Formation of a Phosphorus−Phosphorus Bond by Successive One-Electron Reductions of a Two-Phosphinines-Containing Macrocycle: Crystal Structures, EPR, and DFT Investigations

• DOI: 10.1021/ja010331r
• Publication Date: 2002-07-26T04:39:27Z
• Authors: Laurent Cataldo; Sylvie Choua; Théo Berclaz; Michel Geoffroy; Nicolas Mézailles; Louis Ricard; François Mathey; Pascal Le Floch
• Keywords: Crystal (programming language)

Chemical and electrochemical reductions of the macrocycle 1 lead to formation a radical monoanion anion [1](*)(-) whose structure has been studied by EPR in liquid frozen solutions. In accord with experimental (31)P hyperfine tensors, DFT calculations indicate that, this species, unpaired electron is mainly localized bonding sigma P-P orbital. Clearly, one-electron bond (2.763 A) was formed between two phosphorus atoms which, neutral molecule, were 3.256 A apart (crystal structure). subsequent reduction gives rise dianion [1](2)(-) which could be crystallized using, presence cryptand, Na naphthalenide as reductant agent. As shown crystal structure, [1](2)(-), phosphinine moieties adopt phosphacyclohexadienyl are linked length (2.305(2) only slightly longer than usual bond. When not incorporated macrocycle, no any observed: thus, 3 leads spectrum ion pair [3](*)(-) Na(+); however, at high concentration, these pairs dimerize, and, [(3)(2)](2)(-)[(Na(THF)(2))(2)](2+) (2.286(2) rings boat-type conformation, whole edifice being stabilized carbon-sodium-phosphorus bridges.