Addition-Isomerization Polymerization of Chiral Phosphaalkenes: Observation of Styrene–Phosphaalkene Linkages in a Random Copolymer

Abstract

These studies provide the first evidence for styrene–phosphaalkene connectivities in a phosphaalkene copolymer. The synthesis and structural characterization of new phosphaalkene–oxazolines, ArPC­(Ph)­(3-C6H4Ox) [1a,b, Ar = Mes (1a), Mes* (1b), Ox = CNOCH­( i Pr)­CH2], are reported. The radical-initiated homo- and copolymerization of 1a with styrene affords P-functional poly­(methylene­phosphine) (4a: M n = 5300 g mol–1, PDI = 1.2) and poly­(methylene­phosphine-co-styrene) (5a: M n = 4000 g mol–1, PDI = 1.1). Multinuclear NMR spectroscopic analyses of 4a and 5a provided evidence for the predominance of an addition-isomerization mechanism for the radical polymerization of 1a. In addition, signals could be assigned to CHPh–P­(CHPhAr) (i.e., S–1a) and ArCH2–CH2 (i.e., 1a–S) linkages in copolymer 5a. With a monomer feed ratio of 1a:S (1:2, 33 mol % 1a) the inverse gated 13C­{1H} NMR spectrum suggested an incorporation of 19 mol % 1a in copolymer 5a. Polymers 4a and 5a were further functionalized to Au­(I)-containing macromolecules [4a·AuCl: M n = 13 000, PDI = 1.2; 5a·AuCl: M n = 7500, PDI = 1.1].

PhP=CPh2 and Related Phosphaalkenes: A Solution Equilibrium between a Phosphaalkene and a 1,2‐Diphosphetane

“…We have recently shown that the radical‐initiated polymerization of MesP=CPh 2 using Ph(Me)CH · TEMPO proceeds via an unexpected addition‐isomerization mechanism involving H‐atom transfer from the o ‐Me group of the P ‐Mes substituent. [13e] A similar observation has been made for the anionic polymerization of MesP=C(Ph)Ar (Ar = naphthyl)[13d] and the radical copolymerization of MesP=C(Ph)CMe 2 Ox (Ox = oxazoline) and styrene. [13b] Although still under investigation, this fascinating addition–isomerization polymerization mechanism may apply to all P ‐Mes‐containing phosphaalkenes.…”

“…We have been interested in systematically developing the addition polymerization of E=E′ multiple bonds, by analogy to that of olefins, as a route to new functional polymers , . To this end, we have polymerized the phosphaalkene MesP=CPh 2 and related P ‐Mes monomers by using thermal, radical and anionic methods of initiation and have reported extensively on the novel chemical and physical properties of the resultant poly(methylenephosphine)s . We have recently shown that the radical‐initiated polymerization of MesP=CPh 2 using Ph(Me)CH · TEMPO proceeds via an unexpected addition‐isomerization mechanism involving H‐atom transfer from the o ‐Me group of the P ‐Mes substituent.…”

Thorium(IV) and Uranium(IV) Phosphaazaallenes

“…The reactivity of metal-phosphido complexes is of interest for the development of hydrophosphination catalysts as well as the synthesis of phosphorus-element multiple bonds. For example, phosphaalkenes, P=C, have attracted interest for building blocks in organophosphorus chemistry [1][2][3], ligands to transition metal complexes [4,5], as well as potential applications as functional materials [6][7][8][9][10]. After nearly 20 years of dormancy [11][12][13][14][15], actinide-phosphorus has received greater attention recently [16][17][18][19] with researchers examining similarities and differences in the molecular and electronic structure of its more studied congener, nitrogen.…”

Zig‐Zag Diphosphene Oligomers Linked by Silver(I) Cation

“…Phosphorus has been well‐known as ‘carbon analog’, however phosphorus‐based oligomers or polymers are much less reported . Gates et al . and Protasiewicz et al .…”