Crystal structure of a 1∶2∶1 packing complex formed by bis(isothiocyanato) tetrakis(pyridine) nickel(II), triphenylmethane,and metanol

The structure of the [NiPy₄(NCS)₂]·2(C₆H₅)₃CH·CH₃OH (Py is pyridine) packing complex was determined by single crystal X-ray diffraction analysis (KM-4 diffractometer, λMoK_α, graphite monochromator, ω/2? scan mode, θ_max, 2073 reflections, R=0.059). The unit cell is base-centered monoclinic, space group C2/c, a=20.22(1), b=14.256(7), c=18.836(6) Å, β=87.40(4)^°, Z=4C₆₁H₅₆N₆NiOS₂, d_calc=1.239 g/cm³. The structure is of the island type and consists of molecules of three types. In the trans-[NiPy₄(NCS)₂] molecule, the central atom has a distorted octahedral environment and is coordinated by six nitrogen atoms of two isothiocyanate and four pyridine ligands. In contrast to the phase of the complex itself, this molecule acquires a four-lobe propeller conformation, in which the pyridine rings are rotated relative to the equatorial plane by angles of 52.8(3) and 50.1(2)^°. The triphenylmethane molecule has a three-lobe propeller conformation, as in triphenylmethane clathrates with benzene, thiophene, pyrrole, and aniline, but strongly deviates from threefold axis symmetry. The phenyl rings form dihedral angles of 25(3), 40(4), and 19(4)^° with the planes formed by the bonds of the ternary carbon atoms with hydrogen atoms and by the appropriate carbon atom of the phenyl ring. The methanol molecules are located inside the direct channels running along the c axis and are disordered around the inversion centers.     

THE CRYSTAL AND MOLECULAR STRUCTURE OF THE POTENTIAL ANTIBACTERIAL AGENT 2-PYRIDYL-PHENYL SULPHONE

Abstract

Crystals of 2-pyridyl-phenyl sulphone are monoclinic, space group P2₁/c, with eight molecules in the unit cell of dimensions a = 11.781, b = 5.903, c = 29.748 Å and B = 94.13°. The dihedral angles between the best planes of the two aromatic rings are significantly different in two crystallographically independent molecules (88.4° and 71.9° for molecule A and molecule B, respectively), as well as those between the CSC plane and the pyridine ring (59.4° and 67.4°) and between the CSC plane and the phenyl ring (51.7° and 81.8°). The average bond distances of interest include C?S 1.77(1) and S?O 1.44(1) Å; among the bond angles there are CSO = 108.1(7), CSC = 105.0(6) and OSO = 118.7(6)°. The packing of the molecule in the crystal is determined by the van der Waals interactions and by two intermolecular H?O contacts of 2.43 and 2.49 Å. The observed conformation in the solid state agrees well with results of previous investigations, in the solution state, by means of dipole moment method and theoretical M.O. calculations, for the analogous di-2-pyridyl sulphone.     

Crystal and molecular structure of monomeric yttrium(III) dipivalylmethanate. Arrangement of adsorbed layers

Crystal structure of monomeric yttrium(III) dipivalylmethanate, YO₆C₃₃H₅₇, has been studied by X-ray diffraction. Crystal data: a=17.868(3), b=9.977(2), c=10.633(2) Å, V=1895.7 ų, space group Pmn2₁, Z=2, d_calc=1.116, d_exp=1.119 g/cm³. The compound has a molecular structure and consists of monomeric molecules with a proper symmetry plane m. In the metallocycle lying in this plane, Y-O interatomic distances and O?Y?O bond angles markedly differ from the similar distances and angles in the other two planes. The average Y?O, O?C, and C?C distances are 2.22, 1.25, and 1.46 Å, respectively. As a result of comparative crystal-chemical analysis carried out for related compounds, the coordination polyhedra around the yttrium atoms were found to be trigonal prisms formed by six oxygen atoms of three bidentate ligands. Layers ～1 μm thick were obtained by vapor condensation of the complex on different supports; the layers were investigated by XRD. Irrespective of the type of support, the layers are oriented polycrystalline films with [001] texture axes. Arrangement of the adsorbed molecules of the complex is analyzed. The layers are self-organized into close-packed structures with C(CH₃)₃ groups oriented toward supports.     

The crystal and molecular Structure of Trans-MoCl3(C5H5N)3

Trans-MoCl₃Py₃ (Py 7mdash; pyridine) crystallizes in the monoclinic space group P2₁/c with four molecules in the unit cell. The cell dimensions are: a = 9.229(3), b = 12.555(3), c = 17.920(4) Å and β = 119.33(2)°. Calculated density for Z = 4 is 1.61 gcm^?3 and measured 1.61 ± 0.02 gcm^?3. Structure has been solved from 1594 independent film data and refined to the conventional R factor 9.1%. Three chlorine atoms and three nitrogen atoms of the pyridine molecules form an octahedral coordination about molybdenum in the 1, 2,6 or trans configuration. Distances within octahedron are: Mo? Cl 2.437(5), 2.424(5), 2.423(5) Å, and Mo? N(pyridine) 2.189(13), 2.163(15), 2.223(15) Å. CrCl₃Py₃, CrBr₃Py₃ and MoBr₃Py₃ crystallize in the same space group with comparable cell dimensions and are probably isostructural with trans-MoCl₃Py₃.     

Synthesis,Structure and Raman Data of the New Binuclear Zirconium Complex [Ph4P]2[(ZrCl4Py)2O], with a Zr‐O‐Zr Bridge

The new Zirconium(IV) coordination compound [Ph₄P]₂[(ZrCl₄Py)₂O] (Ph = phenyl, Py = pyridine) was synthesized by dissolving ZrCl₄, [Ph₄P]Cl and a stoichiometric amount of NaOH/Na mixture in pyridine or pyridine/organic solvent mixtures. The title phase was obtained as colourless crystals. The crystal structure of [Ph₄P]₂[(ZrCl₄Py)₂O] was determined. It crystallizes monoclinic, P2₁/c, Z = 4, a = 13.412(2), b = 13.461(2), c = 16.442(3) Å, β = 102.72(1)°. The structure consists of isolated tetraphenylphosphonium cations and [(ZrCl₄Py)₂O]^2? complex anions. The centrosymmetric complex anion contains a linear Zr–O–Zr bridge. Each Zr atom is coordinated by one oxygen dianion, the N atom of one pyridine ring and four chloro ligands in a distorted octahedral geometry. The Raman spectrum of [Ph₄P]₂[(ZrCl₄Py)₂O] is also reported. Most of the observed frequencies can be assigned to vibrations of the tetraphenylphosphonium cations and the pyridine rings.     

Triterpene glycosides of Thalictrum squarrosum. III. Structures of squarrogenins 1 and 2

Two genins — squarrogenin 1 and squarrogenin 2 — have been isolated from nodding meadow rue by the hydrolysis of squarrosides A1 and A2. The compounds are epimeric at C-21 and have the following structures: 1 — (21R, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β-30-triol, C₃₁H₅₀O₅, mp 169–171°C (hexane-acetone), [α] ₅₄₆ ²⁰ ?11.06° (c 4.52; pyridine); and 2 — (21S, 22S, 23R)-21-methoxy-21,23-epoxycycloart-24-ene-3β,22β,30-triol, C₃₁H₅₀O₅, mp 190–193°C (hexane-acetone), [α] ₅₄₆ ²⁰ +106.6° (c 0.3; pyridine). The results of¹H and¹³C NMR spectroscopy and of mass spectrometry for the new compounds are given.     

Synthesis and structure of bismuth-containing complexes [Ph3PMe] 2 + [BiI5]2− and [Ph3PMe] 2 + [BiI5 · C5H5N]2− · C5H5N

The complexes [Ph₃PMe] ₂ ⁺ [BiI₅]^2? (I) and [Ph₃PMe] ₂ ⁺ [BiI₅ · C ₅H₅N]^2? · C ₅H₅N (II) were synthesized by the reaction of bismuth triiodide with triphenylmethylphosphonium iodide, and their structures were determined by X-ray diffraction analysis. The P atom in cation I has slightly distorted tetragonal coordination polyhedron (the CPC angles 109.42(4)° and 109.52(4)°, the bond lengths P-C_Ph 1.779(2), P-C_Me 1.793(1) Å. The Bi atom in the anion of complex I has an ideal trigonal-bipyramidal coordination polyhedron (Bi-I_eq 3.0031(4), Bi-I_eq 3.0485(5) Å). The crystal of complex II consists of the anions [BiI₅ · C ₅H₅N]^2?, solvated pyridine molecules, and two types of crystallographically independent tetrahedral triphenylmethylphosphonium cations (the angles CPC 106.9(1)°–111.7(1)°, the distances P-C_Ph 1.785(3)–1.792(3), P-C_Me 1.793(3), 1.786(3) Å). The Bi atoms in the anion of complex II have a distorted octahedral coordination polyhedron (Bi-I 3.0878(4)–3.1240(3), Bi-N(1) 2.628(3) Å).     

π Groups in ion pair bonding: the structural effects of reduction on the olefinic bond as observed in the molecular structure of Δ9,9′-bifluorenyl bis(lithium tetramethylethylenediamine)

The reaction of 9,9′-bifluorene with n-butyllithium in the presence of tetramethylethylenediamine (TMEDA) results in the formation of Δ^9,9′-bifluorenyl bis-(lithium tetramethylethylenediamine). In the molecular structure of this material, which formally can be considered to be the dianion of the olefin Δ^9,9′-bifluorene, two TMEDALi groups are closely associated with the 9,9′ bond. The fluorenyl groups are twisted relative to each other by an angle of 48.0(5)°, as compared to 42° in the parent olefin. The 9,9′ bond length is increased from 1.39(2) Å in Δ^9,9′-bifluorene to 1.487(5)Å in the dianion.Single crystal X-ray diffraction techniques were used and resulted in a final discrepancy factor of R_w = 0.064 for 2426 observations. The crystal system is monoclinic (C2/c) with a = 10.814(3), b = 16.717(6) and c = 19.766(6) Å, β = 102.55(2)°; ?_obs = 1.10(3) g cm^?3; ?_calc = 1.095 g cm^?3 for four molecules per unit cell.     

Komplexchemie P-reicher Phosphane und Silylphosphane. VII [1]. Bildung und Struktur von [Li(DME)3]2{(SiMe3)[Cr(CO)5]2 P?PP?P[Cr(CO)5]2(SiMe3)}

Transition Metal Complexes of P-rich Phosphanes and Silylphosphanes. VII. Formation and Structure of [Li(DME)₃]₂{(SiMe₃)[Cr(CO)₅]₂ P-P ? P-P[Cr(CO)₅]₂(SiMe₃)} Deep red crystals of the title compound 1 are produced in the reaction of LiP(Me₃Si)₂[Cr(CO)₅] with 1, 2-dibromoethane in DME. The structure of 1 was derived from the investigation of the ³¹P-NMR spectra and confirmed by a single crystal structure determination. 1 crystallizes in the space group P1 (no. 2); a = 1307.8(5)pm, b = 1373.1(5)pm, c = 1236.1(4)pm, α = 106.22(4)°, β = 88.00(3)°, γ = 115.52(4)° and Z = 1. 1 forms a salt composed of a dianion R₂R₄′P₄^2? (R ? SiMe₃, R′ ? Cr(CO)₅) and solvated Li⁺ cations. The zigzag shaped dianion possesses the symmetry 1 -C_i. The distances d(P? P) = 202.5(1)pm and d(P? P) = 221.9(1)pm correspond to a double bond and single bonds, respectively. The distances d(Cr? P) = 251.1(1) pm and 255.3(1) pm are larger than those observed so far which might be caused by the charge distribution in the dianion.     

Element-Element-Bindungen. II. Synthese und Struktur eines anellierten Tetrastibaadamantans,dargestellt aus Antimon(III)-chlorid und Natrium-cyclopentadienid

Element-Element Bonds. II. Synthesis and Structure of an Anellated Tetrastibaadamantane, Formed by Antimony(III) Chloride and Sodium Cyclopentadienide Revising the reaction between antimony(III) chloride and sodium cyclopentadienide in tetrahydrofuran (THF), originally published by FISCHER und SCHREINER [3], we could not verify the stated formation of tetra(cyclopentadienyl)distibane being red both in the solid and in solution. The pale yellow compound isolated instead is sodium [18-cyclopenta-2,4-dienyl-4,8,12-cyclopenta-2,4-diene-1,1,2-triyl-3a,8a-epistibino-tricyclopenta[1,4,7]tristiboninide] = 3 tetrahydrofuran 1 . Shown by an x-ray crystal structure determination (?45°C; monoclinic; Cc; a = 1882.7(9); b = 1183.5(5); c = 1733.8(13) pm; β = 93.38(5)°; Z = 4; R = 0.043) three (μ₃-C₅H₃) units together with four antimony atoms build up a tetrastibaadamantane framework with a (σ-C₅H₅) and a (μ₂-C₅H₃^?) group as additional substituents. Nearly centric above the anionic ring a sodium cation coordinated by three THF molecules is placed. Characteristic bond lengths and angles lie in the following ranges: Sb? C(sp²) 212–216; Sb? C(sp³) 216–228; Na? C 270–284; Na? O 226–235 pm; C? Sb? C 91–97; Sb? C? Sb 109–110°. ¹H and ¹³C-{¹H} n.m.r. spectra are discussed; the ion pair 1 shows a degenerate valency tautomerism in solution.     

The trans-Influence in Platinum (II) Complexes. 1H- and 13C-NMR. and X-ray structural studies of tridentate Schiff's base complexes of platinum (II)

¹H- and ¹³C-NMR. data are reported for the complexes [Pt (1) L] and [Pt (2) L]; 1 = OC₆H₄CH ? NCH₂CH₂O, 2 = OC₆H₄CH ? NC₆H₄O; L = PR₃, AsR₃, C ? N (cyclohexyl), DMSO, pyridine, secondary amine. The molecular structures of [Pt (2) (NHEt₂)] (I) and [Pt (2) (PPh₃)] (II) have been determined by X-ray analysis. Relevant bond distances for I: Pt-N (amine) = 2.076 Å, Pt-N (imine) = 2.017 Å, Pt-O = 1.992 Å and 2.002 Å; for II: Pt-P = 2.248 Å, Pt-N = 2.064 Å, Pt-O = 1.964 and 2.005 Å. Both the solid and solution state data are interpreted in terms of differences in the trans influence of the ligand L. The question of metal-ligand d-p π back bonding to the imine is discussed.     

Crystal and molecular structure of bis(N,N-dipropyl-N′-diphenoxythiophosphoryl-thioureato) nickel(II) [(C6H5O)2P(S)NC(S)N(C3H7)2]2Ni

The Ni complex [C₆H₅O₂P(S)N(C₃H₇₂]₂Ni is monoclinic, space group P2₁/n with a = 8.890(3), b = 21.692(5), c = 11.670(4) Å, β = 108.35(5)°, V = 2136(1) ų, F(000) = 916, M_r = 534.01, Z = 2, D_m = 1.318, D_x = 1.358 Mg m^?3, graphite monochromatized MoKα ^? radiation, π = 0.7107 Å, μ = 0.76 mm^?1, T = 293 K. The structure was solved by a heavy atom method and refined to R = 0.044 for 3095 independent reflexions. The Ni atom lies in the centre of symmetry and is coordinated by four S atoms of the two molecules of the ligand in a planar arrangement. Ni? S bond lengths are 2.205 and 2.226 Å resp., the angles S? Ni? S are 97.65 and 82.35° resp.     

X-ray molecular structure and theoretical study of 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl]benzene

The structural characterisation of the molecule 1,4-bis[2-cyano-2-(o-pyridyl)ethenyl] benzene obtained through Knoevenagel condensation is reported. The single crystals, as light brown rods, were cultured from a chloroform solution using a slow evaporation method at ambient temperature. The compound crystallised in the monoclinic system belonging to the C2/c space group with a = 26.4556(9) Å, b = 3.73562(10) Å, c = 18.4230(6) Å, β = 109.841(4)° and the asymmetric unit comprising Z = 4. The structure is ordered and the molecules of the title compound exhibited a lattice with water molecules located at sites of inversion and two-fold axial symmetries. Thus, only halves of the molecules are symmetrically independent. The lattice is reported and contrasted with X-ray single-crystal diffraction and theoretical calculations of 1,4-bis(1-cyano-2-phenylethenyl)benzene. By using density functional theory (DFT) and second order Moller-Plesset (MP2) theoretical calculations, the ground state geometry in the whole molecule at the B3LYP/6-31+G(d,p), and MP2/6-31+G(d,p) theory levels, respectively, were optimised. The DFT calculations showed a quasi-planar structure of the molecule, whereas the wave function-based MP2 method afforded a non-planar optimised structure with significant torsion angles between the pyridine and phenyl rings.     

Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen von trans-(PNP)[TcCl4(Py)2] und trans-(PNP)[TcBr4(Py)2]

Preparation, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of trans-(PNP)[TcCl₄(Py)₂] and trans-(PNP)[TcBr₄(Py)₂] By reaction of (PNP)₂[TcX₆] with pyridine in the presence of [BH₄]^? (PNP)[TcX₄(Py)₂], X = Cl, Br, are formed. X-ray structure determinations on single crystals of these isotypic Tc^III complexes (monoclinic, space group P2₁/n, Z = 2, for X = Cl: a = 13.676(4), b = 9.102(3), c = 17.144(2) Å, β = 91.159(1)°; for X = Br: a = 13.972(2), b = 9.146(3), c = 17.285(4) Å, β = 90.789(2)°) result in the averaged bond distances Tc? Cl: 2.386, Tc? Br: 2.519, Tc? N: 2.132(3) (X = Cl) and 2.143(4) Å (X = Br). The two pyridine rings are coplanar and vertical to the X? Tc? X-axes, forming angles of 42.28° (X = Cl) and 43.11° (X = Br). Using the molecular parameters of the X-ray structure determination and assuming D_2h point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis based on a modified valence force field. Good agreement between observed and calculated frequencies is obtained with the valence force constants f_d(TcCl) = 1.45, f_d(TcBr) = 1.035, f_d(TcN) = 1.37 (X = Cl) and 1.45 mdyn/ Å (X = Br), respectively.     

Studies on the reactions of (η5cyclopentadienyl)dicarbonylcobalt with phenyl-1-naphthylacetylene and with phenyl-2-naphthylacetylene,and an X-ray crystallographic determination of one of the products: (η5cyclopentadienyl)-[η4-3,3-di-(1-naphthyl)-2,4diphenylcyclobutadiene]cobalt

The reactions of (η⁵-C₅H₅)Co(CO)₂ with both phenyl-1-naphthylacetylene and phenyl-2-naphthylacetylene have been shown to produce all four possible η⁵-cyclobutadiene-cobalt complexes and all six possible η⁴-cyclopentadienone-cobalt derivatives. The structures of the η⁴-cyclobutadiene-cobalt complexes have been assigned on the basis of proton NMR and mass spectral studies, and unequivocally established by means of an X-ray diffraction investigation for one of the isomers as (η⁵-cyclopentadienyl)[η⁴-1,3-di(1-naphthyl)-2,4-diphenylcyclobutadiene]cobalt. This compound is triclinic, a = 10.88(2), b = 15.710(6), c = 8.728(4) Å, α = 95.09(4)°, β = 101.94(2)°, γ = 86.93(3)°. The space group is P$\text{1}$ with Z = 2. The structure was solved by Patterson and Fourier methods and refined by full-matrix least squares methods (4128 reflections above 3σ) to a final R = 0.036. Bond distances and angles are normal but the cyclobutadiene ring is not quite planar. One of the atoms is 0.047 Å out of the plane of the other three apparently to relieve steric stress. The two phenyl rings are almost coplanar with the cyclobutadiene ring (torsion angles 3.9 and 20.4°) while the naphthyl rings are almost perpendicular to it (torsion angles 63.8, 64°).     

Structural chemistry of organotin carboxylates XV. Diorganostannate esters of dicyclohexylammonium hydrogen oxalate. Synthesis,crystal structure and in vitro antitumour activity of bis(dicyclohexyl-ammonium) bisoxalatodi-n-butylstannate and bis(dicyclohexylammonium) μ-oxalatobis(aquadi-n-butyloxalatostannate)

Dicyclohexylamine, oxalic acid dihydrate and di-n-butyltin oxide were reacted in 2:2:1 or 2:3:2 stoichiometries in ethanol solution to yield, respectively bis(dicyclohexylammonium) bisoxalatodi-n-butylstannate (1) and bis(dicyclohexylammonium) μ-oxalatobis(aquadi-n-butyloxalatostannate) (2); the hydrate was also obtained upon recrystallization of 1 from moist acetonitrile solution. The crystal structures of the two ammonium stannates have been determined at room temperature. In 1, the tin atom in the dianion exists in a skewtrapezoidal bipyramidal geometry with the basal plane being defined by two bidentate oxalate ligands; each ligand forms asymmetric Sn? O bonds [Sn? O 2.348(4), 2.110(4) Å and 2.112(4), 2.363(4) Å]. The apical sites are occupied by the two organo groups disposed over the weaker Sn? O bonds. In 2, the two tin centres of the dianion are connected via a tetradentate oxalate ligand situated about a centre of inversion and each tin atom exists in a pentagonal bipyramidal geometry. The pentagonal plane is defined by four oxygen atoms, two from the central ligand [Sn? O 2.282(4), 2.473(4)Å] and two from a ‘terminal’ oxalate ligand [Sn? O 2.239(4), 2.210(4)Å], and the fifth site is occupied by a water molecule of crystallization [Sn? O 2.422(4)Å]; the apical sites are filled by the n-butyl groups. Both compounds feature extended hydrogen-bonded networks involving the oxygen atoms of the dianion and the N-bound hydrogen atoms. Crystals of 1 are monoclinic, space group P2₁/n, with cell dimensions a = 13.408(3), b = 22.461(4), c = 13.996(2)Å, β = 100.97(2)^°; full-matrix least-squares refinement on 3305 reflections with I≥2.5σ(I) converged to R = 0.042 and R_w = 0.046. Crystals of 2 are monoclinic, space group P2₁/n, a = 13.729(3), b = 14.694(2), c = 14.889(2)Å, β = 104.83(2)^º; refinement on 2093 reflections converged to R = 0.030 and R_w = 0.031. The two di-n-butylstannates were screened in vitro against the mammary MCF-7 and WiDr colon carcinoma cell lines, and were found to be as active as cisplatin, a clinically used antineoplastic drug.     

Polysulfonylamine. VII. Aliphatische Trisulfonylamine

Polysulfonyl Amines. VII. Aliphatic Trisulfonyl Amines The compounds N(SO₂R¹)₂(SO₂R²) with R¹ = R² = CH₃ ( 2a ), R¹ = R² = C₂H₅ ( 2b ) and R¹ = CH₃, R² = C₂H₅ ( 2c ) are prepared by cleavage of aminostannanes (CH₃)₃SnN(SO₂R¹)₂ with sulfonyl chlorides R²SO₂Cl. A simple synthesis of 2a from AgN(SO₂CH₃)₂ and CH₃SO₂Cl is described. From the vibrational spectra of 2a , evidence is obtained for a planar NS₃ group in this compound. X-ray structure determinations of 2b and HN(SO₂C₂H₅)₂ ( 3 ) are reported. In 2b , the NS₃ group is approximately planar (S? N? S bond angles 119.0 ± 0.6°, sum of bond angles at N 356.9°); the S? N bond lengths of ca. 173 pm indicate a bond order of 1. In compound 3 , the nitrogen atom has a planar coordination (S? N? S angle 125.3°, sum of bond angles at N 359.3°), the S? N bond lengths of ca. 165 pm correlate with a bond order of 1.3? 1.4.     

Chains of fused rings in the hydrogen‐bonded structure of meso‐­6,13‐di­amino‐6,13‐di­methyl‐1,4,8,11‐tetra­aza­cyclo­tetra­decane–2,2′‐biphenol (1/2)

The title compound is a salt, [C₁₂H₃₂N₆]²⁺·2[HOC₆H₄C₆H₄O]^?. The centrosymmetric cation contains two intramolecular N—H?N hydrogen bonds with an N?N distance of 2.8290 (13) Å, and the pendent amino groups are in axial sites; the anion contains an intramolecular O—H?O hydrogen bond with an O?O distance of 2.4656 (11) Å. The ions are linked into continuous chains by means of four types of N—H?O hydrogen bonds with N?O distances ranging from 2.7238 (12) Å to 3.3091 (13) Å, associated with N—H?O angles in the range 148–160°.     

Crystal structure of bis(isothiocyanato)diaquabis(pyridine)-magnesium(II) solvate with pyridine 1:4

Abstract

Single crystal X-ray structure of solvate of [MgPy₂(H₂O)₂(NCS)₂](Py = Pyridine) complex with pyridine 1:4 at -50 °C is reported. It is monoclinc P2₁/n, with: a = 9.530(5), b = 12.495(4), c = 15.592(5) Å, β = 90.11(4)°, D_calc. = 1.165 g·cm^?3, Z = 2. The number of data are 4215 (measured) and 1251 (unique-observed). The final R values are R = 0.082 (unit weights) and R_w = 0.067. In the centrosymmetric complex molecule the Mg(II) cation is octahedrally coordinated by four N and two O of the three pairs of trans-arranged ligands. Four solvating pyridine molecules form a second coordination sphere, with two pyridines connecting to each water ligand by means of hydrogen bonds.     

Synthesis and crystal structure of the salt of the protonated thiamine cation with the palladium(II) tetrachloride anion [HTA]2[PdCl4]Cl2 · 2H2O

The reaction of thiamine chloride hydrochloride with a solution of palladium chloride in hydrochloric acid gave a protonated thiamine salt [HTA]₂[PdCl₄]Cl₂ · 2H₂O (I) (TA is 4-methyl-3-[(2??-methyl-4??-amino-3??,4??-dihydropyrimidinyl-5??)methyl]-5-(2-hydroxyethyl)thiazolium cation, C₁₂H₁₆N₃O₂S). The crystal structure of I was determined by X-ray diffraction. The crystals are triclinic: a = 11.459(8) ?, b = 12.239(8) ?, c = 6.910(1) ?, ?? = 103.24(3)°, ?? = 76.95(3)°, ?? = 106.04(3)°, Z = 2, space group P $\bar 1$ . The structural units of I are doubly charged [HTA]²⁺ cations, [PdCl₄]^2? and Cl^? anions, and crystallization water molecules combined by hydrogen bonds and electrostatic interactions. The planar thiazolium and pyrimidine rings are in the F conformation, ??_t = 1.0°, ??_p = ?86.6°, and the dihedral angle between the planes is 85.5°. The torsion angles of the hydroxyethyl group are as follows: C(9)C(10)C(11)O(1), 175.6°; S(1)C(9)C(10)C(11), 33.2°; it is involved in the hydrogen bond with the free Cl^? anion. The sulfur atom forms a short (3.052 ?) intermolecular S-Cl contact with the chlorine atom of the [PdCl₄]^2? anion, which forms supramolecular chains.