Change in electron structure of cyclic oxides during their interaction with electron acceptors. Quantum chemical investigation

Geller, N. M.; Éizner, Yu.Ye.; Kropachev, V. A.

doi:10.1002/actp.1981.010320304

Cited by 5 publications

(2 citation statements)

References 13 publications

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“…T h e results of calculations given in Acta Polymerica 36 (1985) Nr 5. T h e results of calculations given in Acta Polymerica 36 (1985) Nr 5.…”

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confidence: 98%

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Correlation between the electronic structure of cyclic oxides and their ability for undergoing anionic polymerization. Quantum chemical investigation

Geller¹,

Éizner²,

Kropachev³

1985

Acta Polymerica

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I t is shown that cyclic oxides can be anionically polymerized if the lowest vacant molecular orbital (LVMO) of a C, atom contains a region which can effectively overlap by the electronic cloud of the anionic active centre. This means that LVMO must be a-symmetrical and a t least one of the C, atoms must contain an approximately spl-hybridized atomic orbital forming a sufficiently great part of LVMO. Zur Korrelation zwischen der elektronischen Struktur cyclischer Oxide und der Moglichkeit ihrer anionischen Polymerisation. Quantenchernische UntersuchungenEs wird gezeigt, daB cyclische Oxide anionisch polymerisiert werden konnen, wenn das niedrigste freie Molekulorbital (LVMO) cines C,-Atoms ein Gebiet urnfaat, daB die Elektronenwolke des anionisch aktiven Zentrums effektiv iiberlappt. Dies bedeutct, daB das LVMO a-symmetrisclr sein muB und mindestens eines der C:-Atome ein naherungsweise spl-hybridisiertes Atomorbital enthalt, das einen hinreichend groBen TPil des LVMO bildet. f l o p p e n q u a ane~rnponnoli cmpykmypba quicnuvecmx omceii uux cnoco6nocmu h: anuonnoli nonuAepuaaquu. ETsan-mosoxu~uuec~oe uccAeaosanue nOKa3aH0, 'IT0 qHKJIHqeCKAe OKACH cnOC06~bI K aHHOHHOfi nOJIMMepH3a~HU TOJIbKO B TOM CJIy'Iae, eCJIII HX H H X H R R BaKaHTHaR MOJIeKyJIRpHaR Op6HTaJIb (H BMO) COAeHtHT Ha C,-aToMe 06JIaCTb, c n o c o 6~y~, 3i$$eKTHBHO nepeKpM-BaTbCR C 3JIeKTpOHHOfi 0 6 o n o~~o~ aHHOHHOP0 aKTUBHOI'O UeHTpa, T.e. HBMO AoJIXHa UMeTb a-CHMMeTpHH, II no KPafiHefi Mepe OAHH 113 CS-aTOMOB AOJIHteH CO~epHtaTb npH6JIH3HTeJIbHO Sp1-PH6pH~H30BaHHyH, aTOMHYI0 Op6HTanb, BSOARilrlyH, B HBMO C 6onburcrw BACOM.

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“…T h e results of calculations given in Acta Polymerica 36 (1985) Nr 5. T h e results of calculations given in Acta Polymerica 36 (1985) Nr 5.…”

mentioning

confidence: 98%

“…BDdegree of bonding of complex components equal t o tlic sum of the order bonds betweell all anion atoms and CO[5]. z, Sbond deficit in the ring equal to the difference between the number of 0 and C atorns forming the ring and the sum of3) The 0 atom is Itre oxygen atom of thc CH,Oanion.…”

mentioning

confidence: 99%

Correlation between the electronic structure of cyclic oxides and their ability for undergoing anionic polymerization. Quantum chemical investigation

Geller¹,

Éizner²,

Kropachev³

1985

Acta Polymerica

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Effect of substituents on the electronic structure of cyclic oxides and its change in the interaction of oxides with an electron acceptor. Quantum chemical investigation

1983

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Electronic characteristics of substituted three-, four-and five-membered cyclic oxides and their complexes with an electron acceptor CH; have been calculated by the CNDO/2 method. The reactivity ratio of these cyclic oxides in their cationic copolymerization is in agreement with the calculated complexation energy of cyclic oxides with the electron acceptor. Der EinfluP der Substituenten auf die elektronische Struktur cyclischer Oxide und die Veranderung dieser Struktur bei der Wechselwirkung der Oxide mit einem Elektronenacceptor. Quantenchemische UntersuchungenDie elektronischen Eigenschaften von substituierten drei-, vier-und funfgliedrigen cyclischen Oxiden sowie ihrer Komplexe mit dem Elektronenacceptor CH; wurden mit Hilfe der CNDO/a-Methode berechnet. Das Reaktivitatsverhaltnis der Oxide bei der kationischen Copolymerisation stimmt mit den berechnetcn Komplexbildungsenergien dieser Oxide mit Elektronenacceptoren gut uberein. Bnusnue aa&ecmumeneii na e~teicmpon~ylo cmpyicmypy yumuuecicux oicuceii u na ee u~&enenue npu saauwoc3eiicnzsuu oicuceii c ~e~mpoltoaicyenmopo&. h"sanmosbxu&uuecicoe uccAedosanueMeTOAOM IIqAII/2 PaCCYMTaHM 3JIeKTpOHHbIe XapaKTepHCTMKH 3aMeqeHHbIX TpeX-, YeTbIpeX-M IIRTKYJIeHHbIX qHKJIHYeCKHX OKMCefi, a TaKme KOMnJIeKCOB 3TMX OKHCefi C 3JIeKTpOHOaKqellTOpOM CHg. OTHOCHTeJIbHaR PeaKqHOH-HaR CllOCO6HOCTb l[HKJIMYeCKHX OKHCefi I I P M MX KaTHOHHOfi COIlOJIMMepM3aqHH KOppeJIMpyeT C paCseTHOfi 3HepFMefi KOMIlJIeKCOO6pa3OBaHHFI qMKJIHYeCKMX OKHCefl C 3JIeKTpOHOaKqellTOpOM.

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Cationic polymerization of 1‐azabicyclo[4.2.0]octane, 2. Reactivities of ions and ion‐pairs

Matyjaszewski

1984

Makromol. Chem.

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The cationic ring-opening polymerization of l-azabicyclo[4.2.0]octane (1) was studied with initiators providing small and large anions, namely FO, BrO, 1 0 , picryl(Pic@), CF,SOF. In nitrobenzene as solvent the macroions and macroion-pairs, independently of the anion size, propagate with the same rate constant k: = k: = 7 , O . lo-, mol-' . l . s -' at 35 "C (AH: = 55 + 5 kJ .mol-', A S : = 105 f 11 J . mol-' . K -I ) .This result strongly indicates that it is not the large size of anions which is exclusively responsible for the equality k: = k l . The structure of the onium ions, their strong solvation, and the resulting weak interactions with anions are primarily responsible for the observed equalities. In methanol as solvent polymerization proceeds 30 times slowlier than in nitrobenzene and ion-pairs are more reactive by 40% than ions, in agreement with Enikolopyan's findings. Experimental partMaterials: 1 -Azabicyclo[4.2.0]octane (1) was synthesized from 2-(2-piperidyl)ethanol according to ref. *). 1-Alkyl l-azoniabicyclo[4.2.O]octane iodides, bromides, picrates, and trifluoro-0025-1 16X/84/$03.00 52 K. Matyjaszewski methanesulfonates were prepared directly from 1 and the corresponding alkyl halide or ester in a 1 : 1 mole ratio in diethyl ether or 1 ,4-dioxane solution. The precipitated salts were crystallized from aceton or nitrobenzene. The l-ethyl-l-azoniabicyclo[4.2.O]octane fluoride was prepared from the corresponding bromide. The bromide was first reduced to the hydroxide in methanol with a five fold excess of silver oxide. After 5 h of stirring the silver bromide and unreacted oxide were filtered off and the solution was treated with 40% HF taken in 5% excess. The solution was dried on the vacuum line over P,O, during 7 days. l-Ethyl-l-azoniabicyclo[4.2.0]octane fluoride forms highly hygroscopic transparent crystals. Nitrobenzene was purified as described previously3). [2H,]-Methanol was dried over CaH, and distilled i. vac. Measurements: Conductometric measurements were performed in the apparatus described in ref. I), using a Tesla BM 484 semi-automatic precision bridge and Radelkis OK-902 cells (I, = 0,81 cm-').'H NMR spectra were recorded on a Perkin Elmer R12B (60 MHz) spectrometer. Raman spectra were recorded on a PHO Coderg Raman Spectrometer (with double monochromator) with ion-argon laser (Spectra Physics) emitting at 4880 A. Results Dksociation constantsQuaternary ammonium salts in polar solvents, e. g. nitrobenzene, are only slightly associated. Therefore, their conductivities are described by the generalized Eq. (1). (1) 1 and 1 , are the equivalent and the limiting equivalent conductivity (A, , = A,--,), Cis the solute concentration, a is the degree of dissociation, fthe activity coefficient, and KA the association constant, being the reciprocal of the dissociation constant: KA = (1a ) / f z . a 2 . C (2)The parameters S, E', and E; depend on the medium properties (temperature, viscosity, dielectric constant) and A,. For solvents with low dielectric constant the 3rd and 4th parameters of R...

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Change in electron structure of cyclic oxides during their interaction with electron acceptors. Quantum chemical investigation

Cited by 5 publications

References 13 publications

Correlation between the electronic structure of cyclic oxides and their ability for undergoing anionic polymerization. Quantum chemical investigation

Correlation between the electronic structure of cyclic oxides and their ability for undergoing anionic polymerization. Quantum chemical investigation

Effect of substituents on the electronic structure of cyclic oxides and its change in the interaction of oxides with an electron acceptor. Quantum chemical investigation

Cationic polymerization of 1‐azabicyclo[4.2.0]octane, 2. Reactivities of ions and ion‐pairs

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