³¹P and ¹³C NMR spectra of cyclohexylphenylphosphines, tricyclohexylphosphine and triphenylphosphine

Abstract

I N T R O D U C T I O NRecently, various complexes containing cyclohexylphenylphosphine ligands have been shown to be powerful catalysts.' Their catalytic properties and activity, however, change dramatically when they function as supported liquid-phase catalysts. In order to understand better these changes, we have undertaken a iimited study of the NMR spectra of iigands having the general formula P(C,H, 1),,(C6H5)3 -,, and the results are reported in this paper. The I3C chemical shifts in the spectra of triphenylphosphine (1) cyclohexyldiphenylphosphine (2) and tricyclohexylphosphine (4) were assigned straightforwardly according to the line intensity and multiplicity, known substituent effects and relative magnitudes of the ' 3C-31 P spin-spin coupling constants.* Similarly assigned were the aromatic carbons and the doublet of the cyclohexyl methine carbon in the spectrum of dicyclohexylphenylphosphine (3). The assignment of the remaining lines required INADEQUATE experiments and the use of a higher magnetic field, as the chemical

BR2BodPR2: highly fluorescent alternatives to PPh3and PhPCy2

“…The compound was purified using column chromatography on silica gel (chloroform-hexane 1 : 4, R f = 0.4) to yield an orange solid (0. 39 Tetrakis(acetonitrile)copper(I)hexafluorophosphate (0.027 g, 0.073 mmol) and 8-(4-diphenylphosphine)phenyl)-4,4-diphenyl-1,3,5,7-tetramethyl-2,6-diethyl-4-bora-3a,4a-diaza-s-indacene (0.100 g, 0.147 mmol) were added together to anhydrous dichloromethane (3 mL) and stirred under nitrogen for two hours. After removal of solvent an orange solid was produced (0.107 g, 93%).…”

Ruthenafuran Complexes Supported by the Bipyridine-Bis(diphenylphosphino)methane Ligand Set: Synthesis and Cytotoxicity Studies

“…Peak positions were calibrated with solvent residue peaks as internal standard. The 31 P{ 1 H} NMR spectra were referenced to external P(C 6 H 5 ) 3 (−4.7 ppm) [ 65 ]. Labeling scheme for H, C and P atoms in the NMR assignments is shown in Figure 4 .…”

Mixed RuIIComplexes Containing Diseleno‐Ligand and α,β‐Diketones Donors with Anticancer Activity. Synthesis, Characterization, Electrochemical and DFT Studies

“…What makes possible this behavior is the pseudo-aromatic nature and the capability of the α,β-diketone to distribute the electron [a] In the same conditions BP3Se 2 possess a single signal centered at 160 ppm [33] and the PPh 3 signal is in À 5 ppm. [59] density. [62] Additionally, the CF 3 groups can modulate the redox potential decreasing the energy of this process through the electron withdrawing.…”

“…Also, the chemical shift indicates a linkage RuÀ P since, free triphenylphosphine presents negative shifts values in the same conditions. [59] Two signals centered at 253 and 290 ppm were founded for 1, this difference can be explained if the Se atom in the low field is trans to electronegative atom Cl and the other chalcogenide is trans to the P of the phosphine ligand. This arrangement (Figure 1 center) is the same as the pdto derivative.…”