Thesis-1999-Birdsall.pdf (3.39 MB)
Dithioimidophosphinates and related systems
thesis
posted on 2012-12-17, 14:54 authored by David J. BirdsallThe condensation reaction of iPr2PCl with hexamethyldisilazane, HN(SiMe3)2,
followed by oxidation with sulfur, selenium or hydrogen peroxide yields
Pr2P(E)NHP(E'),iPr2, where E = S, Se or 0. Single crystal X-ray experiments give a
hydrogen bonded chain in all cases. Analogous PhO, EtO, Et and Ph substituted
compounds were synthesised via condensation reactions between R2P(S)NH2 and
R'P(S)CI yielding R2P(S)NHP(S)R'2 (R =PhO, Ph; R' = iPr, Et, EtO). Further
crystallographic studies revealed iPr2P(S)NHP(S)(OPh)2 and Et2P(S)NHP(S)Ph2 to be
hydrogen bonded dimers and iPr2P(S)NHP(S)Ph2 and Et2P(S)NHP(S)(OPh)2 to be
hydrogen bonded chains. Reacting these compounds with Zn, Cd, Pd and Pt chlorides
led to the formation of tetrahedral and square planar coordination complexes.
Crystallographic studies on the complexes of R2P(E)NHP(E')R'2 revealed surprising
ME2P2N ring geometries, some adopting pseudo "boat" conformations and others
adopting pseudo "chair" conformation. Reactions of R2P(S)NHP(S)R'2 with CuC12
yielded trimeric copper(I) complexes of the type CU3[R2P(S)NP(S)R' 2]3. The
trimeric system was found to be fluxional in solution. Crystallographic studies on the
complexes show the trimer to have CU3S3 core. Further reactions of
R2P(S)NHP(S)R' 2 with various tellurium (H) and (IV) salts yielded complexes of the
types Te[R2P(S)NP(S)R' 2]2 and Te[R2P(S)NP(S)R' 2]Cl2,C6H4.0CH3.
Crystallographic studies on the complexes show the tellurium to adopt pseudo two
coordinate, four coordinate (square planar) and five coordinate (square based
pyramid) arrangements.
Tetradentate ligands of the type R2P(S)NHP(S)Ph(CH2)3P(S)PhNHP(S)R2 (where R =
Ph or OPh) were synthesised by the condensation of NH2P(S)Ph(CH2)3P(S)PhNH2
with R2P(S)CI. Preliminary coordination studies suggest the formation of ML
complexes were M = Zn, Cd and Ni. Molecular modelling techniques were used to
investigate the optimum size of the "spacer groups" which links the two
dithioimidophosphinate ligands. Using MNDOd and DFT optimisations, and with
comparison to unlinked examples, the size of the ideal group was determined with
respect to each particular metal.
History
School
- Science
Department
- Chemistry
Publisher
© D. J. BirdsallPublication date
1999Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.Language
- en