p-Substituted Phenylcyclopropanes: In the anionic polymerizations of 2-phenylcyclopropane-1,1-dicarbonitriles by cyanide ion, a mechanism involving zwitterionic transition state was proposed in the previous work. As an extension of studies in the anionic polymerization of activated cyclopropanes by nucleophiles, we examined the polymerization of p-substituted phenylcyclopropane-1,1-dicarbonitriles having MeO, Me, H, Cl, and $NO_2$ as substituents, and the electronic effect upon the ringopening reaction involved in the anionic polymerization were treated quantitatively by determining the rate constants of polymerizations, conversions and molecular weights of the resulting polymers. A kinetic study of the polymerization has been carried out by means of $^1H$ NMR spectroscopy. The rate constants of polymerization ($K_p$) in DMSO by 2 mole % cyanide ion at $35^\circ{C}$ were p-MeO=0.45, p-Me=0.14, p-H=0.07, p-Cl=0.06 and $p-NO_2=0.011$ liter/mole sec, and the rate constants of polymerization in DMSO by 5 mole % pyridine at $35^\circ{C}$ were p-MeO=0.048, $p-Cl=7.6\times10^{-3}$ and $p-NO_2=1.64\times10^{-3}$ liter/mole sec, respectively. In the kinetic data of ring-opening polymerization, the electronic effect exerted by substituents followed the Hammett relationship ($logk/k_0=\sigma\rho$) when Brown's $\sigma^+$ constants were used. The reaction constant (ρ) obtained with cyanide ion initiator was -1.0 and the reaction constant obtained with pyridine initiator was -0.94. From the above results we can enunciate that the anionic ring-opening polymerization of p-substituted phenylcyclopropanes take place via ion pair mechanism (zwitterionic transition state) in the ring opening reaction. Data of polymerization obtained under various conditions indicate that the anionic ring-opening polymerization proceeded through living system. Furthermore, in the case of the polymerization initiated by pyridine or triethylamine, the formation of macrozwitterion during polymerization is a feasible mechanism.
Vinyloxiranes: Generally oxirane rings undergo ring-opening reaction via carbon-oxygen bond upon ionic or radical attacks, whereas properly substituted oxiranes such as 2-phenyl-3-vinyloxirane and 2,3-divinyloxirane show carbon-carbon bond scission rather than C-O bond scission upon radical attack. 2-Phenyl-3-vinyloxirane was synthesized by the phase transfer reaction of allyldimethylsulfonium chloride with benzaldehyde, and was polymerized in neat or in solution with DTBP at $120^\circ{C}$, AIBN at $65^\circ{C}$ and BPO at $75^\circ{C}$. Results showed that DTBP is the most effective initiator for radical polymerization of the monomer. All the polymers obtained under different radical conditions possessed almost the same structure having vinyl ether groups in the main chain of the resulting polymers. This illustrates the first instance in which an oxirane is polymerized by C-C bond scission rather than C-O bond scission.
Dihydrofurans: The chemistry of 2,3-dihydrofurans is similar to those of vinyl ethers. No different behavior was observed in the cationic polymerization of 2,3-dihydrofuran. In order to observe the stabilization energy-driven ring-opening polymerization of substituted 2,3-dihydrofurans, we have prepared 2,3-dihydrofurans such as 2-phenyl-2,3-dihydrofuran (P-DF), 2-methoxy-5-phenyl-2,3-dihydrofuran(MOP-DF), 2-ethoxy-5-phenyl-2,3-dihydrofuran, and 5-methyl-2-phenyl-2,3-dihydrofuran(MP-DF). These monomers are activated by cation stabilizing groups. Polymerizations were carried out with Lewis acid, $BF_3$ etherate and aluminium trichloride. Results indicated that these dihydrofurans polymerize well by cation initiators. However the dihydrofurans except MOP-DF and EOP-DF fail to undergo ring-opening polymerization. Poly(MOP-DF) and poly(EOP-DF) contain carbonyl groups formed via cationic rearrangement during the ring-opening polymerization.
$\underline{파라 치환된 페닐시클로프로판 유도체의 친핵체에 의한 개환 중합}$ : 활성화된 시클로프로판 유도체에 의한 음이온 중합에 관한 연구의 확장으로 파라 위치에 MeO, Me, H, Cl, 그리고 $NO_2$가 치환된 페닐사이클로프로판 -1, 1- 디카보니트릴 유도체를 합성하여 음이온 중합시에 개환반응에 미치는 치환기의 전자적 효과를 중합속도 상수 측정, 중합율 그리고 얻어진 중합체의 분자량을 측정함으로써 정량적으로 조사하였다. 중합 반응속도는 NMR 분석에 의해 이루어 졌으며 Brown의 $\sigma^+$ 상수를 사용했을 때 치환기의 전자적 효과와 중합 반응 속도는 Hammett 관계식($\logk/k_o=\rho\sigma$) 을 따르는 것을 관찰하였다. 이상의 결과로부터 파라 치환된 페닐 시클로 프로판 유도체의 음이온 중합반응 중의 개환 반응은 ion pair 반응기구 (Zwitterionic 전이상태)를 통하여 일어남을 알 수 있었다.
여러 조건하에서 얻어진 중합 결과에 의하면 음이온 개환 중합은 living system으로 진행되었다. 또한 피리딘이나 트리에틸아민에 의해 중합 개시된 경우는 중합 반응 중에 macrozwitterion의 형성이 가능한 것으로 보인다.
$\underline{비닐옥시란의 라디칼 개환 중합}$ : 일반적으로 옥시란 고리는 이온이나 라디칼 공격에 의해 탄소 - 산소 결합의 개환 반응이 용이하지만 적당한 치환기에 의해 활성화된 옥시란 고리는 탄소 - 산소 결합보다는 탄소 - 탄소 결합의 개환반응이 기대되어 2 - 페닐 - 3 -비닐옥시란을 벤즈알데히드와 알릴디메틸술포니움 클로리드의 Phase transfer 반응을 통해 합성하였고, 라디칼 개시제인 DTBP, AIBN 그리고 BPO를 사용하여 중합을 시도하였다.
얻어진 결과에 의하면 DTBP(di-tert-butyl peroxide)가 비닐옥시란의 라디칼 중합에 가장 효과적인 개시제임을 알 수 있었다. 각기 다른 라디칼 조건하에서 중합된 중합체들은 주사슬에 탄소탄소 결합이 깨져 형성된 비닐에테르기를 갖고 있는 동일한 구조임을 확인하였다.
$\underline{디히드로푸란의 양이온 개환 중합}$ : 치환된 2, 3 - 디히드로푸란 유도체의 안정화 에너지에 의한 개환 중합을 조사하기 위하여 2-페닐 -- 2, 3 - 디히드로푸란 (P-DF), 2-메톡시-5-페닐-2,3-디히드로푸란(MOP - DF), 2 -메톡시- 5 -페닐- 2,3 - 디히드로푸란(EOP - DF) 그리고 5 -메틸 - 2 - 페닐 -2,3 - 디히드로푸란 (MP-DF)을 합성하였다. 중합 반응은 양이온 개시제인 보론트리푸로리드와 알미늄 트리클로리드를 사용하여 진행시켰다. 모든 디히드로푸란 유도체들은 양이온에 의해 중합이 잘 일어났지만 MOP - DF와 EOP - DF를 제외하고는 개환 반응을 통한 중합은 일어나지 않았다.
폴리(MOP - DF)와 폴리(EOP - DF)는 개환 중합 중에 양이온의 재배치에 의해 형성된 카보닐기를 포함하는 구조를 갖고 있다.
