Synthesis and structure of (H2O·HBF4)2(18-crown-6)

The title compound has been prepared by the addition of fluoroboric acid to 18-crown-6 in toluene. The compound crystallizes in the triclinic space group P¯1 witha=7.341(2),b=8.364(2),c=10.631(3)Å,=71.48(2),=67.91(2), =67.94(2)°, andD _c =1.44 g cm^–3 forZ=1. The final conventionalR value was 0.079 based on 1575 observed reflections. The molecule resides on a center of inversion. The (H₂O·HBF₄) moieties are best viewed as fluoroboric acid monohydrate molecules hydrogen bonded to the crown ether, one above and one below the plane of the crown. The FO(water) hydrogen bond separation is 2.474(5)Å, and the O(crown)O(water) separations are 2.834(5) and 2.841(6) Å. The oxygen atoms of the crown ether are planar to 0.23 Å.     

Interaction of cystamine with palladium(II) monoethanolaminate complex: Crystal structure of [Pd(NH2CH2CH2OH)4][Pd6(NH2CH2CH2S)8]Cl6 · 5H2O

The new compound [Pd(NH₂CH₂CH₂OH)₄][Pd₆(NH₂CH₂CH₂S)₈]Cl₆ · 5H₂O (I) is synthesized and its crystal structure is determined. The crystals are monoclinic, a = 25.625(6) Å, b = 9.633(5) Å, c = 24.847(7) Å, β = 91.47(2)°, Z = 4, and space group C2/c. The structural units of crystals I are the centrosymmetric hexanuclear [Pd₆(NH₂CH₂CH₂S)₈]⁴⁺ cations, the mononuclear [Pd(NH₂CH₂CH₂OH)4]²⁺ cations with C ₂ symmetry, the Cl^? anions, and crystallization water molecules. In the hexanuclear cation, the interaction between the Pd atoms occurs through the S atoms of the mercaptoethylaminate ligands. The Pd(2) and Pd(3) atoms and the ligands form two metallochelate fragments in which the N and S atoms are located in cis positions. The average lengths of the Pd-S and Pd-N bonds are equal to 2.274(1) and 2.074(6) Å, respectively. The metallochelate fragments are joined to each other and to their centrosymmetric analogues through the Pd(1) atom, which coordinates four S atoms [the average Pd-S_av bond length is 2.332(1) Å]. In the mononuclear cation, the Pd(4) atom coordinates four N atoms of the monoethylaminate ligands [the Pd-N bond lengths are 2.045(6) and 2.056(6) Å]. The shortest Pd?Pd distance is equal to 3.207(1) Å. The bonding in the structure is provided by numerous hydrogen bonds with the participation of all the H₂O molecules, NH₂ groups, and Cl^? anions.     

Phenylmercury(II) dithiophosphates. Crystal structure of (O,O′-diethyldithiophosphate) phenylmercury(II)

The phenylmercury(II) derivatives PhHgS₂P(OR)₂ (R=C₂H₅, C₆H₁₁ and C₆H₅) have been synthesized. (O,O-diethyldithiophosphate) phenylmercury(II), C₁₀H₁₅HgO₂PS₂, crystallizes in the monoclinic space groupP2₁/c (n° 14) witha=7.330(5),b=18.085(2),c=11.552(4)Å,=105.96(5)°,V=1472.3(6)ų,Z=4,D=2.088 g.cm^–3. The mercury atom is coordinated to the phenyl carbon atom and to a ligand sulphur atom in an almost linear arrangement (C-Hg-S angle, 176.0(2)°. The ligand is almost monodentate, its second sulphur atom only being involved in a weak secondary intermolecular bond.IR and Raman studies of the other two compounds suggest the same coordination scheme. Positive ion FAB and¹³C,³¹P and¹⁹⁹Hg NMR spectra are also discussed.     

Synthesis and crystal structure of Nd(III)–Zn(II) complex

A novel heteronuclear complex, [NdZn₂L₆(NO ₃)(phen)₂] (HL = -methylacrylic acid, phen = 1,10-phenanthroline), was synthesized and characterized by elemental analysis, infrared absorption spectra (IR) and its molecular structure was also determined by X-ray structure analysis. The title complex contains a discrete trinuclear ZnNdZn molecule bridged by carboxylate groups between Zn and Nd ions and crystallizes in space group P¯1 with the cell dimensions: a = 13.601(3) Å, b = 16.859(2) Å, c = 12.575(2) Å, = 110.09(1), = 112.21(1), = 81.10(2).     

Synthesis and structure of (H2O)(12-crown-4)-Co(II)(Co(II)Cl3)(μ-Cl) isolated from a liquid clathrate medium

The crystal structure of (H₂O)(12-crown-4)Co(II)(Co(II)Cl₃)(μ-Cl)1 is reported. Crystal data for1: monoclinic, space groupP2 ₁/m, a=7.958(8) Å,b=12.006(1) Å,c=69.017(9) Å, β=107.896(2)⁰, D_c=1.84 g cm^?3,Z=2,R1=0.025,wR2=0.059. The crown ether acts as a tetradentate ligand and partially completes the binding sphere of the Co(II) ion which also includes one water oxygen atom and a bridging chloride ligand, the latter of which may be regarded to originate from a [CoCl₄]^2? ion.     

Crystal and molecular structure of β-resorcylidene aminoguanidine copper(II) complex

The tridentate Schiff base, -resorcylidene aminoguanidine (RAG)1 was synthesized from 2,4-dihydroxybenzaldehyde and aminoguanidine and complexed with copper(II) to form a copper(II)--resorcylidene aminoguanidine (Cu-RAG)2 complex. X-ray diffraction analysis of compound2 (orthorhombic, Pnma,a=11.674(1);b=6.7198(7);c=17.836(2) ) revealed a square-planar copper(II) cation with a tridentate·ligand bound through two nitrogen atoms (N1 and N3) of the aminoguanidine moiety and an oxygen (O1) of the monodeprotonated dihydroxybenzaldehyde function. The remaining coordination site was occupied by chloride and the structure was rigidly planar as demanded by the restrictions of the crystallographic space group. The unit cell contents exhibited an extended sheet-like structure constructed via hydrogen bonds both intermolecularly and involving two water molecules (O3 and O4) also restricted by the same mirror symmetry. The remaining water (O5) provided for interlayer hydrogen bonding.     

Sterically constraining photoluminescence. X-ray crystal structure of a bulky platinum(II) α-diimine complex

The photoluminescence study of a series of platinum(II) -diimine complexes revealed a dramatic decrease in steady-state phosphorescence intensity when the diimine ligand was substituted in the 2 and 9 positions. Therefore, the molecular structure of the complex Pt(2,9-dmp)(mes)₂ (where mes = 2,4,6-trimethylphenyl, and 2,9-dmp = 2,9-dimethyl-1,10-phenanthroline) was determined by X-ray diffraction methods: monoclinic, space group P2₁/N, a = 7.9335(7), b = 21.952(3), c = 15.3103(3) Å, = 93.4980(5), Z = 4, R = 0.070, R _w = 0.045. The complex has significant distortions from the ideal square planar geometry which may be responsible for the lack of detectable phosphorescence as compared with those complexes lacking substituents in the 2 and 9 positions on the diimine ligand.     

Mercury(II) complex with terpyridine: structure of the 2∶1 solvate of [Hg(terpy)2](CF3SO3)2 with acetone

[Hg(terpy)₂](CF₃SO₃)₂·0.5(CH₃)₂CO crystallizes in the triclinic space group witha=14.631(6),b=15.258(4),c=18.785(7) Å, =69.66(2), =70.72(1), =88.55(1)°. The crystal structure consists of two independent [Hg(terpy)₂]²⁺ cations, four trifluoromethanesulfonate anions and an acetone molecule in the asymmetric unit. Each mercury atom is coordinated by two tridentate terpyridine ligands forming an irregular six-coordination polyhedron. The Hg–N bond lengths range from 2.27(2) to 2.53(2) Å.     

Crystal and molecular structure of [H3O·18-crown-6]2-[ReCl6] isolated from a liquid clathrate medium

The crystal and molecular structure of [H₃O·18-crown-6]₂[ReCl₆]1 is reported. Crystal data for1: trigonal, space group R ,a=13.857(2) Å,c=10.154(2) Å,D _c =2.85 g/cm³,Z=3,R _f =0.073,R _w =0.064. The oxonium ion is observed to be crystallographically disordered lying 0.37 Å on both sides of the plane defined by the crown ether oxygen atoms. The anion resides on a crystallographic position forming a slightly distorted octahedron.     

Influence of Changes in the Central Core on the Mesomorphic Properties of 4,4’ -Dialkoxybenzalazines and Derivatives (II)

Two homologous series of benzalazines were synthesized, namely, the 4,4′-di-n-alkoxy-2-hydroxybenzalazines and 4,4′-di-n-alkoxybenzalazines, and their mesomorphic properties were studied.

All the prepared compounds of these series exhibit mesomorphism and some of them possess crystalline polymorphism also.

A comparative study of the mesomorphic properties of these series with those of 4,4′-di-n-alkoxy-2,2′-dihydroxybenzalazines and the analogous α,α'-dimethylbenzalazines was carried out in order to determine the influence of the central core on the mesomorphic properties.     

Structure of the 1∶1∶1 complex between 1,4,7,10,13,16-hexaoxacyclooctadecane (18-crown-6), 2,3-dichlorophenol,and water

The structure of the title compound, C₁₂H₂₄O₆·C₆H₄OCl₂·H₂O, has been determined by X-ray diffraction methods. The crystals are monoclinic, space groupP2₁ witha=8.628(2),b=13.767(4),c=9.676(2), =96.38(2)°, andD _x =1.295 Mg m^–3 forZ=2; 2355 reflections were recorded on a CAD4 diffractometer using CuK radiation atT=243° K. The structure was solved usingMultan andShelx. The finalR value based on 1901 reflections is 0.071. The 18-crown-6 molecule has approximatelyD _3d symmetry. The host molecule (18-crown-6), the guest molecule (dichlorophenol), and water form a super-molecule. Binding between host and guest is effected by bridging water molecule: the water and dichlorophenol molecule are linked by a very strong hydrogen bond (OO=2.58 Å); weaker interactions exist between water and oxygens of the crown ether (OO distances 2.85 and 2.90 Å).     

Crystal and molecular structure of complex compound [Fe3O(CH3COO)6(H2O)3]2[ZnCl4] ⋅ 2H2O

The X-ray crystal structure of trinuclear iron acetate [Fe₃O(CH₃COO)₆(H₂O)₃]₂ [ZnCl₄] ? 2H₂O was determined. The crystal has a ionic structure. It is monoclinic, a = 25.363(7), b = 14.533(4), c = 15.692(4) Å, β = 103.11(2)°, space group _C2/c, and R = 0.0685. The structure of the cationic complex [Fe₃O(CH₃COO)₆(H₂O)₃]⁺ is typical of trinuclear iron(III) compounds containing a μ₃-O bridge: the iron atoms are situated at the vertices of an almost equilateral triangle with the O atom at the center. Each Fe atom is coordinated by four O atoms of bridging carboxy groups, the μ₃-bridging O atom, and the water molecule in the trans position to the latter O atom. Mössbauer spectroscopy evidence indicates the high-spin state (_S = 5/2) of the iron(III) ions.     

Crystal structure of (ethylenediammonium-N,N′-di-3-propanoic acid) tetrachloropalladate(II) complex

The title compound was obtained by a synthesis from ethylenediamine-N,N-di-3-propanoic acid dihydrochloride (H₂eddp2HCl) and potassium hexachloropalladate(IV) (molar ratio 1:1, in water). Its structure has been determined by single-crystal X-ray diffraction: monoclinic space group P2₁/n, a = 8.198(1), b = 10.282(1), c = 9.080(1) Å, = 103.62(1)°, V = 743.9(2) ų, and Z = 2. The dianionic complex has a square-planar coordination geometry with four chloro ligands, and ethylenediamine-N,N-di-3-propanoic acid as dication in the second coordination sphere. This is the first reported Pd(II) structure with uncoordinated H₂eddp.     

The synthesis and crystal structure of one novel ternary complex of 2,2′-bipyridine N-salicylidenetyrosinatocopper(II)

The crystal structure of copper(II)—salicylidene-aminoacidate Schiff base—nitrogen-donor chelating ligand, [Cu(sal-tyr)(bipy)] (sal-tyr: N-salicylidenetyrosinato; bipy: 2,2-bipyridine) which is obtained by means of one-step synthesis, is presented. It crystallizes in space group P2₁2₁2₁ with a = 9.0356(18) Å, b = 11.992(2) Å, c = 20.618(4) Å. The Cu^II ion is five coordinated by one oxygen atom of carboxylate, the imine nitrogen atom, and the hydroxyl oxygen atom of the salicylidene in the Schiff base anion as well as two nitrogen atoms of bipy, resulting in a seriously distorted square pyramid coordination polyhedron. The phenol group and the apical coordination bond Cu(1)–N(2) are in the same side of the Schiff base chelating plane which could be attributed to the intramolecular C–H s interaction between the H(17) of the bipy and the benzene ring of the phenol. The hydrogen bond between the hydroxyl hydrogen atom of the phenol group and the coordinated oxygen atom of the carboxylate from neighboring molecule is helpful to stabilize the crystal.     

Crystal structure of tetrakis (μ-betaine-O,O′) dichloro-dicopper(II) dichloride tetrahydrated

[Cu₂(bet)₄Cl₂]Cl₂·4H₂O (bet = betaine: IUPAC name: trimethylammonioacetate) is monoclinic, space group P2₁/c, a = 11.0510(10) Å, b = 14.7140(4) Å, c = 11.1620(15) Å, = 107.40(2)°. The dinuclear copper(II) cation [Cu₂(bet)₄Cl₂]²⁺ is counterbalanced by two naked Cl^– ions. The copper(II) ions have a square bipyramidal environment with oxygen atoms from the acetato groups in the basal planes and a chlorine and a copper atom occupying the apical positions. The metal atoms are ₂-bridged by four acetato groups and the molecular symmetry is close to C _2h. The two symmetry-independent chelating betaine molecules are present in their zwitterionic, neutral form.     

Primary to secondary sphere coordination of 18-crown-6 to lanthanide (III) nitrates: Structural analysis of [Pr(NO3)3-(18-crown-6)] and [M(NO3)3(OH2)3]·18-crown-6 (M=Y,Eu, Tb−Lu)

The direct reaction of hydrated lanthanide nitrate salts with 18-crown-6 in 31 CH₃CNCH₃OH has resulted in the isolation and structural characterization of [Pr(NO₃)₃(18-crown-6)] and [M(NO₃)₃(OH₂)₃]·18-crown-6 (M=Y, Eu, Tb–Lu). (The Eu and Yb analogs were confirmed with preliminary cell data only.) [Pr(NO₃)₃(18-crown-6)] is 12-coordinate icosahedral and crystallizes in the orthorhombic space group Pbca with (at 20°C)a=12.230(2),b=15.598(4),c=21.777(9)Å andD _calc=1.89 g cm^–3 forZ=8. The seven isostructural [Pr(NO₃)₃(18-crown-6)] complexes all contain 9-coordinate capped square antiprismatic metal centers hydrogen bonded via the bound water molecules to D_3d 18-crown-6 within the lattice to form hydrogen bonded polymeric chains. Each complex is orthorhombic Pnma with cell parameters as follows: M=Tb (20°C):a=15.242(6),b=14.253(11),c=11.070(6)Å,D _calc=1.83 g cm^–3 forZ=4; M=Dy (20°C):a=15.248(3),b=14.239(5),c=11.058(3)Å,D _calc=1.84 g cm^–3 forZ=4; M=Y (19°C):a=15.260(2),b=14.238(2),c=11.048(3) Å,D _calc=1.64 g cm^–3 for Z=4; M=Ho (20°C):a=15.226(4),b=14.208(15),c=11.028(3)Å,D _calc=1.86 g cm^–3 forZ=4; M=Er (20°C):a=15.250(3),b=14.208(7),c=11.028(3)Å,D _calc=1.87 g cm^–3 forZ=4; M=Tm (20°C):a=15.246(6),b=14.190(16),c=11.013(6) Å,D _calc=1.88 g cm^–3 forZ=4; M=Lu (21°C):a=15.244(9),b=14.158(6),c=10.980(7)Å,D _calc=1.90 g cm^–3 forZ=4.     

Crystal structure of jinshajiangite from the Norra Kärr complex (Sweden)

The structure of the mineral jinshajiangite from the Norra Kärr alkaline complex (Sweden) was determined by single-crystal X-ray diffraction and refined to R = 6.7%. The monoclinic unit-cell parameters are a = 5.350(2) Å, b = 6.909(6) Å, c = 20.96(1) Å, β = 99.83(4)°, sp. gr. P2/m. This mineral is an Fe-rich analogue of surkhobite and perraultite, but it crystallizes in a different space group, and the unit-cell parameters a and b are two times smaller than those of these two minerals. The framework of jinshajiangite from Norra Kärr contains narrow and wide channels, which are occupied by Ca, Na, Ba, and K atoms in an ordered fashion.     

Synthesis and crystal structure of a novel tetraiminediphenolate iron(II) macrocyclic complex: A six-coordinate iron–protein model

A novel tetraiminediphenolate iron(II) macrocyclic complex [Fe(tidf)(CH₃OH)₂](NO₃)₂ (1) has been prepared and characterized by microanalysis, X-ray crystallography, FTIR spectroscopy, and mass spectrometry. The crystal structure (monoclinic, space group C2/c, Z=8, a = 26.8573(6) Å, b = 10.6551(4) Å, c = 23.5371(7) Å, = 107.450(2)°) shows that the iron(II) occupies a distorted octahedral geometry with two methanol molecules bound axially. The macrocyclic ligand is very flexible and adopts a butterfly conformation with a dihedral angle of 112°.     

Synthesis and crystal structure of a new lithium cyclohexaphosphate hydrate: Li6P6O18·10H2O

The synthesis and crystal structure of a novel hydrate of lithium cyclohexaphosphate are reported. Li₆P₆O₁₈·10H₂O crystallizes in the space group C2/c with a = 15.113(5), b = 12.006(2), c = 15.892(2) Å, = 122.85(2)°, and Z = 4. The structure consists of P₆O₁₈ ring layers stacked along the c direction in between which are located the lithiumions and water molecules. Two LiO₄ tetrahedra share common edges with LiO₅ pseudosquare pyramids to form two independant Li₃O₉ units. About 50% of the water molecules have fractional occupancy rates and form fragments of molecules. A linear relationship is established between the relative cell volume V/Z and the hydration degree, n, for all the known hydrates: Li₆P₆O₁₈·nH₂O.     

Crystal and molecular structure of the spin-crossover complex bis(pyridine) [N,N′-ethylenebis (3-carboxysalicylaldimine)] cobalt (II)

The average structure of the title compound, Co(H₂fsa₂en)(py)₂, which has been shown previously to exhibit a thermally induced high-spin low-spin crossover, has been investigated by single-crystal X-ray diffraction. This structure has been solved in the monoclinic space groupC2/c (No. 15), with cell dimensionsa=16.641(5),b=9.496(4),c=16.329(6) Å, and=95.47(3)°;V=2569(3) ų,M _r =571.46,Z=4,D _x =1.478 mg m^–3; MoK radiation (graphite crystal monochromator),=0.71073 Å,(MoK)=7.138 cm^–1;T=295 K andR=0.081 for 681 observed [I>3(I)] independent reflections. The cobalt(II) ion resides on a twofold axis in an elongated octahedral environment, the length of the apical bond (formed with pyridine) being 2.262(12) Å and the mean length of the equatorial bonds (formed with the Schiff base) 2.079(12) Å. These values are consistent with the magnetic behavior, which suggested a distorted surrounding for the metal atom. The packing is essentially governed by the parallelism of the salicylaldimine ligands. The two pyridine rings of the molecule are twisted by ~98° on each side of the basal plane; they are probably affected by orientational disorder or, if ordered, they might be described in a superstructure not yet established.