Cobalt(II), nickel(II), and copper(II) complexes of 14-membered hexaazamacrocycles: synthesis and characterization

Cobalt(II), nickel(II), and copper(II) complexes containing 5,12-di(4-bromophenyl)-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L¹) and 5,12-diphenyl-7,14-dimethyl-1,2,4,8,9,11-hexaazacyclotetradeca-7,14-diene-3,10-dione (H₂L²) have been synthesized. All complexes were characterized by elemental analysis, MALDI TOF-MS spectrometry, and electronic absorption spectroscopy. The crystal structures of two compounds, [Cu₂(H₂L¹)Cl₄]_n and [NiL²], were determined by X-ray powder diffraction. In the polymeric [Cu₂(H₂L¹)Cl₄]_n, the Cu₂Cl₄ units and H₂L¹ molecules are situated on inversion centers. Each Cu(II) has a distorted trigonal-bipyramidal coordination environment formed by N and O from H₂L¹ [Cu–N 2.340(14)?Å, Cu–O 1.952(11)?Å], two bridging chlorides [Cu–Cl 2.332(5), 2.279(5)?Å] and one terminal chloride [Cu–Cl 2.320(6)?Å]. In the [NiL²] complex, the Ni(II) situated on inversion center has a distorted square-planar coordination environment formed by four nitrogens from L² [Ni–N 1.860(11), 1.900(11)?Å].     

Molybdänhalogenidcluster mit sechs terminalen Alkoholatliganden: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH und (C18H36N2O6Na2)2[Mo6Cl8(OC6H5)6]

Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6CH₃OH and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] . The reaction of Na₂[Mo₆Cl₈(OCH₃)₆] and 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6 CH₃OH ( 1 ), which is converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo₆Cl₈ⁱ(OR^a)₆]^2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo₆Cl₈(OC₆H₅)₆]^2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.     

Molybdänhalogenidcluster mit zwei terminalen Alkoholatliganden: Synthese und Kristallstrukturen von (C18H36N2O6Na)2[Mo6Cl12(OCH3)2] und (C18H36N2O6Na)2[Mo6Cl12(OC15H11)2] · 2C4H6O3

Molybdenum(II) Halide Clusters with two Alcoholate Ligands: Syntheses and Crystal Structures of (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ . Reaction of Mo₆Cl₁₂ with two equivalents of sodium methoxide in the presence of 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] ( 1 ), which can be converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ ( 2 ) by metathesis with 9-Anthracenemethanole in propylene carbonate. As confirmed by X-ray single crystal structure determination ( 1 : C2/m, a=25.513(8) Å, b=13.001(3) Å, c=10.128(3) Å, β=100.204(12)°; : C2/c, a=15.580(5) Å, b=22.337(5) Å, c=27.143(8) Å, β=98.756(10)°) the compounds contain anionic cluster units [Mo₆ClCl(OR^a)₂]^2? with two alcoholate ligands in terminal trans positions ( 1 : d(Mo—Mo) 2.597(2) Å to 2.610(2) Å, d(Mo—Clⁱ) 2.471(3) Å to 2.493(4) Å, d(Mo—Cl^a) 2.417(8) Å and 2.427(8) Å, d(Mo—O) 2.006(13) Å; 2 : d(Mo—Mo) 2.599(3) Å to 2.628(3), d(Mo—Clⁱ) 2.468(8) Å to 2.506(7) Å, d(Mo—Cl^a) 2.444(8) Å and 2.445(7) Å, d(Mo—O) 2.012(19) Å).     

Crystal structure of tris(ethylenediamine)cobalt(III) (aqua)hexachloromercurate(II) chloride [Co(En)3]2[Hg2(H2O)Cl6]Cl4

The compound [Co(En)₃]₂[Hg₂(H₂O)Cl₆]Cl₄ (I, En is ethylenediamine) has been synthesized and studied by X-ray diffraction. The crystals of I (a = 21.8745(14) Å, b = 10.6008(6) Å, c=15.4465(12) Å, space group Pna2₁) consist of tris(ethylenediamine)cobalt(III) complexes (the unit cell contains two [Co(En)₃]³⁺ cations of opposite chirality). [Hg₂(H₂O)Cl₆]^2? anions, and isolated chloride ions. The complex anion consists of the tetrahedral [HgCl₄]^2? group (Hg-Cl, 2.44–2.56 Å) and the hydrated molecule [Hg(H₂O)Cl₂] (Hg-Cl, 2.301 and 2.308 Å; Hg-O, 2.788 Å) combined by weak Hg-Cl interactions (2.915 and 3.220 Å).     

Unique Isle Anion [Cu6Cl10]4- in π-Complex of Cu(I) Chloride with 1-(2-Pyridyl)-4-allyl-piperazinium. Synthesis and crystal structure of [(C5H4NH)NC4H8NH(C3H5]2+[Cu3Cl5]2-

Single crystals of [(C₅H₄NH)NC₄H₈NH(C₃H₅)]²⁺[Cu₃Cl₅]^2? are obtained by ac synthesis in ethanol from 1-(2-pyridyl)-4-allyl-piperazinium and Cu(II) dichlorides and their structure is studied by X-ray diffraction analysis (space group P-1, a = 7.246(7) Å, b = 8.54(1) Å, c = 16.41(1) Å, α = 70.76(8)°, β = 77.24(8)°, λ = 80.42(9)°, V = 30(4) ų, Z = 2, R(F) = 0.0686. In the structure of this π-complex, the Cu and Cl atoms form unusual centrosymmetrical Cu₆Cl₁₀ fragments, each fragment being bonded to two 1-(2-pyridyl)-4-allyl-piper-azinium cations via π-interaction Cu-(C=C). A three-dimensional structure is formed by means of N-H…Cl hydrogen bonds. The trigonal-pyramidal surrounding of the Cu(1) atom includes three Cl atoms and the C=C bond, while the tetrahedral surrounding of Cu(2) and the trigonal surrounding of Cu(3) involve the Cl atoms only.     

Halogenometallate von Übergangselementen mit Kationen stickstoffhaltiger heterocyclischer Basen. I. Die Kristallstrukturen von 1,4-Dimethylpiperazinium-tetrachlorocobaltat(II) und -zinkat(II), (dmpipzH2)[MIICl4] (M = Co,Zn)

Halogenometalates of Transition Elements with N-heterocyclic Base Cations. I. The Crystal Structures of 1,4-Dimethylpiperazinium Tetrachlorocobaltate(II) and -zincate(II), (dmpipzH₂)[M^IICl₄] (M = Co, Zn) The compounds (dmpipzH₂)[M^IICl₄] crystallize in the monoclinic space group P2₁/m with a = 6.133(1), b = 14.306(1), c = 6.902(1) Å, β = 90.54(2)°, Z = 2 for M = Co and with a = 6.141(1), b = 14.282(1), c = 6.907(1) Å, β = 90.60(2)°, Z = 2 for M = Zn. The structures consist of tetrahedra [MCl₄]^2? and centrosymmetric cations (dmpipzH₂)²⁺ in the chair form. Bifurcated hydrogen bridging bonds of the N? H …? Cl type connect the nitrogen atom to two chloride ions. Two short distances C …? Cl are interpreted in terms of C? H …?Cl hydrogen bridges.     

Crystal structures of copper(II) complexes with methyliminodiacetate ions and 1,10-phenanthroline or imidazole [Cu(Phen)H<Subscript>2</Subscript>O][Cu(Mida)<Subscript>2</Subscript>]·2H<Subscript>2</Subscript>O and [Cu(Mida)Im]

Methyliminodiacetic acid (H₂Mida) and imidazole react with copper(II) to form crystals of the square pyramidal complex [Cu(Mida)Im]. One N and two O atoms of the Mida ligand (Cu-N 2.010(1) Å, Cu-O 1.955(1) Å, and 1.978(1) Å) and the imidazole N atom (1.950(1) Å) lie at the base of the pyramid. The carboxyl O atom of the neighboring complex lies at the apical position (2.411(1) Å); in this way the individual complexes are linked into infinite zigzag chains. Substitution of imidazole by 1,10-phenanthroline gave [Cu₂(Mida)₂(Phen)H₂O]·2H₂O crystals with two nonequivalent centrosymmetric octahedral anions [Cu(Mida)₂]^2? of face type (Cu-N 2.023 Å and 2.028(2) Å, Cu-O_ax 2.579 Å and 2.530(2) Å, Cu-O_bas 1.952 Å and 1.936(2) Å). The anions serve as bridges in chains between the [Cu(Phen)H₂O]²⁺ cation fragments to which they are bonded by their axial carboxyl groups. The Cu atom of the cation has a [4+1] environment (with the H₂O molecule lying on the axis of the pyramid, and with two N atoms of the ligand and two O atoms of the anions lying at the base).     

Chloroselenate(IV): Darstellung,Struktur und Eigenschaften von [As(C6H5)4]2Se2Cl10 und [As(C6H5)4]Se2Cl9

Chloroselenates(IV): Synthesis, Structure, and Properties of [As(C₆H₅)₄]₂Se₂Cl₁₀ and [As(C₆H₅)₄]Se₂Cl₉ The Se₂Cl₁₀^2? and Se₂Cl₉^? anions were prepared, as the first dinuclear haloselenates(IV), from the reaction of (SeCl₄)₄ with stoichiometric quantities of chloride ions in POCl₃ solutions; they were isolated as yellow crystalline As(C₆H₅)₄⁺ salts. Complete X-ray structural analyses at ?130°C of [As(C₆H₅)₄]₂Se₂Cl₁₀ ( 1 ) (space group P1 , a = 10.296(7), b = 11.271(6), c = 12.375(8) Å, = 74.17(5)°, α = 81.38(5)°, β = 67.69(4)°, V = 1276 ų) and of [As(C₆H₅)₄]Se₂Cl₉ ( 2 ) (space group P2₁/n, a = 12.397(5), b = 17.492(6), c = 14.235(4) Å, α 93.25(3)°, V = 3082 ų) show in both cases two distorted octahedral SeCl₆ groups connected through a common edge in 1 and a common face in 2 . The terminal Se? Cl bonds (average 2.317 Å in 1 , 2.223 Å in 2 ) are much shorter than the Se? Cl bridges (av. 2.661 Å in 1 , 2.652 Å in 2 ). The stereochemical activity of the Se^IV lone electron pair causes severe distortion of the central Se₂Cl₂ ring in the centrosymmetric Se₂Cl₁₀^2? ion. The vibrational spectra of the anions are reported.     

Crystal structure of [ethylenediamine-<Emphasis Type="Italic">N,N</Emphasis>′-di(3-propionato)copper(II)]-<Emphasis Type="Italic">tris</Emphasis>[dichloromercury(II)] [Cu(Eddp)·(HgCl<Subscript>2</Subscript>)<Subscript>3</Subscript>]<Subscript>n</Subscript>

Crystals of [Cu(Eddp)·(HgCl₂)₃]_n (monoclinic, a = 9.7547(7) Å, b = 18.3716(12) Å, c = 11.7811(9) Å, β = 94.828(9)°, Z = 4, space group P2₁/n) are made of infinite sheets involving dimeric complexes [Cu₂(Eddp)₂] interacting with quasi-molecules of HgCl₂ (Hg-Cl 2.29-2.36 Å). In the dimers, copper atoms are squarely surrounded by two N atoms and two O atoms of the ethylendiamine-N,N′-di(3-propionate) anion, and atom from a neighboring Eddp ion in the apical position; the second apical position is occupied by a Cl atom of one of HgCl₂ molecules. Weak Hg-Cl interactions (2.98-3.07 Å) join the molecules of HgCl₂ in almost planar centrosymmetrical Hg₆Cl₁₂ hexamers, and further (Hg-Cl 3.168(3) Å, 3.250(2) Å) in infinite chains of the hexamers. Finally, the dimeric copper complexes are linked to six Hg atoms of four adjacent hexamers by virtue of their oxygen atoms (Hg-O 2.322(8), 2.609(6) Å, 2.730(5) Å).     

Preparation, structural characterisation, and magnetic properties of [Cu(men)2][Cu2Cd2Cl2(CN)6] (men = N-methylethane-1,2-diamine)

The novel complex [Cu(men)₂][Cu₂Cd₂Cl₂(CN)₆] (I) was isolated from the aqueous-ethanol system containing CuCl₂, men (men = N-methylethane-1,2-diamine) and K₂[Cd(CN)₄] in the presence of dilute hydrochloric acid and chemically and spectroscopically characterised. The crystal structure of I consists of [Cu ₂ ^I (CN)₆] and [Cd₂Cl₂(CN)₆] building units bridged by cyanide ligands and forms a three-dimensional skeleton with cavities. [Cu(men)₂]²⁺ cations in which two men ligands are chelated (mean Cu-N is 2.033(6) Å) are located in the cavities. The coordination polyhedron around the Cu(II) atoms is formed as a tetragonal bipyramidal by two weaker axial Cu-Cl bonds (2.8642(12) Å) with chlorido ligands from the skeleton. The Cu(I) and Cd(II) atoms in the skeleton exhibit tetra-(CuC₄ chromophore) and penta-coordination (CdN₃Cl₂), respectively. The temperature-dependent susceptibility measurements indicate a Curie-Weiss-like behaviour and the presence of weak anti-ferromagnetic interaction.     

Syntheses and Crystal Structures of Copper(II) and Copper(I) dpp Complexes, [Cu(dpp)Br2] and [Cu(dpp)2][CuBr2] (dpp = 2,9‐diphenyl‐1,10‐phenanthroline)

The complexes [Cu(dpp)Br₂] ( 1 ) and [Cu(dpp)₂][CuBr₂] ( 2 ) (dpp = 2,9‐diphenyl‐1,10‐phenanthroline) were synthesized and characterized by single‐crystal X‐ray diffraction methods. Reaction of copper(II) bromide with the dpp ligand in dichloromethane at room temperature afforded 1 , which is a rare example of non‐square planar four‐coordinate copper(II) complexes. Complex 1 crystallizes in the monoclinic space group C2/c with a = 15.352(3), b = 13.192(3), c = 11.358(2) Å, β = 120.61(3)°, V = 1979.6(7) ų, Z = 4, D_calc = 1.865 g cm^?3. The coordination geometry about the copper center is distorted about halfway between square planar and tetrahedral. The Cu‐N distance is 2.032(2) Å and the Cu‐Br distance 2.3521(5) Å. Heating a CH₂Cl₂ or acetone solution of 1 resulted in complex 2 , which consists of a slightly distorted tetrahedral [Cu(dpp)₂]⁺ cation and a linear two‐coordinate [CuBr₂]^? anion. 2 crystallizes in the triclinic space group with a = 10.445(2), b = 11.009(2), c = 18.458(4) Å, α = 104.72(3), β = 94.71(3), γ = 103.50(3)°, V = 1973.3(7) ų, Z = 2, D_calc = 1.602 g cm^?3. The four Cu(1)‐N distances are between 2.042(3) and 2.067(3) Å, the distance of Cu(2)‐Br(1) 2.2268(8) Å, and the disordered Cu(3)‐Br(2) distances are 2.139(7) and 2.237(4) Å, respectively. Complex 2 could also be prepared by directly reacting CuBr with dpp in CH₂Cl₂.     

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.     

catena‐Poly­[[bis­[μ‐1,2‐bis(1‐methyl­tetrazol‐5‐yl)­ethane‐κ2N4:N4′]bis[chloro­copper(II)]]‐di‐μ‐chloro]

In the title compound, [Cu₂Cl₄(C₆H₁₀N₈)₂]_n, the ligand has C₂ symmetry, and the Cu and Cl atoms lie on a mirror plane. The coordination polyhedron of the Cu atom is a distorted square pyramid, with the basal positions occupied by two N atoms from two different ligands [Cu—N = 2.0407 (18) Å] and by the two Cl atoms [Cu—Cl = 2.2705 (8) and 2.2499 (9) Å], and the apical position occupied by a Cl atom [Cu—Cl = 2.8154 (9) Å] that belongs to the basal plane of a neighbouring Cu atom. The [CuCl₂(C₆H₁₀N₈)]₂ units form infinite chains extending along the a axis via the Cl atoms. Intermolecular C—H⃛Cl contacts [C⃛Cl = 3.484 (2) Å] are also present in the chains. The chains are linked together by intermolecular C—H⃛N interactions [C⃛N = 3.314 (3) Å].     

Syntheses,structures, and fluorescent properties of three Zn(II) and Cu(II) complexes of different ligands derived from 3,6-bis(2-pyridyl)-1,2-dihydro-1,2,4,5-tetrazine

Three supramolecular complexes [Zn(HL₁ )₂(H₂O)₂(ZnCl₄)₂] (1), [Cu(L₂ )₂Cl₂] (2), and [Zn(L₃ )Cl₂] (3) have been synthesized and characterized by single crystal X-ray diffraction analysis (L₁ = 3,5-di(2-pyridyl)-4-amino-1,2,4-triazole, L₂ = 3,5-di(2-pyridyl)-1,2,4-triazole, and L₃ = 2-pyridinecarboxylic acid (pyridin-2-ylmethylene)-hydrazide). In 1, anion–π interactions between Cl^? and the π-systems of L₁ are observed and anion–π, hydrogen bonding and π–π stacking interactions link the two complex units of [Zn(HL₁ )₂(H₂O)₂]⁴⁺ and [ZnCl₄]^2? to form a 3-D supramolecular network. In 2, π–π stacking interactions between aromatic rings of 1,2,4-triazole and pyridine rings are observed; in 3, hydrogen bonding of Cl ··· H–N and π–π stacking interactions between parallel pyridine rings of L ₃ are observed. The mechanisms of rearrangement reactions of L to L₁ –L₃ are discussed. The fluorescent properties for solid 1 and 3 are also investigated.     

Reaction of hexanuclear niobium and tantalum halide clusters with mercury(II) halides. II. Semiconducting compounds with [Ta6Cl12]3+ unit

A series of paramagnetic clusters of the composition [(Ta₆Cl₁₂)Cl(H₂O)₅][HgX₄] · 9H₂)O (X = Cl, Br, I) has been prepared by the reaction of [Ta₆Cl₁₂]³⁺ methanol-water solutions with HgX₂ and NaX halides. The structure of [(Ta₆Cl₁₂)Cl(H₂O)₅][HgBr₄] · 9H₂O has been solved by X-ray diffraction in the cubic space group Fd 3m. Crystal data: a = 20.036(2) Å, V = 8043.0(1) ų, Z = 8, R = 0.048 (R_w = 0.051). The structure is composed of an octahedral [(Ta₆Cl₁₂)Cl(H₂O)₅]²⁺ cluster cation, tetrahedral [HgBr₄]²⁻ anion and crystal water molecules. The 2mm symmetry of the octahedron is reduced by the statistical distribution of the five water molecules, O(1), and chlorine, Cl(2), at the terminal coordination sites. Thus, the distances Ta-O(1) and Ta-Cl(2) are averaged to the value of 2.32(2) Å. The Ta-Ta and Ta-Cl(1) bond distances are 2.911(1) Å and 2.440(3) Å, respectively, whereas the Hg-Br bond distance is 2.564(3) Å. The cluster [(Ta₆Cl₁₂)Cl(H₂O)₅][HgBr₄] · 9H₂O is semiconducting with two levels governing conductivity with respective activation energies, E_al = 0.24 eV and E_a2 = 0.17 eV.     

catena‐Poly­[[tetrakis(2‐allyl­tetrazole‐κN4)‐tetra‐μ‐chloro‐tricopper(II)]‐di‐μ‐chloro]

In the crystal structure of the title compound, [Cu₃Cl₆(C₄H₆N₄)₄]_n, there are three Cu atoms, six Cl atoms and four 2‐allyl­tetrazole ligands in the asymmetric unit. The polyhedron of one Cu atom adopts a flattened octahedral geometry, with two 2‐allyl­tetrazole ligands in the axial positions [Cu—N4 = 1.990 (2) and 1.991 (2) Å] and four Cl atoms in the equatorial positions [Cu—Cl = 2.4331 (9)–2.5426 (9) Å]. The polyhedra of the other two Cu atoms have a square‐pyramidal geometry, with three basal sites occupied by Cl atoms [Cu—Cl = 2.2487 (9)–2.3163 (8) and 2.2569 (9)–2.3034 (9) Å] and one basal site occupied by a 2‐allyl­tetrazole ligand [Cu—N4 = 2.028 (2) and 2.013 (2) Å]. A Cl atom lies in the apical position of either pyramid [Cu—Cl = 2.8360 (10) and 2.8046 (9) Å]. The possibility of including the tetrazole N3 atoms in the coordination sphere of the two Cu atoms is discussed. Neighbouring copper polyhedra share their edges with Cl atoms to form one‐dimensional polymeric chains running along the a axis.     

Synthesis and X-Ray Structure of New Copper(II) Nitrates: Cu(NO3)2 · H2O and β-modification of Cu(NO3)2

Blue crystals of a Cu(NO₃)₂ · H₂O were synthesized by interaction of CuO with boiling 100% HNO₃. Stable β-Cu(NO₃)₂ modification was obtained by the sublimation of copper(II) nitrate in evacuated ampoule over the 150→100°C temperature gradient for 24 hr. According to X-Ray single crystal analysis Cu(NO₃)₂ · H₂O is monoclinic with a = 6.377(1), b = 8.548(1), c = 9.769(1) Å, β = 100.41(1)°, Z = 4, and space group P2₁/c. β-modification Cu(NO₃)₂ is orthorhombic with a = 14.161(5), b = 7.516(3), c = 12.886(2) Å, Z = 12, and space group Pbcn. In the both structures Cu atoms are square coordinated by 4 O atoms at the distances ranging from 1.92 to 2.02 Å. In each structure there are also additional Cu? O bonds with the distance of 2.33 or 2.35 Å and some weaker ones with the distances in the range of 2.65–2.72 Å. In the Cu(NO₃)₂ · H₂O structure the [CuO₄] squares are connected by the bridging NO₃ groups into zigzag chains, which are linked into layers by the longer Cu? O bonds. In the β-Cu(NO₃)₂ structure the [CuO₄] fragments of two types are joined by the bridging NO₃ groups in a three-dimensional framework. Some correlations were found between N? O distances and coordination functions of O atoms.     

Ba4[WN4]Cl2: The first nitridotungstate(VI) chloride

Transparent yellow crystals of Ba₄[WN₄]Cl₂ were grown at 850°C by the reaction of Ba(NH₂)₂ with W in a KCl melt under flowing nitrogen. The compound crystallizes monoclinic in P2₁/m and Z = 2 with the cell parameters a = 8.447(4) Å, b = 6.143(2) Å, c = 10.727(6) Å and β = 99.04(4)°. The crystal structure contains isolated anions [WN₄]^6? and Cl^?. It is the first nitridotungstate(VI) chloride reported so far.     

Reactions of halogens with platinum(IV) triamine complexes [PtEnPyX3]X (X = Cl, Br)

Platinum(IV) complexes of the tetramine type [PtEnPy₂X₂]X₂ · H₂O (X = Cl, Br) have been found to lose a coordinated pyridine molecule at 125–135°C, thereby transforming into triamines [PtEnPyX₃]X. The complex [PtEnPyCl₃]NO₃ has been isolated. Dissolution of the product of [PtEnPy₂Cl₂]Cl₂ chlorination in HCl results in complete destruction of the five-membered chelate ring. The complex [Pt(NH₃)₂Py₂Cl₂](NO₃)₂ has been isolated. A number of compounds have been studied by X-ray diffraction: [PtEnPy₂Cl₂]Cl₂ · 2H₂O (I) (monoclinic, space group P2₁/c, a = 15.418(2) Å, b = 9.203(1) Å, c = 13.762(3) Å, β = 104.18(2)°, Z = 4, R _hkl = 0.25), [PtEnPyCl₃]NO₃ (II) (monoclinic, space group P2₁/c, a = 8.194(1) Å, b = 8.846(1) Å, c = 19.855(2) Å, β = 97.10(1)°, Z = 4, R _hkl = 0.048), and [Pt(NH₃)₂Py₂Cl₂](NO₃)₂ (III) (orthorhombic, space group Pbca, a = 12.316(2) Å, b = 13.250(3) Å, c = 21.868(4) Å, Z = 8, R _hkl = 0.027). The reaction of [PtEnPyBr₃]Br with bromine gives the polybromide [PtEnPyBr₃]Br · Br₂ · 0.5 H₂O. The chlorination of [PtEnPyCl₃]Cl gives the chloramine complex [Pt(NH₂-CH₂-NH(Cl)PyCl₃]Cl · H₂O.     

Construction of chlorido-bridged dinuclear copper(II) complexes with similar tridentate Schiff bases

Two new chlorido-bridged dinuclear copper(II) complexes [Cu₂Cl₂(L¹)₂] (1) and [Cu₂Cl₂(L²)₂] (2), where L¹ and L² are the deprotonated form of Schiff bases 2-[1-(2-morpholin-4-ylethylimino)ethyl]phenol (HL¹) and 2-[1-(2-piperidin-1-ylethylimino)ethyl]phenol respectively, are prepared and structurally characterized by elemental analysis, IR spectra, and single crystal X-ray crystallography. Complex 1 crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 8.0816(2) Å, b = 19.1780(3) Å, c = 9.6757(3) Å, β = 106.465(2)°, V = 1438.13(6) ų, Z = 2, R ₁ = 0.0409, and wR ₂ = 0.1085. Complex 2 crystallizes in the monoclinic space group P2₁/c with unit cell dimensions a = 7.7640(10) Å, b = 19.930(3) Å, c = 9.628(2) Å, β = 103.890(3)°, V = 1446.2(4) ų, Z = 2, R ₁ = 0.0634, and wR ₂ = 0.1316. Each Cu atom in the complexes is coordinated by three donor atoms of the Schiff bases and by two bridging Cl atoms, forming square pyramidal geometry. The Cl anions are preferred bridging groups for the construction of dinuclear copper complexes with tridentate Schiff bases.