Chemistry of the Trifluoromethyl Group: Part Iii. Phenylbistrifluoromethylphosphine and Related Compounds

Abstract

PART 111. PHENYLBISTRIFLUOROMETHYLPHOSPHINE AND RELATED COMPOUNDS1 ABSTRACT 'I'he reaction of trifluoroiodomethane with tetraphenylcyclotetraphosphine leads to the rormation of ~henvlbistrifluoromethvl~hos~hine and ~he~lvltrifluoromethvliodo~hos~hine. The mechanism of t h e reaction is discusseh and the physfcal and chemical prbpert'ies of these compounds itre reported. Bromine reacts with phenylbistrifluoromethylphosphine to form phenylbistrifluoron~ethyldibromophosphorane which is hydrolyzed to phenyltrifluoromethylphosphinic acicl, CGH~(CF~)P(O)OH. INTRODUC'I'IONIn previous papers in this series, the donor properties of methyl-trifluorometh ylphosphines were studied by the investigation of their ability , t o form complexes with boron trifluoride and platinuin (11) chloride ( I ) , and with a series of nickel (11) salts (2). Since much is known of the corresponding coinplexes of aryl phosphines, it seemed worthwhile to study the donor properties of aryl-trifluoron~ethyl-phosphines. Unlike the inethyl-trifluoroitiethyl-phosphines which have been known for some time (3, 4, 5), the phenyl-trifluoromethyl-phosphines had not been previously reported, although their arsine a~ialogues had been prepared (6). We now report the preparation of phenylbistrifluoroniethylphosphine. DISCUSSION AND RESULTSPhe~~ylbistrifluoron~etl~ylphosphiiie has been prepared by the reaction of trifluoroiodomethane with tetraphe~~ylcyclotetraphospl~i~~e, the properties of which have been reported by other workers (7,8,9). The reaction was performed a t 185', above the melting point of the tetraphosphine, and the other reaction products, besides phenylbistrifluoronlethylphosphine, are phenyltrifluorometl~yliodophosphine, which is a very illvolatile reddish brown liquid, and small amounts of fluoroform and hexafluoroethane.The mechanism of this reaction, involving the interaction of a perfluoroiodoalkane with a four-membered phosphorus ring is of some interest. R free-radical mechanism involving fission of phosphorus-phosphorus bonds by the attack of CFS radicals seems probable. This is supported by the fact that the reaction will occur thermally or on ultraviolet irradiation of the tetraphosphine with trifluoroiodomethane. Since the simultaneous breaking of four P-P l~o n d s is unlikely, the following reaction scheme inay be suggested. For personal use only.

CHEMISTRY OF THE TRIFLUOROMETHYL GROUP: PART V. INFRARED SPECTRA OF SOME PHOSPHORUS COMPOUNDS CONTAINING CF3

“…The preparations of the co~npounds have been described in detail elsewhere (5)(6)(7)(8)(9). Infrared absorption spectra were recorded in the 650-4000 cm-I range, using a Perliin-Elmer model 21 double-beam spectrophotome~er fitted with NaCl optics, and operated a t a slit program setting of 927.…”

Gas‐Phase Fluorination of Hexagonal Boron Nitride

“…The sharp vibrational peak centered around 779 cm −1 is characteristic of the out of the plane (A 2u mode), and the broader peak at ≈1363 cm −1 resembles the in‐plane vibrations (E 1u mode) of the h BN, which matches with the previous reports. [ 29 ] The F‐ h BN samples displayed new peaks at ≈523 cm −1 , between 1020–1070 cm −1 , and 3200 cm −1 (Figure 1c and Figure S2, Supporting Information), which correspond to the newly formed N‐F and B‐F bands; [ 30,31 ] the predominant peaks spotted around 1020–1070 and 3200 cm −1 correspond to the presence of covalent B‐F bonds, [ 4,31,28 ] and the weak signals at 523 cm −1 were assigned to the asymmetric N‐F bending vibrations. [ 32–34 ]…”