Structural investigations of phosphorus-nitrogen compounds. 7. Relationships between physical properties, electron densities, reaction mechanisms and hydrogen-bonding motifs of N3P3Cl(6-n)(NHBut)(n) derivatives
Bartlett, S.W. and Coles, Simon J. and Davies, David B. and Hursthouse, Michael B. and Ibişoğlu, H. and Kiliç, A. and Shaw, Robert A. and Ün, İ. (2006) Structural investigations of phosphorus-nitrogen compounds. 7. Relationships between physical properties, electron densities, reaction mechanisms and hydrogen-bonding motifs of N3P3Cl(6-n)(NHBut)(n) derivatives. Acta Crystallographica Section B: Structural Science 62 (2), pp. 321-329. ISSN 0108-7681.
A series of compounds of the N3P3Cl(6-n)(NHBut)n family (where n = 0, 1, 2, 4 and 6) are presented and their molecular parameters are related to trends in physical properties, which provides insight into a potential reaction mechanism for nucleophilic substitution. The crystal structures of N3P3Cl5(NHBut) and N3P3Cl2(NHBut)4 have been determined at 120K and those of N3P3Cl6 and N3P3Cl4(NHBut)2 have been re-determined at 120K. These are compared with the known structure of N3P3(NHBut)6 studied at 150K. Trends in molecular parameters (phosphazene ring, P-Cl & P-N(HBut) distances, PCl2 angles and endo- and exo-cyclic phosphazene ring parameters) across the series are observed. Hydrogen-bonding motifs are identified, characterised and compared. Both the molecular and hydrogen bonding parameters are related to the electron distribution in bonds and the derived basicities of the cyclophosphazene series of compounds. These findings provide evidence for a proposed mechanism for nucleophilic substitution at a phosphorus site bearing a PCl(NHBut) moiety.
|Additional Information:||The definitive version is available at www.blackwell-synergy.com|
|Keyword(s) / Subject(s):||structure-property relationships, cyclophosphazenes, hydrogen bonding, structural systematics|
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Depositing User:||Sandra Plummer|
|Date Deposited:||07 Jun 2006|
|Last Modified:||17 Apr 2013 12:32|
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