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Journal ArticleDOI

Theoretical vibrational spectra compared to the experiment and the anomeric effect in 2-chloro-1,3,2-dioxaphosphorinane-2-oxide, -sulfide, and -selenide. II. Vibrational spectra and assignments

27 May 2011-Journal of Structural Chemistry (SP MAIK Nauka/Interperiodica)-Vol. 52, Iss: 2, pp 265-271
TL;DR: In this article, a 6-311G* basis set of 2-Chloro-1,3,2-dioxaphosphorinane-2-oxide, -sulfide, and -selenide was used for the assignment of symmetry coordinates.
Abstract: 2-Chloro-1,3,2-dioxaphosphorinane-2-oxide, -sulfide, and -selenide are studied with the help of DFT/B3LYP and several ab initio methods using a 6-311G** basis set. However, due to rather large relative energies of higher conformers in all three cases, the conformational equili-brium mixture contains more than 95% (see the preceding paper in this Journal) of the lowest chair-equatorial conformer (this indicates that the P=X bond is in the equatorial position), so we do not find any conformer bands in the experimental spectra and calculate our theoretical ones for the assignment only from the chair-equatorial conformer. The vibrational infrared and Raman spectra were calculated and are in fair agreement with their experimental counterparts. Potential energy distribution calculations are performed, and the theoretical modes where an experimental counterpart could be found to symmetry coordinates are assigned.
References
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Patent
21 Apr 1983
TL;DR: In this paper, a catalytic process for preparing ethylene polymers having a density of >/=0.94 to /=22 to/=50,000 pounds of polymer per pound of Ti with a catalyst formed from selected organoaluminum compounds and a precursor composition of the formula MgmTi1(OR)nXp(ED)q wherein ED is a selected electron donor compound m is >/ = 0.5 to / =2 to 1.5 m+2 R is a C1 to C14 aliphatic or aromatic hydrocarbon
Abstract: A catalytic process for preparing ethylene polymers having a density of >/=0.94 to /=22 to /=50,000 pounds of polymer per pound of Ti with a catalyst formed from selected organoaluminum compounds and a precursor composition of the formula MgmTi1(OR)nXp(ED)q wherein ED is a selected electron donor compound m is >/=0.5 to /=2 to 1.5 m+2 R is a C1 to C14 aliphatic or aromatic hydrocarbon radical, or COR' wherein R' is a C1 to C14 aliphatic or aromatic hydrocarbon radical, and X is selected from the group consisting of Cl, Br, I or mixtures thereof, which catalyst is in particulate form and impregnated in a porous inert carrier material.

222 citations

Journal ArticleDOI
TL;DR: Several chiral diphosphite ligands containing six stereogenic centers were synthesized and tested in order to study chiral cooperativity in the Rh- and Pt-catalysed asymmetric hydroformylation of styrene.
Abstract: Several chiral diphosphite ligands containing six stereogenic centres were synthesised and tested in order to study chiral cooperativity in the Rh- and Pt-catalysed asymmetric hydroformylation of styrene. The ligands were prepared either by the reaction of 2,4-pentanediol enantiomers with (4R,6R)-4,6-dimethyl-2-chloro-1,3,2-dioxaphosphorinane or that of (1S,3S)-1,3-diphenyl-1,3-propanediol with 4,6-dimethyl-2-chloro-1,3,2-dioxaphosphorinane enantiomers. Thus the chirality was varied both in the chelate backbone and in the terminal groups of the ligands. In case of Pt-catalysed hydroformylation, the stereogenic elements in the bridge have been found to be determinate for the product configuration with a cooperative effect from the terminal groups when the constellations are matched with 40% e.e. maximum enantioselectivity. Some coordination chemistry and the crystal structure determination of these ligands are also reported.

27 citations

Journal ArticleDOI
TL;DR: In this article, the electronic structure and conformational properties of vinylphosphonic acid, vinylphophosphoryl dichloride, and vinylphphosphine oxide have been studied by ab initio quantum mechanical methods.
Abstract: The electronic structure and conformational properties of vinylphosphonic acid, vinylphosphoryl dichloride, and vinylphosphine oxide have been studied by ab initio quantum mechanical methods. Furthermore, the vinylphosphonic acid has been studied experimentally by means of 13 C NMR and ultraviolet spectroscopy. This compound has been synthesized by a modification of the McKenna hydrolysis reaction, improving significantly the yield. The ab initio calculations have been performed with different basis sets, including correlation energy at the MP2/6-31G * level. Topological analysis of charge density has also been carried out. Two conformers, s-cis and s-trans-gauche, have been determined for the internal rotation around the C-P bond, with low rotational barriers

25 citations

Journal ArticleDOI
TL;DR: Values of the affinity and phosphorylation rate constants for this enzyme indicate that k' is responsible for the relatively low values of ki as compared with similar data for the open-chain analogues, O,O-diethyl phosphorothiolates (10(6) M-1 min-1).
Abstract: A new series of cyclic organophosphorus esters, 2-S-[2'-N,N-dialkylamino)ethyl]thio-1,3,2-dioxaphosphorinane 2-oxide and their quaternary derivatives, was synthesized and studied as potential antiglaucoma agents. Thes compounds inhibit acetylcholinesterase (E.C.3.1.1.7)at a bimoecular rate constant (ki) in the range of 10(3)-10(4) M-1 min-1. Values of the affinity (K) and phosphorylation (k') rate constants for this enzyme indicate that k' is responsible for the relatively low values of ki as compared with similar data for the open-chain analogues, O,O-diethyl phosphorothiolates (10(6) M-1 min-1). The mammalian toxicity of the new compounds in terms of acute LD50 values in mice is 1-3 x 10(3) less than that of phospholine, an open-chain analogue. In an initial clinical trial, one member of the new series (alkyl = C2H5) caused a significant decrease of intraocular pressure in aphakic glaucoma, while phospholine proved to be ineffective.

18 citations

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