New Catalysts for Polymerizations of Substituted Acetylenes

2000 ◽  
pp. 146-164 ◽  
Author(s):  
Ben Zhong Tang ◽  
Kaitian Xu ◽  
Qunhui Sun ◽  
Priscilla P. S. Lee ◽  
Han Peng ◽  
...  
Keyword(s):  
Substituted Acetylenes

ChemInform Abstract: 13C NMR Study of Amino and Phosphino Substituted Acetylenes: δ(13C), JCC and JCP.

ChemInform ◽  
1989 ◽  
Vol 20 (32) ◽  
Author(s):  
K. KAMIENSKA-TRELA ◽  
Z. BIEDRZYCKA ◽  
R. MACHINEK ◽  
W. LUETTKE
Keyword(s):  
13C Nmr ◽  
Nmr Study ◽  
Δ 13C ◽  
Substituted Acetylenes

Radikalionen, 61 [1, 2]Dialkylamino-substituierte Acetylene und Allene:Ionisation, Oxidation und AlCl3-katalysierte Wasserstoffübertragung / Radical Ions, 61 [1, 2]Dialkylamino-substituted Acetylenes and Allenes:Ionisation, Oxidation and AlCl3-Catalyzed Hydrogen Transfer

1984 ◽  
Vol 39 (6) ◽  
pp. 763-770 ◽  
Author(s):  
Hans Bock ◽  
Wolfgang Kaim ◽  
Mitsuo Kira ◽  
Louis Réné ◽  
Heinz-Günther Viehe
Keyword(s):  
Radical Cation ◽  
Hydrogen Transfer ◽  
Radical Cations ◽  
Esr Spectra ◽  
Ionization Potentials ◽  
Radical Ions ◽  
Substituted Acetylenes

AbstractThe photoelectron (PE) spectra of bis(dialkylamino) acetylenes R2N-C≡C-NR2 and of tetrakis(dialkylamino) allenes (R2N)2C=C=C(NR2)2 with R = CH3, C2H5 exhibit characteristic ionization patterns which are assigned to π radical cation states of the two molecular halves twisted against each other. The low first ionization potentials between 7.0 eV and 7.7 eV stimu­lated attempts to oxidize using AlCl3 in H2CCl2 or D2CCl2. The hyperfine structured ESR spectra observed can be unequivocally assigned to the ethylene radical cations R2N-HC=CH -NR2˙⊕ which are formed from the obviously non-persistent species R2N-C≡C-NR2˙⊕ via a hydrogen transfer. During the oxidation of the dialkylamino-substituted allenes no paramagnetic intermedi­ates could be detected, presumably due to a rapid dimerisation of the allene radical cation (R2N)2C=C=C(NR2)2˙⊕.

Polymerization of substituted acetylenes and features of the formed polymers

2011 ◽  
Vol 2 (5) ◽  
pp. 1044-1058 ◽  
Author(s):  
Masashi Shiotsuki ◽  
Fumio Sanda ◽  
Toshio Masuda
Keyword(s):  
Substituted Acetylenes

A theoretical study of adiabatic proton transfer to simple substituted acetylenes In Their Ground And Excited States

1989 ◽  
Vol 67 (12) ◽  
pp. 2178-2187 ◽  
Author(s):  
Peter S. Martin ◽  
Keith Yates ◽  
Imre G. Csizmadia
Keyword(s):  
Experimental Data ◽  
Proton Transfer ◽  
Excited States ◽  
Graphical Representation ◽  
Proton Affinities ◽  
Energy Profiles ◽  
Singlet States ◽  
Vinyl Cation ◽  
Substituted Acetylenes ◽  
Ordered Pairs

RHF SCF 3-21G calculations are reported for the 1Σg+, 1A1, 3A′, and 1,3A″ states of simple substituted acetylenes (Y—C≡C—H, where Y = H, F, Cl,CH3, andCF3), the 1A1, 1A′, and 1.3A″ states of their Markovnikov (M) vinyl cations (Y—C+ = CH2), the 1A′ and 1.3A″ states of their anti-Markovnikov (aM) vinyl cations (YCH=C+H), and the corresponding hydrated vinyl cations. Equilibrium electronic structures and the mechanism of adiabatic protonation are described qualitatively via Lewis/resonance schematic representations of the species involved. Calculated proton affinities (PA) suggest that relative to ground state Y—C≡C—H (1Σ+/1A1), Y—C≡C—H* (1.3A″) is of greatly enhanced basicity with respect to protonation of both regiocenters. A graphical representation of the ordered pairs PA(M) versus PA(aM) as a function of substituent Y and electronic state, leads to the conclusions: (1) irrespective of both regiocenter (M/aM) and state (1Σ1+/1A1, 3A, 1.3A″) the PA's for Y—C≡C—H decrease in the order CH3 > H > Cl> F > CF3; (2) in proceeding from CH3C≡CH to CF3C≡CH, a change in protonation regiospecificity (M → aM) is experienced to approximately the same extent for both S0 and S1; (3) T2 exhibits no significant protonation regioselectivity. Critical comparison of the calculated results is made with available experimental data. An approximate picture of the energy profiles for the adiabatic hydrations of Y—C≡C—H via its ground, triplet and singlet states has been developed, based on the fixed points acetylene, vinyl cation and hydrated vinyl cation. Predicted relative reactivities of these three states are in excellent accord with available experimental data on rates of hydration. Keywords: excited states, proton transfer, photohydration.

ChemInform Abstract: Preparations of N- and P-Substituted Acetylenes under Metal-Free Conditions.

ChemInform ◽  
2016 ◽  
Vol 47 (52) ◽  
Author(s):  
Hong Chen ◽  
Qingjuan Zheng ◽  
Wanrong Dong ◽  
Zhihong Peng ◽  
Delie An
Keyword(s):  
Metal Free ◽  
Substituted Acetylenes
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