A multinuclear NMR spectroscopic study of some Mo(CO)4[(R2″PO)2Si(R)R′] complexes [R2″=Ph2, OCH2CMe2CH2O; R, R′ = alkyl, haloalkyl, aryl]

Academic Article


  • It is possible to use multinuclear NMR spectroscopy to measure both the steric and electron donor/acceptor properties of the P‐donor ligands in Mo(CO) [(R ″PO) YRR′] complexes [R ″=Ph , OCH CMe CH O; YR = P(O), Si(Me); R′ = alkyl, haloalkyl, aryl]. The C, Si, P and Mo NMR data for some Mo(CO) [(R ″PO) YRR′] complexes [R ″ = Ph , OCH CMe CH O; YR = P(O), Si(Me); R′ = alkyl, haloalkyl, aryl] are presented and the factors affecting both the chemical shifts and coupling constants are discussed. The linear correlations between the chemical shifts of the cis and trans CO C, the Si, the P and the Mo resonances of the R ″ = Ph complexes and those of the similar resonances of the R ″ = OCH CMe CH O complexes are also discussed. Good linear correlations have previously been found between the differences in the C chemical shifts of the non‐equivalent cis CO, phenyl C‐1 and phenyl C‐2,6 resonances of a series of Mo(CO) [(Ph PO) Si(Me)R′] complexes [R′ = Me, Et, n‐Pr, c‐Hex, t‐Bu and CH Cl] and the E parameters of the R groups. It is now reported that the chemical shift differences of similar complexes with long‐chain alkyl and chloroalkyl R′ groups do not give good correlations with the E parameters. In addition, similar correlations are not observed when the Ph groups are replaced with an OCH CMe CH O group. The factors which affect the poor correlations are discussed. Copyright © 1986 John Wiley & Sons, Ltd. 4 2 2 2 2 2 2 2 4 2 2 2 2 2 2 2 2 2 2 2 2 2 4 2 2 2 a a 2 2 2 13 29 31 95 13 29 31 95 13
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    Author List

  • Gray GM; Redmill KA
  • Start Page

  • 519
  • End Page

  • 526
  • Volume

  • 24
  • Issue

  • 6