Knowledge Bank

The spectra of chromoncene, manganocene and cyclopentadienyl manganese tricarbonyl have been recorded at the third overtone region ($\Delta v=4$) using intraractive photoscoustic spectroscopy. The interpretation of these spectra and their correlation with the electronic structrue of the complences will be presented. These investigations will help in the understanding of mental booding to a conjugatted $\pi$-systems and explain the carralytic reactivity of organonetalle complexes. This work is an expansion of previous investigation involving ferroenc and related corrosponds (soeryiferrocence, nuthenocence, cyclopecediphenyl bictrium tetrachloride). Three additional blue-shifted traditions which were absent in the spectrum of the pure hydrocrbon ligend (cyclopentadimyl) have been observe for these $complexes.1$ These absorpclone were assigned to the different combination of the $C-H$ stretch with $C-C$ nretches and $C-H$ beeds of the cyclopoetadiayl ring. Cyclopentadiemyl mangancse tricarboyl processesa a spcetrum similar to ferrocene and relatted compounds. Spectra of thromocence and mangnacn are differient from those of ferrecene and relatted compounds. Spectra of throenocence and mangano are different from those of ferrcence and other. We explain these differences in therms of the different electronic structures of the complexes.