The crystal structure of tetraphenylphosphonium tetracyanohydroxooxorhenium(V)

Summary The crystal structure of (PPh₄)₂[ReO(OH)(CN)₄]·5H₂O has been determined from three-dimensional x-ray diffraction data. The light brown crystals are monoclinic, space group P2₁/n, with cell dimensionsa=16.753(2),b=19.928(2),c=15.338(2) Å and =101,894(1)°,z=4, D_m=1.45(1) g cm^–3. The anisotropic refinement of the 6088 observed reflections converged to R=0.077.The [ReO(OH)(CN)₄]^2– ion has a distorted octahedral geometry. Bond distances: Re =1.70(1), Re–OH=1.90(1) and ReC_av=2.12(2) Å. The Re atom is displaced by 0.08 Å out of the plane formed by the four carbon atoms towards the terminal oxo ligand.     

Synthesis and X-ray crystal structure of tetraethylammonium bis[1,2-di(carbomethoxy)ethane-1,2-dithiolato]oxotechnetate(V)

Summary The (NEt₄)⁺[TcO{SCH(CO₂Me)CH(CO₂Me)}₂]^– compound has been prepared from technetium(V) gluconate and characterized by single crystal x-ray structural analysis (R factor=0.065).The compound crystallizes in the monoclinic space groupP2₁/c witha=12.722(3),b=13.820(4) andc=18.213(5) Å, =107.13(4)° andZ=4. In the complex the technetium atom is close to the center of the base of a square pyramid in which the oxo oxygen is at the apex and the four sulfur atoms form the basal plane. The Tc-S distances average 2.316 Å. The Tc=O distance is 1.672(6) Å. Considerations about the osteotropic behaviour of DMSA labelled with⁹⁹Tc are deduced from the reported results.     

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 tetraethylammonium salt of tetrahydridopentadecacarbonyltetrarhenate(2−) in two crystallographic forms

The structure of the title compound, (NEt₄)₂[H₄Re₄(CO)₁₅], is reported in two crystallographic modifications, I and II. Both forms axe monoclinic and the cell constants are as follows: I, a 11.355(2), b 21.204(4), c 17.416(3) Å, β 94.15(2)°, space group P2₁/c; II, a 21.831(4), b 17.584(3), c 11.446(2) Å, β 96.02(2)°, space group P2₁,/n. Two sets of 3042 (I) and 2870 (II) independent diffraction intensities, collected by counter methods, were used for the solution and refinement of the two structures. The final conventional R factors have values 5.5% (I) and 6.3% (II), respectively. The crystal packings are compared, showing different conformations of the (NEt₄)⁺ cations. The anions contain a tetrametal cluster formed by an isosceles triangle plus an apically bound metal atom; the carbonyl groups are all terminally bonded to the rhenium atoms. Some differences, present both in the metal atom clusters and in the carbonyl dispositions, are discussed and compared with a third, previously reported, crystallographic modification of the same compound.     

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).

---

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).

---

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.     

Crystal structure and triboluminescence of tetraethylammonium tetrakis(thenoyltrifluoroacetonato)europium

An atomic structure of complex Et₄N[Eu(ТТA)₄] (TTA is the thenoyltrifluoroacetonate anion, Et₄N⁺ is the tetraethylammonium cation) possessing strong luminescence and triboluminescence was determined by X-ray crystallography. The crystal system of centrosymmetric crystals is monoclinic: a = 10.2495(1) Å, b = 20.2162(3) Å, c = 23.5788(3) Å, β = 102.551(1)°, space group P2₁/c, Z = 4, d _calc = 1.625 g cm^–3. The crystals of the compound have an isle structure, which comprises individual complex anions [Eu(TTA)₄]^– and tetraethylammonium cations Et₄N⁺. The structural aspects of a possible model for the formation of triboluminescent properties were considered, the role of cleavage planes and disordering was discussed.     

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.     

The crystal structure of tetrabutylammonium trichlorocarbonylplatinate(II)

Crystals of [C₁₆H₃₆N]⁺[Cl₃COPt]^? are monoclinic, space group P2₁/n, with a 14.949(8), b 8.892(7), c 18.232(10) Å, β 105.5(3)°, Z 4. The structure has been refined by least-squares to a final R of 0.042 for 2358 counter intensities. The PtCl bond lengths in the square-planar anion are not significantly different (mean value 2.291 Å) and the PtC (carbonyl) bond length is 1.82 Å.Conclusions are drawn on the factors affecting the trans influence in this complex and a number of related square planar Pt^II chloro-complexes.     

The crystal structure of iododimethyl(trimethylamine)aluminum

The crystal structure of iododimethyl(trimethylamine)aluminium has been determined from single-crystal X-ray diffraction data collected by counter methods. I(CH₃)₂Al · N(CH₃)₃ crystallizes in the othorhombic space group Pnma with cell dimensions a=12.59(1), b=10.75(1), c=7.58(1)å, and p_calc=1.58 g·cm^?3 for Z=4. Least-squares refinement gave a final weighted R Value of 0.071 for 574 independet observed reflections. Each monomeric molecule lies on a crystallographic mirror plane with the trimethylamine and iododimethylaliminium groups in a staggered configuration about the aluminum  nitrogen bond.