Kristallstrukturen von Me2Si[N(SiMe3)2]2 und [Me2Si(NPh)(NHPh)Li·OEt2]2 / Crystal Structures of Me2Si[N(SiMe3)2]2 and [Me2Si(NPh)(NHPh)Li·OEt2]2

1998 ◽  
Vol 53 (9) ◽  
pp. 977-980 ◽  
Author(s):  
Andreas Mommertz ◽  
Gertraud Geiseier ◽  
Klaus Harms ◽  
Kurt Dehnicke

Abstract The crystal structures of the title compounds are reported. Me2Si[N(SiMe3)2]2: Space group Pbcn, Z = 4, lattice dimensions at 213 K: a = 1487.8(1), b = 1299.4(1), c = 1259.7(1) pm. The compound forms monomeric molecules with crystallographic C2 symmetry and Si-N bond lengths of 177.9(3), 171.6(3) and 175,2(3) pm. [Me2Si(NPh)(NHPh)Li·OEt2]2: Space group P21/n, Z = 2, lattice dimensions at 190 K: a = 1082.7(3), b = 1038.8(2), c = 1641.3(4) pm, β = 91.350(3)°. The compound forms centrosymmetric dimeric molecules in which the lithium atoms are members of a Li2N2 ring with Li-N bond lengths of 206.6(2) and 213.5(2) pm. The hydrogen atom at the nitrogen atom of the HNPh- group is not involved in hydrogen bridging bonds.

1999 ◽  
Vol 52 (10) ◽  
pp. 983 ◽  
Author(s):  
Yang-Yi Yang ◽  
Seik Weng Ng ◽  
Xiao-Ming Chen

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.


1988 ◽  
Vol 43 (10) ◽  
pp. 1219-1223 ◽  
Author(s):  
Johannes Beck

PPh3Au(tolN5tol) is obtained by the reaction of PPh3Au+ClO4- with Tl(tolN5tol). It crystallizes in the monoclinic space group P21/c with the lattice parameters a = 1548.8(5), b = 1070.7(2), c = 1779.1(3) pm, β = 90.33(2)°, Z = 4. In the monomeric complex the gold atom is nearly linearcoordinated by the phosphorus atom of the PPh3 group and nitrogen atom N3 of the pentaazadienido ligand ( N3 - Au - P 178.4°). tolNN(NCH3)NNtol crystallizes in the orthorhombic space group Pccn with the lattice constants a = 2426.7(9), b = 469.3(2), c = 1195.3(4) pm. The unit cell contains four molecules, located on twofold axes. Due to the isolobality of the CH3 and the PPh3Au group, the two structures are closely related. Both contain the typical planar zig-zag chain of five nitrogen atoms with located double bonds N1-N2 and N4 - N5 (from 119.8 to 126.6 pm) and shortened single bonds N2 - N3 and N3 - N4 (132.7 to 140.0 pm).


1985 ◽  
Vol 40 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Bernt Krebs

Abstract The compounds [(C6H5)4As]2 TeCl4 (1), [(C2H5)4 N]2 TeBr4 · CH3CN (2), and [(C2H5)4N]2TeI4 (3) were prepared by the reaction of Te, X2 , and excess (C2H5)4NX (X = Br, I) in acetonitrile solution or by heating of [(C6H5)4 As]2TeCl6 , Te, and (C6H5)4 ASCl for several hours in the same solvent.The structures of 1-3 were determined from single crystal X-ray data.1 crystallizes in the monoclinic space group P21/n with a = 1061.8(2), b = 1614.2(3), c = 1341.7(3) pm, β = 94.21° and Z = 2; 2: tetragonal, P4/mmm, a = 1039.7(2), c = 690.5(1), Z = 1; 3: tetragonal, I4/mmm, a = 1061.7(2), c = 1342.8(4), Z = 2. In 1-3 Te(II) exhibits a square planar coordination. The Te -CI, Te -Br, and Te-I bond lengths were found to be 260.7 (mean), 275.3, and 298.5 pm, respectively.


1988 ◽  
Vol 66 (10) ◽  
pp. 2621-2630 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Mahmood Tajerbashi ◽  
Steven J. Rettig ◽  
James Trotter

Details of the syntheses, physical properties, and crystal structures of the title compounds are reported. Crystals of 5,5-difluoro-2,2-pentamethylene-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are triclinic, a = 6.1576(3), b = 11.2651(3), c = 10.8118(3) Å, α = 109.747(3), β = 105.807(4), γ = 92.976(4)°, Z = 2, space group [Formula: see text], and those of 2,2-pentamethylene-5,5-diphenyl-1,4,6-trioxa-3a-azonia-5-borata-1,2,3,4,5,6-hexahydrobenzo[h]azulene are monoclinic, a = 9.8549(6), b = 10.9242(6), c = 41.263(2) Å, β = 92.717(6)°, Z = 8, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.045 and 0.042 for 2344 and 4248 reflections with I ≥ 3σ(I), respectively. The molecules were both found to possess a seven-membered chelate structure, the O,O-chelatїng ligand being strongly bound to the X2B moiety. Two conformational isomers of the X = Ph compound were found in the solid state. The 2-oxazoline N-oxide moieties present in both compounds are the first to be structurally characterized. Important mean libration-corrected bond lengths are: O—B = 1.491 and F—B = 1.387 Å for X = F; O—B = 1.511 and C—B = 1.620 Å for X = Ph.


1988 ◽  
Vol 66 (3) ◽  
pp. 355-358 ◽  
Author(s):  
Steven J. Rettig ◽  
Alan Storr ◽  
James Trotter

Crystals of [dimethyl(1-pyrazolyl)(2-pyridylmethoxy)gallato-N2,O,N3](η3-allyl)dicarbonylmolybdenum(II) are triclinic, a = 9.632(2), b = 9.798(2), c = 10.255(2) Å, α = 80.16(1), β = 87.38(1), γ = 81.75(1)°, Z = 2, space group [Formula: see text]. The structure was solved by conventional heavy-atom methods and was refined by full-matrix least-squares procedures to R = 0.033 and Rw = 0.037 for 3000 reflections with I ≥ 3σ(I). The molecule has pseudo-octahedral coordination geometry with the tridentate [Me2Ga(N2C3H3)(OCH2(C5H4N))]− ligand facially coordinated and the η3-allyl ligand occupying one coordination site trans to the pyridyl nitrogen atom. Important bond lengths are Mo—O = 2.219(2), Mo—N(py) = 2.212(3), Mo—N(pz) = 2.232(2), Mo—C(allyl) = 2.290(4), 2.189(4), 2.341(4), Mo—CO (trans to O) = 1.928(4), and Mo—CO (trans to N) = 1.952(4) Å.


1988 ◽  
Vol 43 (12) ◽  
pp. 1616-1620 ◽  
Author(s):  
Abderraouf Khabou ◽  
Kurt Dehnicke

Abstract [MONCl3 · NC - C2Cl3]2 has been prepared by the reaction of MONCl3 with trichloromethyl isocyanidedichloride, CCl3NCCl2 , in CH2Cl2 suspension. The compound forms redbrown. mois-ture sensitive crystals, which were characterized by their IR spectrum as well as by a crystal structure determination (2482 independent observed reflexions, R = 0.048). Crystal data (-70 °C): Space group P21/c, Z = 2, a = 674.2(2); b = 2128.2(11); c = 786.0(4) pm: β = 102.81(3)°. [MONCl3 • NC-C2Cl3]2 forms centrosymmetric dimeric molecules via chloro bridges with Mo-Cl bond lengths of 240.7 and 276.0 pm. The longer MoCl bond of the MOCl2MO ring is caused by the trans influence of the nitride ligand; the MoN bond length of 167 pm corresponds with a triple bond. The 2,3,3-trichloroacrylnitrile ligand is bonded by its nitrogen atom with a bond length of Mo -N = 216 pm; the Mo-N≡C-C sequence is almost linear with a remarkable short C-C bond of 143.0 pm.


1993 ◽  
Vol 48 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Gudrun Stieglitz ◽  
Bernhard Neumüller ◽  
Kurt Dehnicke

AbstractThe title compounds have been prepared by the reaction of n-butyllithium with the corresponding diorganophosphanes HPR2 (R = t-Bu, Ph) in DME solutions. Both compounds were characterized by crystal structure determinations.{Li(DME)[P(t-Bu)2]}2: Space group P 1̄, Z = 1, 2027 observed unique reflections, R = 0.055. Lattice dimensions at -80 °C: a = 879.9(3), b = 986.3(1), c = 1064.0(2) pm, α = 70.69(1)°, β = 70.63(2)°, γ - 69.89(2)°. The compound forms centrosymmetric dimers of symmetry Ci with Li-P bond lengths of 260.0 and 257.3 pm for the Li2P2 four-membered ring.[Li(DME)PPh2]∞: Space group P21/n, Z = 4. 3437 observed unique reflections, R = 0.055. Lattice dimensions at - 80 °C: a = 1034.8(2), b = 812.48(9), c = 1978.4(3) pm, β = 103.30(2)°. The compound forms polymeric chains via LiP bridges with Li-P bond lengths o f 256.3 and 254.1 pm.


1992 ◽  
Vol 47 (11) ◽  
pp. 1505-1512 ◽  
Author(s):  
Thorsten Gebauer ◽  
Gerlinde Frenzen ◽  
Kurt Dehnicke

The crystal structures of the title compounds were solved by X-ray methods.[Pd(CH3CN)4](BF4)2: Space group Pbca, Z = 4,812 observed unique reflections, R = 0.057, wR = 0.033. Lattice dimensions at -80 °C: α = 1027.5(5), b = 1242.8(6), c = 1280.3(6) pm. The compound consists of planar [Pd(CH3CN)4]2+ ions with Pd-N bond lengths of 195.6 pm and BF4- anions.[PdCl(μ2-PPh2(HPPh2)]2 • CH2Cl2 crystallizes in two polymorphic forms in the same space group type but with different cell parameters, which depends on the conditions of the synthesis. α-form: Space group P21/c, Z = 4, 4680 observed unique reflections, R = 0.041, wR = 0.033. Lattice dimensions at -80 °C: a = 937.2(2), b = 1750.3(6), c = 1593.9(5) pm, β = 106.32(2)°. β-form: Space group Ρ21/n, Ζ = 4, 2519 observed unique reflections, R = 0.105, wR = 0.067. Lattice dimensions at -80 °C: a = 1118.0(4), b = 1222.4(3), c = 1849.9(4) pm, β = 90.72(2)°. Both polymorphs contain centrosymmetric molecules [PdCl μ2- PPh2)(HPPh2)]2 with Pd-P bond lengths of 226.6 pm for the bridging PPh2 groups and Pd-P bond lengths of 232.2 pm for the terminal HPPh2 ligands.[PdCl(HPPh2){H(OPPh2)2}]: Space group Pbca, Z = 8,3673 observed unique reflections, R = 0.038, wR = 0.032. Lattice dimensions at -80 °C: a = 1736.6(3), b = 1874.4(4), c = 1983.1(4) pm. The palladium atom has planar coordination consisting of the chlorine atom, the phosphorus atom of the HPPh2 ligand (Pd-P bond length 235.5 pm), and by the two phosphorus atoms of the H(OPPh2)2 chelate (Pd-P bond lengths 225.9 and 231.0 pm).


1991 ◽  
Vol 69 (3) ◽  
pp. 397-403 ◽  
Author(s):  
Fernande D. Rochon ◽  
Robert Melanson ◽  
Pi-Chang Kong

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.


1998 ◽  
Vol 53 (3) ◽  
pp. 271-274 ◽  
Author(s):  
B. Steuer ◽  
W. Preetz

Abstract The treatment of [B6H6]2- with an excess of (SCN)2 in dichloromethane in the presence of solid KOH gives the hexaisoselenocyanatodiborate anion [B2(NCSe)6]2- as an intermediate (δ(11B) = -10.3 ppm), from which [BH(NCSe)3]- and elemental selenium are formed. The X-ray structure determinations on single crystals of (n-Bu4N)2[BH(NCSe)3] (1) (triclinic, space group Pi with a = 8.512(2), b = 10.885(3), c = 14.895(4) Å, α = 79.52(2), β = 74.86(2), γ = 86.768(2)°, Z = 2) and (Ph4P)[B3H7(NCSe)] (2) (monoclinic, space group C2, a = 7.686(5), b = 10.366(3), c = 17.533(3) A, β = 108.89°, Z = 4) show that the selenocyanate groups are coordinated exclusively via the N atoms with average bond lengths of B-N = 1.52, C-N = 1.15, C-Se = 1.75 A and angles N-C-Se = 179°, B-N-C = 168.7 - 176.8°. The N-B-N angles of 1 range from 107.5 to 109.5°.


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