The syntheses of a series of substituted polyphosphonates of the type [OP(X)(Ar)O(CH2)12]n (X = O, S, Se; Ar = phenyl, 2,2′‐bithienyl‐5‐yl) are reported. The trueM¯ns for the polyphosphonates range from 1.1 to 4.6 × 104 Da and are significantly higher than those previously reported for polyphosphonates synthesized via polycondensation reactions. Thermal characterization indicates that all of the polymers are in the rubbery state at room temperature and have thermal stabilities as high as 290 °C. The linear absorption spectra, emission spectra, and emission quantum yields of the 2,2′‐bithenyl‐5‐yl substituted polyphosphonates show distinct trends with respect to the chalcogen attached to the phosphorus. Solutions of these polymers show emission at wavelengths ranging from 380 to 400 nm and, depending on the choice of X, the quantum yields are considerably larger than that of 2,2′‐bithiophene. Nonlinear optical measurements of the polyphosphonates with 2,2′‐bithenyl‐5‐yl substituents show that nonlinear absorbance increases with increasing molecular weight of X. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3663–3674

Herein, we present the crystal structure, NMR J analysis, and conformational and natural bond order analyses of tricyclic oxocane (1), resulting in the discovery of a long-range Perlin effect at C4 and C5. The normal Perlin effect (NPE) of Δ(1)JC-H = 18.38 Hz at C5 is the largest to date for a nonanomeric methylene due to an unprecedented through-space n → σ* stabilizing interaction. The NPE at C4 where Δ(1)JC-H = 6.91 Hz is nearly double those found in cyclohexanone.

Alkali metal salts can affect both the activities and regioselectivities of alkene hydroformylation catalysts containing polyether-functionalized phosphorus-donor ligands; however, it is unclear whether these effects arise from direct alkali metal cation binding to the active catalysts. To gain more insight into these effects, a series of phosphite-lariat ether ligands derived from the alkali metal cation binding agents 2-hydroxymethyl-12-crown-4 and 2-hydroxymethyl-15-crown-5 have been prepared. Rhodium­(I) complexes of these ligands have been evaluated as styrene hydroformylation catalysts in the absence and presence of a variety of alkali metal salts. The activities of catalysts containing phosphites derived from 2,2′-biphenol or 1,1′-binaphthol increased significantly (up to 92%) in the presence of alkali metal cations that are “moderately oversized” for archetypal binding to the crown cavity. When this criterion are not met, a decrease in the catalytic activity is observed upon addition of an alkali metal salt. NMR titrations (31P­{1H} and 1H) of two model cis-Mo­(CO)4(phosphite-lariat)2 complexes in which the phosphite was derived from 2,2′-biphenol were carried out to gain insight into the manner in which the alkali metal cations interact with the ligands. Both model complexes bind Li+ through a 2:1 two-site binding mechanism, and the model complex with the larger crown ether also binds Na+ in this fashion. In contrast, 1:1 complexes are formed upon Na+ and K+ binding to the model complex containing the smaller crown ether and upon K+ binding to the model complex containing the larger crown ether. Correlation between increases in catalyst activity and binding mode in complexes containing cations “moderately oversized” for archetypal binding to the crown cavity strongly suggests that the increases are due to a specific type of alkali metal cation binding by the lariat ether groups in these catalysts.

Ring-opening polymerization of anionic polyamide-6 (APA-6) requires both an activator and an initiator for the reaction to occur. Typical processing techniques for liquid-molded thermoplastic composite laminates involve infusion of the reinforcement with a premixed monomer solution containing both activator and initiator species. The technique described here is a step toward simplification and automation of the in situ polymerization process for composite laminates. By depositing the initiation functional group onto the reinforcement, infusion of a single stream of inert monomer solution is possible. The technique simplifies the processing equipment required and reduces the risk of contamination. Two separate methodologies derived from a silane and a diisocyanate were investigated. The soluble diisocyanate method was used to successfully demonstrate the single-stream APA-6 processing technique. Glass fiber surface-initiated polymerization was also demonstrated using the silane-derived initiator. The findings represent the first steps toward a new processing paradigm of APA-6 composites.

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