Beiträge zur Chemie des Phosphors. 105. 1,2,3,4-Tetraphenyl-1,4-bis(trimethylsilyl)-tetraphosphan und 1,2,3,4-Tetraphenyltetraphosphan

Contributions to the Chemistry of Phosphorus. 105. 1,2,34-Tetraphenyl-1,4-bis(trimethylsilyl)-tetraphosphane and 1,2,3,4-Tetraphenyltetraphosphane 1,2,3,4-Tetraphenyl-1,4-bis(trimethylsilyl)-tetraphosphane, Me₃Si? (PPh)₄? SiMe₃ ( 1 ), is obtained by reacting K₂(PPh)₄ with trimethylchlorosilane under suitable conditions. Compound 1 disproportionates almost easier than the corresponding triphosphane (Me₃Si)₂(PPH)₃. Of the six possible diastereomers only 1a (erythro, meso, erythro), 1b (erythro, d,l, erythro), 1 d (threo, d,l, threo), and 1 f (erythro, threo, threo) can be detected in solution by ³¹P-NMR spectroscopy. In consequence of rapid inversion at the P atoms a dynamic equilibrium exists between the different isomers. The assignment of the ³¹P-NMR-spectroscopically observed spin systems to the corresponding diastereomers results from the dependence of the ¹J_PP-coupling constants on the dihedral angle between vicinal free electron pairs as well as on the observed frequency distribution. In the alcoholysis of 1 the corresponding hydride H? (PPh)₄? H ( 2 ) is formed as the main product. It could be isolated in spite of its instability. At room temperature 2 disproportionates rapidly forming mainly (PPh)₄ and H₂(PPh)₂ (ratio 1:2) at first; later on also H₂(PPh)₃, H₂PPh, and (PPh)₅ are found. The corresponding rearrangements follow a four-center mechanism involving predominantly P? P bonds.     

Beiträge zur Chemie des Schwefels. 114. Kristall- und Molekülstrukturen vom Hexathiepan (S6CH2), Pentathian (S5CH2) und Dibenzylpentathian (S5C(CH2C6H5)2)

Contributions to the Chemistry of Sulfur. 114. Crystal and Molecular Structures of Hexathiepane (S₆CH₂), Pentathiane (S₅CH₂), and Dibenzylpentathiane (S₅C (CH₂C₆H₅)₂) The crystal and molecular structures of hexathiepane 1 , pentathiane 2 and dibenzylpentathiane 3 were determined by single crystal X-ray structure analyses. 1 : Monoclinic space group P2₁/c; a = 7.694(4), b = 7.668(4), c = 12.367(6) Å, β = 108.9(1)°; Z = 4, d_calc. = 1.986 g/cm₃. The seven-membered heterocycle exists in twist-conformation. 2 : Monoclinic space group C2/c; a = 10.990(5), b = 6.872(4), c = 15.507(6) Å, β = 94.1(1)°; Z = 8, d_calc. = 1.982 g/cm₃. The six-membered heterocycle exists in chair-conformation. 3 : Monoclinic space group P2₁/c; a = 12.907(8), b = 13.611(8), c = 9.408(6) Å, β = 98.9(1)°; Z = 4, d_calc. = 1.442 g/cm₃. 3 is analogous to 2 a six-membered heterocycle with chair-conformation. The benzylic groups are distorted to each other. Bond lengths, bond angles, and dihedral angles of the heterocyclic sulfur rings arc discussed, especially with regard to a comparison with cyclohexasulfur, cycloheptasulfur. and cyclooctasulfur.     

Beiträge zur Chemie des Hydrazins und seiner Derivate. 52. Kristall- und Molekülstrukturen der tert.-Butyloxycarbonylderivate von Cyclotetraschwefeldihydrazid und Cyclohexaschwefelhydrazid

Contributions to the Chemistry of Hydrazine and its Derivatives. 52. Crystal and Molecular Structures of the tert.-Butyloxycarbonyl Derivatives of Cyclotetrasulfurdihydrazide and Cyclohexasulfurhydrazide The structures of the tert.-butyloxycarbonyl derivatives of cyclotetrasulfurdihydrazide and cyclohexasulfurhydrazide were determined by X-ray analyses. Both sulfur(II)-nitrogen rings exist in crown conformation and contain only sp²-hybridized nitrogen atoms. Bond lengths, bond angles, and dihedral angles are discussed.     

Beiträge zur Chemie des Phosphors. 67. Zur Kenntnis der Cyclotriphosphane (PC6H5)3, (PC6H5)2(PC2H5) und (PC6H5)2(PCH3)

Contributions to the Chemistry of Phosphorus. 67. About the Cyclotriphosphanes (PC₆H₅)₃, (PC₆H₅)₂(PC₂H₅), and (PC₆H₅)₂(PCH₃) The reaction of (CH₃)₃Si(C₆H₅)P? P(C₆H₅)Si(CH₃)₃ with RPCl₂ (R = C₆H₅, C₂H₅, CH₃) yields the cyclotriphosphanes (PC₆H₅)₃ 1 , (PC₆H₅)₂(PC₂H₅) 3 , and (PC₆H₅)₂(PCH₃) 4 , respectively. Besides, the corresponding homo- and mixed-substituted cyclotetraphosphanes, cyclopentaphosphanes, and cyclohexaphosphanes are formed. The relative concentrations of the cyclotriphosphanes in the reaction mixtures decrease continuously, whereas those of the cyclopentaphosphanes increase. The reasons for these ring-interconversion reactions of the cyclophosphanes (PR)_n are discussed. The cyclotriphosphanes 1, 3 , and 4 are characterized by ³¹P chemical shifts between +130 and +160 ppm that are at considerable high field compared to open-chain triphosphanes and cyclophosphanes of different ring-size. The substituents R are situated on both sides of the P₃-ring plane, thus giving rise to two diastereomers of 3 that are observed simultaneously in the statistically expected ratio. The ³¹P n.m.r. parameters of 1 and 3 are reported and discussed.     

Beiträge zur Chemie des Schwefels. 115. Kristall- und MolekülStruktur von Benzopentathiepin

Contributions to the Chemistry of Sulfur. 115. Crystal and Molecular Structure of Benzopentathiepine The structure of benzopentathiepine has been determined from three-dimensional single-crystal X-ray data. The crystal are monoclinic, space group P2₁/c, with 4 molecules in the unit cell of dimensions a = 6.942(4) Å, b = 10.223(10) Å, c = 13.015(8) Å, β = 102,15(10)°. The conformation of the seven-membered ring is the chair form. Details of the conformation are discussed. Bond distances, bond angles, and dihedral angles are compared with those in other molecules, which have similar structure.     

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. 72. Über die Alkyl-cyclomonocarba-phosphane (PR)4CH2, R = CH3, C2H5, t-C4H9

Contributions to the Chemistry of Phosphorus. 72. About the Alkyl Cyclomonocarba Phosphanes (PR)₄CH₂, R = CH₃, C₂H₅, t-C₄H₉ The alkyl-substituted cyclomonocarbaphosphanes (PR)₄CH₂ (R = CH₃ 1 , C₂H₅ 2 , t-C₄H₉ 3 ) are obtained in very good yield by the reaction of the corresponding dipotassium alkylphosphides K₂(PR)_n (n = 2, 3, 4) with methylene chloride. Besides, small amounts of the homocyclic rings characteristic for the given substituent and of the five-membered cyclodicarbaphosphanes (PR)₃(CH₂)₂ with isolated CH₂ groups are formed. For the alkylcyclomonocarbaphosphanes 1 and 2 , configuration isomers could be identified for the first time. The “all-trans” forms are always predominant; the relative amounts of the other isomers decrease strongly with increasing number of cis relationships between the substituents at adjacent phosphorus atoms. The ³¹P n.m.r. parameters for three of the all together six isomers of 1 distinguishable by n.m.r. spectrometry and for the “all-trans” isomers of 2 and 3 are reported and discussed. A definite separation is possible between substituent and configuration influence on the chemical shifts as well as on the coupling constants.     

Beiträge zur Chemie des Hydrazins und seiner Derivate. 56. Kristall- und Molekülstruktur von 1,2-Hydrazindicarbonsäure-diäthylester

Contributions to the Chemistry of Hydrazine and its Derivatives. 56. Crystal and Molecular Structure of Diethyl 1,2-Hydrazinedicarboxylate The structure of Diethyl 1,2-Hydrazinedicarboxylate 1 was determined by an X-ray analysis. 1 crystallizes in the monoclinic space group C2/c with a = 13.279 Å, b = 8.746 Å, c = 7.646 Å, β = 97.30°; Z = 4, d_calc. = 1.328 g/cm³. The molecules contain a 2-fold rotation axis perpendicular to the N? N bond and consist of two planar halfs which are arranged nearly perpendicular to each other. The molecular data and in the crystal existing CO …? HN hydrogen bonds are discussed.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 11. Die Kristall- und Molekülstrukturen der beiden Konfigurationisomeren des Tetraphospha-silaspiro[2.2]pentans (PBut)2Si(PBut)2

Structural Chemistry of Phosphorus Containing Chains and Rings. 11. Crystal and Molecular Structures of the Two Stereoisomers of Tetraphospha-silaspiro[2.2]pentane (PBu^t)₂Si(PBu^t)₂ The spirocyclic compound 1,2,4,5-tetra-tert-butyl-1,2,4,5-tetraphospha-3-silaspiro[2.2]pentane exists in tow diastereomers of point symmetry 4 and 2. The isomer with symmetry 4 even in the solid crystallizes tetragonally in I4₁/a with a = 1247.0, c = 1505.5 pm and Z = 4. The isomer of fairly exact symmetry 2 crystallizes triclinically in P1 with a = 612.8, b = 996.3, c = 1017.2 pm, α = 75.63, β = 72.38, γ = 88.71° and Z = 1. In this disordered structure the surroundings of Si is slightly distorted due to the influence of the substituents. The (average) bond lengths are (4 , 2): d(Si? P) = 220.09(9), 221.5(5); d(P? P) = 225.5(2), 224.2(5); d(P? C) = 189.4(3), 190(2); d(C? C) = 151.4(4), 152(3) pm. The geometry of the substituents in both isomers is quite normal.     

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. 151. Dilithium-dihydrogentetradecaphosphid,Li2H2P14: Darstellung und strukturelle Charakterisierung

Contributions to the Chemistry of Phosphorus. 151. Dilithium Dihydrogen Tetradecaphosphide, Li₂H₂P₁₄: Preparation and Structural Characterization Dilithium dihydrogentetradecaphosphide, Li₂H₂P₁₄ ( 1 ), is obtained as an orange-red solvent adduct Li₂H₂P₁₄ · 6 THF in a purity of 80–90 per cent by reacting P₂H₄ with n-BuLi under suitable conditions. 1 is also formed in the reaction of Li₃P₇ or LiH₄P₅ with P₂H₄, and in the disproportionation of LiH₄P₇. According to its 2D-³¹P-NMR spectrum 1 is a conjuncto-phosphane built up by one P₇(5)^?- and one P₉(3)^?-unit group with structures analogous to norbornane and delta-cyclane, respectively.     

Beiträge zur Strukturchemie phosphorhaltiger Ketten und Ringe. 2. Die Kristall- und Molekülstruktur des Diphosphaborirans (t-BuP)2BNEt2

Structural Chemistry of Phosphorus-containing Chains and Rings. 2. Crystal and Molecular Structure of the Diphosphaborirane (t-BuP)₂BNEt₂ The three-membered P₂B-heterocycles 1,2-di-tert-butyl-3-diethylamino-1,2,3-diphosphaborirane, (t-BuP)₂BNEt₂, crystallizes triclinic in the space group P1 with a = 935.5 pm, b = 985.4 pm, c = 987.4 pm,α = 81.55°, β = 89.40°, γ =69.07°, and Z = 2 formula units. The main structural feature is a short B? N-bond length (138.2 pm) inside a plane P₂BN-group. The endocyclic bond angles are 54.0° on phosphorus and 72.0° on boron. The (average) bond lengths are P? P = 222.5 pm, P? C = 189.5 pm, P? B = 189.3 pm, B? N = 138.2 pm, N? C = 147.2 pm, C? C = 152.6 pm, and C? H = 98 pm. The geometry of the substituents ethyl and tert-butyl is quite normal.     

Beiträge zur Chemie des Phosphors. 169. 31P-NMR-spektroskopischer Nachweis und Struktur von Hexaphosphan(6), P6H6

Contributions to the Chemistry of Phosphorus. 169. ³¹P-NMR Spectroscopic Detection and Structure of Hexaphosphane(6), P₆H₆ Phosphane mixtures containing 5–10 P-% of hexaphosphane(6), P₆H₆, are obtained by thermolysis of a mixture of chain-type phosphorus hydrides P_nH_n+2 (n = 2–7) at 25–35°C. According to the complete analysis of the ³¹P{¹H}-NMR spectrum on the basis of selective population transfer experiments, P₆H₆ has the constitution of 1-phosphino-cyclopentaphosphane. An indication of the constitutional isomer with a six-membered phosphorus-ring and all trans orientation of the hydrogen atoms and the free electron pairs, respectively, has not been found. From the δ(³¹P) data of the phosphanes with five-membered rings P_nH_n (n = 5, 6) a relationship for the chemical shifts of this class of compounds as a function of their structural parameters is derived.     

Triorganoantimon- und Triorganobismutdisulfonate Kristall- und Molekülstrukturen von (C6H5)3M(O3SC6H5)2 (M = Sb,Bi)

Triorganoantimony and Triorganobismuth Disulfonates. Crystal and Molecular Structure of (C₆H₅)₃M(O₃SC₆H₅)₂(M = Sb, Bi) Triorganoantimony disulfonates R₃Sb(O₃SR′)₂ [R = CH₃ = Me, C₆H₅ = Ph; R′ = Me, CH₂CH₂OH, Ph, 4-CH₃C₆H₄. R = Ph; R′ = 2,4-(NO₂)₂C₆H₃], Me₃Sb(O₃SCF₃)₂ · 2 H₂O and triphenylbismuth disulfonates Ph₃Bi(O₃SR′)₂ [R = Me, CF₃, CH₂CH₂OH, Ph, 4-CH₃C₆H₄, 2,4-(NO₂)₂C₆H₃] have been prepared by reaction of Me₃Sb(OH)₂, (Ph₃SbO)₂, and Ph₃BiCO₃, respectively, with the appropriate sulfonic acids. From vibrational data an ionic structure is inferred for Me₃Sb(O₃SCF₃)₂ · 2 H₂O and Me₃Sb(O₃SCH₂CH₂OH)₂, and a covalent structure for the other compounds with a penta-coordinated central atom with trigonal bipyramidal surrounding (Ph or Me in equatorial, unidentate sulfonate ligands in apical positions). Ph₃M(O₃SPh)₂ (M = Sb, Bi) crystallize monoclinic [space group P2₁/c; M = Sb/Bi: a = 1 611.5(8)/1 557.4(9), b = 987.5(6)/1 072,5(8), c = 1 859.9(9)/1 696.5(9) pm, β = 105.71(5)/96.62(5)°; Z = 4; d(calc.) 1.556/1.781 Mg · m^?3; V_cell = 2 849.2 · 10⁶/2 814.8 · 10⁶ pm³; structure determination from 3 438/3 078 independent reflexions (I ≥ 3σ(I)), R(unweighted) = 0.030/0.029]. M is bonding to three Ph groups in the equational plane [mean distances Sb/Bi? C:210.1(4)/219.1(7) pm] and two sulfonate ligands with O in apical positions [distances Sb? O: 210.6(3), 212.8(2); Bi? O: 227.6(5), 228.0(4) pm]. Weak interaction of M with a second O atom of one sulfonate ligand is inferred from a rather short M? O contact distance [Sb? O: 327.4(4), Bi? O: 312.9(5) pm], and from the distortion of equatorial angles [C? Sb? C: 128.4(2), 119.2(2), 112.2(2); C? Bi? C: 135.9(3), 117.8(3), 106.3(3)°]     

Beiträge zur Chemie des Phosphors. 61. Zur Struktur der Salze M(PC6H5)3, [M = K,Na]

Contributions to the Chemistry of Phosphorus. 61 About the Structure of the Salts M (PC₆H₅)₃ (M = K, Na) The structure of the salts M(PC₆H₅)₃ (M = K, Na) was determined by means of ²¹P nmr spectroscopy. Contrary to the opinion presented in the literature on the potassium salt, both compounds have an open chain structure. so that they are 1,3-Dialkali-l,2,3-triphenyl-tri-phosphides. The structure was proved by comparison of the ³¹P nnmr parameters with those of triphenyl-cyclotriphosphane 3 . and 1,2,3 triphenyl-triphosphane 5 . The occurrence of only AB₂ spin systems each for both of the pure salts as well as for an equimolecular mixture of these compounds indicates a fast inter- and possibly intramolecular metal exchange in solution. The latter of which probably takes place in the case of the solved homologue 1,-4-dipotassium-l,2,3,4-tetra-phenyl-tetraphosphide 6. for which the ³¹P nmr data indicate a quasi-cyclic conformation.     

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 und Struktur von Vanadylhalogeniden

Investigations on the Chemistry and Structure of Vanadyl-halogenides Aqueous solutions of VOI₂ can be prepared from VOSO₄ and BaI₂. By concentrating VOI · 3 H₂O is formed; but adducts of VOI₂ with DMSO and DMF can be isolated. The structure of [VO(DMSO)₅]I₂ was determined by X-ray single crystal techniques: Monoclinic; space group P2₁/c; a = 10.696; b = 10.877; c = 24.74 Å; ß = 109.87°; Z = 4. – Other new compounds are VO(OCH₃)Br · 3 pyr and VOBr₂ · 2 H₂O · 2 eth, which can be decomposed to VOBr₂. The structures of VOCl₂ and VOBr₂ were determined from crystal powders (space group I mmm). IR and reflection spectra (4–50 kK) and magnetic moments of all compounds were measured.     

Beiträge zur Chemie der Alkylverbindungen von Übergangsmetallen. 55. Darstellung und Eigenschaften von Niobocenium- und Tantalocenium-Salzen – Kristall- und Molekülstruktur von [(C5H5)2NbCl2][BF4] · CH3CN

Contributions to the Chemistry of Organo Transition Metal Compounds. 55. Preparation and Properties of Niobocenium and Tantalocenium Salts — Crystal and Molecular Structure of [(C₅H₅)₂NbCl₂][BF₄] · CH₃CN Niobocenium and tantalocenium compounds of the type [(C₅H₅)₂MCl₂]X (X = BF₄, PBh₄, PF₆) were synthesized from the metallocene dichlorides and ferricenium salts, [(C₅H₅)₂Fe]X, in methylene dichloride or tetrahydrofuran. With acetonitrile as solvent [(C₅H₅)₂MCl₂]X · CH₃CN complexes are formed. Stable methyl compounds of the type [(C₅H₅)₂M(CH₃)₂]X were obtained, when (C₅H₅)₂Ta(CH₃)₂ is oxidized by means of ferricenium salts. The new complexes were characterized by elemental analysis, i. r., and ¹H n.m.r. spectra. The structure of [(C₅H₅)₂NbCl₂][BF₄] · CH₃CN has been determined by X-ray structure analysis. The compound crystallizes in the orthorhombic space group Cmcm with a = 8.324(12), b = 19.581(13), c = 9,563(8) Å and Z = 4. The coordination geometry of the Nb atom is tetrahedrally.     

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.