Beiträge zur Chemie des Phosphors. 142. P6(t-Bu)5H – das erste Cyclotetraphosphan mit P2-Seitenkette

Contributions to the Chemistry of Phosphorus. 142. P₆(t-Bu)₅H – the First Cyclotetraphosphane with a P₂ Side Chain The thermolysis of 1, 2-di-tert-butyldiphosphane, H(t-Bu)P? P(t-Bu)H, leads to formation of the hitherto unknown hexaphosphane P₆(t-Bu)₅H ( 1 ). In the first instance the iso-P₅H₅ derivative P₅(t-Bu)₄H [3] is formed, which reacts further with H₂(t-BuP)₂ or H₂(t-BuP)₃ yielding 1 . Compound 1 has been isolated in the pure state and structurally characterized as 1-(1,2-di-tert-butyldiphosphino)-2, 3, 4-tri-tert-butyl-cyclotetraphosphane, i. e. as a four-membered ring compound with a P₂ side chain. Due to the chirality of the P atoms in the side chain, 1 exists as a mixture of two configurational isomers, the threo-and the erythro-form.     

Beiträge zur Chemie des Phosphors. 225 [1, 2] Lithium-pentahydrogenoctaphosphid

Contributions to the Chemistry of Phosphorus. 225. Lithium Pentahydrogen Octaphosphide Lithium pentahydrogen octaphosphide, LiH₅P₈ ( 1 ), belongs to the first reaction products of the metallation of P₂H₄ with n-butyllithium to be detected. Compound 1 is also formed in the reactions of the tricyclic heptaphosphide Li₃P₇ or the monocyclic pentaphosphide LiH₄P₅ with P₂H₄. In all cases, LiH₄P₇, LiH₈P₇, and further not yet identified polyphosphides are formed additionally. The composition and the structure of 1 have been elucidated by ³¹P-NMR studies, above all a complete analysis of its low-temperature ³¹P{¹H}-NMR spectrum. Hence, compound 1 is 7-lithium-2,5,6-trihydrogen-3-phosphino-bicyclo[2.2.1]heptaphosphide and has a norbornane-type P₇ skeleton. At room temperature 1 decomposes to furnish more phosphorus-rich lithium polyphosphides.     

Beiträge zur Chemie des Phosphors. 138. P5(t-Bu)4H – das erste Derivat von iso-P5H5

Contributions to the Chemistry of Phosphorus. 138. P₅(t-Bu)₄H — the First Derivative of iso-P₅H₅ The thermolysis of 1,2-di-tert-butyldiphosphane, H(t-Bu)P? P(t-Bu)H, yields under suitable conditions the compound P₅(t-Bu)₄H ( 1 ) as the main product. Besides, the tert-butylphosphanes t-BuPH₂, P₆(t-Bu)₅H ( 2 ), H₂(t-BuP)₃, and (t-BuP)₄ are formed. 1 has been isolated in the pure state and structurally characterized as 1-(tert-butylphosphino)-2,3,4-tri-tert-butyl-cyclotetraphosphane. Hence, compound 1 is a derivative of iso-P₅H₅ with a branched phosphorus skeleton built up by a four-membered ring and a phosphorus side chain.     

Beiträge zur Chemie des Phosphors, 45. Triphenyl-cyclotriphosphan - ein Derivat des P3H3

Contributions on the chemistry of phosphorus. 45. Triphenyl cyclotriphosphane - a derivative of P₃H₃ Triphenyl-cyclotriphosphane-dipotassium ( 2 ) can be prepared without solvent by metallation of pentaphenyl-cyclopentaphosphane ( 3 ) with the stoichiometric amount of potassium in benzene, moreover by precipitation of the corresponding reaction solution in tetrahydrofuran with toluene or petroleum ether. However, 2 · THF is formed when the solvent is removed completely, 2 or 2 · THF react with iodine at - 78°C to give the compounds K₂(C₆H₅P)₃ (4) or 4 · THF. These decompose in solution under formation of potassium iodide and triphenyl-cyclotriphosphane ( 1 ), not described before. 1 could be isolated in a pure state. It differs from 3 by its characteristic melting behaviour and the osmometric molecular weight, but especially by the i.r. and mass spectrum. 1 is stable at ? 20 °C for several weeks, but rearranges easily to give the more stable 3 , especially at somewhat higher temperatures.     

Beiträge zur Chemie des Phosphors. 183. Lithium-tetrahydrogenheptaphosphid und Lithium-octa-hydrogenheptaphosphid

Contributions to the Chemistry of Phosphorus. 183. Lithium Tetrahydrogen Heptaphosphide and Lithium Octahydrogen Heptaphosphide Lithium tetrahydrogen heptaphosphide, LiH₄P₇ ( 1 ), and lithium octahydrogen heptaphosphide, LiH₈P₇ ( 2 ), belong to the first reaction products of the metalation of P₂H₄ with n-butyllithium that can be identified. Both compounds are also formed on reaction of Li₃P₇ with excess P₂H₄. 1 also results from the reaction of LiH₄P₅ with P₂H₄. Whereas 1 can be isolated as an orange-red crystalline solvent adduct in a purity of 60-70 per cent, 2 cannot be enriched further due to its extreme reactivity. The composition and the structure of 1 and 2 have been elucidated from their ³¹P-NMR spectra. Hence, 1 has a P₇ skeleton analogous to that of norbornane, whereas 2 as a precursor in the formation of 1 from P₂H₄ and n-BuLi is an open-chain doubly branched heptaphosphide.     

Beiträge zur Chemie des Phosphors. XXXIX. Zur Hydrolyse des Diphosphor-tetrajodids

In the preparation of Ba₂H₂(H₂P₂O₄)₃ by P₂I₄ hydrolysis in barium acetate/acetic acid buffer solution P(II)—P(IV), P(IV)—P(IV), P(III), and P(V) acid are formed in addition to about 17% of the starting phosphorus as P(II)—P(II) acid after separating the Ba₂H₂(H₂P₂O₄)₃. Thus in this reaction a total of 64% of P₂I₄ Phosphorus can be detected as hypodiphosphorous acid H₄P₂O₄. The precipitated yellow reaction product, obtained by water hydrolysis of P₂I₄, contains no solid phosphorus hydride — as believed previously — but as a result of elementary analysis, iodometry, and chromatography, a high molecular-weight phosphorus, hydrogen and oxygen containing substance of statistical stoichiometry with oxydation number ～0 for phosphorus. P? H, P?O, and P? O? P groups could be detected by IR-spectroscopy, but not P? OH groups. The P₂I₄ hydrolysis probably proceeds via a yellow coloured initial product with trivalent phosphorus, and yields a very complex reaction mixture in which also the intermediates partially still react further.     

Beiträge zur Chemie des Phosphors. 111. 1,2-Dichlor-1,2-di-tert-butyldiphosphan

Contributions to the Chemistry of Phosphorus. 111. 1,2-Dichloro-1,2-di-tert-butyl-diphosphane The reaction of tri-tert-butyl-cyclotriphosphane, (t-BuP)₃, with phosphorus(V) chloride (molar ratio 1:2) leads to the title compound Cl(t-Bu)P? P(t-Bu)Cl ( 1 ), which is remarkably stable against disproportionation reactions. As the first 1,2-dichloro-1,2-diorganyldiphosphane, 1 has been isolated in a pure state and was thoroughly characterized. At room temperature, 1 exists in a mixture of the d,l and meso form (about 20:80). The mutual repulsion of the negative polarized Cl atoms and their preferred gauche arrangement to the free electron pairs of neighboured P atoms leads to a gauche-conformation of the lone electron pairs in the d,l- and to a trans-conformation in the meso-configuration.     

Beiträge zur Chemie des Phosphors. 181 [1, 2]. Dinatrium-hydrogenhenicosaphosphid Na2HP21

Contributions to the Chemistry of Phosphorus. 181. Dinatrium Hydrogen Henicosaphosphide Na₂HP₂₁ The hydrogen henicosaphosphide Na₂HP₂₁ ( 2 ) has been obtained as the final product in the reaction of trisodium henicosaphosphide, Na₃P₂₁ ( 1 ), with acetylacetone or glacial acetic acid. The attack of the proton occurs at the phosphide P atom of the P₇(5)? middle group analogous to norbornane, the site of greatest nucleophilicity of the P₂₁^3? ion. The basicity of the HP₂₁^2? ion toward the above-mentioned protonating agents is not sufficient for the formation of P₂₁H₃; a rearrangement of the P₂₁(3) skeleton takes place on reaction with stronger acids.     

Beiträge zur Chemie des Phosphors. 43. Gaschromatographische Trennung von Phosphanen

Monophosphane (PH₃), diphosphane (P₂H₄), and triphosphane-5 (P₃H₅) could be separated in mixtures by isothermal gas chromatography. On the basis of the experiences hereby obtained, further gas chromatographic separations were carried out with a programmed temperature mode. For the identification of the chromatographic peaks a mass spectrometer as a second detector was applied. In the temperature range from ?60°C to +60°C, it was possible for the first time to separate mixtures of diphosphane and higher phosphanes without any decomposition in the gas chromatographic column. Besides monophosphane and diphosphane, triphosphane-3 (P₃H₃), triphosphane-5 (P₃H₅), and tetraphosphane-6 (P₄H₆) could be eluated as undecomposed components. By this, a fundamental basis for the application of gas chromatography to the quantitative analysis of mixtures of phosphanes and to the development of a gas chromatographic method for the preparative isolation of individual higher phosphanes has been established.     

Beiträge zur Chemie des Phosphors. 240 [1]. Zum reaktiven Verhalten von Diphosphan-boran,P2H4 · BH3

Contributions to the Chemistry of Phosphorus. 240. On the Reactive Behaviour of Diphosphane-borane, P₂H₄ · BH₃ Under mild temperature conditions, the thermal decomposition of diphosphane-borane ( 1 ) gives rise to the formation of phosphane-borane, PH₃ · BH₃, and triphosphane-2-borane, PH₂? PH(BH₃)? PH₂ ( 2 ). In the presence of diphosphane-1,2-bis(borane), triphosphane-1,3-bis(borane), BH₃? PH₂? PH? PH₂? BH₃ ( 3 ), is formed additionally. The thermolysis product at room temperature is a polymeric solid of varying composition which contains phosphorus, boron, and hydrogen. Compound 1 reacts with metalating agents such as n-BuLi, LiBH₄, and NaBH₄ to furnish the borane-trihydrogendiphosphide ion, [PH₂? PH? BH₃]^?, which immediately disproportionates to give the corresponding mono-and triphosphane derivatives. In the presence of an excess of THF-borane and in the case of a 1 : 1 molar ratio of 1 : NaBH₄, the disproportionation does not occur and the new diphosphide derivative sodium-1,1,2-tris(borane)-1,2,2-trihydrogendiphosphide, Na[(BH₃)₂PH? PH₂BH₃] ( 4 ) can be obtained. The action of additional NaBH₄ yields the diphosphide dianion with four coordinated BH₃ groups.     

Beiträge zur Chemie des Phosphors. 87. 1,2-Di-tert-butyl-3-iso-propyl-cyclotriphosphan,ein stabiles gemischt-substituiertes Cyclotriphosphan

Contributions to the Chemistry of Phosphorus. 87. 1,2-Di-tert-butyl-3-iso-propyl-cylclotriphosphane, a Stable Mixed-substituted Cyclotriphosphane The first kinetically stable mixed-substituted cyclotriphosphane, 1,2-di-tert-butyl-3-iso-propyl-cyclotriphosphane, (PBu^t)₂(PPrⁱ) ( 1 ), was synthesized by [2+1]-cyclocondensation of K(Bu^t)P–P(Bu^t)K with PrⁱPCl₂ in n-pentane. Mainly (PBu^t)₄ as well as mixed-substituted cyclotetra- and cyclopentaphosphanes are formed as by-products. 1 could be isolated in a pure state by high vacuum distillation and was thoroughly characterized. It forms two diastereomers, the more stable of which with a cis-standing tert-butyl and iso-propyl group can be stored without decomposition under inert conditions at room temperature for several days. Through thermolysis of 1 beside other alkylcyclophosphanes the mixed-substituted cyclotetraphosphanes (PBu^t)₂(PPrⁱ)₂ ( 2 ) and (PBu^t)₃(PPrⁱ) ( 3 ) are formed and their ³¹P NMR parameters are reported.     

Beiträge zur Chemie des Phosphors. 143. Li4P26 und Na4P26, die ersten Salze mit Hexacosaphosphid(4−)-Ionen

Contributions to the Chemistry of Phosphorus. 143. Li₄P₂₆ and Na₄P₂₆, the First Salts with Hexacosaphosphid(4?) Ions The hexacosaphosphides Li₄P₂₆ ( 1 ) and Na₄P₂₆ ( 2 ) are formed besides other polyphosphides in the reaction of white phosphorus with lithium dihydrogenphosphide or sodium. 1 also results from the decomposition of Li₂HP₇ in tetrahydrofuran at room temperature and can be obtained pure as a crystalline solvent adduct Li₄P₂₆ · 16 THF. According to 2D?³¹P-NMR spectroscopic investigations the P₂₆^4? ion is a conjucto-phosphane of two P₇(5)^?-and two P₉(3)^?-unit groups with structures analogous to norbornane and deltacyclane, respectively.     

Beiträge zur Chemie des Phosphors. 119. Tri-isopropyl-cyclotriphosphan, (i-PrP)3, und Tri-sec-butyl-cyclotriphosphan, (s-BuP)3

Contributions to the Chemistry of Phosphorus. 119. Tri-isopropyl-cyclotriphosphane, (i-PrP)₃, and Tri-sec-butyl-cyclotriphosphane, (s-BuP)₃ The dehalogenation of isopropyldichlorophosphane and sec-butyldichlorophosphane with magnesium leads to the title compounds (i-PrP)₃ ( 1 ) and (s-BuP)₃ ( 2 ) respectively. The corresponding cyclotetraphosphanes, and in the case of 1 also (i-PrP)₅, are formed as by-products. 1 and 2 are relatively stable triorganyl-cyclotriphosphanes. They were isolated in a pure state and have been fully characterized. Due to the chiral P-bonded carbon atoms 2 forms four diastereomers, which could be identified by NMR spectroscopy.     

Beiträge zur Chemie des Phosphors. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphan,P6BuO2

Contributions to the Chemistry of Phosphorus. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, P₆Bu O₂ Under suitable conditions, the reaction of tetra-tert-butylhexaphosphane, P₆Bu ( 1 ), with cumene hydroperoxide gives rise to the corresponding dioxide P₆BuO₂ ( 3 ) which could be isolated as the adduct P₆BuO₂ · 0.7 C₉H₁₂O₂. According to a complete analysis of the ³¹P{¹H}-NMR spectrum compound 3 is 2,3,4,6-tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, in which the oxygen atoms are bonded exocyclically to the five-membered phosphorus ring of 1 . When the oxidation reaction proceeds a fission of the bicyclic P₆ skeleton takes place.     

Beiträge zur Chemie des Phosphors. 106. Synthese und Eigenschaften des Diphosphacyclopropans (t-BuP)2CHMe

Contributions to the Chemistry of Phosphorus. 106. Synthesis and Properties of the Diphosphacyclopropane (t-BuP)₂CHMe The new 1,2-di-tert-butyl-3-methyl-1,2-diphosphacyclopropane (1,2-di-tert-butyl-3-methyl-diphosphirane), (t-BuP)₂CHMe ( 1 ), is obtained by reacting K(t-Bu)P? P(t-Bu)K with 1,1-dichloroethane under suitable conditions. 1 can be isolated by high vacuum distillation and is stable for months when stored under inert gas at room temperature. Particularly, no dimerization to the corresponding 1,2,4,5-tetraphosphacyclohexane takes place. The NMR parameters indicate an increase of the exocyclic bond angles compared to (t-BuP)₂CH₂. The signs of all CP coupling constants have been determined by spin tickling experiments. The ²J(CCP)-coupling of the methyl group at the ring carbon depends strongly on the dihedral angle.     

Beiträge zur Chemie des Phosphors. 245 [1], LiP7(BNEt2)2 und P7(BNEt2)4Cl: Zwei neuartige polycyclische Boraphosphane

Contributions to the Chemistry of Phosphorus. 245, LiP₇(BNEt₂)₂ and P₇(BNEt₂)₄Cl: Two Novel Polycyclic Boraphosphanes The directed synthesis of a noval tetracyclic heteropolyphosphane skeleton from a tricyclophosphane has been achieved by condensation of Li₃P₇ · 3DME with Cl(Et₂N)B‐B(NEt₂)Cl to the diboranonaphosphanide LiP₇(BNEt₂)₂ ( 1 ). When the reaction proceeds the mixed‐substituted diboranonaphosphane P₇(BNEt₂)₄Cl ( 2 ) is formed. According to their ³¹P NMR spectra 1 and 2 possess a B₂P₇(3) skeleton analogous to that of the hydrocarbon deltacyclane. Additional weak signals in the ³¹P NMR spectrum of 2 indicate that also small amounts of the symmetrically substituted diborane(4) P₁₄B₆(NEt₂)₆ ( 3 ) are formed.     

Beiträge zur Chemie des Phosphors. 168 [1]. Zur Kenntnis der Isomere von Tetraphosphan(6), P4H6

Contributions to the Chemistry of Phosphorus. 168. About the Isomers of Tetraphosphane(6), P₄H₆ Additional informations about the ³¹P-NMR parameters of d,l- and meso-n-P₄H₆ as well as of iso-P₄H₆ have been obtained by ³¹P-NMR spectroscopic investigations of mixtures of phosphanes containing 26—48 P-% of tetraphosphane(6). On the basis of the differences in the ³J(PP)-coupling constants the observed AA′BB′-spin systems have been reassigned to the various diastereomers of n-P₄H₆.     

Beiträge zur Chemie des Phosphors. 219 [1]. Tetraisopropyl-octadecaphosphan(4), P18i-Pr4 – Darstellung und kernresonanzspektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 219. Tetraisopropyloctadecaphosphane(4), P₁₈i-Pr₄ — Preparation and Structure Determination by Nuclear Magnetic Resonance Tetraisopropyloctadecaphosphane(4) ( 1 ) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product, and has been isolated in 95% purity. According to NMR-spectroscopic investigations, 1 contains a conjuncto-phosphane skeleton consisting of a P₁₁(5)- and a P₉(3)-structural element analogous to that of deltacyclane, joined through a common P₂-bridge. Thus, 1 is 8,14,16, 18-tetraisopropyloctacyclo[13.2.1.0^2,13.0^3,11.0^4,9.0^5,7.0^6,10.0^12,17]octadecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1 a and 1 b , which differ from each other in their spatial arrangements of the isopropyl group at P₈.     

Beiträge zur Chemie des Phosphors. 167 [1, 2]. Konstitutions- und Konfigurationsisomere von Pentaphosphan(7), P5H7

Contributions to the Chemistry of Phosphorus. 167. Constitutional and Configurational Isomers of Pentaphosphane(7), P₅H₇ Phosphane mixtures containing 10—15 P-% of pentaphosphane(7), P₅H₇, are obtained by thermolysis of diphosphane, P₂H₄, or as residue from distillation of crude diphosphane [3]. According to the complete analysis of the ³¹P{¹H}-NMR spectrum on the basis of selective population transfer experiments, P₅H₇ exists as a mixture of three diastereomers of n-P₅H₇ — 1a (erythro, erythro), 1b (erythro, threo), 1c (threo, threo) — and of the constitutional isomer 2-phosphinotetraphosphane 2 (iso-P₅H₇, largest relative isomeric abundance). The correlation between the diastereomers and the observed spin systems results from the preferred gauche orientation of neighboring free electron pairs, the dependence of ¹J(PP) on dihedral angles, and the ³J(PP) long range couplings. From the ³¹P-NMR data of the phosphane molecules P_nH_n+2 with n = 1—5 general relationships for the δ(³¹P) values and the ¹J(PP) coupling constants of chain-type phosphorus hydrides as a function of their structural parameters are derived.     

Beiträge zur Chemie des Phosphors. 128. Synthese des Diphosphastanna-cyclopropans (t-BuP)2Sn(t-Bu)2

Contributions to the Chemistry of Phosphorus. 128. Synthesis of the Diphosphastanna-cyclopropane (t-BuP)₂Sn(t-Bu)₂ The first three-membered P₂Sn heterocycle, 1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastanna-cyclopropane (1,2,3,3-tetra-tert-butyl-1,2,3-diphosphastannirane) ( 1 ), has been synthesized by [2+1] cyclocondensation of K(t-Bu)P—P(t-Bu)K with (t-Bu)₂SnCl₂. 1 is stable at room temperature. Besides, (t-BuP)₂[Sn(t-Bu)₂]₂ ( 2 ), (t-BuP)₄Sn(t-Bu)₂ ( 3 ), and (t-BuP)₄ are formed. In the reaction with Et₂SnCl₂, the six-membered ring compound [(t-BuP)₂SnEt₂]₂ ( 4 ) is the main-product; the four- and five-membered cyclostannaphosphanes (t-BuP)₃SnEt₂ ( 5 ) and (t-BuP)₃(SnEt₂)₂ ( 6 ) are also formed. 1 could be isolated in the pure state and has been unambiguously characterized as a three-membered heterocycle with a P₂Sn skeleton. The ³¹P-NMR parameters of the other new cyclostannaphosphanes 2–6 are reported.