摘要:

AbstractAlkylation of the easily accessible methyl ester ofL‐Na,3‐dibenzoylhistidine with the aid of trimethyl‐ and triethyloxonium fluoroborate followed by decomposition with water and acid hydrolysis yieldedL‐1 ‐methyl‐ andL‐1‐ethylhistidine respectively. Comparison with naturalL‐1‐methylhistidine confirmed the structure

ISSN:0165-0513    

DOI:10.1002/recl.19720910302

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

摘要:

AbstractThe carbon (1s) electron binding energies (Eb) of methyl acetate (CH3:285.6, CO: 289.5 and OCH3: 286.5 eV) correlate well with CNDO/2‐charges (slope 5.6 eV/unit charge), with Pauling charges (slope 5.1) and with Extended Hückel charges (slope 2.4).If the Eb‐values are corrected for molecular potentials (V), again good correlations are found (slope 22.0, 20.9 and 18.6 resp.). Because it did not make much difference which method was used for calculating charges (q), tests have been made to establish whether charge calculations based on electronegativities could be used for a large series of C(1s) binding energies. For adjacent charges of equal signs, a correction was introduced and it was also found that Jolly's (or Johnson's) electronegativity values gave better results than the Pauling values.Resonably good correlations were obtained for the function Eb= α + βq + κV with κ = 0, κ = 1 and κ ≠ 0. Introduction of a γq2term did not improve the correlation. The best fit was obtained with Eb= 285.3 + 11.75 q + 0.48 V ±

ISSN:0165-0513    

DOI:10.1002/recl.19720910303

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19720910301

出版商:WILEY‐VCH Verlag    

年代:1972

数据来源: WILEY