Linear Conjugated Systems Bearing Aromatic Terminal Groups. X. Syntheses and Electronic Spectra of α,ω-Di-1-naphthyl- and α,ω-Di-2-naphthylpolyenes
作者:Akio Yasuhara、Shuzo Akiyama、Masazumi Nakagawa
DOI:10.1246/bcsj.45.3638
日期:1972.12
Syntheses of di-1-naphthyl- and di-2-naphthylpolyenes (In, n=1–4,6 and In′, n=1–6) have been carried out by the Wittig reaction. Naphthaldehydes (III and III′), 3-naphthyl-2-propenals (V and V′), 5-naphthyl-2,4-pentadienals (VI and VI′) and muconic aldehyde were used as carbonyl components. Naphthylmethyltriphenylphosphonium halides (IV and IV′), 3-naphthyl-2-propenyltriphenylphosphonium bromides (XI and XI′) and 5-(2-naphthyl)-2,4-pentadienyltriphenylphosphonium bromide (XII′) were synthesized and converted into the corresponding phosphoranes by reaction with phenyllithium. The reaction of carbonyl moiety with phosphorane by a proper combination afforded dinaphthylpolyenes (In and In′). The electronic spectra of di-1-naphthylpolyenes (In) showed broad and structureless absorption curves. In contrast, the absorption curves of di-2-naphthylpolyenes (In′) exhibited a distinct vibrational fine structure. It was found that the bathochromic shift of the longest-wavelength peak (λmax) along with the increase of the number of double bond (n) can be expressed by the following empirical formula:λmax=45.4n0.7+302 (nm in tetrahydrofuran)
通过 Wittig 反应合成了二-1-萘基和二-2-萘基多烯(In,n=1-4,6 和 In′,n=1-6)。萘醛(III 和 III′)、3-萘基-2-丙烯醛(V 和 V′)、5-萘基-2,4-戊二烯醛(VI 和 VI′)和粘液醛被用作羰基成分。合成了萘甲基三苯基卤化鏻(IV 和 IV′)、3-萘基-2-丙烯基三苯基溴化鏻(XI 和 XI′)和 5-(2-萘基)-2,4-戊二烯基三苯基溴化鏻(XII′),并通过与苯基锂反应转化成相应的膦。羰基与膦烷通过适当的组合反应生成了二萘基多烯(In 和 In′)。二-1-萘基多烯(In)的电子光谱显示出宽阔的无结构吸收曲线。相反,二-2-萘基多烯(In′)的吸收曲线则表现出明显的振动精细结构。研究发现,随着双键数(n)的增加,最长波长峰(λmax)的浴色偏移可以用以下经验公式表示:λmax=45.4n0.7+302(四氢呋喃中的纳米数)