| | 61 | Author
| Hirom Itsu Terao, TsutomuO., Kichiro Koto, Shi-Qi, AlarichW. Eiss2 | Requires cookie* | | | Title
| 81 Br NQR and Crystal Structure of Ethylammonium Tribromomercurate(II), CHgCHjNI-^HgBrg  | | | | Abstract
| The 81Br NQR triplet spectrum of (CH3 CH2 NH)®(HgBr3)e was measured in the range 77 K to near the m.p. (99~106°C). decreases strongly with increasing temperature, exhibiting 136.784 MHz at 77 K and 128.129 MHz at 298 K. v2 decreases from 82.060 MHz at 77 K to 76.322 MHz at 298 K. v3 increases with temperature, showing v3 = 81.292 MHz at 77 K and 84.903 MHz at 298 K. Replacement of the ammonium hydrogens by deuterium produces a negative shift of Vj and positive ones of v2 and v3 at high temperatures. These shifts change with temperature from | — 0| up to |~ 2 0 0 | kHz. The crystal structure of the title compound was determined at room temperature: P 21/m, Z = 2, a = 1021.6(8) pm, b = 643.0(6) pm, c = 691.8(6) pm, ß = 96.96 (4)°. The coordination of the mercury atom by the bromines is trigonal bipyramidal; by formation of bridges Hg • • ■ Br • • ■ Hg by one of the three bromines (Br(2)) of the planar HgBr® ions a double chain of trigonal bipyramids is formed, running along the b-axis of the crystal. B r 1' and Br(3) are single bonded to Hg. The hydrogen bonds N -H • • • Br(1 and N -H • ■ • Br(' (twice), connect the H g-B r chains to planes lying parallel to the be plane at x = 0. The relations between the Br-NQR spectrum and the structure are discussed. | | | |
Reference
| Z. Naturforsch. 49a, 202—208 (1994); received August 16 1993 | | | |
Published
| 1994 | | | |
Keywords
| Mercury(II) Bromide Complex, Crystal Structure, 81Br NQR, * H -2D isotope effect, H-bonding | | | |
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| default:Reihe_A/49/ZNA-1994-49a-0202.pdf | | | | Identifier
| ZNA-1994-49a-0202 | | | | Volume
| 49 | |
| 62 | Author
| Unsymmetrische Diorganomagnesiumverbindungen, Heiko Viebrock, Dirk Abein, Erwin Weiss+ | Requires cookie* | | | Title
| Über Metallalkyl-und -arylverbindungen, 51. Mittig.* On Metal Alkyl and Aryl Compounds, Part 51 Unsymmetrical Diorganomagnesium Compounds. MgRR'(L) and Solvens Separated Ion Pairs with R = Me | | | | Abstract
| Amine adducts of diorganomagnesium compounds MgR2(L) are soluble in hydrocarbons and therefore valuable synthons for reactions in non-polar solvents. In this way unsymmetri-cally substituted derivatives MgRR'(L) become available by substituting one organic group by a different carbanion via acid-base reactions, according to eq. (1): R2Mg(L) + HR' -> RR'Mg(L) + HR (1) with HR' being stronger CH-acids than HR. Using the amin adducts R2Mg(L) (R = Me, Et) with chelating amines (L = tetramethyl ethylenediamine, TMED A, pentamethylethylenetriamine, PMDTA) and the strong CH-acids cyclopentadiene, indene, fluorene and alkynes the following compounds have been synthe sized and their structures derived by X-ray analyses: MgMe(?/3-cyclopentadienyl)(tmeda) (1), MgMe(?73-indenyl)(tmeda) (2), MgMe(^1-fluorenyl)(tmeda) (3), [Mg2Me2(pmdta)2]2+[fluo-renyl]2-benzene (4) and [Mg2Et(phenylethynyl)3(tmeda)]2-benzene (5). It is remarkable, that cyclopentadienyl, indenyl, and fluorenyl ligands have a lower hapticity than rj5 to the metal, due to steric repulsion by the other ligands. In 4 the bulky tridentate base PMDTA prevents any direct interaction between the fluorenide anion and magnesium, giving solvens separated ion pairs with the unusual and hitherto rare example of an organomagnesium cation [Mg2Me2(pmdt)2]2+. The 1:3 compound 5 has a more complicated structure, related to that of alkali metal alkynyl magnesates. | | | |
Reference
| (Z. Naturforsch. 49b, 89—99 [1994]; eingegangen am 17. August 1993) | | | |
Published
| 1994 | | | |
Keywords
| Unsymmetrical Diorganomagnesium Compounds, Synthesis, Crystal Structure, Base Adducts, Chelating Di-and Triamines | | | |
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| default:Reihe_B/49/ZNB-1994-49b-0089.pdf | | | | Identifier
| ZNB-1994-49b-0089 | | | | Volume
| 49 | |
| 63 | Author
| H. Bocka, J. M. Eureta, J. W. Bats3, Z. Havlasb | Requires cookie* | | | Title
| Strukturen sterisch überfüllter Moleküle, 39 [1,2] Einkristall-und Gasphasen-Strukturen von l,4-Bis(trimethylsiloxy)benzol Structures of Sterically Overcrowded Molecules 39 [1,2] Single Crystal and Gas Phase Structures o f l,4-Bis(trimethylsiloxy)benzene | | | | Abstract
| l,4-Bis(trim ethylsiloxy)benzene has been crystallized both by vacuum sublimation and from «-heptane solution, which each yielded colourless plates with identical monoclinic unit cell dim ensions (P 2 Jn, Z = 4). The conform ation o f C[ symmetry shows the two (H 3C)3SiO-substituents to be conrotationally twisted around the 0 -(C 6H4) -0 axis by dihedral angles o f ± 60°. According to the photoelectron spectroscopic ionisation pattern and its K oopm ans' as signment, IEV" = -e f MI, by AM 1 eigenvalues, the gas phase structure should also be o f C, symmetry. The results o f geometry-optimized M N D O , A M I or P M 3 calculations for the monosubstituted derivative H 5C6-O S i(C H 3)3 are compared with respect to the quality o f their fit to the measured data. Ausgangspunkt: Molekülkonformationen sterisch überfüllter 1,4-Benzol-Derivate | | | |
Reference
| Z. Naturforsch. 49b, 288—2 (1994); eingegangen am 1. Oktober 1993 | | | |
Published
| 1994 | | | |
Keywords
| Sterically Overcrowded Organosilicon M olecules, Single Crystal Structure, Photoelectron Spectroscopy, Quantum Chemical Calculations | | | |
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| default:Reihe_B/49/ZNB-1994-49b-0288.pdf | | | | Identifier
| ZNB-1994-49b-0288 | | | | Volume
| 49 | |
| 65 | Author
| Mitra Ghassemzadeh, Klaus Harms, Kurt Dehnicke, Dieter Fenske | Requires cookie* | | | Title
| //2-Halogenokomplexe von N-Bromsuccinimid und N-Bromphthalimid. Die Kristallstrukturen von PPh4[X(N-Bromsuccinimid)2] und von PPh4[X(N-Bromphthalimid)2] mit X = CI und Br /i2-Halogeno Complexes of N-Bromosuccinimide and N-Bromophthalimide. The Crystal Structures of PPh4 [X(N-Bromosuccinimide)2] and PPh4 [X(N-Brom ophthalim ide)2] with X = Cl and Br | | | | Abstract
| The ,«2-halogeno complexes PPh4[X(N-bromosuccinimide)2] and PPh4[X(N-bromophthali-mide)2] with X = Cl and Br have been prepared by reactions of N-bromosuccinimide and N-bromophthalimide, respectively, with the corresponding tetraphenylphosphonium halides PPh4X in acetonitrile solutions. The compounds form pale yellow crystal needles, which were characterized by IR spectroscopy and by crystal structure determinations. PPh4[Cl(N-Bromosuccinimide)2] (1): Space group Z = 4, structure solution with 2516 observed unique reflections, R = 0.040. Lattice dimensions at -2 5 °C: a = 1775.9(1), b = 764.3(1), c = 2341.7(2) pm, ß = 101.84(1)°. | | | |
Reference
| Z. Naturforsch. 49b, 593—601 (1994); eingegangen am 22. Dezember 1993 | | | |
Published
| 1994 | | | |
Keywords
| «2-Halogeno Complexes, N-Bromosuccinimide, N-Bromophthalimide, IR Spectra, Crystal Structure | | | |
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| default:Reihe_B/49/ZNB-1994-49b-0593.pdf | | | | Identifier
| ZNB-1994-49b-0593 | | | | Volume
| 49 | |
| 66 | Author
| Armin Weiss, Stefan Dick | Requires cookie* | | | Title
| Der zweikernige Fe(III)-Komplex von N,N,N',N'-Tetrakis(2-pyridylmethyl)-2-hydroxy-l,3-diaminopropan - Molekül-und Kristallstruktur und seine Wechselwirkung mit Montmorillonit The Binuclear Fe(III) Complex of N,N,N',N'-Tetrakis(2-pyridylmethyl)-2-hydroxy-l,3-diaminopropane - Molecular and Crystal Structure and its Interaction with Montmorillonite | | | | Abstract
| of [Fe2(H P T P)(0 H)(N 0 3)2](C104)2 (HPTP = N,N,N',N'-tetrakis(2-pyridyl-methyl)-2-hydroxy-l,3-diaminopropane) were grown by slow diffusion of diethylether into a solution of the complex salt in acetonitrile. Crystal data: space group R3, a = 4280,1(15) pm, c -1147,6(7) pm, Z = 18. The complex exhibits a binuclear Fe(III) core with (w-oxo)(//-alkoxo) ligands as bridging units. The nitrate anions coordinate each with a short and a long F e -O bond. The coordination spheres of the iron atoms can be looked at as distorted edge-shearing pentagonal bipyramides. The complex cation was introduced into the interlayer region of montmorillonite by cation exchange in acetonitrile. The results of X-ray, IR-and UV/VIS experiments suggest that the cation exchange is reversible. In the interlayer region the dinuclear cations are arranged in a rather loosely packed way, thus creating channels similar to those in pillared smectites or zeolites, respectively. | | | |
Reference
| Z. Naturforsch. 49b, 1051—1058 (1994); eingegangen am 17. Januar 1994 | | | |
Published
| 1994 | | | |
Keywords
| Binuclear Iron(III) Complex, Hem erythrin Model, Crystal Structure, Montmorillonite, Cation Exchange Reaction Yellow crystals | | | |
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| default:Reihe_B/49/ZNB-1994-49b-1051.pdf | | | | Identifier
| ZNB-1994-49b-1051 | | | | Volume
| 49 | |
| 67 | Author
| G. Ar Zeller, Ette Schier, B. Ert, Schm Idbaur | Requires cookie* | | | Title
| The Crystal Structure of [Bis(tri-'butyl-phosphine)gold(I)] Chloride | | | | Abstract
| The title compound is available from the reaction of labile gold(I) chloride com plexes and an excess of the ligand ('Bu3P), or from the N aBH 4 reduction of ('Bu3P)AuCl. It forms dark red cubic crystals, [a = 14.297(1) A at -5 6 °C, space group P2j3, Z = 4], with isolated chloride anions and [('Bu3P)2Au]+ cations of C3 symmetry, with linear two-coordinate gold centers. | | | |
Reference
| Z. Naturforsch. 49b, 1243—1246 (1994); received June 8 1994 | | | |
Published
| 1994 | | | |
Keywords
| G old(I) Complexes, Phosphine Complexes, Gold(I) Coordination, Steric Effect, Crystal Structure | | | |
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| default:Reihe_B/49/ZNB-1994-49b-1243.pdf | | | | Identifier
| ZNB-1994-49b-1243 | | | | Volume
| 49 | |
| 68 | Author
| Axel Fischer, Ion Neda, PeterG. Jones, Reinhard Schmutzler | Requires cookie* | | | Title
| Darstellung und Kristallstrukturen einiger Ubergangsmetall-Komplexverbindungen mit Liganden mit dem 4,5-Benzo-3-methyl-l,3?2-oxazaphosphorinan-6-on-Gerüst Synthesis and X-Ray Crystal Structures of Some Transition-Metal Complexes Involving Ligands with the 4,5-Benzo-3-methyl-l,3,2-oxazaphosphorinan-6-one Framework | | | |
Reference
| Z. Naturforsch. 49b, 1481—1493 (1994); eingegangen am 21. Februar 1994 | | | |
Published
| 1994 | | | |
Keywords
| 2-Substituted 4, 5-Benzo-3-m ethyl-l, 3, 2-oxazaphosphorinan-6-ones Ligands, Platinum Complexes, M olybdenum Complexes, Single Crystal X-Ray Structure Analysis | | | |
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| default:Reihe_B/49/ZNB-1994-49b-1481.pdf | | | | Identifier
| ZNB-1994-49b-1481 | | | | Volume
| 49 | |
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