Nickelchelate von β‐Mercaptozimtaldehyden und deren Azomethinen

Abstract

Die Synthese α‐unsubstituierter dimerer β‐Mercaptozimtaldehyde 1 a – d, zugänglich über die β‐Chlorvinylaldehyde, sowie daraus abgeleiteter Azomethine 2 a – f wird beschrieben. Die dargestellten Verbindungen und einige ihrer diamagnetischen Nickelchelate werden u. a. IR‐, UV/VIS‐, NMR‐ und massenspektroskopisch charakterisiert. Eine Template‐Reaktion mit o‐Phenylendiamin am Nickelchelat des p‐Chlor‐β‐mercaptozimtaldehyds 3 b ergibt ein makrocyclisches Chelat system des Typs NiN2S2.

Structural studies on aryl‐substituted enaminoketones and their thio analogues. Part I. Analysis of high‐resolution 1H, 13C NMR and 13C CP MAS spectra combined with GIAO‐DFT calculations

“…As was already mentioned in the introduction, the data obtained in the present work consists of three parts: (i) the 1 H and 13 C NMR spectra measured in the CDCl 3 solution; (ii) the σ ( 1 H) and σ ( 13 C) shielding constants calculated by the use of the GIAO-DFT method and (iii) the 13 C CP MAS NMR spectra. Table 1a contains the 1 H NMR chemical shifts and 1 H shielding constants for both groups of compounds for the enaminone fragments and alkyl substituents, whereas Table 1b shows the data for the aromatic rings.…”

“…Table 1a contains the 1 H NMR chemical shifts and 1 H shielding constants for both groups of compounds for the enaminone fragments and alkyl substituents, whereas Table 1b shows the data for the aromatic rings. The 13 C NMR experimental and theoretical results for the carbonyl compounds (series a) are presented in Table 2a and b, and for their thiocarbonyl counterparts (series b) in Table 3a and b.…”

“…However, this was not an easy task since only a few signals could be assigned on the basis of the general knowledge of 13 C NMR spectroscopy. These are the signals which correspond to the C1(O) and C1(S) atoms and appear at ca 190 and 210 ppm, respectively.…”

“…An analysis of the high-resolution 1 H, 13 C NMR and 13 C CP MAS spectra obtained for a set of aryl-substituted enaminoketones 1a-4a and their thio analogues 2b-5b ( Fig. 1) was combined with investigation of the 1 H and 13 C chemical shielding constants calculated by the use of the widely applied method of gauge including atomic orbitals (GIAO) B3PW91/6-311++G(d,p) using the B3PW91/6-311++G(d,p) optimized geometries.…”

“…1) was combined with investigation of the 1 H and 13 C chemical shielding constants calculated by the use of the widely applied method of gauge including atomic orbitals (GIAO) B3PW91/6-311++G(d,p) using the B3PW91/6-311++G(d,p) optimized geometries. The same combination of functionals and basis set was applied to compute the proton-proton and carbon-proton coupling constants.…”