- Comparative study of inclusion complexation of tetraalkylphosphonium and ammonium salts with cucurbit[7]uril
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Inclusion complexation of tetraalkylphosphonium salts (PSs) with cucurbit[7]uril (CB[7]) was studied spectrophotometrically using methylene blue as a chemical indicator. Differences in the inclusion behaviour caused by the central ions in PSs and tetraalkylammonium salts (ASs) are described herein. The inclusion complexation constant (K) of PS3 with a C3-alkyl chain is remarkably smaller than those of the other PSs, indicating that PS3 is most suitable for clathrate-hydrate formation in bulk solution. In the AS inclusions, AS4 with a C4-alkyl chain showed the small K value. Furthermore, the K values of PSs with CB[7] were measured under high pressure. The K values of CB[7] increased with increasing external pressure and decreasing solvent polarity. From the high-pressure results, the volume change (ΔVrepel) caused by water molecules released from the CB[7] cavity was evaluated. A volumetric study for the inclusion of PSs with CB[7] indicated that in PS6 and PS8 with long C6 and C8 chains, respectively, one alkyl chain was encapsulated in the CB[7] cavity. In the other PSs with short chains, two alkyl chains could be accommodated in the cavity. Based on the effects of temperature, substituents, and external pressure, differences in the inclusion mechanisms of PSs and ASs for CB[7] are discussed.
- Hagiwara, Seiya,Hanaya, Tadashi,Matsumoto, Yuki,Sueishi, Yoshimi
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- METHOD FOR PREPARING QUATERNARY PHOSPHONIUM SALTS
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A two-step pathway for preparing high pure quaternary phosphonium salts is disclosed. In the first step, hydrogen phosphide (PH3) or a higher phophine reacts with a protonic compound to produce a phosphonium salt, which then reacts with a carbo
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Paragraph 0041
(2015/06/24)
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- Synthesis and Structure of Cp3U=CHPMe3: A Compound with a U=C Multiple Bond
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Green, crystalline Cp3U=CHPMe3 has been synthesized by the reaction of Cp3UCl with Li2PMe2 or CH2=PMe3.Its crystal structure has been determined by single crystal X-ray diffraction.The short U=CH bond distance, 2.274(8) Angstroem, and large U-C-P angle, 143.5(5) deg, indicate uranium-carbon multiple bond character.The 1J(13C1H) coupling constants within the CH group between uranium and phosphorus in Cp3U=CHPMe3 (95 Hz), Cp3U=CHPMe2Ph (100 Hz), and Cp3U=CHPPh2Me (113 Hz) are surprisingly small, but no agostic interaction UCHP can be derived from the structural data.
- Cramer, Roger E.,Bruck, Michael A.,Edelmann, Frank,Afzal, Dawood,Gilje, John W.,Schmidbaur, Hubert
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p. 417 - 420
(2007/10/02)
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- Synthesis, characterization, and properties of the η2-acyl complexes Mo(η2-COCH2CMe3)X(PMe3) 4 (X = Cl, Br)
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The η2-acyl complexes of molybdenum Mo(η2-COCH2CMe3)X(PMe3) 4 (X = Cl (1a), Br (1b)) have been prepared by the action of Mg(CH2CMe3)X on the carbonyl carbonate Mo(CO3)(CO)(PMe3)4. Complex 1 decomposes in solution with dissociation of PMe3. This reaction occurs faster in the presence of small amounts of water (2-3 drops) with formation of the hydroxo species [MoX(CO)(PMe3)2(μ-OH)]2 (X = Cl (2a), Br (2b)). Carbonylation of 1a, at room temperature and pressure, affords successively Mo(η2-COCH2CMe3)Cl(CO)(PMe 3)3 and Mo(η2-COCH2CMe3)Cl(CO)2(PMe 3)2. Finally, the reaction of Mo(CO3)(CO)(PMe3)4 with CH2Cl2 yields the 7-coordinate anionic compound MoCl3(CO)(PMe3)3, which is isolated as the tetramethylphosphonium salt, [PMe4][MoCl3(CO)(PMe3)3] (3). The crystal structure of 1b has been determined by X-ray crystallography. It crystallizes in the orthorhombic space group, P212121, with a = 10.021 (2) A?, b = 16.752 (3) A?, c = 16.855 (5) A?, and Dcalcd = 1.36 g cm-3 for Z = 4. A total of 1098 independent observed [Fo > 5σ(Fo)] reflections were used in the least-squares refinement, which led to a final conventional R value of 0.051. The molybdenum atom has an approximate pentagonal-bipyramidal geometry, the η2-acyl ligand residing in the pentagonal plane. The acyl and bromo ligands are trans; important distances include Mo-Br = 2.687 (5) A?, Mo-C = 2.00 (3) A?, Mo-O = 2.21 (2) A?, and Mo-P = 2.48 (4) A?, average.
- Carmona, Ernesto,Mu?oz, Miguel A.,Rogers, Robin D.
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p. 1598 - 1601
(2008/10/08)
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- Silylated Aminophosphonium Salts and Aminophosphonium Methylides
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The reaction of the aminophosphonium methylides (Et2N)3P=CH2, Me(Et2N)2P=CH2, (Me2N)3P=CH2, or Me(Me2N)2P=CH2 (1a-d) with the chlorosilanes Me3SiCl and (t-Bu)2SiCl2, resp., yield silylated phosphonium salts 2a-d (Scheme 1).Treatment of these with strong b
- Schmidbaur, Hubert,Pichl, Reinhard,Mueller, Gerhard
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p. 789 - 794
(2007/10/02)
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- Reaktion von Acetyl-Uebergangsmetallkomplexen mit Phosphor-Yliden - ein weiteres Beispiel zur Halogenid/Metallat-Analogie
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The reaction of the acetyl metal complexes LnM-C(O)CH3Mo> with the phosphorus ylides (CH3)3P=CH2, C2H5(CH3)2P=CH2, (C2H5)3P=CHCH3 and (C4H9)3P=CH2 in the ratio 1:2 yields the corresponding acetyl-substituted ylides R3P=CR'C(O)CH3 3a - d (R = CH3, C2H5, n-C4H9; R' = H, CH3) and phosphonium metalates 4a - d, 6a, b via heterolysis of the Fe-C-?-bond and transylidation.With CH3C(O)Cl an analogous way of reaction is observed, which however can be repeated to give the diacetyl ylides R3P=C(COCH3)2 8a, b (R = CH3, n-C4H9).The new compounds are characterized by spectroscopic methods (NMR, IR) and further reactions.
- Malisch, Wolfgang,Blau, Herbert,Haaf, Franz Jakob
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p. 2956 - 2970
(2007/10/02)
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- A New Synthesis and the Molecular Structure of Trimethyl(silylmethylene)phosphorane in the Gas Phase, Determined by Electron Diffraction
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Trimethyl(silylmethylene)phosphorane (1) has been prepared in a reaction of H3SiCH2CH2Cl and (CH3)3P=CH2 in a molar ratio 1 : 2.C2H4 is evolved in a β-elimination process, followed by formation of +Cl- in a transylidation step. - The molecular structure of (CH3)3P=CHSiH3 in the gas phase has been determined by electron diffraction.Principal bond lengths (ra) are: P-C = 180.7(8), P=C = 165.3(11), Si-C = 185.2(20) pm.The angles between the P-C(methyl) bonds are 103.4(13) deg and the Si-C=P angle is 123.4(8) deg, consistent with a planar configuration of the methylene carbon atom.The molecule adopts a conformation in which the Si-C bond is twisted 25 deg from a position in which it eclipses one P-C bond, but there is a large amplitude torsional vibration about the P-C bond.
- Ebsworth, E. A. V.,Rankin, David W. H.,Zimmer-Gasser, Beate,Schmidbaur, Hubert
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p. 1637 - 1645
(2007/10/02)
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