A number of organometallic complexes involving manganese, bonded to silicon, tin, lead and phosphorus ligands, and nickel, bonded to various trialkylphosphine ligands, has been synthesized and their crystal structures, vibrational, and multinuclear magnetic resonance spectra have been obtained. The FT-IR and FT-Raman spectra of the manganese carbonyl compounds in the carbonyl region (2200--1850 cm--1) have been assigned. Solid-state, CP-MAS, 13C, 29Si, 31P, 117Sn, 119Sn and 207Pb NMR spectra of substituted pentacarbonylmanganese(I) and tetracarbonylmanganese(I) complexes feature asymmetric sextets, whereas those containing a group 14 (IVA) element bridging two pentacarbonylmanganese(I) moieties show asymmetric sextets. The uneven splitting arises from spin-spin coupling and second-order quadrupole-dipole effects, which are not eliminated by magic angle spinning. The solid-state NMR spectra of the manganese complexes have been analyzed to give the isotropic chemical shifts, the chemical shift tensors, one-bond spin-spin coupling constants, 55Mn nuclear quadrupole coupling constants, effective dipolar coupling constants and the anisotropies; in the spin-spin coupling for each complex. The results provide new insights into the relationship between spin-spin coupling and quadrupolar coupling in bimetallic complexes involving a quadrupole transition-metal and a spin-1/2 nucleus. / For the para-substituted triaryltin complexes, the 13C, 55Mn and 119Sn chemical shifts and one-bond spin-spin constants in solution show excellent correlations with pairs of substituent constants (sigmaI, sigmaR). However, there is no correlation of the chemical shifts or spin-spin coupling with either Hammett (sigmaP) or Taft (sigmaP o) constants or the Mn-Sn bond lengths, rMn-Sn. The results obtained from dual substituent parameter (DSP) analysis indicate that both resonance effects (sigmaR) and inductive effects (sigma I) are important in determining the NMR parameters. / Crystal structures and high-resolution solution and solid-state 31P NMR spectra were obtained for several dihalobis(trialkylphosphine)nickel(II) complexes. The crystal structures and NMR results indicate that these complexes are trans square-planar in the solid-state. The chemical shifts and shift tensors were obtained and found to vary with the electronic properties of the halogens. The 31P isotropic chemical shifts in the solution spectra of dibromo- and diiodiobis(tribenzylphosphine)nickel(II) are very different from those found for the solid-state, and chemical exchange effects were observed in all spectra. The mechanism of exchange appears to involve the formation of dimers with bridging halides.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.34928 |
| Date | January 1998 |
| Creators | Christendat, Dharamdat. |
| Contributors | Gilson, Denis F. R. (advisor), Butler, Ian S. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001610058, proquestno: NQ44384, Theses scanned by UMI/ProQuest. |
Page generated in 0.0029 seconds