Koordinationsambivalenz und elektronenstruktur ein- und zweikerniger methylcyclopentadienyldicarbonylmangan-komplexe der cyanpyridine und terephthalsäuredinitrile

摘要: Abstract The ambident cyanopyridine ligands form N(pyridine) and N′(nitrile) coordinated mono- binuclear complexes with the (C 5 H 4 CH 3 )(CO) 2 Mn fragment. All three possible forms for 4-cyanopyridine could be isolated, whereas mononuclear compounds were obtained as most stable species in N 1 -coordinated 3-cyanopyridine CN 2-isomer. IR, NMR, UV/VIS spectroscopy well electrochemistry ESR of anion radicals demonstrate superior π back-bonding via pyridine nitrogen centers, isolation nitrile is attributed to kinetic stability CNMn bond. While terephthalonitrile was found exclusively neutral complexes, its radical prefers coordinate a second metal fragment, illustrating excellent coordination properties reduced nitriles. A complex isolated stronger π-acceptor, tetrafluoroterephthalonitrile.