Beiträge zur Chemie des Phosphors, 73: 1,2‐Diphenyldiphosphan

Abstract

Licht, Phosphide sowie starke Sauren und Basen beschleunigt. Mit K(Ph)P -P(Ph)K, Me,Si(Ph)P -P(Ph)SiMe, oder PZPh, reagiert 1 zu den unsymmetrischen Diphosphanen K(Ph)P -P(Ph)H, Me3Si(Ph)P -P(Ph)H bzw. Ph,P -P(Ph)H. Die NMR-, IR-und Raman-Spektren von 1 werden diskutiert. Contributions to the Chemistry of Phosphorus, 73"*)1,2-DiphenyIdiphosphane 1,2-Diphenyldiphosphane (1) is formed, contrary to results given in the literature, by the reaction ofKHPPh with 1,2-dibromoethane. Pure 1 is obtained by hydrolysis or alcoholysis of Me,Si(Ph)P -P(Ph)SiMe, in the dark. It is stable at -30°C. 1 disproportionates at room temperature to give PhPH,, higher homologues of the series H, [PPh],, especially H,[PPh13, and cyclic phenylphosphanes [PPh],, mainly [PPh],. These rearrangements are accelerated by light, phosphides, and strong acids and bases. With K(Ph)P -P(Ph)K, Me3Si(Ph)P -P(Ph)SiMe,, and P,Ph, 1 reacts to give the asymmetric diphosphanes K(Ph)P-P(Ph)H, Me,Si(Ph)P-P(Ph)H, and Ph,P -P(Ph)H, respectively. The NMR, IR, and Raman spectra are discussed.

Catalytic PH Activation by Ti and Zr Catalysts

“…[46,47] Literature precedent has shown disproportionation of (PhPH) 2 affords PhPH 2 , cyclic oligomers (RP) n and Ph(H)PA C H T U N G T R E N N U N G (PPh) n P(H)Ph (predominantly n = 3). [46] Upon prolonged heating three additional signals appeared which were assigned to (PPh) 4 , [48] (PPh) 5 [49] and (PPh) 6 . [48] By integration, (PPh) 5 is the major product although it is also known that (PPh) 4 and (PPh) 6 disproportionate to (PPh) 5 upon heating.…”

“…31 P NMR spectra of the reaction mixtures (Figure 1) showed resonances at d À65.1 and À68.4 ppm that were assigned to meso and racemic (PhPH) 2 . [40,45,46] In addition, a series of minor peaks located between d À35 and À70 ppm have been tentatively assigned to Ph(H)PP(Ph)P(Ph)P(H)Ph and higher oligomers Ph(H)PA C H T U N G T R E N N U N G (PPh) n P(H)Ph. [46,47] Literature precedent has shown disproportionation of (PhPH) 2 affords PhPH 2 , cyclic oligomers (RP) n and Ph(H)PA C H T U N G T R E N N U N G (PPh) n P(H)Ph (predominantly n = 3).…”

“…[40,45,46] In addition, a series of minor peaks located between d À35 and À70 ppm have been tentatively assigned to Ph(H)PP(Ph)P(Ph)P(H)Ph and higher oligomers Ph(H)PA C H T U N G T R E N N U N G (PPh) n P(H)Ph. [46,47] Literature precedent has shown disproportionation of (PhPH) 2 affords PhPH 2 , cyclic oligomers (RP) n and Ph(H)PA C H T U N G T R E N N U N G (PPh) n P(H)Ph (predominantly n = 3). [46] Upon prolonged heating three additional signals appeared which were assigned to (PPh) 4 , [48] (PPh) 5 [49] and (PPh) 6 .…”

Syntheses, Crystal Structures and Reactivity of Organometallic Tantalum(IV) Phosphinidene Complexes: trans-[{Cp*TaCl(μ-PR)}2] (Cp* = C5Me5, R = Cy, tBu, Ph), cis- and trans-[{Cp*TaCl(μ-PMes)}2] (Mes = 2,4,6-Me3C6H2) and cis-[{Cp′TaCl(μ-PMes)}2] (Cp′ = C5H4Me)

“…[33] Cy: δ ϭϪ68.3 (s, PCy) 4 , Ϫ84.3 and Ϫ87.5 (m, rac-and meso-P 2 H 2 Cy 2 ), [29] Ϫ111.0 (t, PH 2 Cy) ppm. [29,34] Ϫ67.4, Ϫ70.9 (m, meso-and rac-P 2 H 2 Ph 2 ; the signal for the unstable diphosphane disappears after two days), [35,36] Ϫ122.1 (t, PH 2 Ph) ppm. 13 13 (20 mL) was cooled to Ϫ70°C, and one equivalent of LiPHMes (0.15 g, 0.98 mmol) was added to the stirred reaction mixture over 3 h. The resulting suspension was stirred at Ϫ70°C for 2 h, and then slowly warmed to room temperature and stirred overnight.…”

Phosphinocyclopentadienid via Cyclopentadienylphosphid/ Phosphinocyclopentadienide via Cyclopentadienylphosphide

“…Als K ronenether-N atrium salz haben die beiden D iastereo m eren 2 fast gleich große PP-K opplungskonstanten. In gleicher G rö ß e w ird '/pp auch für die beiden diastereo m eren D iphosp h an e H -P h P -P h P -H [13] und für die threo/threo- Die Gleichgewichte (b) der zugehörigen N eutral verbindungen tendieren natürlich noch weiter nach links; ein Cyclopentadienylphosphan lagert dem ent sprechend nicht ins Phosphonium-ylid um [26,27].…”