ISSN:
0009-2940
Keywords:
Arene complexes
;
Chromium compounds
;
Substituent effects
;
Push-pull chromophores
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The tricarbonylchromium complexes chlorobenzene 1 reacts with terminal alkynes 2 through a palladium-copper-catalyzed coupling to give a variety of Cr(CO)3-complexed phenylethynyl arenes, heteroarenes and ferrocene 3 in good to excellent yield. Due to the electron-withdrawing nature of the Cr(CO)3 group these novel complexes can be regarded as organometallic push-pull chromophores. Analogously, the corresponding free ligands 4 (phenylethynyl arenes, heteroarenes and ferrocene) were synthesized by coupling iodobenzene and 2. The crystal structure analysis of the singly Cr(CO)3-complexed tolane 3e reveals a strong deviation from coplanarity of both phenyl rings by an angle of 50.9(2)° presumably due to crystal packing. Correlations are established between selected substituent parameters (σP, σI, σR, σP+ and Δπ) and the carbonyl carbon resonances in the 13C-NMR spectra for the complexes 3. The overall electronic substituent effect is transmitted to the carbonyl groups by both mesomeric and inductive mechanisms. The push-pull complexes 3 display relatively small negative solvochromicities of longest wavelength absorption band (MLCT band).
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19961291206
Permalink
