202932-96-5Relevant academic research and scientific papers
Platinum(II) phosphido complexes as metalloligands. Structural and spectroscopic consequences of conversion from terminal to bridging coordination
Scriban, Corina,Wicht, Denyce K.,Glueck, David S.,Zakharov, Lev N.,Golen, James A.,Rheingold, Arnold L.
, p. 3370 - 3378 (2008/10/09)
Treatment of the terminal phosphido complexes Pt(dppe)(Me)(PPh(R)) (R = Ph (1), i-Bu (6)) with Pt(dppe)(Me)(OTf) gave the cationic μ-phosphido complexes [(Pt(dppe)(Me))2(μ-PPh(R))][OTf] (R = Ph (7), i-Bu (8)). Similarly, Pt((R,R)-Me-Duphos)(Me)(PPh(i-Bu)) (10) was converted to [(Pt((R,R)-Me-Duphos)(Me))2(μ-PPh(i-Bu))][OTf] (11). A fluxional process in 8 and 11, presumably involving hindered rotation about the Pt-PPh(i-Bu) bonds, was observed by NMR spectroscopy; it resulted in two diastereomers for 8 and four for 11 at low temperature. Coordination of the metalloligand 10 to the [Pt((R,R)-Me-Duphos)(Me)]+ fragment, yielding 11, resulted in structural changes at the Pt-phosphido group, whose geometry changed from distorted pyramidal to tetrahedral. Decomposition of 6 also gave the cation 8, while oxidation of 6 with H2O2 gave the crystallographically characterized phosphido oxide complex Pt(dppe)(Me)(P(O) Ph(i-Bu)) (12).
Terminal platinum(II) phosphide complexes: Synthesis, structure, and thermochemistry
Wicht, Denyce K.,Paisner, Sara N.,Lew, Belinda M.,Glueck, David S.,Yap, Glenn P. A.,Liable-Sands, Louise M.,Rheingold, Arnold L.,Haar, Christopher M.,Nolan, Steven P.
, p. 652 - 660 (2008/10/08)
A series of terminal Pt(II) phosphide complexes Pt(dppe)(Me)(PRR′) (R = H; R′ = Mes* (1), R′ = Mes (2), R′ = Ph (3), R′ = Cy (4); R = R′ = Mes (5); R = R′ = Ph (6); R = R′ = Cy (7); R = R′ = Et (8); R = Ph, R′ = i-Bu (9)) has been prepared by proton transfer from the appropriate phosphine to the methoxide ligand of Pt(dppe)(Me)(OMe) (10) (dppe = Ph2PCH2-CH2PPh2; Mes* = 2,4,6-(t-Bu)3C6H2; Mes = 2,4,6-Me3C6H2; Cy = cyclo-C6H11). Complexes 1 and 2 were also made by deprotonation of the cations [Pt(dppe)(Me)(PH2Ar)][BF4] (Ar = Mes* (13); Ar = Mes (14)). For comparison to 1, the arylthiolate and aryloxide complexes Pt(dppe)(Me)(EMes*) (E = S (11); E = O (12)) were also prepared from 10. NMR studies of the proton-transfer equilibria between Pt(dppe)(Me)(X), Pt(dppe)(Me)(Y), and the acids HY and HX (see Bryndza, H. E.; Fong, L. K.; Paciello, R. A.; Tam, W.; Bercaw, J. E. J. Am. Chem. Soc. 1987, 109, 1444-1456 and Bryndza, H. E.; Domaille, P. J.; Tam, W.; Fong, L. K.; Paciello, R. A.; Bercaw, J. E. Polyhedron 1988, 7, 1441-1452) provide an approximate partial ranking of Pt-P bond strengths in this series: Pt-PHPh > Pt-PHMes > Pt-PHMes*; Pt-PPh2 > Pt-PMes2. Complementary solution calorimetry investigations probe the role of entropie effects on the equilibria. Both steric and electronic factors appear to be important in controlling relative Pt-P bond strengths. The Pt-S bonds in 11 and Pt(dppe)(Me)(SPh) are stronger than the analogous Pt-P bonds in 1 and 3. Complexes 1 and 5·THF were structurally characterized by X-ray crystallography.
