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81.
Joseph Grobe Elke Maria Reifer Bernt Krebs Mechtild Lge Markus Prill 《无机化学与普通化学杂志》2000,626(2):478-488
Alternative Ligands. XXXV. Syntheses of Bidentate P‐Donor/Sn‐Acceptor Ligands: Coordination Experiments with Cp*Rh(CO)2 and CpRh(C2H4)2 Donor/acceptor ligands Me2Sn(CH2CH2PMe2)2 ( 1 ) and Me2Sn(OCH2PMe2)2 ( 2 ) have been prepared by radical reaction of Me2PVi with Me2SnH2 and by substitution of chlorine in Me2SnCl2 or of ethoxy groups in Me2Sn(OEt)2 by MOCH2PMe2 (M = Li, Na) and HOCH2PMe2, respectively. 2 cannot be isolated in pure form from the product mixture because, due to condensation reactions, the “ladder structure” [Me2Sn(OCH2PMe2)2OSnMe2]2 ( 3 ) is formed. The molecular structure of 3 was determined by X‐ray diffraction studies of single crystals. Attempts to produce the thiophosphoryl derivative of 3 result in the degradation of the ladder structure giving the thermally labile phosphane sulfide Me2Sn(OCH2P(S)Me2)2. Ligands 1 and 2 besides Me2PCH2CH2SnMe3 ( 4 ) have been used for the preparation of rhodium(I) complexes from Cp*Rh(CO)2 ( 5 ) or CpRh(C2H4)2 ( 10 ) as educts. The thermal reaction of 5 with 4 yields Cp*Rh(CO)PMe2CH2CH2SnMe3 ( 6 ), that of 5 with 1 a mixture of the mononuclear derivative Cp*Rh(CO) · PMe2CH2CH2SnMe2CH2CH2PMe2 ( 7 ) and the binuclear complex [Cp*Rh(CO)PMe2CH2CH2]2SnMe2 ( 8 ). The related system [Cp*Rh(CO)PMe2CH2O]2SnMe2 produced by reaction of 5 with 2 can only be detected in solution but, because of some side‐products, was not fully characterized. From 10 and 4 a mixture of mono‐ and disubstituted products, CpRh(C2H4)PMe2CH2CH2SnMe3 ( 11 ) and CpRh(PMe2CH2CH2SnMe3)2 ( 12 ), is obtained. Reaction of 1 with 10 yields a mixture of the complexes CpRh(C2H4)PMe2CH2CH2SnMe2CH2CH2PMe2 ( 13 ) and CpRh(Me2CH2CH2)2SnMe2 ( 14 ). Some of the NMR data (13C, δδSn) of 14 can be interpreted in terms of the expected Rh → Sn interaction. A definite proof by X‐ray diffraction on single crystals, so far, was not possible. 相似文献
82.
Perfluoromethyl Element Ligands. XLI. [1] Compounds of the Type (F3C)2EE′R with Pseudohalide Character (E = P, As; E′ = S, Se, Te) Perfluoromethyl phosphorus and -arsenic compounds of the type (F3C)2EE′R (E = P, As; E′ = S, Se, Te; R = organic group) are prepared either by dismutation (metathesis) of E2(CF3)4 with (RE′)2 or by reaction of the iodine compounds (F3C)2EI with mercury(II) organosulfanides Hg(SR)2 and characterized by spectroscopic (1H, 19F, 31P-NMR; IR; MS) as well as analytical investigations (C, H). 相似文献
83.
Ingrid Bartz Joseph Grobe Kai Lütke‐Brochtrup Bernt Krebs Joachim Kuchinke Mechtild Lge 《无机化学与普通化学杂志》2001,627(6):1334-1346
Alternative Ligands. XXXVI. Novel Rhodium(I) Complexes with Donor/Acceptor Chelating Ligands In order to generate metal base/Lewis‐acid interactions in rhodium(I) phosphane complexes the binuclear complex [Rh(CO)2Cl]2 was reacted in benzene with dipod ligands of the type R2M′(OCH2PMe2)x(CH2CH2PMe2)2–x (R = F, Me; M′ = Si, Ge; x = 0–2) using the Ziegler dilution principle with the aim to produce mononuclear compounds in which with formation of five‐membered chelate rings in principle Rh → M′ contacts are possible. The reactions of ligands 1 – 7 (Table 1) with [Rh(CO)2Cl]2 proceed under CO elimination and, in spite of large turnovers, lead to a variety of products 8 – 14 (Table 1), in case of 11 , 13 and 14 accompanied by degradation of the corresponding ligands. Intact ligands are present in the 16‐membered rings of the binuclear complexes 8 – 10 and 12 , for which, due to the molecular structure, Rh → M′ interactions can be excluded. In the reaction of Me2Si(OCH2PMe2)2 ( 4 ) with [Rh(CO)2Cl]2 the unusual binuclear system 11 with a central Rh2O2 four‐membered ring and two RhO(SiMe2OCH2PMe2) six‐membered rings is formed. Small amounts of the mononuclear compounds Rh(CO)Cl(Me2PCH2OH)2 ( 13 ) and Rh(CO)Cl3(Me2PCH2OH)2 ( 14 ), respectively, are obtained in crystalline form from the reaction mixtures of [Rh(CO)2Cl]2 with Me2Ge(OCH2PMe2)(CH2CH2PMe2) ( 6 ) or Me2Ge(OCH2PMe2)2 ( 7 ). The new complexes were characterized by analytic (C, H), spectroscopic (NMR, IR, MS) and, except for 12 , by single crystal structural analyses. 相似文献
84.
85.
Joseph Grobe Duc Le Van Ulrike Althoff Bernt Krebs Mechtild Dartmann Rolf Gleiter 《Heteroatom Chemistry》1991,2(3):385-394
The one-pot reaction of the alcohol adducts F3CP(H)CF2OR of perfluoro-2-phosphapropene with secondary amines in a 1:3 molar ratio affords the stable phosphaalkenes F3CPC(OR)NR2 (R = Me, Et) 1–4 in yields of 58%. NMR and He(I) PE spectroscopic investigations show that the lone pair electrons on nitrogen and oxygen participate in n/π conjugation. In contrast to typical low-coordinated double bonds the new derivatives do not react with alcohols, amines, and 1,3-dienes. The derivatives are more closely related to the phosphaalkenes F3C(F)NR2 than to perfluoro-2-phosphapropene. The reaction of F3C(OEt)NMe2 ( 3 ) with Cr(CO)5THF yields the η1(P) complex Cr(CO)5[F3CPC(OEt)NMe2] ( 7 ) with an unusually long sp2 PC bond (1.809 Å). 相似文献
86.
Joseph Grobe Duc Le Van Marianne Hegemann Bernt Krebs Mechtild Lge 《Heteroatom Chemistry》1994,5(4):337-341
The reaction of di(isopropyl)aminophosphaethyne 1 with iodomethane or the methyl ester of trifluormethylsulfonic acid (methyl triflate) yields the ionic 1λ3, 3λ3-diphosphetene derivatives + X− ( 2a : X = I; 2b : X = CF3SO3). On the basis of NMR spectroscopic and X-ray diffraction studies, the cation can be described as a combination of an amino-2-phosphaallylic cation and its methylated derivative. 相似文献
87.
R. E. Wagner M. R. Ware A. M. Vikartofsky Q. Su R. Grobe 《International Journal of Theoretical Physics》2012,51(12):3787-3804
We analyze the spatial and temporal dynamics of virtual particles in the vacuum states of the one-dimensional ? 2- and ? 4-model systems. The properties of the vacuum state for the ? 2-system can be found analytically, which allows us to compute all spatial and temporal correlations exactly. For large spatial and temporal separations, the correlation functions approach a non-vanishing finite constant associated with the occurrence of multiple vacuum bubbles, in contradiction to lowest-order perturbation theory. Long-range inter-bubble correlations suggest that virtual particles can actually enhance the occurrence of another bubble due to stimulated emission. We argue that many of the vacuum’s properties can be explained in the usual particles terms. 相似文献
88.
We study the bosonic pair creation from the vacuum by an external force field of arbitrary strength and shape in space and
time. Our approach is similar to the computational quantum field theory developed for fermions. The non-perturbative solutions
enable us to study the single and multiple boson-antiboson pair dynamics. The closed-form analytical expressions are based
on the set of solutions to the time dependent Klein-Gordon equation that may be obtained numerically. In contrast to the dynamics
for electron/positron pairs, the boson pair creation is not limited by the Paul exclusion principle and reveals an enhancement
of the vacuum’s decay rate. 相似文献
89.
I. Bartz J. Grobe A. Krummen N. Krummen R. Martin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The coordinating properties of dipod and tripod phosphorus ligands LI = R2M′ (OCH2PMe2) n(CH2CH2PMe2) 2-n and LII = RM′ (OCH2PMe2)n(CH2CH2PMe2)3-n (M′ = Si, Ge) with separated donor and acceptor centres have been investigated using electron rich metal complex fragments, e. g. M(CO)m, (M = Cr, MO, W), π-C5H5Co, RhCl(CO) or Ni(CO), as bonding partners. 相似文献
90.
Due to the mesomeric interaction of the nitrogen lone pair with the As=C double bond, the perfluoroarsapropene derivative F3CAs=C(F)NEt2 ( 1 ) is sufficiently stable to serve as a ligand in transition metal carbonyl complexes. 1 was coordinated to chromium by reaction with the photochemically generated labile complex Cr(CO)5(THF), yielding the monosubstituted pentacarbonyl derivative Cr(CO)5[F3CAs=C(F)NEt2] ( 2 ). Already at room temperature, this is slowly transformed into the binuclear complex [F3CAs=C(F)NEt2][Cr(CO)5]2 ( 3 ) by replacing 1 from a neighbouring molecule by the stronger donor 2 . In a closed system 3 obviously exists in an equilibrium with 1 and 2 . Both complexes are related to the previously studied derivatives of the 2‐dimethylamino‐perfluoro‐1‐phosphapropene ligand. The products were identified by spectroscopic (IR, NMR) investigations and comparison with the related phosphaalkene complexes. 相似文献