Vielgliedrige heterocyclische Verbindungen. 12. Mitteilung. Polymethylen‐imine

Růžička, L.; Kobelt, Margrit; Häfliger, O.; Prelog, V.

doi:10.1002/hlca.19490320224

Cited by 69 publications

(20 citation statements)

References 15 publications

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“…This is also true for the corresponding cyclic alcohols, ketones, and amines, which affects adversely the usual reactivity for these functional groups toward their respective coreactants. This negative effect was attributed by the investigators − to steric hindrance imparted by the tightly compacted molecular cyclic polymethylene chain when n is 9, 10, or 11, and because the functional group is directed inward rather than outward from the composite bulk of that cyclic structure. This point of view was supported by the respective IR spectra for these cyclic molecules. , …”

Section: Resultsmentioning

confidence: 99%

“…This negative effect was attributed by the investigators − to steric hindrance imparted by the tightly compacted molecular cyclic polymethylene chain when n is 9, 10, or 11, and because the functional group is directed inward rather than outward from the composite bulk of that cyclic structure. This point of view was supported by the respective IR spectra for these cyclic molecules. , …”

Section: Resultsmentioning

confidence: 99%

“…This array was not extended to include the members of series nos. 1, 21, and 22 having p > 2 because of the uncertainty regarding the validity of such extrapolation owing to the special effect of steric hindrance that is exhibited by cyclic polymethylenes when the ring size is 9−11 members, as discussed earlier. − …”

Section: Resultsmentioning

confidence: 99%

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Polymer Swelling. 20. Sorption of Cyclic Mono- and Polyethers by Poly(styrene-co-divinylbenzene)

and

Tiers

1997

J. Phys. Chem. B

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The adsorption parameters (α, with respect to polystyrene) for 20 cyclic aliphatic ethers were established experimentally in the usual way. Among this set of ethers are members from three cyclic structural categories, namely, the polymethylene oxides [(CH2) n O; n = 2−9], the polymethylene formals [(CH2) n OCH2O; n = 2−11], and the polyethylene oxides [(CH2CH2O) e ; e = 1−5], and some of the corresponding methyl or gem-dimethyl modifications thereof. The data obtained thereby were used to establish the log α vs N linear relationships (eq 1) for each of the subsets of homologous series contained in each of these structural categories, as described in the text. These linear relationships were then used to calculate the α-values for the many remaining members that are not yet available for experimental measurement in our laboratory. The results obtained thereby show that the α-values for the cyclic ethers in a given homologous series are uniformly greater than those for the corresponding set of acyclic ethers. They also confirm that methyl groups have a marked negative effect on α when positioned on the carbon atoms adjacent to the adsorbed ether oxygen atom, but they have the opposite effect when located one or more carbon atoms removed from adjacency. The magnitude of this positive effect appears to increase with the distance from the adsorption site. These observations parallel those observed in our earlier studies involving the corresponding acyclic aliphatic ethers.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Polymer Swelling. 20. Sorption of Cyclic Mono- and Polyethers by Poly(styrene-co-divinylbenzene)

and

Tiers

1997

J. Phys. Chem. B

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“…Characterizations by IR, NMR, and elemental analysis all confirm the proposed structure. Found: C, 52.6; H, 10.4;N,10;C1,25.1. Calcd C,53.7;H,9.7;N,10.4;C1,26.2.…”

Section: Reaction Of C-caprolactam With Na+[alh2(0ch2-ch20me)2]-mentioning

confidence: 98%

Anionic polymerization of lactams in the presence of metal dialkoxyaluminum hydrides: presentation of a new mechanism

Mougin¹,

Veith²,

Cohen³

et al. 1992

Macromolecules

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Metal dialkoxyaluminum hydrides (1) form a new class of catalysts for anionic polymerization of lactams. Propagation proceeds in their presence-as it does in the presence of conventional catalysts such as alkali metal hydrides-by successive additions of the anionically active species to the end-standing Nacyllactam function carried by the polymer chain. However, this is the only similarity between the two polymerization processes. The active species generated when c-caprolactam (2) is treated with sodium dialkoxyaluminum hydride is the sodium salt of 2-(dialkoxyaluminoxy)-1-azacycloheptane (6) and is therefore quite different in terms of nucleophilicity from the mere activated monomer, sodium caprolactamate. The new reactive salt (6) is obtained upon deprotonation of a lactam monomer at ita amide position followed by the reduction of its carbonyl function. During lactam polymerization, after each monomer addition, the active species is re-formed in two steps: first, proton exchange followed by instantaneous reduction of the lactamate formed by transfer of both hydrogen and the Al(OR)Z group from the previous monomer unit added. This displacement regenerates the end-standing N-acyllactam and the salt of the (dialkoxyaluminoxy)-azacycloheptane (6), allowing propagation to proceed by addition of 6 to this latter function. This new mechanism still propagates by an "activated monomer" mechanism but it also involves the transfer of the dialkoxyaluminum hydride group throughout polymerization.

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“…The enthalpy of formation of cycloheptadecanone has been experimentally determined [205]. Its oxime was synthesized and then rearranged as part of a study of large-ring heterocycles [206]. To our regret, no calorimetric measurement on the intermediate oxime or the corresponding large-ring heterocycle was reported.…”

Section: Issuementioning

confidence: 99%

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

2014

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Vielgliedrige heterocyclische Verbindungen. 12. Mitteilung. Polymethylen‐imine

Abstract: Durch Reduktion der Cyclanon‐isoxime mit Lithiumaluminiumhydrid in Äther bzw. Tetrahydro‐furan wurden die Polymethylenimine mit 7‐ bis 21‐gliedrigem Ring hergestellt.

Cited by 69 publications

References 15 publications

Polymer Swelling. 20. Sorption of Cyclic Mono- and Polyethers by Poly(styrene-co-divinylbenzene)

Polymer Swelling. 20. Sorption of Cyclic Mono- and Polyethers by Poly(styrene-co-divinylbenzene)

Anionic polymerization of lactams in the presence of metal dialkoxyaluminum hydrides: presentation of a new mechanism

Interplay of thermochemistry and structural chemistry, the journal (volume 24, 2013, issues 5–6) and the discipline

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