Synthesis, structure and reactivity of ferrio-chloro-phosphanes, -arsanes and -stibanes [(CO)2(eta5-C5Me5)FePn(Cl)R] (Pn = P, As, Sb); R = tetramethylcyclopentadienyl, 2,7-di-tert-butylfluorenyl, 2,7-di-tert-butyl-9-trimethylsilylfluorenyl) as precursor to novel metallo-phosphaalkenes, -arsaalkenes, and -stibaalkenes.
Reaction of one equivalent of the complexes [FeCp*(CO)2PnCl2] (Pn = P, As, Sb) with tetramethylcyclopentadienyllithium afforded compounds [FeCp*(CO)2[Pn(Cl)(C5Me4H)]]. Dehydrochlorination by means of tert-butyllithium led to decomposition. Only in the case of the phosphorus compound was evidence for the initial formation of a phosphaalkene given by 31P NMR spectroscopy. Similarly treatment of equimolar amounts of [FeCp*(CO)2PnCl2] with 2,7-di-tert-butyl-9-H-fluorenyllithium or 2,7-di-tert-butyl-9-trimethylsilylfluorenyllithium yielded the asymmetrically substituted ferriopnicogenanes [FeCp*(CO)2[Pn(Cl)-9-R-Fl*]] (Pn = P, As, Sb; R = H, Me3Si; Fl* = 2,7-di-tert-butylfluorenylidene). Dehydrohalogenation of [FeCp*(CO)2[Pn(Cl)-9-H-Fl*]] with lithium diisopropylamide resulted in the formation of the anticipated phosphaalkene [FeCp*(CO)2[P = Fl*]], whereas in the case of the arsenic and antimony derivatives the novel ferriopnicogenanes [FeCp*(CO)2[Pn(9-H-Fl*)2]] (Pn = As, Sb) were obtained as products. The new compounds were characterized by elemental analyses and spectra (IR, 1H, 13C, 29Si, 31P NMR). The molecular structures of [FeCp*(CO)2[Pn(Cl)(C5Me4H]]] (Pn = As, Sb), [FeCp*(CO)2[As(Cl)(9-Me3Si-Fl*)]] and [FeCp*(CO)2[Sb(9-H-Fl*]2] were elucidated by single X-ray diffraction analyses.
Weber
Lothar
L
Fakultät für Chemie der Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany. lothar.weber@uni-bielefeld.de
Pumpenmeier
Lars
L
Stammler
Hans-Georg
HG
Neumann
Beate
B
D000475:Alkenes / Q000737:chemistry*; D000965:Antimony / Q000737:chemistry*; D001151:Arsenic / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010720:Phosphines / Q000737:chemistry*
D000475:Alkenes; D005290:Ferric Compounds; D009942:Organometallic Compounds; D010720:Phosphines; D002713:Chlorine; D000965:Antimony; C044646:phosphine; D001151:Arsenic