N(CH₂)₃NH₂) with preliminary precipitation of chlorine ions by silver salts gave binuclear Pt(II) acetamidates [Pt₂(CH₃)₂N(CH₂)₂NH₂)₂(μ-NHCOCH₃)₂](NO₃)₂ · H₂O (I), [Pt₂(NH₂(CH₂)₃NH₂)₂)(μ-NHCOCH₃)₂](NO₃)₂ · H₂O (II), and [Pt₂(CH₃)₂N(CH₂)₃NH₂)₂(μ-NHCOCH₃)₂](HSO₄)₂ (III), whose crystal structures were determined. Crystals of I are monoclinic: a = 14.459(2) Å, b = 17.197(3) Å, c = 9.822(2) Å, β = 105.923(10)°, V = 3348.6(8) ų, space group P2(1)/c, Z = 4, R _hkl = 0.0419 for 6663 reflections. Complex I is a binuclear acetamidate with bridging (NHCOCH₃)^? ligands, one of which is bound to two Pt atoms through the N and O atoms, and the other ligand is bound only through the N atom. The Pt-Pt distance is 2.987(1) Å. Crystals of II are monoclinic: a = 10.213(7) Å, b = 13.373(9) Å, c = 16.533(11) Å, β = 97.971(9)°, V = 2236(3) ų, space group P2(1)/n, Z = 4, R _hkl = 0.557 for 6462 reflections. The Pt-Pt distance is 3.057(1) Å. Crystals of III are monoclinic: a = 10.557(12) Å, b = 18.531(2) Å, c = 14.4744(17) Å, β = 108.705(2)°, V = 2682(5) ų, space group P2(1)/n, Z = 4, R _hkl = 0.569 for 8506 reflections. The Pt-Pt distance is 3.202(1) Å. Complexes II and III are binuclear acetamidates, in which two chelating Pt(Tm) or Pt(N,N-DimeTm) moieties are coordinated through the N and O atoms of (NHCOCH₃)^? cis-bridges.     

Syntheses and Structures of Zinc(II) Co‐Ordination Polymers Bridged by Flexible Bidentate Nitrogen Ligands

The reaction of Zn(NO₃)₂·6H₂O and bpp (bpp = 1,3‐Bis(4‐pyridyl)pronpane) in CH₃OH afforded the complex [Zn(bpp)(NO₃)₂]_n, 1 . The IR has been recorded and the structure has been determined. Crystal data for 1: Space group P2(1)/n, a = 11.749(1), b = 11.413(1), c = 11.942(1) Å, β = 96.06(6)°. V = 1592.5(3) ų, Z = 4 with final residuals R1 = 0.0484 and wR2 = 0.0984. The complexes show supramolecular structure in the solid state by intermolecular hydrogen bonding interaction.     

Synthesis,characterization and some reactions of trans-[Co(NH3)4(CH3NH2)Br]2+ and trans-[Co(NH3)4(CH3NH2)(NO3)]2+ complexes

The preparation of trans-[Co(NH₃)₄(CH₃NH₂)Br]²⁺ and trans-[Co(NH₃)₄(CH₃NH₂)-(NO₃)]²⁺ complexes is described. The UV-VIS spectra of the complexes indicate a decrease of the ligand field compared to the parent pentaammines. Infrared spectra match with the pattern of the corresponding pentaammines. The catalyzed (by Hg²⁺) aquation of the trans-bromomethylamine complex go under retention of the stereochemical configuration. The base hydrolysis (studied at 25°C) products show trans to cis rearrangement for both complexes. ¹H NMR spectroscopy is used for identification of the stereochemical configuration of the compounds.     

Structure and Phase Transitions in Ethylenediammonium Dichloride and its Salts with Antimony Trichloride

During the mixing of ethylenediammonium dichloride and antimony trichloride except of reported earlier [NH₃(CH₂)₂NH₃]₅(Sb₂Cl₁₁)₂ · 4 H₂O a new salt [NH₃(CH₂)₂NH₃](SbCl₄)₂ was obtained. The crystals are monoclinic at 295 K, space group C2/m, a = 13.829(3), b = 7.408(1), c = 7.588(2) Å; β = 103.18(3)°; V = 756.9(3) ų; Z = 2; d_c = 2.585, d_m = 2.56(2) g · cm^–3. The structure consists of anionic sublattice built of Sb₂Cl₈^2– units composed of two SbCl₅^2– square pyramids connected by edge. The ethylenediammonium cations are located in anionic cavities. The cations are disordered. Each methylene carbon atom is split between two positions. The X‐ray diffraction, DSC, TGA and dilatometric methods were used to investigate properties of ethylenediammonium dichloride and its two salts with antimony trichloride. In [NH₃(CH₂)₂NH₃]Cl₂ one phase transition of first order and of the order‐disorder type was found at 402 K. The [NH₃(CH₂)₂NH₃]₅(Sb₂Cl₁₁)₂ · 4 H₂O undergoes one transition at 355 K which is accompanied by the dehydration of the sample. In [NH₃(CH₂)₂NH₃](SbCl₄)₂ two phase transitions of the order‐disorder type: of first order at 238 K and of second order at 267 K were found. All those transitions in ethylenediammonium salts share common features. They were related to the changes in the molecular dynamics of ethylenediammonium cations. In the low temperature phases cations are ordered, while above T_c they are characterised by overall reorientations along the axis passing through opposite nitrogen atoms.     

Crystal structure and magnetic properties of tetra(monomethylammonium)hexachloroytterbatochloride(CH3NH3)4YbCl7

(CH₃NH₃)₄YbCl₇ has been synthesized from a solution of CH₃NH₃Cl and YbCl₃ in a mixture of ethnole/acetonitrile. The structure was solved from 1464 single crystal data by Patterson methods and refined to a final R_w = 0.035 space group P2, a = 9.972(6) Å, b = 7.605(5) Å, c = 12.866(6) Å, β = 90.53(4)°. The structure consists of alternating [YbCl₆]^3? octahedra and of tetrahedrally arranged [(CH₃NH₃)₄Cl]³⁺ units. Raman spectra display a splitting of frequencies related to the CH₃NH₃⁺ group in agreement with the structure determination. The magnetic susceptibility shows a remarkable deviation from a Curie-Weiss law below 170 K which may be explained by crystal field effects of Yb³⁺.     

A study of the structure and properties of mixed-ligand Cu(II) complexes with hexafluoroacetylacetone and methyl-, phenyl-ketoimines

The synthesis and X-ray single crystal study of two mixed-ligand Cu(II) complexes are performed: (CH₃C(NCH₃)CHC(O)CH₃)(CF₃C(O)CHC(O)CF₃)Cu (1) (space group P2₁/c, a = 7.0848(12) Å, b = 17.854(3) Å, c = 11.837(2) Å, β = 100.495(6)°, V = 1472.4(4) ų, Z = 4), (CH₃C(NC₆H₅)CHC(O)CH₃)· (CF₃C(O)CHC(O)CF₃)Cu (2) (space group P-1, a = 9.1119(4) Å, b = 9.6954(4) Å, c = 11.1447(6) Å, α = 113.784(2)°, β = 92.383(2)°, γ = 95.402(2)°, V = 893.52(7) ų, Z = 2). The structures are molecular, formed from neutral mixed-ligand copper complexes. The central copper atom has the (3O+N) coordination environment with average Cu-O distances of 1.948 Å and Cu-N of 1.932 Å; the chelate O-Cu-N angle (average) is 94.0°. In the structures, the complexes are linked into dimeric associates with Cu…Cu distances of 3.197 Å (for 1) and 3.246 Å (for 2). The volatility of mixed-ligand complexes 1 and 2 is in between of that of the starting homo-ligand complexes.     

Monoammoniates of Aluminium Halides: The Crystal Structures of AlBr3 · NH3 and AlI3 · NH3

Single crystals of AlBr₃ · NH₃ and AlI₃ · NH₃ sufficient in size for X‐ray structure determinations were obtained by evaporation/ sublimation of the respective compound from its melt. The ammoniates were synthesized by the reaction of the pure halide with NH₃ at ‐78°C and following homogenization by slowly heating the reaction mixture up to the melting points of the ammoniates (124°C and 126°C, respectively). The X‐ray structure determinations for both monoammoniates were successfully carried out for the heavy atom positions (no hydrogen atoms): AlBr₃ · NH₃: Pbca, Z = 16, a = 11.529 (5) Å, b = 12.188 (2) Å, c = 19.701 (4) Å AlI₃ · NH₃: Pbca, Z = 8, a = 13.536 (5) Å, b = 8.759 (2) Å, c = 14.348 (4) Å The structures contain tetrahedral molecules Al(NH₃)X₃ with X = Br, I. They are not isotypic. The main difference is given for the coordination of NH₃ by X^‐ from neighbouring molecules. In Al(NH₃)Br₃ one of the two crystallographically independent NH₃ ligands has 6Br^‐ and the other 7Br^‐ as neighbours whereas in Al(NH)₃I₃ only 5I^‐ surround the one kind of NH₃.