N-Phosphino-amidines and -guanidines: synthesis, structure and P,N-chelate chemistry.

Baiget, Lise; Batsanov, Andrei S.; Dyer, Philip W.; Fox, Mark A.; Hanton, Martin J.; Howard, Judith A.K.; Lane, Philip K.; Solomon, Sophia A.

Abstract

The syntheses of the cyclic N-phosphino-amidines and -guanidines Ph2PN(Pri)C(NPri2)N(Pri) (1) and Ph2PN(c-Hex)C(R)N(c-Hex) [R = piperazino (2), morpholino (3), Me (4), and Ph (5)] are reported. DFT studies have identified the preferred structures for compounds 1–5 with the E-configuration being the most stable form for the N-phosphino-amidines, while the Z-conformation is preferred for the N-phosphino-guanidines something that highlights the potential of such systems to act as κ2-P,N-chelates. The differences in donor characteristics of 2–5 have been probed through the study of their corresponding P(V) selenide derivatives (6–9) and their complexes with the cis-RhCl(CO) (10–12) and cis-PdCl2 (13–17) fragments. In line with the DFT studies both the amidines and guanidines are found to coordinate as κ2-P,N-chelates, with the latter being moderately weaker donor ligands. The molecular structures of compounds 3 and 4, together with those of the Rh and Pd complexes 10 and 15, respectively, have been determined in the solid state by X-ray crystallography, the latter confirming bidentate κ2-P,N-chelation.

Citation

Baiget, L., Batsanov, A. S., Dyer, P. W., Fox, M. A., Hanton, M. J., Howard, J. A., Lane, P. K., & Solomon, S. A. (2008). N-Phosphino-amidines and -guanidines: synthesis, structure and P,N-chelate chemistry. Dalton Transactions, 2008(8), 1043-1054. https://doi.org/10.1039/b715736c

• Journal Article Type: Article
• Acceptance Date: Nov 21, 2007
• Online Publication Date: Jan 8, 2008
• Publication Date: Jan 8, 2008
• Deposit Date: Dec 14, 2011
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 2008
• Issue: 8
• Pages: 1043-1054
• DOI: https://doi.org/10.1039/b715736c
• Public URL: https://durham-repository.worktribe.com/output/1533116