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Featured researches published by Frank Kunkel.
Zeitschrift für Naturforschung B | 1995
Frank Weller; Hak-Chul Kang; Werner Massa; T. Rübenstahl; Frank Kunkel; Kurt Dehnicke
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.
Zeitschrift für anorganische und allgemeine Chemie | 2001
Frank Kunkel; Cäcilia Maichle-Mössmer; Joachim Strähle; Kurt Dehnicke
Crystal Structure of Ph3PNBr · Br2 Ph3PNBr · Br2 (1) has been prepared besides of other products from the reaction of Ph3PNH with bromine, forming orange-yellow single crystals which are characterized by IR-spectroscopy and by a crystal structure determination. Space group P21/n, Z = 4, lattice dimensions at 20 °C: a = 916.76(10), b = 1351.42(8), c = 1494.9(2) pm, β = 96.191(5)°, R1 = 0.0538. 1 has a molecular structure in which the Br2 molecule is coordinated at the nitrogen atom of the N-bromine-phosphoraneimine Ph3PNBr in a linear arrangement N–Br–Br with bond lengths N–Br of 224.5(6) pm and Br–Br of 248.4(1) pm. The nitrogen atom of 1 is ψ-tetrahedrally coordinated in addition by the phosphorus atom with a P–N distance of 165.3(6) pm and by the covalently bonded bromine atom with a bond length of 188.9(6) pm.
Zeitschrift für Naturforschung B | 1997
Ralf Hillwig; Frank Kunkel; Klaus Harms; Bernhard Neumüller; Kurt Dehnicke
The crystal structures of PbMe3I and BiPh2Cl have been determined by X-ray methods. Both compounds form polymeric chains via bent μ2-halogeno bridges and almost linear X-M-X units (X = I, Cl). PbMe3I: Space group P212121, Z = 2; lattice dimensions at -50 °C: a = 653.0(1), b = 1034.0(2), c = 1124.5(2) pm, R = 0.049. BiPh2Cl: Space group P42, Z = 4; lattice dimensions at -50 °C: a = b = 847.5(2), c = 1644.9(4) pm, R = 0.044
Zeitschrift für Naturforschung B | 1997
Frank Kunkel; Klaus Harms; Hak-Chul Kang; Werner Massa; Kurt Dehnicke
Abstract Triphenylantimony reacts with S3N2Cl2 in dichloromethane solution to give yellow crystals of the cyclostibathiazene derivative [xxx], As a by-product orange single crystals of [(Ph3SbCl2)2·S4N4] were isolated, in which the molecular compounds Ph3SbCl2 and S4N4 only form van der Waals contacts with one another. Both compounds are characterized by crystal structure determinations. [xxx]: Space group P21/n, Z = 4; lattice dimensions at -80°C: a = 759.4(1), b = 1448.5(3); c = 1557.6(2) pm; β = 91.09(1)°, R = 0.026. The complex has a molecular structure in which the Sb atom is coordinate in a distorted trigonal-bipyramidal fashion with one phenyl group and one of the nitrogen atoms of the planar [xxx] ring in the apical positions. [(Ph3SbCL)2·S4N4]: Space group C2/c, Z = 8 ; lattice dimensions at -60°C: a = 1549.3(1), b = 1017.7(1), c = 2623.9(1) pm, β = 105.56(2)°, R = 0.050.
Zeitschrift für Naturforschung B | 1995
Frank Kunkel; Hella Folkerts; Sigrid Wocadlo; Hak-Chul Kang; Werner Massa; Kurt Dehnicke
[S(NPMe3)3]Cl · CH2C12 and [S(NPPh3)3]S4N5 were prepared by the reaction of Me3SiNPMe3 or Me3SiNPPh3 with sulfur dichloride and S3N2Cl2, respectively, in CH2Cl2 solutions as colourless, moisture sensitive crystals. The corresponding selenium compound was prepared from SeCl4 and Me3SiNPMe3 in acetonitrile solution; it crystallizes from toluene solutions with one mole of toluene per formula unit. All complexes have been characterized by IR spectroscopy and by crystal structure determinations. [S(NPMe3)3]Cl-CH2Cl2: Space group Pna21, Z = 8 , 3930 observed unique reflections, R = 0.033. Lattice dimensions at -120 °C: a = 1200.9(1), b = 1020.2(1), c = 1790.5(1) pm. [S(NPPh3)3]S4N5: Space group P63, Z = 2, 2586 observed unique reflections, R = 0.054. Lattice dimensions at -100 °C: a = b = 1334.7(2), c = 1652.6(2) pm. [Se(NPMe3)3]Cl · C7H8: Space group C2/c, Z = 8 , 1475 observed unique reflections, R = 0.059. Lattice dimensions at -40 °C: a = 1853.6(8), b = 1159.2(4), c = 2053.2(4) pm. β = 101.92(3)°. All compounds contain cations [E(NPR3)3]+ (E = S, Se) with pyramidal structures. Bond lengths and bond angles are in average: S-N 162.5 pm, S-N-P 120.5° (R = Me), S-N 161.8 pm, S-N-P 119.2° (R = Ph), Se-N 177.8 pm, Se-N-P 120.3°.
Zeitschrift für Naturforschung B | 1995
Frank Kunkel; Kurt Dehnicke; Helmut Goesmann; Dieter Fenske
Abstract [SnCl4(Ph2PCH2-CH2PPh2)] CH2Cl2 has been characterized by a crystal structure determ ination. Space group P21/c, Z = 4, 5565 observed unique reflections with I > 2 σ(I), R = 0.043. Lattice dimensions at -70 °C: a = 1141.4(6), b = 2178.3(11), c = 1399.1(7) pm, β = 108.96(3)°. The complex forms monomeric molecules with the 1.2-bis(diphenylphosphino)ethane as chelating ligand. Bond lengths (average): Sn - P 266.7 pm, Sn - Cl 241.8 pm.
Zeitschrift für anorganische und allgemeine Chemie | 1997
Frank Kunkel; Klaus Harms; Hak-Chul Kang; Werner Massa; Kurt Dehnicke
Zeitschrift für Naturforschung B | 1997
Frank Kunkel; Klaus Harms; Kurt Dehnicke
Zeitschrift für Naturforschung. B, A journal of chemical sciences | 1997
Frank Kunkel; Klaus Harms; Hak-Chul Kang; Werner Massa; Kurt Dehnicke
Zeitschrift für Naturforschung. B, A journal of chemical sciences | 1997
Frank Kunkel; Klaus Harms; Kurt Dehnicke