scholarly journals Synthese und Struktur von C5Me5Pd(PR3)X: Palladiumkomplexe mit einem unsymmetrisch gebundenen Pentamethylcyclopentadienylring [1] / Synthesis and Structure of C5Me5Pd(PR3)X: Palladium Complexes with an Unsymmetrically Bonded Pentamethylcyclopentadienyl Ring [1]

1983 ◽  
Vol 38 (6) ◽  
pp. 733-737 ◽  
Author(s):  
H.-J. Kraus ◽  
H. Werner ◽  
C. Krüger

Abstract The complexes C5Me5Pd(PR3)X (1-4) are prepared from [Cl(PR3)Pd]2(μ-OCOCH3)2 and TIC5Me5. Attempts to replace the halide ligand by a second C5Me5 or a C5H5 unit remained unsuccessful. The X-ray structure analysis of C5Me5Pd[P(i-Pr)3]Cl (3) indicates that the five-membered ring shows a tendency of η1-bonding towards the metal.

1995 ◽  
Vol 50 (12) ◽  
pp. 1811-1817 ◽  
Author(s):  
Max Herberhold ◽  
Christian Köhler ◽  
Wolfgang Milius ◽  
Bernd Wrackmeyer

N,N′-Dialkyl sulfur diimides (1), R(NSN)R [R = Me (a), Et (b), nPr (c), nBu (d)] react with cyclic bis(amino)stannylenes such as 1,3-di-tert-butyl-4,4-dimethyl-1,3,4,2λ2-diazasilastannetedine (2) or 1,3-di-tert-butyl-4,4,5,5-tetramethyl-1,3,4,5,2λ2-diazadisilastannolidine (3) in a 2:1 ratio to give the new spiro-tin(IV) compounds 5a-d, 6b and 6c, built from the respective cyclic bis(amino)stannylene and a seven-membered ring in which the two sulfur diimide groups are coupled via a N-N bond and across the tin atom. A 1:1 adduct 4 is proposed as an intermediate which is the final product 4e in the case of R = tBu (1e). The products were characterized by multinuclear magnetic resonance (1H, 13C, 15N, 29Si, 119Sn NMR), and in the case of 5c the molecular structure was determined by single crystal X-ray structure analysis [monoclinic, space group C2/c ; a = 1504.1(3), b = 1393.3(3), c = 1688.6(3) pm; β = 115.71(3)°].


1983 ◽  
Vol 38 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Herbert W. Roesky ◽  
Pierre Schäfer ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick

Abstract The six membered ring of composition (CH3)2NCN3S2Cl2 3 a was prepared from N,N-dimethylguanidinhydrochloride and trithiadiazindichloride. 3 a was characterized on the basis of mass, 1H, 13C NMR spectra and X-ray structure analysis. Crystals of 3 a are monoclinic, space group P21/c, with a = 660.3(6), b = 834.5(7), c = 1774.7(15) pm, β = 112.83(6)° and Z = 4. The C2N unit lies approximately in the plane of the [-CNSNSN-] ring, with both Cl atoms on the same side of the ring.


1992 ◽  
Vol 47 (2) ◽  
pp. 171-174 ◽  
Author(s):  
H. W. Roesky ◽  
T. Raubold ◽  
M. Noltemeyer ◽  
M. Witt ◽  
R. Bohra

1The reaction of ClSO2N = PPh2Cl () with NH3 yields H2NSO2N = PPh2NH2 (2).This compound is converted to Me3Si(H)NSO2N = PPh2N(H)SiMe3 (3) by Me3SiNMe2. 3 reacts with WOCl4 under elimination of (Me3Si)2O and ClSO2NH2 to yield the eight-membered ring system (Cl3WNPPh2N)2 (4).The molecular structure of 4 was investigated by an X-ray structure analysis.


1994 ◽  
Vol 49 (3) ◽  
pp. 309-314 ◽  
Author(s):  
Peter Sartori ◽  
Ralf Jüschke ◽  
Roland Boese ◽  
Dieter Bläserb

AbstractReactions of di-silver-1,n-alkanedisulfonates 1a (n = 1) and 1b (n = 2) with Cl2SiR1R2 lead to the monomerie 3,3-diorganyl-2,4-dioxa-1,5-dithia-1,1,5,5-tetraoxid-3-silacyclohexanes (for n = 1) 2a (R1 = R2 = Me), 3a (R1 = Me and R2= Ph) and 4a (R1 = R2 = Ph) and -heptanes (for n = 2) 2b (R1 = R2 = Me), 3b (R1 = Me and R2 = Ph) and 4b (R1 = R2 = Ph). In the case of 2a-4a a competition reaction is observed leading to the dimerization products 5a (R1 = Me and R2 = Me), 6a (R1 = Me and R2 = Ph) and 7a (R1 = Ph and R2 = Ph). The six-membered ring-systems of 2a-4a are compared with related silanes. An X-ray structure analysis is per­formed for the 3,3-diphenyl-2,4-dioxa-1,5-dithia-1,1,5,5-tetraoxid-3-silacycloheptane (4b).


1989 ◽  
Vol 44 (7) ◽  
pp. 796-799 ◽  
Author(s):  
Gabriele Reber ◽  
Jürgen Riede ◽  
Nils Wiberg ◽  
Gerhard Wagner ◽  
Gerhard Müller

According to an X-ray structure analysis 1,5-bis(di-tert-butylmethylsilyl)-2,2,4,4,6,6,7,7-octamethyl-3-oxa-2,4,6,7-tetrasilabicyclo[3.1.1]heptane (1) is a rigid bicyclic molecule consisting of a 1,3-disilacyclobutane ring whose 2,4 positions are bridged by a Me2Si—O—SiMe2 fragment. The four-membered ring is non-planar with a dihedral angle of 33.8° along the C—C axis. The intraring valence angles at carbon are significantly smaller than those at silicon leading to a transannular Si ··· Si distance of only 2.558(1) Å (triclinic, space group P 1̄ with a = 9.125(2), b = 12.668(2), c = 15.499(3) Å, α = 101.25(1), β = 87.87(1), γ = 96.88(1)°, V = 1744.4 Å3 R (wR) = 0.044 (0.051) for 316 refined parameters and 5156 observables).


1988 ◽  
Vol 43 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Bernhard Glaser ◽  
Erwin P. Mayer ◽  
Heinrich Nöth ◽  
Wilfried Rattay ◽  
Ulrich Wietelmann

Abstract [2+2]-Cycloadditions of 9-Fluorenylidentetramethylpiperidinoboranes have been studied with selected olefines, acetylenes and iminoboranes. No reactions with olefines were observed. While propiolic methylester reacts exclusively at the carbonyl bond producing the oxaboretane 5, alkines such as diethylamino-alkines, cyclo-octine and phenylacetylene provide access to the'1,2-dihydroboretenes 6, 3 and 2. Tetramethylpiperidinoiminoboranes make 1.2.4-azadiboretidines 7 available.6a and 7a contain a folded four-membered ring as shown by X-ray structure analysis. There is only a weak 1,3-intraannular interaction due to BN-;r-bonding of the boron atoms with their exocyclic amino group.


1996 ◽  
Vol 51 (7) ◽  
pp. 959-962 ◽  
Author(s):  
Stephan von Beckerath ◽  
Ingo-Peter Lorenz ◽  
Riad Fawzi ◽  
Manfred Steimann

The photolytically induced CO-substitution reaction of CpMn(CO)3 with N-benzyl-aziridine leads to the first mono coordinate aziridine complex, . It is stable against thermal C2H4 elimination up to 135°C. No nitrene complexes {Cp(CO)2Mn}nNBz (n = 1, 2) were detected.The X-ray structure analysis of shows the intact three-membered ring ligand and the pyramidal configuration of the nitrogen atom.


1977 ◽  
Vol 55 (10) ◽  
pp. 1619-1623 ◽  
Author(s):  
George I. Birnbaum

In order to determine the orientation of the isopropenyl group and confirm the stereochemistry at other chiral centers in lubimin (1) and hydroxylubimin (2), two antifungal sesquiterpenes, an X-ray structure analysis of 2 was carried out. Crystals of 2 are orthorhombic, space group P212121, a = 6.190, b = 7.210, c = 63.082 Å, Z = 8. The structure was solved by direct methods and refined to R = 0.045. In both independent molecules the six-membered ring is chair-shaped with all four substituents equatorially oriented. The five-membered ring, attached by a spiro junction, is a half-chair with the isopropenyl substituent in an equatorial position. This side-chain is trans to the methyl-bearing carbon in the six-membered ring.


1990 ◽  
Vol 45 (11) ◽  
pp. 1597-1599 ◽  
Author(s):  
Wong-Wee-Choy Wong-Chi-Man ◽  
Hans Pritzkow ◽  
Walter Siebert

Hydroboration, 3,3-Dimethyl-(e)-1-chlorodimethylsilyl-1-chloro-dimethylaminoboryl-butene-1,1,3-Bis(dimethylamino-2,2,5,5-tetramethyl-4,6-bis-(t-butylethylene)-1,3-dibora-2,5-disilacyclohexaneHydroboration of chlorodimethyl(3.3-dimethylbutynyl)silane with HBCl2/BCl3 yields 3.3-dimethyl-(e)-1-chlorodimethylsilyl-1-dichloroboryl)-butene-1 (1 a), in which a chlorine atom at the boron can be substituted using Me3SiNMe, to give the corresponding chlorodimethylaminoboryl derivative 1 b. Dehalogenation of 1 b with Na/K alloy does not lead to the three-membered ring compound 2, but surprisingly yields the 1,3-dibora-disilacyclohexane derivative 3. The X-ray structure analysis shows a six-membered ring with a chair conformation, a small angle B 1–Si 2–B 1′ = 95.4(1)°, and long Si–B bonds (2.038 Å).


1995 ◽  
Vol 50 (12) ◽  
pp. 1833-1838 ◽  
Author(s):  
Ion Neda ◽  
Michael Farkens ◽  
Holger Thönnessen ◽  
Peter G. Jones ◽  
Reinhard Schmutzler

The reactions o f 2-hydro-1,3,5-trim ethyl-1,3,5-triaza-2-oxo-2λ4 -phosphorinan-4,6-dione 1 with the triazine derivatives, 1,3,5-trimethyl- and 1,3,5-tribenzyl-hexahydro-1,3,5-triazine, are described. The reaction of three equivalents of 1 with one equivalent of the triazine derivative gave 2 and 3. Both compounds were characterized via their 1H, 13C, and 31P NMR spectra, mass spectra and, in the case of 2, by an X-ray crystal structure analysis, which showed an almost planar six-membered ring; hydrogen bonds of the form N-H···O link the molecules in centrosymmetric pairs. The reactions of 1 with the aldehydes glyoxylic acid, 2-hydroxybenzaldehyde and 3,4,5-trimethoxybenzaldehyde gave addition products. The C (:O) group o f the aldehyde is inserted into the P -H bond o f 1. The resulting compounds 4 ,5 and 6 were characterized through their 1H, 13C, and 31P NMR spectra, and mass spectra.


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