scholarly journals Crystal structures of 2-bromo-1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane and 2-bromo-1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane

2018 ◽  
Vol 74 (8) ◽  
pp. 1142-1146
Author(s):  
Eva M. Gulotty ◽  
Richard J. Staples ◽  
Shannon M. Biros ◽  
Peter P. Gaspar ◽  
Nigam P. Rath ◽  
...  
Keyword(s):  
Free Radical ◽  
Crystal Structures ◽  
Steric Hindrance ◽  
Rotation Axis ◽  
Rotational Symmetry ◽  
Bond Distance ◽  
Bond Angles ◽  
Bond Lengths ◽  
Radical Initiator ◽  
Radical Bromination

The synthesis and crystal structures of two tris(trialkylsilyl)silyl bromide compounds, C9H27BrSi4 (I, HypSiBr) and C27H63BrSi4 (II, TipSiBr), are described. Compound I was prepared in 85% yield by free-radical bromination of 1,1,1,3,3,3-hexamethyl-2-(trimethylsilyl)trisilane using bromobutane and 2,2′-azobis(2-methylpropionitrile) as a radical initiator at 333 K. The molecule possesses threefold rotational symmetry, with the central Si atom and the Br atom being located on the threefold rotation axis. The Si—Br bond distance is 2.2990 (12) Å and the Si—Si bond lengths are 2.3477 (8) Å. The Br—Si—Si bond angles are 104.83 (3)° and the Si—Si—Si bond angles are 113.69 (2)°, reflecting the steric hindrance inherent in the three trimethylsilyl groups attached to the central Si atom. Compound II was prepared in 55% yield by free-radical bromination of 1,1,1,3,3,3-hexaisopropyl-2-(triisopropylsilyl)trisilane using N-bromosuccinimide and 2,2′-azobis(2-methylpropionitrile) as a radical initiator at 353 K. Here the Si—Br bond length is 2.3185 (7) Å and the Si—Si bond lengths range from 2.443 (1) to 2.4628 (9) Å. The Br—Si—Si bond angles range from 98.44 (3) to 103.77 (3)°, indicating steric hindrance between the three triisopropylsilyl groups.

Synthesis and Crystal Structures of Three Carboxylate- Bridged Tetranuclear Copper(II) - Lanthanide(III) Complexes of Ph3P+CH2CH2CO2−

1999 ◽  
Vol 52 (10) ◽  
pp. 983 ◽  
Author(s):  
Yang-Yi Yang ◽  
Seik Weng Ng ◽  
Xiao-Ming Chen
Keyword(s):  
Oxygen Atom ◽  
Crystal Structures ◽  
Triclinic Space Group ◽  
Coordination Environment ◽  
Space Group ◽  
Bond Angles ◽  
Bond Lengths ◽  
Metal Atoms ◽  
Apical Site

Three tetranuclear copper(II)–lanthanide(III) complexes of triphenylphosphoniopropionate (Ph3P+CH2CH2CO2−,tppp), namely [Cu2Ln2(tppp)8(H2O)8](ClO4)10·2H 2 O [Ln = EuIII, NdIII or CeIII], were synthesized and characterized by crystallography. The EuIII complex crystallizes in the triclinic space group P1 – with a 16.249(7), b 17.185(11), c 17.807(11) Å, α 69.750(10), β 89.230(10), γ 84.070(10)˚, V 4639(5) Å3, Z 1. In the crystal structures, four tppp ligands bridge a pair of CuII and tetraaquo-EuIII atoms (Cu···Eu 3.527(2) Å) through their µ2-carboxylato ends to form a dinuclear subunit; two of these subunits are additionally linked by one of the CuII -bonded carboxylato oxygen ends, across a centre of inversion, to furnish a dimeric tetranuclear [Cu(tppp)4 Eu(H2O)4]2 species (Cu···Cu 3.323(2) Å). This CuII -bonded oxygen atom occupies the apical site of the square-pyramidal coordination environment of the CuII atom. The EuIII atom is eight-coordinated in a square-antiprismatic geometry. The NdIII and CeIII complexes are isomorphous to the EuIII complex, and only minor differences in bond lengths and bond angles involving the metal atoms are noted.

scholarly journals Comparison of molecular structures of cis-bis[8-(dimethylphosphanyl)quinoline]nickel(II) and -platinum(II) complex cations

2020 ◽  
Vol 76 (12) ◽  
pp. 1813-1817
Author(s):  
Masatoshi Mori ◽  
Takayoshi Suzuki
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Steric Hindrance ◽  
Molecular Structures ◽  
Coordination Geometry ◽  
Donor Group ◽  
Bending Deformation ◽  
Bond Lengths ◽  
Square Planar ◽  
Chelate Ligands

The crystal structures of the complexes (SP-4-2)-cis-bis[8-(dimethylphosphanyl)quinoline-κ2 N,P]nickel(II) bis(perchlorate) nitromethane monosolvate, [Ni(C11H12NP)2](ClO4)2·CH3NO2 (1), and (SP-4-2)-cis-bis[8-(dimethylphosphanyl)quinoline-κ2 N,P]platinum(II) bis(tetrafluoroborate) acetonitrile monosolvate, [Pt(C11H12NP)2](BF4)2·C2H3N (2), are reported. In both complex cations, two phosphanylquinolines act as bidentate P,N-donating chelate ligands and form the mutually cis configuration in the square-planar coordination geometry. The strong trans influence of the dimethylphosphanyl donor group is confirmed by the Ni—N bond lengths in 1, 1.970 (2) and 1.982 (2) Å and, the Pt—N bond lengths of 2, 2.123 (4) and 2.132 (4) Å, which are relatively long as compared to those in the analogous 8-(diphenylphosphanyl)quinoline complexes. Mutually cis-positioned quinoline donor groups would give a severe steric hindrance between their ortho-H atoms. In order to reduce such a steric congestion, the NiII complex in 1 shows a tetrahedral distortion of the coordination geometry, as parameterized by τ4 = 0.199 (1)°, while the PtII complex in 2 exhibits a typical square-planar coordination geometry [τ4 = 0.014 (1)°] with a large bending deformation of the ideally planar Me2Pqn chelate planes. In the crystal structure of 2, three F atoms of one of the BF4 − anions are disordered over two sets of positions with refined occupancies of 0.573 (10) and 0.427 (10).

Reaction products of ammonium pertechnetate(VII) with triphenylphosphine and crystal structures of mer-Tc(PPh3)2Cl3(DMF) •2PPh3 and NH2(CH3)2+DMAH+ [TcCl6]2−•PPh3O

1991 ◽  
Vol 69 (3) ◽  
pp. 397-403 ◽  
Author(s):  
Fernande D. Rochon ◽  
Robert Melanson ◽  
Pi-Chang Kong
Keyword(s):  
Key Words ◽  
Crystal Structures ◽  
Bond Distance ◽  
Acetone Solution ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Group A

The reaction of NH4TcO4 with PPh3 in DMF solution in the presence of HCl produces mer-Tciii(PPh3)2Cl3(DMF)•2PPh3 (1). When the reaction is done in acidic DMA, the yellow product isolated was identified as NH2(CH3)2+DMAH+ [TcCl6]2−•PPh3O (2). The dimethylammonium cation was produced from the reaction of the solvent (DMA) with aqueous HCl. The reaction of NH4TcO4 with PPh3 in acidic acetone solution produces yellow (PPh3H)2[TcCl6] (≈15% yield) and some orange crystals (≈65% yield) identified by X-ray diffraction as [Ph3P-C(CH3)2-CH2-CO-CH3]+ [Tc(PPh3)Cl5]−. The cation was produced from the reaction of acetone used as solvent with HCl and PPh3. The crystals of 1 are monoclinic with P21/m space group, a = 11.393(4), b = 24.993(11), c = 12.398(4) Å, β = 106.98(3)°, Z = 2. The structure was refined to R = 0.072 and wR = 0.058. The Tc—O bond distance is 2.115(12) Å while the Tc—P bond lengths are 2.496(5) and 2.499(5) Å and the Tc—Cl are 2.399(5) and 2.342(3) Å. The C atoms of the DMF ligand are disordered. The crystals of 2 are triclinic, [Formula: see text] space group with a = 8.627(5), b = 13.308(7), c = 14.401(9) Å, α = 97.62(5), β = 91.31(5), γ = 106.42(5)°, and Z = 2. The structure was refined to R = 0.060 and wR = 0.076. The proton on DMAH+ is hydrogen bonded to the oxygen of PPh3O with a distance [Formula: see text] Key words: technetium, DMF, triphenylphosphine, dimethylacetamide.

Aminkomplexe von Silber(I)-disulfonylamiden, Teil I: Sekund¨are Amine [1]

2011 ◽  
Vol 66 (5) ◽  
pp. 449-458
Author(s):  
Eva-Maria Zerbe ◽  
Christoph Wölper ◽  
Peter G. Jones
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Secondary Amine ◽  
Linear Arrays ◽  
Bond Angles ◽  
Bond Lengths ◽  
Ionic Compounds ◽  
State 1 ◽  
Molecular Compounds

We report the crystal structures of five amine-complexed silver(I) disulfonylamides of composition L2AgX (L = secondary amine, X = disulfonylamide anion) [1: bis(2,2,6,6-tetramethylpiperidine)- silver(I) dimesylamide, 2: bis(2,2,6,6-tetramethylpiperidine)(1,1,3,3-tetraoxo-1,3,2-benzodithiazolido) silver(I), 3: bis(diethylamine)(dimesylamido)silver(I), 4: bis(diethylamine)silver(I) 1,1,3,3-tetraoxo- 1,3,2-benzodithiazolide, 5: bis(dicyclohexylamine)silver(I) 1,1,3,3-tetraoxo-1,3,2-benzodithiazolide]. In the solid state 1, 4 and 5 are ionic compounds, whereas 2 and 3 appear to be molecular, but with long Ag-Ndisulfonylamide bonds (ca. 2.5 Å ), almost linear Namine-Ag-Namine bond angles (171, 158°) and S-N bond lengths more typical of purely ionic disulfonylamides. The packing of these complexes is governed by the formation of chains via motifs of Ag・ ・ ・O contacts and classical hydrogen bonds. The interaction motifs vary slightly depending on the steric demand of the amine substituents. For the molecular compounds, either new motifs appear (3) or intramolecular classical hydrogen bonds are formed, and linear arrays of molecules are generated by non-classical hydrogen bonds (2)

scholarly journals Crystal structure of tris(phenylselenolato-κSe)tris(tetrahydrofuran-κO)thulium(III)

2014 ◽  
Vol 70 (11) ◽  
pp. m389-m389
Author(s):  
Esther M. Takaluoma ◽  
Raija Oilunkaniemi ◽  
Christian W. Lehmann ◽  
Risto S. Laitinen
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Rotation Axis ◽  
Van Der Waals ◽  
Van Der Waals Interactions ◽  
Octahedral Coordination ◽  
Coordination Environment ◽  
Bond Angles ◽  
Bond Lengths

In the title compound, [Tm(C6H5Se)3(C4H8O)3], the TmIIIatom lies on a threefold rotation axis and is coordinated by three phenylselenolate ligands and three tetrahydrofuran ligands leading to a distortedfac-octahedral coordination environment. The Tm—Se and Tm—O bond lengths are 2.7692 (17) and 2.345 (10) Å, respectively, and the bond angles are 91.32 (6)° for Se—Tm—Se, 92.6 (2) and 94.4 (2)° for Se—Tm—O, and 81.2 (3)° for O—Tm—O. In the crystal, the discrete complexes are linked by van der Waals interactions only. The crystal was refined as a non-merohedral twin (ratio = 0.65:0.35).

Die Kristallstrukturen der silylierten Phosphanimine Me3SiNPPh3 und Me3SiNPPh2 - C2H4 - PPh2NSiMe3 / Crystal Structures of the Silylated Phosphanimines Me3SiNPPh3 und Me3SiNPPh2 - C2H4 - PPh2NSiMe3

1995 ◽  
Vol 50 (7) ◽  
pp. 1050-1054 ◽  
Author(s):  
Frank Weller ◽  
Hak-Chul Kang ◽  
Werner Massa ◽  
Thilo Rübenstahl ◽  
Frank Kunkel ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Bond Angle ◽  
Structure Refinement ◽  
Space Group ◽  
Bond Angles ◽  
Bond Lengths ◽  
Single Bonds

The crystal structures of two silylated phosphanimines have been determined. Me3SiNPPh3: Space group P 1̃, Z = 2, structure refinement with 2907 observed unique reflections with Fo > 5 σ(Fo), R = 0.052. Lattice dimensions at 19 °C: a = 876.6(1), b = 1125.8(1), c = 1151.2(1) pm, α = 61.71(1)°, β = 88.08(1)°, γ = 87.18(1)°. The compound forms monomeric molecules with a SiNP bond angle of 140.2° and bond lengths PN of 154.2 pm and SiN of 168.6 pm which correspond with PN double and SiN single bonds. Me3SiNPPh2 - C2H4 -PPh2N SiMe3: Space group P31, Z = 3, structure refinement with 4251 independent reflections, R = 0.061 for 3587 reflections with I > 2σ(I). Lattice dimensions at - 80 °C: a = b = 1591.4(1), c = 1165.8(1) pm. The compound forms monomeric molecules with a c/s-conformation of the PNSiMe3 groups. Bond angles and bond lengths (average) are SiNP = 140.8°, PN = 153.8 pm, SiN = 165.6 pm.

Crystal Structure Studies on p-Substitutedbenzenesulphonamides 4-X-C6H4SO2NH2 (X = CH3, NH2 F, Cl or Br)

2003 ◽  
Vol 58 (11) ◽  
pp. 656-660 ◽  
Author(s):  
B. Thimme Gowda ◽  
K. Jyothi ◽  
Jozef Kožíšek ◽  
Hartmut Fuess
Keyword(s):  
Crystal Structures ◽  
Phenyl Ring ◽  
Bond Angle ◽  
Amine Group ◽  
Torsion Angles ◽  
Bond Angles ◽  
Lattice Constants ◽  
Bond Lengths ◽  
Crystal Type ◽  
Uniform Substitution

Effect of ring substitution on the crystal structures of p-substitutedbenzenesulphonamides, p-XC6H4SO2NH2 (X = F, Cl, Br, CH3 or NH2) has been studied by determining the crystal structures of 4-chlorobenzenesulphonamide (4-ClC6H4SO2NH2) and 4-bromobenzenesulphonamide (4-BrC6H4SO2NH2) and analyzing the results along with the structures of 4-methylbenzenesulphonamide (4-CH3C6H4SO2NH2), 4-fluorobenzene-sulphonamide (4-FC6H4SO2NH2) and 4-aminobenzenesulphonamide (4-NH2C6H4SO2NH2). The crystal type, space group, formula units and lattice constants in Å of new structures are: (4-ClC6H4SO2NH2); monoclinic, P21/n, Z = 4, a = 6.6276(10), b = 16.219(3), c = 7.5716(10), β = 93.387(14)°; (4-BrC6H4SO2NH2): monoclinic, P 21/n, Z = 4, a = 6.5660(10), b = 16.4630(10), c = 7.6900(10), β = 92.760(10)°. Orientation of the amine group with respect to the phenyl ring is given by the torsion angles C(2)-C(1)-S-N: 70.9° and C(6)-C(1)-S-N: −108.5°. Similarly, the orientation of S, O(1) and O(2) with respect to the ring are given by torsion angles. The comparison of bond lengths and bond angles of 4-fluoro-, 4-chloro-, 4-bromo-, 4-methyl- and 4-amino-benzenesulphonamides reveal that the S-N and C-S bond lengths decrease with the introduction of electron-withdrawing substituents such as F, Cl or Br, while these groups do not have significant effects on the S-O distances. The effect on ring C-C distances was not uniform. Substitution of F, Cl or Br decreases the O-S-N bond angle, but increases the O-S-N, N-S-C(1) and C(3)-C(4)-C(5) bond angles.

Die Kristallstrukturen von PPh4[AsCl4(THF)2] und PPh4[AsBr4(THF)2] / The Crystal Structures of PPh4[AsCl4(THF)2] and PPh4[AsBr4(THF)2]

1992 ◽  
Vol 47 (5) ◽  
pp. 680-684 ◽  
Author(s):  
Birgit Siewert ◽  
Ulrich Müller
Keyword(s):  
Crystal Structures ◽  
Uv Irradiation ◽  
Octahedral Coordination ◽  
Trans Configuration ◽  
X Ray Diffraction ◽  
Electron Pairs ◽  
X Ray ◽  
Bond Angles ◽  
Bond Lengths ◽  
Stereochemical Activity

In the effort to react W(CO)6 with (PPh4)2[As2Cl8] and Cr(CO)6 with PPh4[As2SBr5] in tetrahydrofurane under UV irradiation the title compounds were obtained as main products. Their crystal structures were determined by X-ray diffraction. PPh4[AsCl4(THF)2], monoclinic, P2/c, Z = 2, a = 881.6(3), b = 809.0(6), c = 2418.6(9) pm, β = 99.44(4)°, R = 0.086 for 1619 observed unique reflexions. PPh4[AsBr4(THF)2], monoclinic, C 2/c, Z = 4, a = 2459.2(5), b = 748.2(3), c = 1784.3(4) pm, β = 94.02(2)°, R = 0.080 for 1513 reflexions. In both compounds ions [AsX4(THF)2]- are located on inversion centers; they have octahedral coordination with trans configuration; the stereochemical activity of the lone electron pairs does not show up in deviations of the bond angles, but in increased bond lengths. The PPh4+ ions are stacked to columns in the b direction.

Die Kristallstrukturen von Ph3PNPh, [Ph3PN(H)Ph][AuI2] und von 2,3-Bis(triphenylphosphoranimino)maleinsäure-N-methylimid / The Crystal Structures of Ph3PNPh, [Ph3PN(H)Ph][AuI2] and of 2,3-Bis(triphenylphosphoranimino)maleic Acid-N-methylimide

1988 ◽  
Vol 43 (2) ◽  
pp. 138-148 ◽  
Author(s):  
Eberhard Böhm ◽  
Kurt Dehnicke ◽  
Johannes Beck ◽  
Wolfgang Hiller ◽  
Joachim Strähle ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Maleic Acid ◽  
Staudinger Reaction ◽  
Space Group ◽  
X Ray ◽  
Bond Angles ◽  
Bond Lengths ◽  
Structure Determinations ◽  
Ray Methods

[Ph3PN(H)Ph][AuI2] (2) is formed by the reaction of AuI with N-Phenyl-iminotriphenylphosphorane, Ph3PNPh in a toluene suspension. 2,3-Bis(triphenylphosphinimino)maleic acid-N-methylimide (3) has been prepared by the Staudinger reaction of 2,3-bis(azido)maleic acid-N-methylimide with PPh3 in THF solution in the form of red crystals. Crystal structure determinations of three iminophosphoranes were carried out by X-ray methods.Ph3PNPh (1): space group P21/c, Z = 4, 2176 independent observed reflexions, R = 0.057. Lattice dimensions (-30 °C): a = 1126.4, b = 1148.6, c = 1476.0 pm; β = 97.21°. The compound forms monomeric molecules with P=N = 160.2 pm and an PNC angle of 130.4°.[Ph3PN(H)Ph][AuI2] (2): space group P1̄, Z = 2, 1780 independent observed reflexions, R = 0.057. Lattice dimensions (18 °C); a = 824.9, b = 1022, c = 1476.2 pm; α = 89.23°, β = 87.41°, γ = 85.65°. The compound consists of ions [Ph3PN(H)Ph]⊕ with P=N = 162.4 pm and PNC = 129.3°, and anions [AuI2]⊖ with Au-I = 261.9 and 259.3 pm, IAuI = 176.8°.(Ph3P)2N2C4O2 (NMe) (3): space group P1̄, Z = 2, 4972 independent observed reflexions, R = 0.050. Lattice dimensions (-90 °C): a = 904.7, b = 993.8, c = 2017.4 pm; α = 101.55°, β = 96.39°, γ = 105.81°. The compound forms monomeric molecules with syn-conformation of the two NPPh3 groups. Bond lengths: P=N = 157.1; 155.3 pm, bond angles: PNC = 133°; 136°

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