1079-65-8Relevant articles and documents
Synthesis, crystal structures, and quantum chemical calculations of Novel Phosphonium Salt-1,5-diphospha-3-phosphonia-tricyclo pentane cations
Bani-Fwaz, Mutasem Z.,Fazary, Ahmed E.,Becker, Gerd
, p. 51 - 65 (2017)
This work deals with reactions between the kinetically stable 2-tert-butyl-1λ3-phospha-alkyne, tBu-C[tbnd]P, and various halodiorganylphosphines (X = Cl, Br). The isolated ionic salts with the 2,4-di-tert-butyl-3,3-diorganyl-1λ3,5λ3-diphospha-3-phosphonia-tricyclo[2.1.0.02,5]pentane cations, [R2C2tBu2P3]⊕ (R = ethyl, isopropyl, methyl, phenyl), were characterized by spectroscopic methods; additionally, the results of X-ray structure analyses were confirmed by quantum chemical calculations with Gaussian 03 program which were performed on the hydrogen substituted phosphonium and phosphenium cations in order to ascertain optimized structural data and relative energies for different isomers. As for the phosphonium cation ([H2P(CH)2P2]⊕) generated from our work the conventional trigonal bipyramidal framework of point group C2v represents the absolute minimum on the potential energy surface. To our surprise this situation is followed by a second one which has to be attributed to the so-called housene structure of point group C1 showing a somewhat higher energy value + 77.9 kJ/mol. Quite a reverse situation is encountered for the phosphenium cation [P(CH)2P2]⊕. Here the pseudo square-based pyramidal nido structure of point group C2v known from Russell's tetrachloroaluminate(III) compound is found to be the only minimum on the potential energy surface. A phosphenium cation with a trigonal bipyramidal framework of point group C2v is higher in energy by only 35.7 kJ/mol, but due to one imaginary frequency it has to be considered the structure of a transition state. The opened housene structure corresponds neither to a minimum nor to a saddle point on the potential energy surface. In the pseudo square-based pyramidal nido structure (point group C2v) of the phosphenium cation [P(CH)2P2]⊕ the s-orbital and all p-orbitals of the apical four-coordinate phosphorus atom are used to form two P–C and two P–P bonds. Further addition of two hydrogen atoms to entail the phosphonium cation [H2P(CH)2P2]⊕ of point group symmetry C2 not only increases the coordination number of the apical phosphorus atom to six but also requires two electrons and two orbitals for P–H bonding. These are no longer available to the bonding system within the nido structure; as a consequence, its energy increases to +246.6 kJ/mol and the cation rearranges to give the conventional structure of ours.
NMR STUDY OF (C6H5)3-nPXn (X = Cl, Br, I; n = 0-3) AND (C6H5)3-nPXnCr(CO)5 COMPOUNDS
Vincent, E.,Verdonck, L.,Kelen, G. P. van der
, p. 239 - 248 (1980)
The 31P chemical shift of the (C6H5)3-nPXn ligands (X = Cl, Br, I; n = 0-3) is dominated by the electronegativity of the substituents. ? bonding is only important for derivatives with three strongly electronegative substituents.The 3
Vibrational study of diphenylphosphorus halides Ph2PX (X = Cl, Br, I)
Verdonck, L.,Ryck, P. H. de,Roelandt, F. F.,Kelen, G. P. van der
, p. 299 - 302 (1984)
The Raman and i.r. spectra of diphenylphosphorus halides, Ph2PX (X = Cl, Br, I), have been measured and concerted assignments have been made confirmed by an approximate normal coordinate analysis for the skeletal vibrations of Ph2PCl using a three mass mo
Bromine Cation Initiated vic -Diphosphination of Styrenes with Diphosphines under Photoredox Catalysis
Otomura, Nobutaka,Okugawa, Yuto,Hirano, Koji,Miura, Masahiro
, p. 3402 - 3407 (2018/04/16)
An N -bromosuccinimide (NBS)-initiated vic -diphosphination of styrenes with diphosphines proceeds under visible-light-promoted Ir(ppy) 3 photoredox catalysis to deliver the corresponding 1,2-diphosphinoethane derivatives in good yields. The NBS is a bromine cation source and generates a bromophosphine, which undergoes a single-electron reduction by the excited iridium species to form phosphinyl radicals of key species in the diphoshination reaction. The newly developed photoredox catalysis demonstrates better reaction efficiency, functional group compatibility, and scalability than the previous photocatalysis using N -fluorobenzenesulfonimide (NFSI) and silylphosphine.
Studies on the efficient generation of phosphorus-carbon bonds via a rearrangement of PIII esters catalysed by trimethylhalosilanes
Dabkowski, Wojciech,Ozarek, Alfred,Olejniczak, Sebastian,Cypryk, Marek,Chojnowski, Julian,Michalski, Jan
body text, p. 1747 - 1756 (2009/09/25)
Halotrimethylsilanes Me3SiX (X = Br, I) catalyse rearrangements of tricoordinate phosphorus esters R′R″P-OR into the corresponding phosphoryl systems R′R″P(O)R. This provides a simple and efficient route to a variety of structures containing phosphorus-carbon bonds, under mild conditions and with good yields. The reaction mechanism was investigated in detail by 31P NMR spectroscopy and independent synthesis of the reaction intermediates. It has been demonstrated that the primary products of this catalytic reaction are halogeno PIII structures R′R″PX and silyl ethers ROSiMe3 and that they subsequently react to give the corresponding phosphorus silyl esters - Me 3SiOPR′R″-and alkyl halides RX. At higher temperatures these intermediates then react to form R′R″P(P)R compounds. This paper also features the surprising observation that when esters Ph 2POR and halotrimethylsilanes Me3SiX (X = Br, I) are used in 2:1 ratio, phosphonium salts Ph2R2P+X - and trimethylsilyl diphenylphosphinate - Ph2P(O) OSiMe3 - are formed as the major products. Experimental evidence indicates that the mechanisms of both reactions are fundamentally different from that of the Michaelis-Arbuzov reaction. Me3SiCl is not reactive and this paper explains why.
Stabilization of (Halogenoacetyl)organylphenylphosphanes - Crystal Structure of Br(OC)4Mn
Lindner, Ekkehard,Merkle, Ralf Dieter,Hiller, Wolfgang,Fawzi, Riad
, p. 659 - 668 (2007/10/02)
The very reactive bromo- and chloroacetylorganylphenylphosphanes X1X2X3CC(O)PRPh (1ax-dx, 1ay, by) are stabilized with BrMn(CO)5 (2) with formation of the complexes Br(OC)4Mn1X2X3> (3ax-dx, 3ay, by) and characterized in this way by their mass, IR and NMR spectra.According to an X-ray structural analysis 3dx crystallizes in the monoclinic space group P21/n with Z = 4.In the IR spectra of 3ax-cx and 3ay, by appear more than the expected four CO absorptions indicating the presence of rotamers.Reductive cyclization of Br(OC)4Mn (3by) with activated magnesium results in the formation of the cyclobutanone derivative (4).
SYNTHESIS AND INFRARED STUDY OF (C6H5)nPX3-nCr(CO)5 (X=Cl, Br, I, H; n=0-3) AND (C6H5)2PRCr(CO)5 (R=METHYL, ETHYL, i-PROPYL, t-BUTYL) COMPOUNDS
Vincent, E.,Verdonck, L.,Kelen, G. P. van der
, p. 33 - 40 (2007/10/02)
A method for the preparation of (C6H5)nPX3-nCr(CO)5 complexes in the crystalline state is described.The carbon-oxygen stretching vibration, νCO(A1 eq.), of the complexes with X=Cl, Br, I is mainly determined by the inductive effect of the (C6H5)nPX3-n group.For X=H, the νCO band is defined by the concomitant influence of the ?, ? and steric effects.
