Miscibility of poly(methoxymethyl methacrylate) and poly(methylthiomethyl methacrylate) with poly(methyl methacrylate)

10.1007/BF01033111Polymer Bulletin236643-646POBU

Miscibility of poly(4-vinyl pyridine) with polysulfone and carboxylated polysulfone

10.1007/BF00296713Polymer Bulletin295521-525POBU

Evidence for C–H cleavage by an iron–superoxide complex in the glycol cleavage reaction catalyzed by myo-inositol oxygenase

myo-Inositol oxygenase (MIOX) activates O(2) at a mixed-valent nonheme diiron(II/III) cluster to effect oxidation of its cyclohexan-(1,2,3,4,5,6-hexa)-ol substrate [myo-inositol (MI)] by four electrons to d-glucuronate. Abstraction of hydrogen from C(1) by a formally (superoxo)diiron(III/III) intermediate was previously proposed. Use of deuterium-labeled substrate, 1,2,3,4,5,6-[(2)H](6)-MI (D(6)-MI), has now permitted initial characterization of the C–H-cleaving intermediate. The MIOX·1,2,3,4,5,6-[(2)H](6)-MI complex reacts rapidly and reversibly with O(2) to form an intermediate, G, with a g = (2.05, 1.98, 1.90) EPR signal. The rhombic g-tensor and observed hyperfine coupling to (57)Fe are rationalized in terms of a (superoxo)diiron(III/III) structure with coordination of the superoxide to a single iron. G decays to H, the intermediate previously detected in the reaction with unlabeled substrate. This step is associated with a kinetic isotope effect of ≥5, showing that the superoxide-level complex does indeed cleave a C–H(D) bond of MI

Miscibility of some phenoxy/polymethacrylate blends

10.1007/BF00300038Polymer Bulletin306691-696POBU