Beiträge zur Chemie des Phosphors. 217 [1]. Hexaisopropyl-octadecaphosphan(6), P18i-Pr6—Darstellung und kernresonanzspektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 217. Hexaisopropyloctadecaphosphane(6), P₁₈i-Pr₆ – Preparation and Structure Determination by Nuclear Magnetic Resonance Hexaisopropyl-octadecaphosphane(6) ( 1 ) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product, and has been purely isolated as a yellow solid. According to NMR-spectroscopic investigations, 1 contains a new conjuncto-phosphate skeleton consisting of a P₁₁(5)- and a P₉(5)-structural element analogous to that of brexane, joined through a common P₂-bridge. Thus, 1 is 5,7,8,14,16,18-hexaisopropyl-heptacyclo[13.2.1.0^2,13.0^3,11.0^4,9.0^6,10.0^12,17]octadecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1a and 1b , which probably differ from each other by inversion of the configuration at the (PR)₂-bridge of the P₉(5) partial structure analogous to that of brexane.     

Beiträge zur Chemie des Phosphors. 223. Hexaisopropyl-icosaphosphan(6), P20i-Pr6 — Darstellung und kernresonanz-spektroskopische Strukturbestimmung von zwei Konstitutionsisomeren

Contributions to the Chemistry of Phosphorus. 223. Hexaisopropylicosaphosphane(6), P₂₀i? Pr₆ — Preparation and Structure Determination of Two Constitutional Isomers by Nuclear Magnetic Resonance Hexaisopropyl-icosaphosphane(6) has been obtained by reaction of i-PrPCl₂ with P₄ and magnesium and subsequent thermolysis of the crude reaction product. The compound is formed as a mixture of two constitutional isomers 1 and 2 of equal abundance, which have been almost purely isolated by HPLC as a mixture of the diastereomers 1 a , 1 b and in the form of the separate configurational isomers 2 a and 2 b , respectively. According to NMR-spectroscopic investigations, the new conjuncto-phosphane skeletons of 1 and 2 consist of a P₁₃(5)- and a P₉(5)-structural element analogous to that of brexane and of two P₁₁(5)-partial skeletons, respectively, joined in each case through a common P₂-bridge. Thus, 1 is 6,7,9,16,17,20-hexaisopropyloctacyclo[10.8.0.0^2,14.0^3,11.0^4,8.0^5,10.0^13,18.0^15,19]icosaphosphane and 2 is 7,9,15,17,19,20-hexaisopropyl-octacyclo[14.2.1.1^5,8.0^2,14.0^3,12.0^4,10.0^6,11.0^13,18]icosaphosphane. The phosphorus hydrogen compound P₂₀H₆ [22, 2c] should exhibit the same constitutional isomerism.     

Beiträge zur Chemie des Phosphors. 212. Tetraisopropyl-dodecaphosphan(4), P12i-Pr4 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 212. Tetraisopropyldodecaphosphane(4), P₁₂i-Pr₄ – Preparation, Properties, and Molecular Dynamics According to an earlier crystal structure analysis, tetraisopropyldodecaphosphane(4) ( 1 ) exhibits the symmetry C₂, and the substituents are arranged in all-trans position [3]. We have now found by NMR spectroscopic studies that in solution a second configurational isomer of the symmetry C_S ( 1b ) exists in addition to the molecule present in the crystal ( 1a ). The transformation of 1a into 1b , which can only occur through a quasi synchronous inversion at the atoms P³ and P⁴ or P⁹ and P¹⁰, takes place at a noticeable rate already below room temperature.     

Beiträge zur Chemie des Phosphors. 230. Hexaisopropyl-tetradecaphosphan(6), P14i-Pr6, und Hexaisopropyl-hexadecaphosphan(6), P16i-Pr6 — Bildung und 31P-NMR-spektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 230. Hexaisopropyltetradecaphosphane(6), P₁₄i-Pr₆, and Hexaisopropylhexadecaphosphane(6), P₁₆i-Pr₆ — Formation and Structural Determination by ³¹P-NMR Spectroscopy Hexaisopropyltetradecaphosphane(6) ( 1 ) and hexaiso-propylhexadecaphosphane(6) ( 2 ) are formed together with other isopropylpolycyclophosphanes by the reaction of i-PrPCl₂ with P₄ and magnesium and have been enriched to 30 mol% and 10 mol%, respectively. According to ³¹P-NMR spectroscopic investigations, the novel conjuncto-phosphane skeletons of 1 and 2 are the annelation products of a P₅ ring with a P₁₁(5) or a P₁₃(5) partial skeleton, respectively, joined by a common P₂ bridge. Thus, 1 is 4,5,6,10,12,14-hexaisopropylpentacyclo-[9.2.1.0^2,9 .0^3,7 .0^8,13]tetradecaphosphane and 2 is 5,6,7,11,14,15-hexaisopropylhexacyclo[7.7.0.0^2,13 .0^3,10 .0^4,8 .0^12,16]hexadecaphosphane. The phosphorus hydrides P₁₄H₁₆ and P₁₆H₆ have the same skeletal structures which are also intermediate stages in the formation of Hittorf's phosphorus.     

Beiträge zur Chemie des Phosphors. 222. Pentaisopropyl-tridecaphosphan(5), P13i-Pr5– Struktur in Lösung und im Kristall

Contributions to the Chemistry of Phosphorus. 222. Pentaisopropyltridecaphosphane(5), P₁₃iPr₅ – Structure in Solution and in the Crystal In an earlier investigation [3] pentaisopropyltridecaphosphane(5) ( 1 ) had been obtained by reacting i-PrPCl₂, P₄ and magnesium and subsequently thermolysing the crude reaction product, but had been structurally characterized only incompletely. We have now corroborated the earlier postulated constitution by NMR spectroscopic studies and an X-ray structural analysis. Thus 1 is 3,4,7,10,11-pentaisopropyl-pentacyclo[7.4.0.0^2,6.0^5,13.0^8,12]tridecaphosphane. In solution two configurational isomers 1 a and 1 b exist in the relative abundance of about 2 : 1, which have the symmetry C₁ and C_s, respectively. When crystallizing pure 1 b precipitates, which at room temperature in solution is retransformed into the isomeric mixture 1 a , 1 b by inversion of the configuration. Any indications of an additional symmetric diastereomer have not been found. Obviously, in isomer 1 b the inversion barrier of the atom P⁷ is markedly higher than for the atoms of the two-atom bridges P³? P⁴ and P¹⁰? P¹¹, respectively.     

Beiträge zur Chemie des Phosphors. 200. Tetraisopropyl-tetradecaphosphan(4), P14(i-Pr)4 – Darstellung und strukturelle Charakterisierung

Contributions to the Chemistry of Phosphorus. 200. Tetraisopropyl-tetradecaphosphane(4), P₁₄(i-Pr)₄ – Preparation and Structural Characterization Tetraisopropyl-tetradecaphosphane(4) ( 1 ) has been obtained by reacting i-PrPCl₂, P₄, and magnesium and subsequently thermolysing the crude reaction product, and has been isolated in pure form. Whereas the ³¹P{¹H}-NMR spectrum provides only limited structural information, the ¹³C{¹H, ³¹P}-DEPT-NMR and the ¹H{³¹P}-NMR spectrum of 1 reveals the presence of two symmetrical configurational isomers 1a and 1c and one asymmetrical diastereomer 1b . This would only be possible, if 1 is 3,4,10,11-tetraisopropyl-hexacyclo[6.6.0.0^2,6.0^5,14.0^7,12.0^9,13]tetradecaphosphane. When crystallizing 1 pure 1a precipitates, which at +10°C in solution is retransformed into the isomeric mixture 1a , 1b , 1c by inversion of the configuration.     

Beiträge zur Chemie des Phosphors. 179. Triisopropyl-undecaphosphan(3), P11(i-Pr)3 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 179. Triisopropyl-undecaphosphane(3), P₁₁(i-Pr)₃ – Preparation, Properties, and Molecular Dynamics Triisopropyl-undecaphosphane(3) ( 1 ) has been obtained by reacting i-PrPCl₂, P₄, and magnesium and subsequently thermolysing the crude reaction product, and has been isolated in pure form. According to a two dimensional ³¹{¹H} n.m.r. spectrum 1 is a 4, 7, 11-triisopropylpentacyclo[6.3.0.0^2,6.0^3,10. 0^5,9]undecaphosphane. Compound 1 is formed as a mixture of two configurational isomers 1a and 1b , which differ from each other in the orientation of the isopropyl groups. When crystallizing pure 1b precipitates, which in solution is retransformed into the isomeric mixture 1a , 1b by inversion of the configuration.     

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 Siliciums und Germaniums. XXXIII [1]. Zur Darstellung von Kaliumsilyl

Reines, monoglyme- und kaliumhydridfreies, kristallines Kaliumsilyl wird aus Monosilan und Na/K-Legierung in Monoglyme unter Anwendung einer speziellen Art der Dosierung von Monosilan erhalten. Die analytische Charakterisierung der Verbindung ist durch Hydrolyse sowie durch Umsetzung mit Benzylchlorid und nachfolgende gaschromatographische Untersuchung des Reaktionsproduktes möglich. Löslichkeitsuntersuchungen von Kaliumsilyl in verschiedenen Solventien haben in Monoglyme eine zunehmende Löslichkeit mit abnehmender Temperatur ergeben. Die Leitfähigkeit einer Lösung von Kaliumsilyl in Monoglyme ist gemessen worden. Contributions to the Chemistry of Silicon and Germanium. XXXIII. On the Preparation of Potassium Silyl Pure, crystalline potassium silyl, free of glyme and potassium hydride, is prepared from monosilane and Na/K alloy, using a special method of dosing the monosilane. The substance was characterized by hydrolysis and by gaschromatographic investigation of the products from its reaction with benzyl chloride. Studying the solubility of potassium silyl in different solvents an increasing solubility in glyme is observed while the temperature is lowered. The conductivity of a solution of potassium silyl in glyme has been measured.     

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. 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. 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. 235. Zur Darstellung größerer Mengen von Diphosphan(4) im Laboratorium

Contributions to the Chemistry of Phosphorus. 235. On the Preparation of Larger Amounts of Diphosphane(4) in the Laboratory The preparation of several hundred grammes of diphosphane(4) by hydrolysis of calcium phosphide in a semicontinuous process as well as the handling of larger amounts of this compound are reported. In comparison with earlier results [12], the yield has been raised by 37 percent with simultaneous increase of the accessible total amount. The white solid which is formed in the preparation and purification of diphosphane(4) is not, as was believed in earlier work [25, 8], triphosphane(5) or another, novel phosphorus hydride but is rather a clathrate compound of diphosphane(4) or the phosphanes P_nH_n+2 (n = 2–4) and water, respectively.     

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. 233. Li3P7O3 und Li2HP7O2 – die ersten Oxido-heptaphosphane(3)

Contributions to the Chemistry of Phosphorus. 233. Li₃P₇O₃ and Li₂HP₇O₂ – the First Oxido Heptaphosphanes(3) The novel oxido heptaphosphanes(3) Li₃P₇O₃ ( 1 ) and Li₂HP₇O₂ ( 2 ) have been obtained by the reaction of trilithium heptaphosphide with cumene hydroperoxide. The compounds 1 and 2 are also formed from lithium pentaphosphacyclopentadienide and cumene hydroperoxide. They are sensitive to oxidation and are pale yellow solids whose structures have been elucidated by means of NMR and IR spectroscopic investigations. In each case, the oxygen atoms are bonded as lithiumoxido groups exocyclically to the heptaphosphanortricyclene skeleton.     

Beiträge zur Chemie des Phosphors. 236. Über einige physikalische und chemische Eigenschaften von Diphosphan(4)

Contributions to the Chemistry of Phosphorus. 236. On Several Physical and Chemical Properties of Diphosphane(4) The density of diphosphane(4) has been measured between ?78°C and +18°C and the value d₄²⁰ = 1.014 · 0.002 extrapolated. The refractive index of P₂H₄ was determined to be n²⁰ = 1.66 ± 0.01. The surface tension at 0°C and ?50°C was measured to be σ = 34 and 42 dyn · cm^?1, respectively. In the UV absorption spectrum, gaseous P₂H₄ exhibits a broad absorption band at λ_max = 2 220 Å, in n-hexane solution, this band is shifted somewhat to shorter wave-lengths. The molar extinction coefficient was determined to be ? ≈? 900 1 · mol^?1 · cm^?1. As a result of photolytic decomposition, absorptions for PH₃ and more phosphorus-rich hydrides also occur. The solubility behavior of P₂H₄ in various organic solvents and the stabilities of the resultant solutions have been investigated. At 0°C, the solubility of diphosphane(4) in water was found to be ± 035 ± 0.003 g P₂H₄/100 g solution and that of water in diphosphane(4) to be 43.2 ± 1.6 g H₂O/100 g solution. The system diphosphane(4)/methanol also exhibits a miscibility anomaly. The IR spectra of liquid P₂H₄ and of its solutions in various solvents revealed, in accord with the results of nuclear magnetic resonance spectroscopy [7], that diphosphane(4) is practically not associated. Weak interactions through hydrogen bridging bonds occur with pyridine and methanol in which P₂H₄ serves as the proton donor and, in the latter case, also as proton acceptor. For the thermolysis of diphosphane(4), it has been found that the primary step comprises a disproportionation with inter-molecular elimination of PH₃ and formation of triphosphane(5). With further progress of the thermolysis, in dependence on the reaction conditions, mixtures of various phosphanes of differing composition are formed. Photolysis gives rise to phosphane mixtures having similar compositions. With aqueous silver salt and iodine solutions, diphosphane(4) reacts as a reducing agent; with sodium hydroxide solution, it reacts by a slow disproportionation as well as by formation and degradation of the subsequently formed polyphosphides. On reaction with triphenylmethyl, triphenylmethane and a yellow solid of varying composition are formed. The reaction of diazomethane with diphosphane(4) leads to the preferential insertion of the carbene in the P? P bond and formation of methylenebis(phosphane).     

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. 231. Li3P7S3 und Li2HP7S2 — die ersten Sulfido-heptaphosphane(3)

Contributions to the Chemistry of Phosphorus. 231. Li₃P₇S₃ and Li₂HP₇S₂ — the First Sulfido Heptaphosphanes(3) The novel sulfido heptaphosphanes(3) Li₃P₇S₃ ( 1 ) and Li₂HP₇S₂ ( 2 ) have been obtained by the reaction of Li₃P₇ with sulfur in tetrahydrofuran under suitable conditions. The compounds 1 and 2 are also formed from LiP₅ and sulfur and are only stable in solution below room temperature. According to a complete analysis of the ³¹P{¹H}-NMR spectra, in each case, the sulfur atoms are bonded as sulfido groups exocyclically to the heptaphosphanortricyclene skeleton. Compound 2 reacts with chloro(trimethyl)silane or acetylacetone at one of the two sulfido groups while compound 1 does not form any product with retention of the P₇(3) framework.     

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. 157. Dilithium-hexadecaphosphid,Li2P16: Darstellung aus Li2HP7 und 31P-NMR-spektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 157. Dilithium Hexadecaphosphide, Li₂P₁₆: Preparation from Li₂HP₇ and Structure Determination by ³¹P-NMR Spectroscopy . Dilithium hexadecaphosphide, Li₂P₁₆ ( 1 ), is purely obtained as a crystalline solvent adduct Li₂P₁₆ · 8 THF by the disproportionation of Li₂HP₇ in tetrahydrofuran under suitable conditions. The constitution of 1 has been deduced from its 1D- and 2D-³¹P-NMR spectrum (in dimethylformamide). The structure of the P₁₆^2? ion in solution is identical with that in solid (Ph₄P)₂P₁₆ [20]. As a conjuncto-phosphane the P₁₆^2? is made up of two P₉(3)^?-unit groups analogous to deltacyclane, which are linked via the diatomic bridges as a common zero-bridge.