二茂铁基长链烷基β－二酮的合成及表征

Synthesis and Characterization of Ferrocenyl Long-Chain Alkyl β-Diketones

通过乙酰基二茂铁与酯的缩合反应，合成了五个二茂铁基长链烷基β─二酮化合物ＦｃＣＯＣＨ＿２ＣＯＣ＿ｎＨ＿（２ｎ＋１）（Ｆｃ＝Ｃ＿５Ｈ＿５ＦｅＣ＿５Ｈ＿４，ｎ＝５～９）。用元素分析、ＵＶ─Ｖｉｓ、ＩＲ、１￣ＨＮＭＲ、ＭＳ对化合物进行了表征。测试结果表明，β─二酮化合物仅以烯醇形式存在。

he five new Ferrocenyl long-chain alkyl β-diketones with a general formulaC_5H_5FeC_5H_4COCH_2COC_nH_(2n+1) (n=5-9) were synthesized by Claisen condensation of acetylferro-cene with ester. These compounds were characterized by elementary analysis, UV-Vis,IR, 1￣HNMR and MS spectra. The β-diketones show a sawtoothed increase in melting point withincreasing carbon number of alkyl group. There are three absorption bands at about 268nm,310nm and 452nm in the UV-Vis spectra. The absorption band observed at 310nm is due to the π-π￣* transition of intramolecular hydrogen bonded chelate ring. The IR spectra show the character-istic absorptions of η￣5-Cp group at about 3104cm￣(-1), 1112cm￣(-1), 1004cm￣(-1) and 824cm￣(-1), and ν_(OH),ν(O-C)、ν(C-O) for the enol form near 3432cm￣(-1)、1619cm￣(-1) and 1554cm￣(-1). In 1￣HNMR spectra, the pres-ence of OH protonic chemical shifts in the 15.90～15.70×10￣(-6) region also indicate that the exis-tent state of the β-diketones is in the enol form. The molecular ion peak at m/e 354 (relative in-tensity 86%), and peaks of major cationic fragments C_5H_5FeC_5H_4C≡O￣+ (m/e213, 28%),[C_5H_5FeC_5H_4]￣+ (m/e185, 57%) and +￣O≡CCH_2COC_7H_(15) (m/e169, 36%) in the FAB-mass spec-trum of compound Ⅲ was observed.