Determination of the Stereoselectivity Factor for an Asymmetric Enantiomer-Differentiating...
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CORRECTIONS Frederik C. Krebs* and Mikkel Jørgensen: High Carrier Mobility in a Series of New Semiconducting PPV-Type Polymers. Volume 36, Number 12, June 17, 2003, pp 4374-4384. Page 4379. The ionization potentials of the polymers ranged from 5.35 to 5.70 eV (see Table 4). MA049379Q 10.1021/MA049379Q Published on Web 04/28/2004 Zhiyuan Zhong, Pieter J. Dijkstra, and Jans Feijen*: Determination of the Stereoselectivity Factor for an Asymmetric Enantiomer-Differentiating Polymerization: A Revisit. Volume 36, Number 21, October 21, 2003, pp 8198-8200. With respect to our Note, eq 2 is correct provided that the optical purity of the unreacted monomer R/R 0 has negative values, and eq 1 is an incorrect version of eq 2 due presumably to a typographical error in typesetting ref 3. Our derivation of eqs 9 and 10 is equivalent to derivations presented previously, for example in ref 4. In fact, eq 9 is precisely equivalent to eq 2 if the factor R/R 0 is equated with -ee m . Our determined values of the stereoselectivity factors of 0.18 (from eq 2) and 5.5 (from eq 10) are, of course, simply reciprocally related due to the change of sign. In other words, had we chosen to define ee m as {[R] - [S]}/{[R] + [S]} which nevertheless may give a negative value, we would have obtained the value 0.18 again. In fact, the generally accepted definition of ee m takes the absolute value of |[R] - [S]| in the numerator [Eliel and Wilen, Stereochemistry of Organic Compounds, Wiley-Interscience: New York, 1994]. MA049279K 10.1021/MA049279K Published on Web 04/28/2004 Frederik C. Krebs* and Mikkel Jørgensen: Simple Synthesis of Monomers for Regioregular Poly(dialkyl- biphenylenevinylene) Conducting Polymers through Directional Polymerization. Volume 35, Number 27, December 31, 2002, pp 10233-10237. Page. 10234. The values quoted for E F VAC , ∆, and IP in Table 1 should have appeared as shown below. MA049380P 10.1021/MA049380P Published on Web 04/29/2004 Table 4. Results from the Photoelectron Spectroscopy on Thin Films of the Polymers 8a-g on Polycrystalline Silver Substrates Having a Work Function of 4.2 eV EF VB EF VAC cutoff ∆ IP 8a 0.90 4.70 45.30 0.50 5.60 8b 1.05 4.50 45.50 0.30 5.55 8c 0.70 4.65 45.35 0.45 5.35 8d 0.80 4.65 45.35 0.45 5.45 8e 0.90 4.65 45.35 0.45 5.55 8f 1.10 4.60 45.40 0.40 5.70 8g 0.90 4.70 45.30 0.50 5.60 Table 1. Data from the Photoelectron Spectra for Thin Films of the Polymers 13 and 14 Spin-Coated onto Polycrystalline Gold Substrates with a Work Function of 4.9 eV compd EF VB EF VAC cutoff ∆ IP 13 1.60 4.75 45.25 -0.15 6.35 14 2.40 4.75 45.25 -0.15 7.15 4740 Macromolecules 2004, 37, 4740
Transcript of Determination of the Stereoselectivity Factor for an Asymmetric Enantiomer-Differentiating...
CORRECTIONS
Frederik C. Krebs* and Mikkel Jørgensen: HighCarrier Mobility in a Series of New SemiconductingPPV-Type Polymers. Volume 36, Number 12, June 17,2003, pp 4374-4384.
Page 4379. The ionization potentials of the polymersranged from 5.35 to 5.70 eV (see Table 4).
MA049379Q
10.1021/MA049379QPublished on Web 04/28/2004
Zhiyuan Zhong, Pieter J. Dijkstra, andJans Feijen*: Determination of the StereoselectivityFactor for an Asymmetric Enantiomer-DifferentiatingPolymerization: A Revisit. Volume 36, Number 21,October 21, 2003, pp 8198-8200.
With respect to our Note, eq 2 is correct provided thatthe optical purity of the unreacted monomer R/R0 hasnegative values, and eq 1 is an incorrect version of eq 2due presumably to a typographical error in typesettingref 3.
Our derivation of eqs 9 and 10 is equivalent toderivations presented previously, for example in ref 4.
In fact, eq 9 is precisely equivalent to eq 2 if the factorR/R0 is equated with -eem.
Our determined values of the stereoselectivity factorsof 0.18 (from eq 2) and 5.5 (from eq 10) are, of course,simply reciprocally related due to the change of sign.In other words, had we chosen to define eem as {[R] -[S]}/{[R] + [S]} which nevertheless may give a negativevalue, we would have obtained the value 0.18 again.
In fact, the generally accepted definition of eem takesthe absolute value of |[R] - [S]| in the numerator [Elieland Wilen, Stereochemistry of Organic Compounds,Wiley-Interscience: New York, 1994].
MA049279K
10.1021/MA049279KPublished on Web 04/28/2004
Frederik C. Krebs* and Mikkel Jørgensen: SimpleSynthesis of Monomers for Regioregular Poly(dialkyl-biphenylenevinylene) Conducting Polymers throughDirectional Polymerization. Volume 35, Number 27,December 31, 2002, pp 10233-10237.
Page. 10234. The values quoted for EFVAC, ∆, and IP
in Table 1 should have appeared as shown below.
MA049380P
10.1021/MA049380PPublished on Web 04/29/2004
Table 4. Results from the Photoelectron Spectroscopy onThin Films of the Polymers 8a-g on PolycrystallineSilver Substrates Having a Work Function of 4.2 eV
EFVB EF
VAC cutoff ∆ IP
8a 0.90 4.70 45.30 0.50 5.608b 1.05 4.50 45.50 0.30 5.558c 0.70 4.65 45.35 0.45 5.358d 0.80 4.65 45.35 0.45 5.458e 0.90 4.65 45.35 0.45 5.558f 1.10 4.60 45.40 0.40 5.708g 0.90 4.70 45.30 0.50 5.60
Table 1. Data from the Photoelectron Spectra for ThinFilms of the Polymers 13 and 14 Spin-Coated onto
Polycrystalline Gold Substrates with a Work Function of4.9 eV
compd EFVB EF
VAC cutoff ∆ IP
13 1.60 4.75 45.25 -0.15 6.3514 2.40 4.75 45.25 -0.15 7.15
4740 Macromolecules 2004, 37, 4740
