Das P(SiMe2)3P

P(SiMe₂)₃P Li₃P (produced from the elements) forms with Me₂SiCl₂ at 20°C in toluene the bicyclic compound P(SiMe₂)₃P 4 beside small amounts of ClMe₂Si? P(SiMe₂)₂P? SiMe₂Cl and traces of P₄(SiMe₂)₆ 7. 4 can be transformed into 7 by thermal treatment. With the formation of 4 the existence of a bicyclic silylphosphane is confirmed which has already been mentioned in connection with P(SiEt₂)₃P [1], but could not be proven until now.     

Untersuchungen zur Metallierung der Cyclophosphane P4(Cme3)3(Sime3), P4(Cme3)2(Sime3)2, P4(Sime3)4

Investigations Concerning the Metallation of the Cyclotetraphosphanes P₄(Cme₃)₃(Sime₃), P₄(Cme₃)₂(Sime₃)₂, and P₄(Sime₃)₄ The reaction of white phosphorus with LiCme₃ and me₃SiCl yields P₄(Sime₃)(Cme₃)₃ 1 . With n-buLi this crystalline cyclotetraphosphane forms the crystalline LiP₄(Cme₃)₃. In the same manner, n-buLi, with trans-P₄(Sime₃)₂(Cme₃)₂ 2 to yields LiP₄(Sime₃)(Cme₃)₂, which in contrast to LiP₄(Cme₃)₃ decomposes within a few hours yielding P(Sime₃)₂n-bu 6 , P(Sime₃)₃ 8 , LiP(Sime₃)₂ 9 and also the cyclic compounds P₄(Sime₃)(Cme₃)₃ 10 , LiP₄(Cme₃)₃ 11 and LiP₃(Cme₃)₂ 12 . The composition of the product mixture depends on the molar ratio of 2 to LiC₄H₉. At a molar ratio of 1:1 11 and 12 are not jet observed. At molar ratios of 1:1.5 and 1:2 P(Sime₃)₃ is not found. The amount of 11 and 12 grows with increasing concentration of n-buLi. On addition of n-buLi the solution of P₄(Sime₃)₄ immediately turns red. Li₃P₇ and Li₂P₇(Sime₃) (among others) are formed so fast that the first intermediates in the lithiation sequence so far could not be elucidated. These results demonstrate clearly that replacement of two me₃Si groups in P₄(Sime₃)₄ by two me₃C groups excludes the rearrangement of LiP₄(Sime₃)(Cme₃)₂ to a P₇-molecule.     

三苯基膦亚铜配合物光解反应的ESR研究

用自旋捕捉技术-柱色谱-电子自旋共振相结合的方法研究了(Ph3)3CunXn(n=1,2; x=Cl,Br,I,CN)和(Ph3P)(biL)CuX(X=Cl,Br,I;biL-2,2'-二吡啶基-1,10-菲绕啉光解中的活性自由基.通过在苯基自由基,二苯基膦自由基与苯基丁基氧化氮之间生成的自旋加合物的电子顺磁共振谱的超精细结构,证实了苯基自由基和二苯基膦自由基的生成.标题化合物对某些反应具有催化活性.     

Das iso-Tetraphosphan P[P(SiMe3)Me]2[P(SiMe3)2]

H ? C Bond Cleavage in Ferrocene by Organylruthenium Complexes Cp*(Me₃P)₂RuCH₂CMe₃ ( 1 ) reacts at 85°C with ferrocene ( 2 ) by cleavage of one H? C bond in 2 to give CpFe[η⁵-C₅H₄Ru(PMe₃)₂Cp*] ( 3 ) (Cp = η⁵-C₅H₅; Cp* = η⁵-C₅Me₅) and neopentane. The ruthenium atom in 3 has a distorted tetrahedral geometry, the planar Cp ligands in the ferrocenyl fragment are eclipsed. Solutions of 3 in [D₆]benzene or [D₈]THF exhibit H? D exchange of the ferrocenyl protons. In the [D₈]THF molecule only the α-deuterium atoms are exchanged. Reaction pathways for this exchange are discussed.     

Bildung und struktur der Cyclophosphane P4(CMe3)2[P(CMe3)2]2 und P4(SiMe3)2[P(CMe3)2]2

Formation and Structure of the Cyclophosphanes P₄(CMe₃)₂[P(CMe₃)₂]₂ and P₄(SiMe₃)₂[P(CMe₃)₂]₂ n-Triphosphanes showing a SiMe₃ and a Cl substituent at the atoms P¹ and P², like (Me₃C)₂P? P(SiMe₃)? P(CMe₃)Cl 3 or (Me₃C)₂P? P(Cl)? P(SiMe₃)₂ 4 are stable only at temperatures below ?30°C. Above this temperature these compounds lose Me₃SiCl, thus forming cyclotetraphosphanes, P₄(CMe₃)₂[P(CMe₃)₂]₂ 1 out of 3 , P₄(SiMe₃)₂[P(SiMe₃)₂]₂ 2a (cis) and 2b (trans) out of 4 . The formation of 1 proceeds via (Me₃C)₂P? P?PCMe₃ 5 as intermediate compound, which after addition to cyclopentadiene to give the Diels-Alder-adduct 6 (exo and endo isomers) was isolated. 6 generates 5 , which then forms the dimer compound 1 . Likewise (Me₃C)₂P? P?P-SiMe₃ 8 (as proven by the adduct 7 ) is formed out of 4 , leading to 2a (cis) and 2b (trans). Compound 1 is also formed out of the iso-tetraphosphane P[P(CMe₃)₂]₂[P(CMe₃)Cl] 9 , which loses P(CMe₃)₂Cl when warmed to a temperature of 20°C. 1 crystallizes monoclinically in the space group P2₁/a (no. 14); a = 1762.0(15) pm; b = 1687.2(18) pm; c = 1170.5(9) pm; β = 109.18(5)° and Z = 4 formula units in the elementary cell. The molecule possesses E conformation. The central four-membered ring is puckered (approx. symmetry 4 2m; dihedral angle 47.4°), thus bringing the substituents into a quasi equatorial position and the nonbonding electron pairs into a quasi axial position. The bond lengths in the four-membered ring of 1 (d (P? P) = 222.9 pm) are only slightly longer than the exocyclic bonds (221.8 pm). The endocyclic bond angles \documentclass{article}\pagestyle{empty}\begin{document}$ \bar \beta $\end{document}(P/P/P) are 85.0°, the torsion angles are ±33° and d (P? C) = 189.7 pm.     

NaMn6(P2O7)2(P3O10) and KCd6(P2O7)2(P3O10)

The crystal structures of two new diphosphates, sodium hexamanganese bis­(diphosphate) triphosphate, NaMn₆(P₂O₇)₂(P₃O₁₀), and potassium hexacadmium bis­(diphosphate) triphosphate, KCd₆(P₂O₇)₂(P₃O₁₀), confirm the rigidity of the M₆(P₂O₇)₂(P₃O₁₀) matrix (M is Mn or Cd) and the relatively fixed dimensions of the tunnels extending in the a direction of the unit cell. The compounds are isomorphous; the P₂O₇^4? anion and the alkali metal cations lie on mirror planes. Bond‐valence analysis of the bonding details of the atoms found within the tunnels permits a prediction of the conductivity.     

Die Strukturen der Heptahetero-Nortricyclene P7(Sime3)3 und P4(Sime2)3

The Structures of the Heptahetero-Nortricyclenes P₇(Sime₃)₃ and P₄(Sime₂)₃ Tris(trimethylsilyl)heptaphospha-nortricyclene P₇(Sime₃)₃ 1 and Hexamethyl-trisila-tetraphospha-nortricyclene P₄Si₃me₆ 2 are structural analogons to the hetero-nortricyclenes P and P₄S₃. 1 crystallizes in the space group P2₁ with a = 965.7 pm, b = 1746.5 pm, c = 693.3 pm, β = 99.61° and Z = 2 formula units. In the P₇ system tge P? P bond lengths differ functionally, namely 221.4 pm in the three-membered ring, 219.2 pm at the ring atoms and 217.9 pm at the bridgehead atom. The P? Si and Si? C bond lengths are 228.8 pm and 187.8 pm respectively. 2 crystallizes in the space group R3 with a_R = 1129.3 pm, α_R = 50.01° (hexagonal axes: a = 954.7 pm, c = 2956.9 pm) and Z = 2 formula units. In the P₄Si₃ systems the bond lengths are P? P = 220.2 pm, P? Si = 228.3 pm and 224.7 pm (to the bridgehead atom). The Si? C bond lengths are 187.3 pm. The structures are discussed with related compounds.     

Conformation of P(O)SCH3 and P (S) OSi (CH3)3 groups in 1,3,2-dioxaphospholanes

Conclusions Based on the dipole moment data, either a cis or near-cis orientation of the phosphoryl and methyl groups, or of the thiophosphoryl and trimethylsilyl groups, is realized in the 2-oxo-2-methylthio- and the 2-thiono-2-trimethylsiloxy-4-methyl- and -4,5-dimethyl-1,3,2-dioxaphospholanes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1880–1883, August, 1976.The authors are indebted to A. N. Vereshchagin and V. A. Naumov for their valuable counsel.     

Extending the coordination chemistry of molecular P(4)S(3): the polymeric Ag(P(4)S(3))(+) and Ag(P(4)S(3))(2)(+) cations

Upon reacting P(4)S(3) with AgAl(hfip)(4) and AgAl(pftb)(4) [hfip = OC(H)(CF(3))(2); pftb = OC(CF(3))(3)], the compounds Ag(P(4)S(3))Al(hfip)(4) 1 and Ag(P(4)S(3))(2)(+)[Al(pftb)(4)](-) 2 formed in CS(2) (1) or CS(2)/CH(2)Cl(2) (2) solution. Compounds 1 and 2 were characterized by single-crystal X-ray structure determinations, Raman and solution NMR spectroscopy, and elemental analyses. One-dimensional chains of [Ag(P(4)S(3))(x)](infinity) (x = 1, 1; x = 2, 2) formed in the solid state with P(4)S(3) ligands that bridge through a 1,3-P,S, a 2,4-P,S, or a 3,4-P,P eta(1) coordination to the silver ions. Compound 2 with the least basic anion contains the first homoleptic metal(P(4)S(3)) complex. Compounds 1 and 2 also include the long sought sulfur coordination of P(4)S(3). Raman spectra of 1 and 2 were assigned on the basis of DFT calculations of related species. The influence of the silver coordination on the geometry of the P(4)S(3) cage is discussed, additionally aided by DFT calculations. Consequences for the frequently observed degradation of the cage are suggested. An experimental silver ion affinity scale based on the solid-state structures of several weak Lewis acid base adducts of type (L)AgAl(hfip)(4) is given. The affinity of the ligand L to the silver ion increases according to P(4) < CH(2)Cl(2) < P(4)S(3) < S(8) < 1,2-C(2)H(4)Cl(2) < toluene.     

Quenching of I(2P1/2) by O3 and O(3P)

Oxygen-iodine lasers that utilize electrical or microwave discharges to produce singlet oxygen are currently being developed. The discharge generators differ from conventional chemical singlet oxygen generators in that they produce significant amounts of atomic oxygen. Post-discharge chemistry includes channels that lead to the formation of ozone. Consequently, removal of I(2P1/2) by O atoms and O3 may impact the efficiency of discharge driven iodine lasers. In the present study, we have measured the rate constants for quenching of I(2P1/2) by O(3P) atoms and O3 using pulsed laser photolysis techniques. The rate constant for quenching by O3, (1.8 +/- 0.4) x 10(-12) cm3 s-1, was found to be a factor of 5 smaller than the literature value. The rate constant for quenching by O(3P) was (1.2 +/- 0.2) x 10(-11) cm3 s-1.     

RbGa3(P3O10)2: a new gallium phosphate isotypic with RbAl3(P3O10)2

Rubidium trigallium bis(triphosphate), RbGa₃(P₃O₁₀)₂ has been synthesized by solid‐state reaction and studied by single‐crystal X‐ray diffraction at room temperature. This compound is the first anhydrous gallium phosphate containing both GaO₄ tetra­hedra (Ga1) and GaO₆ octa­hedra (Ga2 and Ga3). The three independent Ga atoms are located on sites with imposed symmetry 2 (Wickoff positions 4a for Ga1 and 4b for Ga2 and Ga3). The GaO₄ and GaO₆ polyhedra are connected through the apices to triphosphate groups and form a three‐dimensionnal host lattice. This framework presents inter­secting tunnels running along the [001] and <110> directions, where the Rb²⁺ cations are located on sites with imposed symmetry 2 (Wickoff position 4a). The structure also exhibits remarkable features, such as infinite helical columns created by the junction of GaO₄ and PO₄ tetra­hedra.     

Bildung und Struktur des iso-Tetraphosphans P[P(SiMe3)Me]3

Formation and Structure of iso-Tetraphosphane P[P(SiMe₃)Me]₃ The reaction of MeP(SiMe₃)₂ with PCl₃ (molar ratio 3:1, ?78°C, n-pentane) yields by cleaving of the P? Si bond P[P(SiMe₃)Me]₃ 1 with Cl₂P? P(SiMe₃)Me and ClP[P(SiMe₃)Me]₂ as intermediates. The reaction rate decreases by the increase of phosphorylation. The last reaction step (formation of 1 ) occurs while warming up to room temperature. 1 forms colorless hexagonal crystals, melting point 65 ± 1°C. Tris(trimethylsilyl-methyl-phosphino)phosphane 1 crystallizes monoclinically in the space group Cc (No. 8) with Z = 8 formula units per unit cell. The molecules possess approximated C₃ symmetry and have (RRR) and (SSS) configurations, respectively. The bond distances d?(P? P) = 220.1 pm, d?(P? C) = 186.5 pm, and d?(P? Si) = 225.2 pm are normal and within the expected range of known distances. According to repulsive interactions between the non bonded electron pairs of the terminal P atoms and the protons of the methyl groups the angles at the central and terminal P atoms are enlarged to ? P P P = 105.1° and ? P P C = 106.9°, respectively.     

Die ungewöhnliche Umwandlung von P(SnMe3)3 in P4(SnMe2)6

The Unusual Transformation of P(SnMe₃)₃ to P₄(SnMe₂)₆ The stannylated phosphine P(SnMe₃)₃ reacts in the presence of small amounts of [(ZnCl)₂Fe(CO)₄(THF)₂] in THF (tetrahydrofurane) at room temperature forming insoluble P₄(SnMe₂)₆ ( 1 ). This compound crystallizes as colourless needles directly from the reaction mixture (space group Cmcm, a = 1593.6(3) pm, b = 1118.2(2), c = 1602.5(3), Z = 4). Reaction of ZnCl₂ with P(SnMe₃)₃ under the same reaction conditions leads to the complex [ZnCl₂{P(SnMe₃)₃}THF] ( 2 ) (space group Pccn, a = 1593, 6(3) pm, b = 1118, 2(2), c = 1602, 5(3), Z = 8.     

Biodegradation of microbial polyesters P(3HB) and P(3HB-co-3HV) under the tropical climate environment

The biodegradation of poly(3-hydroxybutyrate), P(3HB), and its copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(3HB-co-3HV) produced by a locally isolated bacteria identified as Erwinia sp. USMI-20 were carried out by using soil burial test and immersion test method at various places under the tropical environment in West Sumatra, Indonesia. The isolation of P(3HA)-degrading microorganisms was done by the in vitro rapid plate test method and was further characterized by using biochemical reactions. Our results showed that P(3HB) biodegraded at a rate of 3.6% per week in activated sludge, 1.9% per week in soil, 1.5% per week in lake water and 0.8% per week in Indian Ocean sea water. The degradation rates for P(3HB-co-3HV) were 17.8% per week in activated sludge, 6.7% per week in soil, 3.2% per week in lake water and 2.7% per week in Indian Ocean sea water. The biodegradation of both polymers were highest after burial into activated sludge with a half-life (T_1/2) of 14 weeks and the time for 100% degradation (T_100%) of 28 weeks for P(3HB), and a T_1/2 of 3 weeks and T_100% at 6 weeks for P(3HB-co-3HV). In this study, 10 bacteria which were responsible for the biodegradation of P(3HB) and P(3HB-co-3HV) film were isolated and identified from the various places studied under the tropical environment. They were Bacillus sp. FAAC-2202, Enterobacter sp. FAAC-2207, Bacillus sp. FAAC-2209 and Proteus sp. FAAC-2203 obtained from activated sludge, Bacillus sp. FAAC-2201 and Alcaligenes sp. FAAC-2210 from soil, Alcaligenes sp. FAAC-2205, Micrococcus sp. FAAC-2206 and Pseudomonas sp. FAAC-2208 from lake water and Proteus sp. FAAC-2204 from Indian Ocean sea water.     

Vinyl C-F cleavage by Os(H)3Cl(P(i)Pr3)2

Os(H)(3)ClL(2) (L = P(i)Pr(3)) reacts at 20 degrees C with vinyl fluoride in the time of mixing to produce OsHFCl([triple bond]CCH(3))L(2) and H(2). In a competitive reaction, the liberated H(2) converts vinyl fluoride to C(2)H(4) and HF in a reaction catalyzed by Os(H)(3)ClL(2). A variable-temperature NMR study reveals these reactions proceed through the common intermediate OsHCl(H(2))(H(2)C=CHF)L(2), via OsClF(=CHMe)L(2) and OsHCl(H(2))(C(2)H(4))L(2), all of which are detected. DFT(B3PW91) calculations of the potential energy and free energy at 298 K of possible intermediates show the importance of entropy to account for their thermodynamic accessibility. Calculations of unimolecular C-F cleavage of coordinated C(2)H(3)F confirms the high activation energy of this process. Catalysis by HF is thus suggested to account for the fast observed reactions, and scavenging of HF with NEt(3) changes the product to exclusively Os(H)(2)Cl(CCH(3))L(2). The analogous reaction of Os(H)(3)ClL(2) with H(2)C=CF(2) produces exclusively OsHFCl(=CCH(3))L(2) and HF, and the latter is again suggested to catalyze C-F scission via the observed intermediates Os(H)(2)Cl(CF(2)CH(3))L(2) and OsHCl(=CFMe)L(2).