Study of the aqueous reactions of K[Pt(DMSO)Cl3] with nitrile ligands and crystal structures of Cl(DMSO)Pt(μ-C4H8NO)2Pt(DMSO)Cl and Cl(DMSO)Pt(μ-C5H10NO)2Pt(DMSO)Cl

1992 ◽  
Vol 70 (9) ◽  
pp. 2476-2484 ◽  
Author(s):  
Fernande D. Rochon ◽  
Radia Boughzala ◽  
Robert Melanson

The aqueous reactions of K[Pt(DMSO)Cl3] with nitriles were studied in different conditions of pH. At normal pH (≈2.4), the ligands RCN, where R is an alkyl group, produced the yellow complexes Pt(DMSO)(R-CN)Cl2. Infrared spectroscopy suggested cis isomers. The 195Pt NMR spectra of the compounds show a resonance around −3000 ppm. The same reactions in neutral medium (pH adjusted to ~7 with NaOH) produced acetamido-bridged dimers (DMSO)ClPt(μ-RCONH)2Pt(DMSO)Cl with all the ligands studied: propionitrile, butyronitrile, dimethylacetonitrile, trimethylacetonitrile, fluoroacetonitrile, chloroacetonitrile, bromoacetonitrile, and dibromoacetonitrile. The results of 195Pt NMR spectroscopy show a head-to-tail isomer, since only one signal around −2750 ppm is observed for each complex. These dimeric compounds are all blue or green depending on the ligand. The same dimers are obtained with all the haloacetonitrile ligands when the pH is not adjusted (≈2.4). The crystal structures of Cl(DMSO)Pt(μ-C4H8NO)2Pt(DMSO)Cl (1) and Cl(DMSO)Pt(μ-C5H10NO)2Pt(DMSO)Cl (2) were determined. The results confirm that the dimers are head-to-tail isomers with the DMSO ligands located in trans position to the O-acetamido atoms. The two crystals belong to the Pna21 space group with a = 11.112(4), b = 20.414(9), c = 10.161(4) Å for 1 and a = 11.607(6), b = 20.113(11), and c = 10.641(5) Å for 2. The structures were refined to R = 0.054 for 1 and R = 0.056 for 2. The Pt—Cl bond lengths are 2.328(10), 2.293(10) Å for 1 and 2.317(9), 2.317(10) Å for 2, while the Pt—S bond lengths are 2.173(10), 2.193(10) for 1 and 2.180(9), 2.176(9) Å for 2. The Pt—O bonds vary from 1.91(2) to 2.08(2) and the Pt—N from 1.88(2) to 2.03(2) Å. The dihedral angle between the two Pt(II) planes is 36°.

1991 ◽  
Vol 56 (9) ◽  
pp. 1908-1915 ◽  
Author(s):  
Jaroslav Holeček ◽  
Antonín Lyčka ◽  
Milan Nádvorník ◽  
Karel Handlíř

Infrared spectroscopy and multinuclear (13C, 17O, and 119Sn NMR spectroscopy have been used to study the structure of bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids (1-C4H9)2. Sn(X(COO)2), where X = (CH2)n (n = 0-8), CH=CH (cis and trans) and C6H4 (ortho and para).The crystalline compounds are formed by linear or cyclic oligomers or polymers whose basic building units represent a grouping composed of the central tin atom substituted by two 1-butyl groups and coordinated with both oxygen atoms of two anisobidentate carboxylic groups derived from different molecules of a dicarboxylic acid. The environment of the tin atom has a shape of a trapezoidal bipyramid. When dissolvet in non-coordinating solvents, the compounds retain the oligomeric character with unchanged structure of environment of the central tin atom. In the media of coordinating solvents the bis(1-butyl)tin(IV) carboxylates of dicarboxylic acids form complexes whose central hexacoordinated tin atom binds two molecules of the solvent trough their donor atoms. Carboxylic groups form monodenate linkages in these complexes.


1984 ◽  
Vol 39 (8) ◽  
pp. 1114-1117 ◽  
Author(s):  
Willi Kafitz ◽  
Kurt Dehnicke ◽  
Eberhard Schweda ◽  
Joachim Strähle

AbstractReNF4 · ReF5(NCl) is prepared by direct fluorination of ReNCl4 with fluorine between 80 °C and 130 °C. The red crystals are extremely sensitive to moisture. The complex is characterized by the IR spectrum and by an X-ray structural investigation. ReNF4 · ReF5(NCl) crystallizes orthorhombically in the space group Pnma with 4 formula units per unit cell and with the cell dimensions a = 1440, b = 848, c = 776 pm (419 observed, independent reflexions, R = 13.9%). The complex consists of the molecules ReNF4 and ReF5(NCl), which are linked by a linear asymmetric fluorine bridge. The bridging fluorine atom is in trans-position to the nitrido ligand Re -F - 228 pm) and to the nitreno ligand (Re -F = 159 pm and Re= N - Cl 164 pm) correspond to triple 188 pm). The Re ≡ N bond lengths Re= N bonds.


1994 ◽  
Vol 72 (7) ◽  
pp. 1675-1683 ◽  
Author(s):  
Jacques Poitras ◽  
André L. Beauchamp

The reaction of NbCl5 and TaCl5 with 7-azaindole (Haza) at room temperature in benzene or dichloromethane yielded MCl5(Haza) addition compounds. Under more severe conditions, the same compound was obtained with TaCl5. For NbCl5, some reduction to Nb(IV) was observed and NbCl5(Haza), NbCl4(Haza)2, and the (H2aza)+ ion were identified in the reaction mixture by infrared spectroscopy. Oxidative coupling of two azaindole units via N7—C6 also took place during the reaction, since the 7-(azaindol-6-yl)azaindolium cation was found as counter-ion in the crystal structures of two complex salts. In the crystals of (H2aza-aza)[NbOCl4(Haza)]•0.5CH2Cl2([Formula: see text]a = 7.255 Å, b = 12.412 Å, c = 14.277 Å, α = 89.03°, β = 85.60°, γ = 76.66°, Z = 2, R = 0.062), the anion is the roughly octahedral [NbOCl4(azaindole)]− species containing a neutral N7-coordinated azaindole trans to the Nb=O bond. The [NbOCl5]2− salt ([Formula: see text]a = 7.527 Å, b = 10.168 Å, c = 10.467 Å, α = 66.41°, β = 84.07°, γ = 85.51°, Z = 1, R = 0.037) contains the distorted octahedral [NbOCl5]2− ion disordered over two orientations. The infrared spectra suggest monomeric octahedral structures for the MCl5(Haza) and NbCl4(Haza)2 complexes. 1H NMR spectroscopy shows that NbCl5(Haza) is not dissociated in CD2Cl2.


1991 ◽  
Vol 46 (5) ◽  
pp. 639-646 ◽  
Author(s):  
W. S. Sheldrick ◽  
C. Martin

The phenyliodoantimonates(III) [Et4N][Ph2SbI2] (1), [Et4N]2[Ph2Sb2I6] (2) and [Hpy]3[Ph2Sb2I7] (3) have been prepared and their structures established by X-ray structural analysis. The anion [Ph2SbI2]⁻ displays a ψ-trigonal bipyramidal structure with axial Sb–I distances of 2.925(1) and 3.109(1) A. In the dimeric anions [Ph2Sb2I6]2- and [Ph2Sb2I7]3- the antimony atoms exhibit ψ-octahedral geometries. As observed for [Ph2SbI2]⁻, terminal Sb–I bonds in trans-position to one another display significantly different lengths. The anion [Ph2Sb2I7]3- displays Ci- symmetry with a bridging iodine atom at the crystallographic centre of symmetry. Long Sb—I distances of 3.404(1) A are observed to this atom. A structural correlation of opposite Sb–X distances (X = Cl, Br, I) in linear three centre X–Sb ··· X interactions is presented. The sum of the bond valences in iodoantimonates(III) is a minimum for symmetrical I–Sb–I three centre bonds, reflecting thereby the antibonding influence of the Sb 5 s-orbital. This influence is considerably smaller for bromoantimonates(III) and may be effectively neglected for chloroantimonates(III).


1995 ◽  
Vol 50 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Peter Dierkes ◽  
Gerlinde Frenzen ◽  
Sigrid Wocadlo ◽  
Werner Massa ◽  
Stefan Berger ◽  
...  

The crystal structures of the thioether complexes [MCl4(SEt2)2] with M = Mo and W have been solved by X-ray methods. Both compounds crystallize isotypically in the triclinic space group P1̄ with two formula units per cell unit. The metal atoms are octahedrally coordinated by four chlorine atoms and by the two sulfur atoms of the thioether molecules in transposition (symmetry Ci) with bond lengths (average): Mo-Cl 233.1, Mo-S 253.4, W-Cl 233.1, and W-S 251.7 pm. Both complexes were also characterized by 1H and 13C NMR spectroscopy as well as by measurement of the magnetic susceptibilities in the temperature range from 1.8 to 350 K.


2001 ◽  
Vol 79 (5-6) ◽  
pp. 760-774 ◽  
Author(s):  
Harry Adams ◽  
Sylvana C Agustinho ◽  
Krystyna Chomka ◽  
Brian E Mann ◽  
Stephen Smith ◽  
...  

The crystal structures of [Fe3(CO)10L2] (L2 = dppm, (Ph2P)2NH, {(EtO)2P}2O) and [Fe3(CO)9(dppm){P(OMe)3}] (dppm = (Ph2P)2CH2) have been determined. [Fe3(CO)10L2] (L2 = dppm, (Ph2P)2NH, {(EtO)2P}2O) adopt a stereochemistry in the crystal with the bidentate ligand across an unbridged Fe-Fe edge, resulting in one phosphorus ligand being unusually in the axial position. In contrast, [Fe3(CO)9(dppm){P(OMe)3}] adopts a stereochemistry in the crystal with the bidentate ligand across the bridged Fe-Fe edge. The structures of the [Fe3(CO)10L2] (L2 = dppm, (Ph2P)2NH, {(EtO)2P}2O) support the Mann concerted bridge - opening bridge - closing mechanism of carbonyl fluxionality rather than the Johnson libration mechanism. The fluxionality of the compounds in the 13C NMR spectra is explained by a combination of the concerted bridge - opening bridge - closing, merry-go-round, and trigonal twist mechanisms, and ΔG‡ values were determined.Key words: iron carbonyls, crystal structures, 13C NMR spectroscopy, fluxionality, mechanisms.


1989 ◽  
Vol 44 (9) ◽  
pp. 1003-1006 ◽  
Author(s):  
Kurt Merzweiler ◽  
Dieter Fenske ◽  
Eva Hartmann ◽  
Kurt Dehnicke

The title compound has been prepared by the reaction of N,N,N′-tris(trimethylsilyl)benzamidine with tantalum pentachloride in CH2Cl2 suspension, forming amber-coloured, moisturesensitive crystals, which were characterized by an X-ray structure determination. Space group P 21/n, Z = 2, 4895 observed independent reflexions, R = 0.059. Lattice dimensions (-65°C): a = 1165.2(6), b = 1335.4(6), c = 1629.0(7) pm, β = 93.23(4)°. The complex forms centrosymmetric molecules dimerized via chloro bridges TaCl2Ta with TaCl bond lengths of 247.2(2) and 277.1(2) pm, the longer one being in trans-position to the imido group, which can be formulatedas [xxx] (bond lengths Ta=Ν = 183.5(8), C=N = 134(1) pm, bond angle TaNC = 162.7(7)°).


1985 ◽  
Vol 40 (8) ◽  
pp. 1005-1009 ◽  
Author(s):  
Thomas Godemeyer ◽  
Kurt Dehnicke ◽  
Dieter Fenske

AbstractThe title compound results from a slow reaction between two m oles of PPh4[W2NCl10], dissolved in dichlorom ethane, upon addition of carbon tetrachloride. The red crystals are characterized by X-ray diffraction. (PPh4)2[W3N2Cl14] · CCl4 · CH2Cl2 crystallizes triclinically in the space group P1̄ with two formula units per unit cell. The cell dimensions at -100 °C are: a = 1430, b = 1462, c = 1655 pm , α = 74.6°, β = 79.0°, γ = 82.4° (10,908 independent, observed reflexions, R = 0.078). The structure consists of PPh4⊕ ions, trinuclear finitrido anions [W3N2Cl14]2⊝ and enclosed molecules of CCl4 and CH2Cl2. The tungsten atom s of the anion are linked by almost linear nitrido bridges (~176°) with different WN bond lengths (mean values 184 pm and 207 pm ), corresponding to double and single bonds. The equatorial WCl4 groups are in eclipsed conformation; the two chlorine atoms in trans-position to the nitrido groups have mean bond lengths of 240 pm which is 9 pm longer than the equatorial W -Cl bonds. The IR spectrum is reported.


1993 ◽  
Vol 48 (8) ◽  
pp. 1105-1111 ◽  
Author(s):  
Michael Plate ◽  
Peter Hofacker ◽  
Werner Massa ◽  
Birgit Schwarz ◽  
Bernhard Neumüller ◽  
...  

[WCl4(Ph-C≡C-I)(THF)] has been prepared by the reaction of trans-[WCl4(SEt2)2] with Ph - C≡C - I in THF solution, whereas [WCl4(Ph-C≡C-Te-nC4H9)(THF)] has been synthesized by the reaction of Ph-C≡C-Te-nC4H9 with tungsten hexacloride in the presence of C2Cl4 and THF. Both complexes were characterized by IR spectroscopy and by crystal structure determinations.[WCl4(Ph-C≡C-I)(THF)]: Space group P21/c, Z = 4, 2617 observed unique reflections, R = 0.064. Lattice dimensions at –70°C: a = 1518.2(3), b = 714.5(1), c = 1540.0(3) pm, β = 90.09(3)°.[WCl4(Ph-C≡C-Te–nC4H9)(THF)]. Space group P1̄, Z = 2, 3911 observed unique reflections, R = 0.067. Lattice dimensions at 20°C: a = 844.0(3), b = 974.6(4), c = 1002.4(3) pm, α = 76.00(4), β= 105.14(1), γ = 82.03(3)°.Both complexes have molecular structures, in which the tungsten atoms are seven-coordi-nate by four chlorine ligands, by the two alkyne carbon atoms, and in trans position to the latter by the oxygen atom of the THF molecule. The WC bond lengths are 198 and 200(1) in the telluro complex and 206 and 196(1) pm in the iodine derivative.


1993 ◽  
Vol 48 (7) ◽  
pp. 1019-1022 ◽  
Author(s):  
Gerlinde Frenzen ◽  
Dorothea Wolff von Gudenberg ◽  
Kurt Dehnicke

The crystal structure of [ReCl4(PhC = CPh)(OPCl3)] was solved with X-ray methods. Space group P1̄, Z = 2, 2085 observed unique reflections, R = 0.029. Lattice dimensions at -70°C: a = 857.0(2), b = 937.9(2), c = 1249.6(2) pm, α = 87.43(3)°, β = 83.48(3)°, γ = 89.80(3)°. [ReCl4(PhC ≡ CPh)(OPCl3)] has a molecular structure with the alkyne ligand bonded side-on (bond lengths Re-C 198.9(8) and 198.6(7) pm). The oxygen atom of the solvating POCl3 molecule is coordinated in trans position to the ReC2 unit of the alkyne ligand (bond length Re-O 226.7(5) pm).


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