The process of potassium metal dissolution in tetrahydrofuran containing 15-crown-5 and the properties of the solution were studied. The changes in concentration of potassium anions and electrons as a function of time were determined by means of 39K NMR and ESR spectroscopies. Enhanced stability of the solution with 15-crown-5 relative to that containing 18-crown-6 or 12-crown-4 was revealed.

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Cyclohexano-15-crown-5, cyclohexano-18-crown-6, dicyclohexano-15-crown-5, and dicyclohexano-18-crown-6, but not dicylohexano-16-crown-5, in THF dissolve potassium metal to form dark blue potassium alkalide solutions at ambient temperature. On standing, the potassium alkalide complexes decompose and the solutions turn colorless at differing rates. Identification of the products provides insight into the decomposition mechanism.

Dipotassium polyoxaalkane-a,w-diolates (1 -5) and ethylene were found to be formed in the decomposition reaction of solutions of 18-crown-6 in tetrahydrofuran containing dissolved potassium. A mechanism of that decomposition process due to the action of the potassium anion is proposed.

Carbonyl groups were found to be present in polymers of 2,3-epoxypropyl phenyl ether obtained by anionic polymerization. On the basis of quantitative analyses these groups were assumed to be formed in a reaction involving chain transfer to the monomer which proceeds in a manner different from that reported in the literature. Results of the present study were compared with those referring to the polymerization of methyloxirane, phenyloxirane and some chlorophenyl2,3-epoxypropyl ethers.0025-1 16X/86/$03 .OO

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Die Veranderung der ffbertragungsgeschwindigkeit im Verlauf der anionischen Propylenoxidpolymerisation wurde untersucht. Die tfbertragung wird wesentlich durch den OH-Gehalt des Systems beeinflult. Dieser EinfluB kann durch Wasserstoffbruckenbindungen zum Epoxidsauerstoff erklart werden. Bisher bestehende Differenzen zwischen der kinetischen und der mechanistischen Beschreibung der Ketteniibertragung konnen auf dieser Basis beseitigt werden. 0 p e a q u u nepdarJu npu anuonnoi6 nonwpuaayuu omupanoe. Vacmb I I I . AunMcuKa odpaaoeanu~ iieoi6nt.u ceRaei6 npu noawpuaayuu ol~ucu nponmna HccnenosaHo M~M~H~H M~ CKOPOCTH nepeaarxn qem B xone ~H M O H H O~~ n o m i~e p~s~a w OKMCM nponmeaa. Ha peaw UMH) lIepeAaqM CyqeCTBeHHO BJIBIIeT COAepmaHMe OH-rpynn B CMCTeMe. 3 T O BJIMFiHMe MOXeT 6hITb 0 6 ' b~c~e~o BOAOPOnHMMM CBR3RMM K aIIOKCE€~€IOMy KMCJIOpOAy. CyilleCTBOBaBIUHe A0 C I l X n O p pa3JIM'IMH B OnMCaHMM MeXaIlUIUBMa M KHHeTHKM IIepeAa'IH qeUM MOrJ' P 6blTb y C T p a H e H H H a aTOL OCHOBB.On the chain transfer reaetion in the anionic pdyrnerizatiun of oxiranes. 111. The dynamics of the formation of double bonds in the polymerization of propylene oxide The variation of the rate of chain-transfer in the course of anionic polymerization of propylene oxide is investigated. The essential influence on the chain-transfer reaction is assumed t o be the liydroxyl group-concentration. This influence is explained by the formation of hydrogen bonds towards the epoxide oxygen atoms. Existing differences between the kinetic and mechanistic models of the chain-transfer reaction could be removed by this way.

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