168398-77-4Relevant academic research and scientific papers
Reactivity of cationic transition-metal phosphenium complexes
Nakazawa, Hiroshi,Yamaguchi, Yoshitaka,Miyoshi, Katsuhiko
, p. 129 - 132 (1996)
Reactivity of cationic transition-metal phosphenium complexes has been investigated. Reaction of mer-[(bpy)(CO)3M{PN(Me)CH2CH2NMe}]+ (M = Cr, Mo, W) with X-(X = Me, OEt) exhibits a nucleophilic attack at the phosphenium phosphorus, whereas that with L (L = phosphine, phosphite) shows CO/L substitution. Iron phosphenium complexes, [Cp(CO)RFe-{PN(Me)CH2CH2NMe}]+ undergoes a migratory insertion of the phosphenium ligand into the Fe-alkyl bond.
Cationic phosphenium complexes of group 6 transition metals: Reactivity, isomerization, and X-ray structures
Nakazawa, Hiroshi,Yamaguchi, Yoshitaka,Mizuta, Tsutomu,Miyoshi, Katsuhiko
, p. 4173 - 4182 (2008/10/09)
The reaction of cationic diamino-substituted phosphenium complexes of group 6 transition metals mer-[(bpy)(CO)3M{PN(Me)CH2CH2NMe}]+ (M = Cr, Mo, W) with L (L = PN(Me)CH2-CH2NMe(OR) (R = Me, Et), PPh3) proceeds with substitution of L for CO to produce [(bpy)-(CO)2LM{PN(Me)CH2CH2NMe}]+. During the reaction, the phosphenium ligand remains intact. The product consists of trans (two phosphorus ligands are mutually trans) and cis isomers, and they equilibrate. The cis form is electronically and the trans form is sterically favored. A similar reaction takes place when cationic monoamino-substituted phosphenium complexes are treated. Complexes trans-[(bpy)(CO)2{PN(Me)CH2CH 2NMe(OMe)}Mo{PN-(Me)CH2CH2NMe}]·OTf (trans-2a·OTf) (OTf = SO3CF3) and trans-[(phen)(CO)2{PN(t-Bu)CH2-CH 2O(OMe)}Mo{PN(t-Bu)CH2CH 2O}]·OTf·CH2Cl2 (trans-2j·OTf·CH2Cl2) have been characterized by X-ray diffraction. The bond distance of Mo-P(phosphenium) is significantly shorter than that of Mo-P(phosphite) for both complexes: for trans-2a, 2.254 A? vs 2.495 A? and, for trans-2j, 2.238 A? vs 2.529 A?, indicating a significant double bond character between Mo and P(phosphenium). For both complexes, the P-N bond distances in phosphenium and in phosphite ligands are almost equal, indicating that there is no significant N → P(phosphenium) π donation. The role of the amino groups on the phosphenium phosphorus is probably to protect the approach of a nucleophile to phosphenium phosphorus by high pπ lone pair density flanking the phosphenium center.
