VERBINDUNGEN MIT DEM 1,3-DIMETHYL-1,3- DIAZA-2-PHOSPHETIDIN-4-ON GRUNDGERüST: SYNTHESE VON 1,3-DIMETHYL-2-PHENYLIMINO- 1,3-DIAZA-2λ4-PHOSPHETIDIN-4-ON-DERIVATEN. RÖNTGENSTRUKTURANALYSE VON 4,6- DIMETHOXY -5,10-DIPHENYL-1,3,7,9- TETRAMETHYL-l,3,5,7,9,10-HEXAAZA- 4λ5,6λ55-DIPHOSPHADISPIRO[3.1.3.1]DECAN-2,8-DION

Abstract

Die Umsetzung einer Reihe von λ³P-Diazaphosphetidinonen, MeNC(:O)N(Me)PY (Y [dbnd] NEt₂: 1, N(CH₂)₄; 2, NPh₂; 3, OMe; 4, N(cyc)₂; 5), mit Phenylazid wird beschrieben. Die dabei primär entstandenen 2-Phenylimino-λ⁴P-diazaphosphetidinone, MeNC(:O)N(Me)P(:NPh)Y sind mit Ausnahme des sterisch anspruchsvollen Dicyclohexylderivats, Y [dbnd] N(cyc)₂; 12, unbeständig und dimerisieren rasch zu den entsprechenden Diazadiphosphetidinen, 7 und 9–11. Aus 7 bildet sich in Lösung unter Abspaltung von MeN[dbnd]C[dbnd]NMe das A4P, λ⁴P,λ⁵P-Diazadiphosphetidin 8. Die neuen Verbindungen 8–12 wurden analytisch, ₁H-, ₁₃C- und ³¹P-NMR-spektroskopisch sowie durch ihre Massenspektren charakterisiert. Darüber hinaus wurde von Verbindung 11 eine Röntgenstrukturanalyse durchgeführt. Das Molekül besitzt kristallographische zweizählige Symmetric. Die Geometrie am Phosphor ist verzerrt trigonal bipyramidal, mit P—N-Bindungslängen 173.9. 179.2 pm (axial) sowie 168.3, 168.7 pm (äquatorial).

Compounds involving the 1,3-dimethyl-1,3-diaza-2-phosphetidin-4-one framework: Synthesis of 1,3- dimethyl-2-phenylimino-l,3-diaza-2λ⁴-phosphetidin-4-one derivatives. X-ray crystal structure analysis of 4,6-dimethoxy-5,10-diphenyl-l,3,7,9-tetramethyl- 1,3,5,7,9,10-hexaaza-4λ⁵,6λ⁵-diphosphadispiro- [3.1.3.l]decan-2,8-dione.

The reactions of a series of λ³P-diazaphosphetidinones MeNC(:O)N(Me)PY (Y [dbnd] NEt₂,; ₁, N(CH₂)₄; 2, NPh2,; 3, OMe; 4, N(cyc)₂; 5), with phenyl azide are described. The initially formed 2-phenylimino-λ⁴P-diazaphosphetidinones, MeNC(:O)N(Me)P(:NPh)Y, are. except for the bulky dicyclohexyl derivative 12, unstable and dimerize rapidly to the corresponding diazadiphosphetidines, 7 and 9–11. The λ⁴P,λ⁴P-diazadiphosphetidine 8 is formed from 7 in solution by elimination of MeN[dbnd]C[dbnd]NMe. The novel compounds 8–12 were characterized by analysis, n.m.r. and mass spectroscopy; additionally, an X-ray crystal structure analysis of 11 was carried out. The molecule possesses crystallographic twofold symmetry. The P-N bond lengths are 173.9, 179.2 pm (axial) and 168.3, 168.7 pm (equatorial).     

Determination of Four Active Oxygen Species Such as H2O2, •OH, •O2 −, and 1O2 by Luminol and CLA-Chemiluminescence Methods and Evaluation of Antioxidative Effects of Hydroxybenzoic Acids

Abstract

Simple and rapid chemiluminescence (CL) assays for H₂O₂, ?OH, ?O₂ ^? and ¹O₂ using 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) or 2-methyl-6-phenyl-3,7-dihydroimidazo[1,2-α]pyrazin-3-one (CLA) as CL reagents were developed. The means of the intra-assay relative standard deviations of ten replicate measurements of H₂O₂ (25-120 μM), ?OH generated from Fe(II) ion (2.5-10 μM) in the presence of 980 μM H₂O₂, ?O₂ ^? generated from hypoxanthine (HX) (7-50 μM) in the presence of 9 × 10^?3 units xanthine oxidase (XO) and ¹O₂ generated from NaOCl (3-12 mM) in the presence of 97.6 μM H₂O₂ were found to be 4.0%, 2.8%, 2.4% and 8.7%, respectively. To validate the proposed methods, the scavenging abilities of three standard antioxidative compounds, such as L-ascorbic acid, (±)-α-tocopherol and superoxide dismutase (SOD) were examined for four active oxygen species and compared with those by anelectron spin resonance (ESR) spin-trapping method. In addition, the CL methods were also applied to establish the relationships between the decrease of CL intensity and the structures as well as redox characters of syringic acid, 3-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid. From the obtained results, the scavenging effects to H₂O₂, ?OH, ?O₂ ^? and ¹O₂ of other dihydroxybenzoic acids were also evaluated.     

Hydrothermal synthesis,characterization, and luminescence of two new arsenic–vanadium compounds with a γ-[As8V14O42(H2O)]4− anion

Two new compounds, [Zn(phen)₃]₂[γ-As₈V₁₄O₄₂(H₂O)]?·?4H₂O (1) and [Cd(phen)₃]₂[γ-As₈V₁₄O₄₂(H₂O)]?·?2H₂O (2) (phen?=?1,10′-phenanthroline), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, infrared spectrum, and thermogravimetric analysis. Compound 1 crystallizes in the triclinic space group P 1 with a?=?11.429(4)?Å, b?=?15.760(5)?Å, c?=?15.952(5)?Å, α?=?108.825(5)°, β?=?92.194(5)°, γ?=?104.155(5)°, V?=?2615.6(15)?ų, Z?=?1; 2 crystallizes in the triclinic space group P 1 with a?=?11.450(4)?Å, b?=?15.629(6)?Å, c?=?16.302(6)?Å, α?=?109.177(5)°, β?=?92.628(5)°, γ?=?104.251(4)°, V?=?2644.8(17)?ų, Z?=?1. Single-crystal structural analysis shows that both 1 and 2 consist of a new type of [γ-As₈V₁₄O₄₂(H₂O)]^4? cluster anion.     

Synthesis and efficiency of 5-(2-hydroxyphenylazo)-indazoles as new reagents for the determination of vanadium

Summary Four azo compounds based on 5-aminoindazole have been synthesized and characterized by elemental analysis as well as different spectroscopic techniques. The potentiality of the prepared compounds as new chromophoric reagents for the spectrophotometric determination of VO ₂ ⁺ was studied by extensive investigation of optimum conditions favouring the formation of the coloured complexes. The effect of interfering ions on the determination of VO ₂ ⁺ was investigated.Beer's law is obeyed in the concentration range of 1.0–12 µg/ml. The detection limits are 0.8, 0.9, 0.7, and 1.1 µg/ml using reagent1a,1b,1c, and1d, respectively. The standard deviations of the proposed method are 0.098, 0.111, 0.089, and 0.078. The molar absorptivities are 5.8, 6.7, 6.1, and 8.2×10³l·mol^–1·cm^–1 for1a–d, respectively, whereasSandell sensitivities are found to be 0.0187, 0.0163, 0.0174, and 0.0146 µg·cm^–2 using the same reagents. The ability of using these reagents as metallochromic reagents in complexon III titrations was also studied.

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Synthese und Leistungsfähigkeit von 5-(Hydroxyphenylazo)-indazolen als neue Reagentien zur Bestimmung von Vanadium

Zusammenfassung Vier von 5-Aminoindazol abgeleitete Azoverbindungen wurden synthetisiert und mittels Elementaranalyse sowie mit Hilfe verschiedener spektroskopischer Techniken charakterisiert. Die Einsatzmöglichkeiten der Verbindungen als Reagentien zur spektrophotometrischen Bestimmung von VO ₂ ⁺ wurde durch ausführliche Untersuchungen zur Ermittlung der optimalen Bedingungen für die Ausbildung der gefärbten Komplexe ausgetestet. Der Einfluß von Fremdionen auf die Ergebnisse wurde ebenfalls untersucht. DasBeer'sche Gesetz wird im Konzentrationsbereich von 1.0–12µg/ml befolgt. Die Nachweisgrenzen liegen bei 0.8, 0.9, 0.7 und 1.1 µg/ml für die Reagentien1a–d. Die entsprechenden Standardabweichungen betragen 0.098, 0.111, 0.089 und 0.078. Die Komplexe zeigen molare Extinktionen von 5.8, 6.7, 6.1 und 8.2×10³l·mol^–1·cm^–1 und Empfindlichkeiten nachSandell von 0.0187, 0.0163, 0.0174 und 0.0146 für die jeweiligen Verbindungen1a–d. Die Verwendungsmöglichkeit der neuen Verbindungen als metallochrome Reagentien bei Titrationen mit Komplexon III war ebenfalls Gegenstand der Untersuchungen.

     

Crystal structure of anhydrous alum RbFe3+(SeO4)2

Summary The compound RbFe(SeO₄)₂ was prepared hydrothermally by reaction of Rb₂CO₃ and FeC₂O₄·2H₂O with H₂O and H₂SeO₄ at 490 K. Single crystal X-ray methods revealed isotypy with KAl(SO₄)₂. RbFe(SeO₄)₂ crystallizes in space group P321;Z=1;a=5.005(1)Å,c=8.548(2) Å,V=185.4 ų; 781 unique data up to 80 °2;R,R _w =0.045, 0.042. The structure is best described as sheets of [Fe(SeO₄)₂]^– parallel (001), interconnected by Rb⁺. FeO₆ trigonal prims and SeO₄ tetrahedra have bond lengths of 1.99 Å and 1.63 Å, respectively. The Rb atom is [6 + 6] coordinated with Rb-O distances of 3.04 Å and 3.48 Å.

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Die Kristallstruktur des wasserfreien Alauns RbFe³⁺(SeO₄)₂

Zusammenfassung Die Verbindung RbFe(SeO₄)₂ wurde hydrothermal dargestellt durch Reaktion von Rb₂CO₃ und FeC₂O₄·2H₂O mit H₂O und H₂SeO₄ bei 490K. Einkristallröntgenmethoden belegten die Isotypie mit KAl(SO₄)₂ RbFe(SeO₄)₂ kristallisiert in der Raumgruppe P321;Z=1;a=5.005(1) Å,c=8.548(2) Å,V=185.4 ų; 781 unabhängige Daten bis 80 °2;R,R _w =0.045, 0.042. Die Struktur läßt sich am besten als Schichten von [Fe(SeO₄)₂]^– parallel (001) beschreiben, die durch Rb⁺ verbunden sind. FeO₆ trigonale Prismen und SeO₄ Tetraeder weisen Bindungslängen von 1.99 Å bzw. 1.63 Å auf. Das Rb-Atom ist [6+6] koordiniert mit Rb-O Abständen von 3.04 Å und 3.48 Å.

     

Self-assembled tetrameric H2O clusters in the crystal lattice of [Cu(μ2-OH){Ph2P(O)NP(O)Ph2-κ1O,O′}(1,10-phen-κ2N,N′)]2·2H2O

Abstract

The synthesis and characterization of the dinuclear Cu(II) complex [Cu(μ²-OH){Ph₂P(O)NP(O)Ph₂-κ¹O,O′}(1,10-phen-κ²N,N′)]₂·2H₂O (1), 1,10-phen?=?1,10-phenanthroline, is described. X-ray crystallographic studies reveal that the Cu(II) centers of 1 are bridged by two OH^? groups and are coordinated by the (O,O)?= Ph₂P(O)NP(O)Ph₂^? ligand in a monodentate fashion, unprecedented for Cu(II). The crystal lattice of 1 also contains H₂O molecules, which are involved in the formation of a hydrogen bonding network with bridging OH^? groups and noncoordinated O atoms of the (O,O) ligand. These H₂O molecules are arranged in the crystal lattice of 1 as tetrameric clusters. The packing of molecules in the structure of 1 was investigated by Hirshfeld Surface analysis.     

Thermal behaviour of CO2 laser-irradiated CeO2 doped with Yb2O3

Results concerning the thermal behaviour of Yb₂O₃-doped CeO₂ samples irradiated with CO₂ laser beams in continuous wave are presented.

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Zusammenfassung Es werden Ergebnisse einer Untersuchung des thermischen Verhaltens von CeO₂-Proben dargelegt, die mit CO₂-Laser bestraht wurden.

     

Efficient Conversion of Tetrahydropyranyl (THP) Ethers to Their Corresponding Thiocyanates With in-situ–Generated Ph3P(SCN)2

Immediate and efficient one-pot conversion of tetrahydropyranyl (THP) ethers to their corresponding thiocyanates by in-situ–generated Ph₃P(SCN)₂ is described. Primary and secondary alkyls and also benzylic THP ethers are converted to their corresponding thiocyanates in excellent yields at room temperature by this method.     

The Use of the CS2N− 3/HSO− 3/O2 Reaction for the Analytical Determination of Dissolved Oxygen

Abstract

A new analytical Spectrophotometric method has been developed for the determination of dissolved O₂ in the range 4.6 × 10^?6?4.1 × 10^?5M, based on the CS₂N^? ₃/HSO^? ₃/O₂ reaction. In one single experiment 2.3 × 10^?5 M of oxygen can be determined with an uncertainty of ± 7 × 10^?7M for a confidence level of 95%.     

Supramolecular inclusion of a pillared double-layered host by an anion-directed second-sphere coordination

In this paper, we have illustrated the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with varieties of guest molecules. A flexible molecule N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine (L1) bearing doubly protonated H-bond donors was designed, capable of forming N–H…Cl hydrogen bonds with a crystallographically unique chloride anion, to construct an anion-directed ligand. The pillared double-layered host framework was constructed by an anion-directed ligand and primary coordination sphere [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interactions. A variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of novel supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2).

We have presented herein the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with a variety of guest molecules. A novel type of a pillared double-layered host framework was constructed by a second-sphere coordination between the anion-directed ligand (L1 = N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine) and [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interaction, and a variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2)

     

Insertion of Phosphenium Ions into a Bicyclo[1.1.0]Tetraphosphabutane Iron Complex

By reacting [{Cp‴Fe(CO)₂}₂(µ,η^1:1-P₄)] (1) with in situ generated phosphenium ions [Ph₂P][A] ([A]⁻ = [OTf]⁻ = [O₃SCF₃]⁻, [PF₆]⁻), a mixture of two main products of the composition [{Cp‴Fe(CO)₂}₂(µ,η^1:1-P₅(C₆H₅)₂)][PF₆] (2a and 3a) could be identified by extensive ³¹P NMR spectroscopic studies at 193 K. Compound 3a was also characterized by X-ray diffraction analysis, showing the rarely observed bicyclo[2.1.0]pentaphosphapentane unit. At room temperature, the novel compound [{Cp‴Fe}(µ,η^4:1-P₅Ph₂){Cp‴(CO)₂Fe}][PF₆] (4) is formed by decarbonylation. Reacting 1 with in situ generated diphenyl arsenium ions gives short-lived intermediates at 193 K which disproportionate at room temperature into tetraphenyldiarsine and [{Cp‴Fe(CO)₂}₄(µ₄,η^1:1:1:1-P₈)][OTf]₂ (5) containing a tetracyclo[3.3.0.0^2,7.0^3,6]octaphosphaoctane ligand.     

Fading of a novel colorimetric receptor after recognizing H2PO4−

A novel selective and sensitive colorimetric receptor 1 (1, 10-phenanthroline-2, 9-dialdehyde bis-(-p-nitrophenylureasemicarbo-hydrazone)) based on urea showing distinctive color fading phenomenon towards H₂PO₄^? ion was reported. Fancifully, the recognition process of receptor 1 to H₂PO₄^? was not interfered by the existence of others anions. We have probed the binding mechanism of 1-H₂PO₄^? that H₂PO₄^? ion induced competitive hydrogen binding process via intramolecular hydrogen-bond by UV–vis, fluorescence, ¹H NMR titrations and ESI-MS experiments.     

Cadmium(II) complexes with phosphine tellurides: synthesis and multinuclear (31P, 125Te,and 113Cd) NMR characterization in solution

New cadmium(II) complexes with phosphine telluride ligands of the type CdX₂(R₃PTe)_n [X?=?ClO₄^?, n?=?4: R?=?n-Bu (1), Me₂?N (2), C₅H₁₀?N (3), C₄H₈?N (4) or OC₄H₈?N (5); X?=?Cl^–, n?=?2: R?=?n-Bu (6), Me₂?N (7), C₅H₁₀?N (8), C₄H₈?N (9) or OC₄H₈?N (10)] have been synthesized and characterized by elemental analyses, IR and multinuclear (³¹P, ¹²⁵Te, and ¹¹³Cd) NMR spectroscopy. In particular, the solution structures of these complexes were confirmed by ¹¹³Cd NMR at low temperature, which displays a quintuplet for each of the perchlorate complexes and a triplet for each of the chloride complexes due to coupling with four and two equivalent phosphorus atoms, respectively, indicating a four-coordinate tetrahedral geometry for the metal center. These multiplet features were further accompanied by one bond Te–Cd couplings, clearly showing that the ligand is coordinated to the metal through tellurium. The results are discussed and compared with those obtained for closely related phosphine chalcogenide analogs.     

两种3D微孔Zn-MOF对水溶液中Fe3+、Cr2O72-和丙酮分子的荧光传感(英文)

通过溶剂热法合成了2种三维微孔锌金属有机框架材料,其分子式为[Zn₃(DBA)(OH)(1,10-phen)₂]_n (1)和{[Zn₂(HDBA)(4,4′-bipy)_1.5]·H₂O}_n (2)(H₅DBA=3,5-二(2′,4′-对羧基苯基)苯甲酸;1,10-phen=1,10-菲咯啉;4,4′-bipy=4,4′-联吡啶)。结构分析表明,配合物1为三核锌基金属单元的三维微孔骨架,配合物2为双核锌基的微孔结构。与2相比,配合物1在水中具有较强的发光性能,可作为检测Fe³⁺、Cr₂O₇^2-和丙酮分子的发光传感器,具有较高的选择性和灵敏度。     

Quantum chemistry studies on the Ru-M interactions and the P NMR in [Ru(CO)3(Ph2Ppy)2(MCl2)] (M = Zn, Cd, Hg)

To study the Ru-M interactions and their effects on ³¹P NMR, complexes [Ru(CO)₃(Ph₂Ppy)₂] (py = pyridine) (1) and [Ru(CO)₃(Ph₂Ppy)₂MCl₂] (M = Zn, 2; Cd, 3; Hg, 4) were calculated by density functional theory (DFT) PBE0 method. Moreover, the PBE0-GIAO method was employed to calculate the ³¹P chemical shifts in complexes. The calculated ³¹P chemical shifts in 1-3 follow 2 > 3 > 1 which are consistent to experimental results, proving that PBE0-GIAO method adopted in this study is reasonable. This method is employed to predict the ³¹P chemical shift in designed complex 4. Compared with 1, the ³¹P chemical shifts in 2-4 vary resulting from adjacent Ru-M interactions. The Ru → M or Ru ← M charge-transfer interactions in 2-4 are revealed by second-order perturbation theory. The strength order of Ru → M interactions is the same as that of the P-Ru → M delocalization with Zn > Cd > Hg, which coincides with the order of ³¹P NMR chemical shifts. The interaction of Ru → M, corresponding to the delocalization from 4d orbital of Ru to s valence orbital of M²⁺, results in the delocalization of P-Ru → M, which decreases the electron density of P nucleus and causes the downfield ³¹P chemical shifts. Except 2, the back-donation effect of Ru ← M, arising from the delocalization from s valence orbital of M²⁺ to the valence orbital of Ru, is against the P-Ru → M delocalization and results in the upfield ³¹P chemical shifts in 4. Meanwhile, the binding energies indicate that complex 4 is stable and can be synthesized experimentally. However, as complex [Ru(CO)₃(Ph₂Ppy)₂HgCl]⁺5 is more stable than 4, the reaction of 1 with HgCl₂ only gave 5 experimentally.     

Synthesis and Structure of a Neutral Trimetallic Biicosahedral Cluster, (Ph3P)10Au11Ag12Pt2Cl7. A Comparative Study of Molecular and Crystal Structures of Vertex-Sharing Biicosahedral Mixed-Metal Nanoclusters

The synthesis and structure of a new, neutral Au–Ag–Pt vertex-sharing biicosahedral cluster, [(Ph₃P)₁₀Au₁₁Ag₁₂Pt₂Cl₇] (3), is reported. The title cluster was synthesized via a new synthetic strategy based on preformed clusters. The title cluster crystallizes in a monoclinic unit cell of P2₁/m space-group symmetry with lattice parameters a=16.553(14) Å, b=25.130(7) Å, c=29.633(13) Å, =103.03(5); V=12009.3 ų and Z=2. The structure was refined to R₁=7.7% and R₂=9.2% for 3585 independent reflections (242°) with I>3. The metal core of the title structure can be described as two Pt-centered Au₆Ag₆ icosahedra sharing a common Au atom. The four metal pentagons adopt the staggered–eclipsed–staggered (ses) configuration, or, the R(0) rotamer. The ten triphenylphosphine ligands coordinate to the ten peripheral (surface) Au atoms in a radial fashion. There are five doubly-bridging chloride ligands connecting two Ag₅ pentagons and two more chloride ligands coordinating terminally to two apical Ag atoms. The title cluster completes the series of Au-shared biicosahedral clusters with 0, 1, and 2 Pt atom(s) occupying the two icosahedral centers, as exemplified by [(p-Tol₃P)₁₀Au₁₃Ag₁₂Cl₇]²⁺ (1), [(Ph₃P)₁₀Au₁₂Ag₁₂PtCl₇]⁺ (2), and the title cluster [(Ph₃P)₁₀Au₁₁Ag₁₂Pt₂Cl₇] (3), respectively. The structure of the title cluster satisfies the site preference rules established for mixed-metal vertex-sharing polyicosahedral nanoclusters. The molecular structural invariance and the ubiquity of the P2₁/m space group for the crystal structures of the biicosahedral cluster series with Ph₃P as phosphine ligands and conforming to the R(0) rotameric metal configuration are discussed. Furthermore, endo- and exo-icosahedral chemistries, and rotamerism and roulettamerism of an extensive series of vertex-sharing biicosahedral nanoclusters, as well as their bonding implications, are described via a comparative study.     

X-ray Crystal Structure of (CNSSS)2(M)2 (M = AsF6 −, SbF6 −, Sb2F11 −)

The crystal structures of (CNSSS)₂(AsF₆)₂, (CNSSS)₂(SbF6)₂, and two phases of (CNSSS)₂(Sb₂F₁₁)₂ have been determined. The AsF₆ ^?, SbF₆ ^?, and α-Sb₂F₁₁ ^? salts crystallize as reddish-brown plates whereas the β-Sb₂F₁₁ ^? salt crystallizes as green rods. The dication ^ß+SSSNCCNSSS^+ß (1²⁺) is the same in all four structures and consists of two 7π rings linked by a sp²-sp² C-C bond (1.462 Å in 1 (AsF₆)₂). The packing in the four structures is similar with stacks of dications along the a-axis and alternating sheets of dications and anions lying in the bc-plane. The differences in the dication-dication contacts is reflected in the variable temperature magnetic data.     

PHOSPHORORGANISCHE VERBINDUNGEN 921

Abstract

Optisch aktive Phosphinigsäureamide R¹R²PNR₂ 4 (R¹ [dbnd] Ph, R² [dbnd] Me bzw. Et, R [dbnd] Et) sind durch kathodische Spaltung bzw.Cyanolyse optisch aktiver Amidophosphoniumsalze [R¹R²R³PNR₂]X (R¹ [dbnd] Ph. R² [dbnd] Me bzw. Et. R³ [dbnd] Bz bzw. All, R [dbnd] Et) unter Erhaltung der Konfiguration in hohen Ausbeuten zugänglich.

Optisch aktive Amidophosphoniumverbindungen, z.B. Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 oder Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12 werden erhalten:

a) aus den optisch aktiven tertiären Phosphinen, z.B. R-(+)Benzyl-methyl-phenyl-phosphin 6 bzw. S-(-)Ethyl-methyl-phenyl-phosphin 13 durch Umsetzung mit Alkyl- oder Arylaziden über die Phosphinimine 7 mit anschließender Alkylierung.

b) durch Alkylierung der optisch aktiven Phosphinigsäureamide 4. Die unter a) und b) genannten Umsetzungen verlaufen unter Erhaltung der Konfiguration.

c) Bei der Umsetzung optisch aktiver tertiärer Phosphine mit N-Halogenaminen entstehen nur racemische Amidophosphoniumsalze.

Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-methyl-phenyl-diethylamido-phosphoniumbromid 8 oder R-(-)-Ethyl-methyl-phenyl-diethylamido-phosphoniumiodid 10 werden bei der Einwirkung wäßriger Alkalien unter Inversion zu den entsprechenden Phosphinoxiden 9 bzw. 11 abgebaut. Optisch aktive Amidophosphoniumsalze, z.B. S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 12, werden mit LiAlH₄ retentiv unter Abspaltung des Aminliganden in die zugrundeliegenden optisch aktiven tertiären Phosphine übergeführt. Die Olefinierung von Benzaldehyd mit S(+)-Benzyl-ethyl-phenyl-diethylamido-phosphoniumbromid 5 ergibt unter Retention Stilben und optisch aktives Ethyl-phenyl-phosphinsäure-diethylamid 17, das auch durch Oxidation von R(-)-4 mit H₂O₂ erhalten wird. Schwefelung von R(-)-4 liefert das optisch aktive Ethyl-phenyl-thiophosphinsäure-diethylamid 18.

Das optisch aktive Phosphinigsäure-diethylamid 4 racemisiert allein und in Kohlenwasserstoffen gelöst bei 130°C nach einer Reaktion nullter Ordnung. Die Racemisierung wird durch Austausch der sekundären Aminogruppe über cyclische Assoziate verursacht. Beweis: Verbindungen mit unterschiedlichen. Substituenten am Phosphor- und Stickstoff tauschen beim dreistündigen Erhitzen auf 200°C die sekundären Aminogruppen aus. Es entstehen neue Phosphinigsäureamide in annähernd äquivalenten Mengen.

In Nitrobenzol bildet sich mit Phosphinigsäureamiden ein Charge-Transfer-Komplex, der im Falle des optisch aktiven Ethyl-phenyl-phosphinigsäure-diethylamids 4 bereits bei Zimmertemperatur eine schnelle Racemisierung bewirkt.

Optisch aktives Ethyl-phenyl-phosphinigsäure-diethylamid 4 liefert als Co-Katalysator bei der Homogenhydrierung von α-Ethylstyrol mit (RhCl-Hexadien-1,5)₂ 2-Phenylbutan mit einer optischen Ausbeute von 34%.     

Reaktionen koordinierter Liganden. IX [1]. Reaktionen und Molekülstruktur von Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphan-P2)eisen(0) – einem Monosubstitutionsprodukt des Pentacarbonyleisens mit äquatorialem Phosphanliganden

Die Struktur von Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphan-P²)-eisen(0) ( I ) wurde röntgenographisch bestimmt. I kristallisiert in der Raumgruppe P1 . Es weist trigonal bipyramidale Koordination am Fe-Atom auf. Der Phosphanligand befindet sich in äquatorialer Position mit einem Fe? P? ;Abstand von 226,2(1) pm. Der mittlere Abstand Fe? C für die axial gebundenen CO-Gruppen beträgt 178,8(3) pm und unterscheidet sich nicht signifikant von dem für die äquatorial gebundenen CO-Gruppen. Die P? P? Abstände im Triphosphanliganden unterscheiden sich um 1,9 pm [225,6(2) und 223,7(1) pm]. Mit PtCl₂ bildet I einen Komplex ( III ) der Zusammensetzung (CO)₄FePPh(PPh₂)₂PtCl₂, in dem die terminalen Phosphoratome an das Platin koordiniert sind und einen viergliedrigen Ring bilden. Beim Erhitzen lagert sich I unter Wanderung der Fe(CO)₄-Einheit von der medialen in die terminale Position der Triphosphankette in den isomeren Komplex II um. Die Bestrahlung von I mit UV-Licht liefert als Hauptprodukte Ph₂P? PPh₂ und (CO)₄Fe? PPhH? PPh₂. Reactions of Coordinated Ligands. IX. Reactions and Molecular Structure of Tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphane-P²)iron(0) – a Monosubstitution Product of Pentacarbonyliron with an Equatorial Phosphane Ligand The structure of tetracarbonyl(1,1,2,3,3-pentaphenyltriphosphane-P²)iron(0) (I) was determined by X-ray analysis. The molecule displays a trigonal-bipyramidal coordination geometry at the iron atom with the phosphane ligand in an equatorial position and an Fe? P distance of 226.2(1) pm. The average Fe? C axial distance of 178.8(3) pm is not significantly different from that of 178.0(5) pm for the average Fe? C equatorial distance. A difference of 1.9 pm is observed between the two P? P distances [225.6(2) and 223.7(1) pm]. With PtCl₂ I yields a complex of composition (CO)₄FePPh(Ph₂P)₂PtCl₂ (III) in which the terminal phosphorus atoms of I are coordinated to platinum forming a four membered ring system. On heating, complex II , an isomer of I , is formed by migration of the Fe(CO)₄-unit from the medial to the terminal position within the triphosphane chain. Irradiation of I with UV light affords Ph₂P? PPh₂ and Fe(CO)₄? PPhH? PPh₂ as main products.