Disubstituted derivatives of (L—L)Fe₂(CO)₆ (L—L = fluorocarbon bridged ligand)

Abstract

The complexes (L—L)Fe2(CO)6 react with a range of bidentate ligands to give the complexes (L—L)′(L—L)Fe2(CO)4 ((L—L) = fluorocarbon-bridged ligand such as f4fars, f4AsP etc. (L—L)′ = fluorocarbon- and hydrocarbon-bridged ligands such as f4AsP diars etc.). Spectroscopic studies, in particular magnetically perturbed Mössbauer measurements, indicate that (L—L)′ in most complexes is chelated to one iron atom, FeA. This leaves one CO group on FeAcis to the FeA—FeB bond and three on FeB. A smaller class of derivatives appear to have (L—L)′ bridging the two iron atoms cis to the FeA—FeB bond. The sign of Vzz is positive at both iron sites in the bridged derivatives. It is negative at FeA and positive at FeB in the other complexes.

A new route to achiral and chiral 1,2-bis(phosphino)ethanes, 1-arsino-2-phosphinoethanes, and 1,3-bis(phosphino)propanes and the molecular structure and catalytic activity of some rhodium(i) complexes derived thereof Dedicated to Professor Wolfdieter A. Schenk, a respected colleague and creative scientist, on the occasion of his 60th birthday.

“…The one-pot procedure for the new unsymmetrical 1,2bis(phosphino)ethanes is not only remarkable because of its easy synthetic approach, short reaction times and efficiency (except for 2d), but also because it can be extended to related 1-arsino-2phosphinoethanes (see Scheme 1). As far as we know, up to now only two compounds of the general composition R 2 AsCH 2 CH 2 PR′ 2 , namely Ph 2 AsCH 2 CH 2 PPh 2 12 and Me 2 AsCH 2 CH 2 PPh 2 13 have been reported in the literature; however, for the latter of those no detailed preparative procedure and analytical data were given. The new method described herein furnishes the bidentate systems 3a-c in good yields.…”

A New Synthetic Route to Unsymmetrical 1,2-Bis(phosphanyl)ethanes and 1,2-Arsanyl(phosphanyl)ethanes with and without a Stereogenic Center

“…Up to now, only two examples of compounds of the general composition R 2 AsCH 2 CH 2 PR' 2 , namely Ph 2 AsCH 2 CH 2 PPh 2 [10] and Me 2 AsCH 2 CH 2 PPh 2 , [11] were known; however, for the latter of those no detailed preparative procedure and analytical data were given. Moreover, the synthetic strategy can be extended to related 1,2-arsanyl(phosphanyl)ethanes (Scheme 1).…”

“…Moreover, the synthetic strategy can be extended to related 1,2-arsanyl(phosphanyl)ethanes (Scheme 1). Up to now, only two examples of compounds of the general composition R 2 AsCH 2 CH 2 PR' 2 , namely Ph 2 AsCH 2 CH 2 PPh 2 [10] and Me 2 AsCH 2 CH 2 PPh 2 , [11] were known; however, for the latter of those no detailed preparative procedure and analytical data were given. The new synthetic method described herein furnishes the chelating systems 3 a ± c in good yields.…”

Ein neuer Weg zu unsymmetrischen 1,2-Bis(phosphanyl)ethanen und 1-Arsanyl-2-phosphanylethanen mit und ohne stereogenes Zentrum

“…Von Verbindungen der allgemeinen Zusammensetzung R 2 AsCH 2 CH 2 PR' 2 waren bisher nur Ph 2 AsCH 2 -CH 2 PPh 2 [10] und Me 2 AsCH 2 CH 2 PPh 2 [11] bekannt, wobei von letzterem noch keine genaue Synthesevorschrift und keine analytischen Daten vorliegen. Nach der von uns entwickelten Methode sind die Chelatliganden 3 a ± c problemlos und mit guten Ausbeuten erhältlich.…”

“…Die Eintopfsynthese der erstmals hergestellten unsymmetrischen 1,2-Bis(phosphanyl)ethane 2 a ± d zeichnet sich nicht nur durch einfache Durchführbarkeit, kurze Reaktionszeiten und hohe Effizienz (Ausnahme 2 d) aus, sondern sie lässt sich auch auf 1-Arsanyl-2-phosphanylethane übertragen (siehe Schema 1). Von Verbindungen der allgemeinen Zusammensetzung R 2 AsCH 2 CH 2 PR' 2 waren bisher nur Ph 2 AsCH 2 -CH 2 PPh 2 [10] und Me 2 AsCH 2 CH 2 PPh 2 [11] bekannt, wobei von letzterem noch keine genaue Synthesevorschrift und keine analytischen Daten vorliegen. Nach der von uns entwickelten Methode sind die Chelatliganden 3 a ± c problemlos und mit guten Ausbeuten erhältlich.…”