The crystal structure of tetraethylammonium aquatetracyanooxorhenate(V)

Summary The crystal structure of the tetraethylammonium salt of [ReO(H₂O)(CN)₄]^– has been determined from threedimensional x-ray diffraction data. The light blue crystals are monoclinic, space group P2₁/m witha=8.760(1),b=9.518(5),c=11.718(1) Å, =102.63(1)^o with two molecules per unit cell. The final R value using 2009 observed reflections and anisotropic thermal parameters for all the non-hydrogen atoms was 0.038. The [ReO(H₂O)(CN)₄]^– ion has a distorted octahedral geometry with the rhenium atom displaced by 0.30 Å out of the plane formed by the four carbon atoms of the cyano ligands towards the oxo ligand. Bond distances: Re=O=1.667(8), Re–OH₂=2.142(7) and Re–C (average)=2.11(1) Å.     

Synthesis and crystal structure of tetraphenylphosphonium isocyanurate pentahydrate

A new complex [Pb(Crypt-222)(H₂O)₂]⁺ · 2(iso-PrO)₂P(S)N⁻C(S)Ph (I) was prepared and studied by X-ray diffraction: space group C2/c, a = 16.170 ?, b = 10.405 ?, c = 34.116 ?, β = 103.32°, Z = 4. The monoclinic structure of I was solved by direct methods and refined by full-matrix least-squares calculation in the anisotropic approximation to R = 0.098 for 6414 independent reflections (CAD4 automated diffractometer, λMoK _α). In structure I, the host-guest [Pb(Crypt-222)(H₂O)₂]⁺ cation is located on a twofold crystallographic axis. The Pb²⁺ cation is coordinated by all eight heteroatoms (6O + 2N) of the cryptand ligand and by two O atoms of water molecules. The Pb²⁺ coordination polyhedron (CN = 10) is a highly distorted two-base-centered dicapped trigonal prism. The crystal structure of I contains one independent thiophosphoramidate anion with deprotonated nitrogen. In crystal I, the complex cation is connected to two thiophosphoramidate anions by ion-ion hydrogen bonds, O(w)-H...S.     

The crystal structure of 4,4′-dipyridinium tetracyanooxothiocyanatorhenate(V)

Summary The light purple crystals of (4,4-dipyridinium) [ReO(NCS)(CN)₄] crystallize in the monoclinic space group P2₁/m witha=6.615(1),b=16.043(1),c=8.405(1) Å,=93.20(1)°,z=2. The anisotropic refinement of the 1770 observed reflections converged to R=0.041.The [ReO(NCS)(CN)₄]^2– ion has a distorted octahedral geometry. The rhenium atom is displaced by 0.30 Å out of the plane formed by the four carbon atoms towards the terminal oxo ligand. Bond distances: Re=0 =1.67(1), Re–N=2.12(1) and Re–C_av=2.11(1)Å. The thiocyanate ion is nitrogen bonded to the rhenium atom.     

Synthesis and crystal structure of an unusual mixed crystal containing an oxorhenium(V) and imidorhenium(V) complex

An unusual mixed crystal of a square-pyramidal oxorhenium(V), [ReOCl(Hdua)], and an octahedral imidorhenium(V) complex, [Re(dua)Cl₂(PPh₃)], was prepared from the reaction of trans-[ReOCl₃(PPh₃)₂]_and (6Z)-6-(2-aminobenzylideneamino)- 5-amino-1,3-dimethylpyrimidine-2,4(1H,3H)-dione (H₃dua) in ethanol. Characterization was performed by single crystal X-ray structure determination and IR spectroscopy. The chelate Hdua is coordinated as a tridentate diamido-imine, and dua is chelated as an imido-imino-amide.     

The crystal and molecular structure of the tetraphenylphosphonium salt of the anion bromotri-μ-carbonyloctacarbonyl-tetrahedro-tetrairidate(-1)

Crystal of [Ir₄Br(CO)₁₁] (PPh₄) are orthorhombic, space group P2₁2₁2₁, with a 13.276(3), b 18.347(4), c 16.041(4) Å. The structure has been elucidated by the analysis of 2876 observed intensities recorded on an automatic diffractometer, and refined by the least-squares method to R  0.043. The anion contains a tetrahedral cluster of iridium atoms (mean IrIr 2.710 Å). The carbonyl arrangement differs from that of the parent Ir₄(CO)₁₂, and is similar to that known for Co₄(CO)₁₂ and Rh₄(CO)₁₂, with one terminal CO group in the basal M₃(CO)₉ moiety replaced by the bromide ligand; two of the bridging CO groups become markedly assymetric.     

Syntheses, characterization, crystal structure and antifungal activity of four tetraphenylphosphonium bis(N-R-sulfonyldithiocarbimato)zincate(II) salts

Four new compounds of the general formula: (Ph₄P)₂[Zn(RSO₂NCS₂)₂] where Ph₄P = tetraphenylphosphonium cation, R = 4-FC₆H₄ (1), 4-ClC₆H₄ (2), 4-BrC₆H₄ (3) and 4-IC₆H₄ (4), were obtained by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO₂NCS₂K₂) with zinc(II) acetate dihydrate in dimethylformamide. All compounds crystallize in the centrosymmetric space group of the triclinic system. The compounds 2, 3 and 4 are isostructural but compound 1 crystallizes as hemihydrate. The elemental analyses and the IR, ¹H NMR and ¹³C NMR data for 1-4 are consistent with the formation of bis(dithiocarbimato)zinc(II) complexes. These compounds are active against the phytopathogenic fungus Colletotrichum gloeosporioides.     

Antimony(V) and bismuth(V) complexes of lapachol: synthesis, crystal structure and cytotoxic activity

Antimony(V) and bismuth(V) complexes of lapachol have been synthesized by the reaction of Ph?SbCl? or Ph?BiCl? with lapachol (Lp) and characterized by several physicochemical techniques such as IR, and NMR spectroscopy and X-ray crystallography. The compounds contain six-coordinated antimony and bismuth atoms. The antimony(V) complex is a monomeric derivative, (Lp)(Ph?Sb)OH, and the bismuth(V) complex is a dinuclear compound bridged by an oxygen atom, (Lp)?(Ph?Bi)?O. Both compounds inhibited the growth of a chronic myelogenous leukemia cell line and the complex of Bi(V) was about five times more active than free lapachol. This work provides a rare example of an organo-Bi(V) complex showing significant cytotoxic activity.     

The crystal structure of bis-trimethylbenzylammoniumtetrachlorocuprate (II)

The crystal structure of bis-trimethylbenzylammonium tetrachlorocuprate (II) was determined. The structure for the [CuCl₄]^2– ion proposed in the spectroscopic work, i.e. a flattened tetrahedron of D _2d, symmetry, was confirmed. It was shown, further, that the four S ₄ axes of the four [CuCl₄]^2– ions in the unit cell are practically parallel, because they lie almost parallel to the glide planes of symmetry. This fact proved to be of great importance for further collection and elaboration of spectral data. The unit cell has dimensions a=9.584, b=9.104, c=28.434 Å, =92°50, space group P2 ₁/n, and contains 4 molecules. R=0.077 (computed on the 2861 observed independent reflections only).

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Zusammenfassung Die Kristallstruktur von [C₆H₅CH₂N(CH₃)₃]₂CuCl₄ wird bestimmt, wobei die aus spektroskopischen Studien vorgeschlagene Struktur des Ions [CuCl₄]^2– bestätigt wird (gestauchtes Tetraeder der Symmetrie D _2d). Ferner wird gezeigt, daß die S ₄ Achsen der vier [CuCl₄]^2–. Ionen in der Einheitszelle praktisch parallel sind; diese Tatsache erwies sich als sehr wichtig bei der Messung und Auswertung des Spektrums. Die Einheitszelle hat die Dimensionen a=9.584, b=9.104, c=28.434 Å, =92°50, Raumgruppe P2 ₁/n, und enthält vier Moleküle. R=0.077 (nur mit Hilfe der 2861 unabhängigen Reflexionen berechnet).

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Résumé La structure cristalline du tetrachlorocuprate (II) de bis-trimethylbenzylammonium a été déterminée. La structure de l'ion [CuCl₄]^2– proposée dans l'étude spectroscopique, c.a. d'un tétraèdre plat de symétrie D _2d, a été confirmée. On a montré, de plus, que les quatre axes S ₄ des quatre ions [CuCl₄]^2– dans la maille élémentaire sont pratiquement parallèles, car ils sont presque parallèles aux plans de symétrie de glissement, fait qui s'avère de grande importance pour l'accumulation et la mise au point des données spectrales. La maille élémentaire a pour dimensions a=9.584, b=9.104, c=28.434 Å, =92°50, groupe d'espace P2 ₁/n, et contient quatre molécules. R=0.077 (calculé à l'aide seulement de 2861 réflexions indépendantes observées).

     

The crystal structure of thenoyltrifluoroacetonatocarbonyltriphenylphosphinerhodium (I)

The crystal structure of thenoyltrifluoroacetonatocarbonyltriphenylphosphinerhodium (I), [Rh(TTA) (CO) PPh₃], has been determined by single crystal X-ray diffraction. 2665 independent observed reflections were used for the structure determination. The crystals are monoclinic, space group P2₁/n with a = 13.26Å; b = 10.86Å; c = 18.92Å; β = 69.8° with four molecules in the unit cell. The final R value for all the reflections was 0.052. The compound was prepared by substitution of one of the carbonyl groups in Rh(TTA) (CO)₂ by triphenylphosphine. The structure determination shows that the carbonyl group trans to the oxygen nearest to the thenoyl ring was substituted by the phosphine group. The distance between the rhodium atom and the latter oxygen atom is 0.033Å longer than the other RhO distance.     

Oxo methyls of molybdenum(V), tungsten(V) and rhenium(V): X-ray crystal structure of (Me4WO)2Mg(thf)4

The interaction of MgMe₂ or MeLi with MOCl₄ (M = W or Mo) leads to the paramagnetic (d¹) complexes (Me₄MO)₂Mg(thf)₄ and (Me₄MO)Li(thf)₂, respectively. The structure of (Me₄WO)₂Mg(thf)₄ has been determined by X-ray crystallography and shown to consist of Mg²⁺ co-ordinated by thf and square pyramidal Me₄WO⁻ units. The preparation of the diamagnetic rhenium(V) compound (Me₄ReO)Li(thf)₂ is also reported.     

The crystal structure of poly(tetramethylene terephthalate)

The unit cell of poly(tetramethylene terephthalate) is triclinic with parameters a = 5.96 Å, b = 4.83 Å, c (fiber axis) = 11.62 Å, α = 115.2. β = 99.9, and γ = 111.3°; space group P1 , calculated crystalline density 1.41 g/cc. The plane of the benzene ring is found to be inclined by about 15° from the fiber axis, contributing to a shortening of the fiber period as compared to the period expected on the basis of analogy with other members of the terephthalate ester series. The remaining shortening of the fiber period occurs in the ? O? °CH₂? °CH₂? segment of the chain. No abnormally short distances among neighboring chain atoms were observed. A typical texture pattern was found in specimens of this polymer that were cold rolled and subsequently annealed. In this texture the c axis of the unit cell is highly oriented in the rolling direction; the a and b axes of the unit cell are oriented preferentially so that the terephthalate residue lies as close as possible to the plane of rolling.     

The crystal structure of bis(trimethyltin)carbonate

The crystal structure of bis(trimethyltin)carbonate, (Me₃Sn)₂CO₃ shows the presence of different tin-atom sites in a polymeric structure which arises as a result of a tridentate mode of coordination of the carbonate dianion.