- STRUTURAL CHARACTERIZATION OF 1,2,4,5-TETRAPHENYLCYCLO-3,6-DICARBA-1,2,4,5-TERAPHOSPHINE: A HIGHLY FOLDED CHAIR CONFORMATION
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The title compound crystallyzed in the monoclynic space group P21/c, with the followingunit cell parameters: a = 11.235(8), b = 8.473(2), c = 26.136(10) Aengstroem, β = 102.07(5) grad, V = 2432(3) Aengstroem3, Z = 4.1657 unique data were used to solve (direct methods) and refine the structure to give R = 0.126 and Rw = 0.118.The six-membered ring system is in a highly folded chair conformation with the phenyl group substituents on the phosphorous atoms oriented in the equatorial positions.The dihedral angles of the P-CH2-P plane with the P4 basal plane is a remarkable 101.8 grad (avarage).This dihedral angle is the closestto perpendicular ever observed for a monocyclic ring system.
- Laneman, Scott A.,Fronczek, Frank R.,Stanley, George G.
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- Linear Oligophosphaalkanes, XIX. - Partial Alkylation of Phenylphosphane with Dihalomethanes CH2X2 (X = Cl, Br) - A Facile Synthesis of Methylenebis(phenylphosphane), HPhP-CH2-PPhH
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The reaction of PhPHNa with CH2X2 (X = Cl, Br) in tetrahydrofuran affords methylenebis(phenylphosphane), HPhP-CH2-PPhH (2), phenylphosphane, methylphenylphosphane, PhPHMe, and 1,2,3,4-tetraphenylcyclo-5-carba-1,2,3,4-tetraphosphane, CH2(PPh)4 (3).HPhP-CH2-PPhH (2) may be obtained in a facile one-step synthesis with yields up to 70percent by reaction of PhPH2 with CH2Cl2 and KOH in dimethyl sulfoxide/H2O or dimethylformamide/H2O.The formation of PhPHMe and CH2-(PPh4)4 may be explained by a reaction scheme including P-phenylphosphaalkene PhP=CH2 and HPhP-CH2Cl as reactive intermediates.The reactions between PhPHM (M = Na, K) and CH2Cl2 or CH2Br2 respectively, have been studied by independent experiments.
- Langhans, Klaus P.,Stelzer, Othmar
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p. 1707 - 1712
(2007/10/02)
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- Synthesis and Properties of Open-Chain and Cyclic 1λ3,3λ3-Diphosphaalkanes RR'P-CH2-PR'R
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Disecondary methylenediphosphanes R(X)PCH2P(X)R with their adjustable positive or negative polarity (X = H, Cl), which are useful building blocks for organophosphorus synthesis, were prepared by multi-step substitution of chlorine atoms in methylenebis(di
- Schmidbaur, Hubert,Schnatterer, Stefan
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p. 2832 - 2842
(2007/10/02)
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