Comparison of the solid and liquid solution states of representative phosphoranes by phosphorus-31 NMR

Dennis, L.W.; Bartuska, Victor J.; Maciel, Gary E.

doi:10.1021/ja00365a042

Cited by 36 publications

(13 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Anet and Yavari warned that lattice energy and the resultant crystal-packing effects in the solid state can render the solid-state conformation different from that in solution . For a range of pentacoordinated phosphorus compounds, Maciel et al showed that the solid-state and solution conformations did not vary significantly . Similar conclusions were reached by Holmes and co-workers. , However, for the 12H-dibenzo[d,g][1,3,2]dioxasilocin derivatives of this study, the solid-state and solution conformations may be different , which appears to be the case for 1 where the solution state conformation is predominantly a TB and the solid-state conformation is a BB.…”

Section: Resultssupporting

confidence: 85%

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

et al. 1997

View full text Add to dashboard Cite

The conformation of the eight-membered membered 12H-dibenzo[d,g][1,3,2]dioxasilocin ring system was investigated both in the solid-state by X-ray crystallography and in solution by NOE experiments. Ab initio Hartree−Fock calculations were performed to locate all stationary points for the unsubstituted 12H-dibenzo[d,g][1,3,2]dioxasilocin ring system. The MM2* force field was parametrized to reproduce our ab initio results, and these data were compared to the experimental data. The transition states for conformational interchange were identified. The pseudoequatorial preference for a methyl substituent on either the C(12) carbon atom or silicon is greater than the difference in energy between a boat-chair and twist-boat conformation in 2,4,8,10-tetra-tert-butyl-substituted 12H-dibenzo[d,g][1,3,2]dioxasilocins. The conformations observed in the solid-state X-ray crystal structures of 12H-dibenzo[d,g][1,3,2]dioxasilocins are sensitive to crystal-packing forces and may be different from that in solution.

show abstract

Section: Resultssupporting

confidence: 85%

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

et al. 1997

View full text Add to dashboard Cite

show abstract

“…31 P NMR chemical shifts (Chart ) are representative values for each of the coordination geometries. , Increasingly negative values from about 125 ppm to −147 ppm occur as the coordination number increases from phosphite to phosphate to pentaoxyphosphorane. This implies, as is normally the case for phosphorus compounds, , that the structures are retained in solution . For all of the structures reported here and for the comparisons that have been made, the ring conformation is boatlike when donor interaction is present (a syn conformation) and chairlike in the absence of donor interaction (an anti conformation) .…”

Section: Resultsmentioning

confidence: 88%

“…Solid state 31 P NMR measurements also confirm the retention of solid state structure in solution. See refs and for comparison between these two states for oxyphosphoranes.…”

Section: Referencesmentioning

confidence: 99%

Chloro- and Fluoro-Substituted Phosphites, Phosphates, and Phosphoranes Exhibiting Sulfur and Oxygen Coordination¹

et al. 1999

View full text Add to dashboard Cite

New cyclic phosphoranes, O(2)S[Me(t-Bu)C(6)H(2)O](2)PCl(3) (1), O(2)S[Me(t-Bu)C(6)H(2)O](2)P(OC(6)H(4)-m-CF(3))(3) (2), and O(2)S[(t-Bu)(2)C(6)H(2)O](2)PCl(3) (3), containing sulfone donor groups and halogen substituents were synthesized by oxidative addition reactions of a diol with a tricoordinated phosphorus precursor. Cyclic phosphates, O(2)S[(t-Bu)(2)C(6)H(2)O](2)P(O)Cl (4) and O(2)S[Me(t-Bu)C(6)H(2)O](2)P(O)(OC(6)H(4)-m-CF(3)) (5), resulted from hydrolysis reactions of 3 and 2, respectively. Phosphate O(2)S[Me(t-Bu)C(6)H(2)O](2)P(O)(OC(6)F(5)) (6) was prepared from a known phosphorane precursor and independently from the reaction of an N-oxide molecule with a parent phosphite, O(2)S[Me(t-Bu)C(6)H(2)O](2)P(OC(6)F(5)). Two additional compounds containing a sulfur atom in place of the sulfone group, a cyclic phosphite, S[Me(2)C(6)H(2)O](2)P(OC(6)F(5)) (7), and a cyclic phosphate, S[Me(2)C(6)H(2)O](2)P(O)Cl (8), were synthesized. X-ray analysis and NMR data were obtained on all of these compounds to establish the role of electronegative ligands in promoting donor interaction. Compounds 1-3 were hexacoordinate as a consequence of oxygen atom coordination while 7 and 8 were trigonal bipyramidal due to sulfur atom coordination. The chlorine atom and the pentafluorophenoxy group promote similar degrees of coordination in these compounds. The results support the conclusion that the sulfur atom and oxygen atom of the sulfone group show similar coordination abilities in donor action with phosphoranes containing strongly electronegative ligands while in the presence of less electronegative ligands sulfur is the stronger coordinating agent. With phosphates and phosphites the sulfur atom exerts the stronger donor action independent of the electronegativity of the attached ligands.

show abstract

“…The bicyclic phosphorane 5 is of interest for another reason: Holmes et al found for analogous (R ‫ס‬ Ph) and similar bicyclic systems that these species, depending on the groups bonded to phosphorus, show a tendency to exist in a more or less ideal square-pyramidal structure in the solid state [7,8,11]. In contrast, the majority of phosphoranes favor a trigonal-bipyramidal coordination at phosphorus.…”

Section: Discussion Of the Structure Ofmentioning

confidence: 99%

The reaction of triphenylmethylhalophosphines with tetrachloro-orthobenzoquinone: Oxidation?isomerization?dehydrohalogenation

et al. 1999

View full text Add to dashboard Cite

Comparison of the solid and liquid solution states of representative phosphoranes by phosphorus-31 NMR

Cited by 36 publications

References 0 publications

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

Chloro- and Fluoro-Substituted Phosphites, Phosphates, and Phosphoranes Exhibiting Sulfur and Oxygen Coordination¹

The reaction of triphenylmethylhalophosphines with tetrachloro-orthobenzoquinone: Oxidation?isomerization?dehydrohalogenation

Contact Info

Product

Resources

About

Comparison of the solid and liquid solution states of representative phosphoranes by phosphorus-31 NMR

Cited by 36 publications

References 0 publications

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems1

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems1

Chloro- and Fluoro-Substituted Phosphites, Phosphates, and Phosphoranes Exhibiting Sulfur and Oxygen Coordination1

The reaction of triphenylmethylhalophosphines with tetrachloro-orthobenzoquinone: Oxidation?isomerization?dehydrohalogenation

Contact Info

Product

Resources

About

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

Steric Consequences on the Conformation of Medium-Sized Rings: Solution NMR, Solid-State Crystallographic, ab Initio Molecular Orbital Calculations, and Molecular Mechanics Studies on Substituted Eight-Membered Organosilicon Ring Systems¹

Chloro- and Fluoro-Substituted Phosphites, Phosphates, and Phosphoranes Exhibiting Sulfur and Oxygen Coordination¹