BİS-(TSİKLOPENTADİENİLDİKARBONİLDӘMIR(I)) KOMPLEKSİNİN METİL HOMOLOQLARININ SİNTEZİ, İQ- VӘ 1H NMR-SPEKTROSKOPİYA ÜSULLARI İLӘ TӘDQİQİ

Abstract

Three dimer complexes of iron [MenC5H5–nFe(CO)2]2 (n = 2, 3, 5) were obtained from the interaction of methyl homologues of cyclopentadiene (1,3-dimethyl-, 1,2,4-trimethyl- and 1,2,3,4,5-pentamethylcyclopentadien)with iron pentacarbonyl. The complexes were characterized by melting temperatures, infrared (IR) and proton magnetic resonance (1 H NMR) spectra. It was determined that despite the monotonous increase in the melting temperature of the complexes in the [C5H5Fe(CO)2]2  [Me2C5H3Fe(CO)2]2  [Me3C5H2Fe(CO)2]2  [Me5C5Fe(CO)2]2 sequence, the complexes with 2 and 3 methyl groups in the ring (n = 2, 3) undergo severe thermal decomposition during melting. The investigation (analysis) of the reasons for the change in the frequencies of the valence vibration of the CO bond in the indicated order allowed to associate the observed thermal behavior of the complexes with the steric and electronic interactions between the methyl and carbonyl groups. The obtained results suggest that among the four studied complexes, the complexes with two and three methyl groups in the cyclopentadienyl ring ([Me2C5H3Fe(CO)2]2,[Me3C5H2Fe(CO)2]2) are more promising as precursors in the synthesis of carbon nanotubes.