110718-08-6Relevant academic research and scientific papers
Preparation and characterization of triphospholene complexes of zerovalent platinum: Crystal and molecular structure of [Pt{(CF3)P(CF3)P(CF3)PC(CF 3)=C(CF3)}(PPh3)2]
Phillips, Ian G.,Ball, Richard G.,Cavell, Ronald G.
, p. 4074 - 4079 (2008/10/08)
The triphospholene (CF3)P(CF3)P(CF3)P(CF3)C=C(CF 3) (L) reacts with [Pt(PEt3)4] or [Pt(η2-C2H4)(PPh3)2] at -50°C in chloroform or toluene solution to give unidentified red complexes that decompose at +25°C to give the complexes [Pt(L)(PR3)2] (R = Et (I), Ph (II)). The latter complex (II) (η2(C4,C 5)-1,2,3,4,5-pentakis(trifluoromethyl)-1,2,3-triphosphol-4-ene) bis(triphenylphosphane)platinum(0), [Pt{(CF3)P(CF3)P(CF3)PC(CF 3)=C(CF3)}(PPh3)2], crystallizes in the monoclinic space group P21/n with four molecules per unit cell of dimensions a = 12.244 (2) A?, b = 17.400 (3) A?, c = 21.209 (5) A?, and β = 96.70 (2)°. The structural determination that gave the positional parameters for all the non-hydrogen atoms converged to R1 = 0.038 and R2 = 0.029 for 7049 reflections having 2θMo Kα ≤ 56.00° and I > 3σ(I). The structure analysis revealed that the triphospholene ligand in II is almost planar and is coordinated to the metal through its olefinic functional group. Principal bond lengths in II are as follows: C=C, 1.490 (9) A?; P-P, 2.175 (3) and 2.191 (4) A?; Pt-C(olefin)av, 2.096 (6); and P-C(olefin)av, 1.837 (8) A?. One fluorine of the unique PCF3 group of the coordinated ring approaches to within 3.309 A? of the metal. This agostic Pt-F interaction appears to persist in solution in both complexes as indicated by an unusual spin-spin coupling constant between Pt and F in the 19F NMR spectrum and an anomalously large shift to low field of the phosphorus resonance for the phosphorus atom with which the coupled fluorines are associated.
