کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5132071 | 1491477 | 2017 | 11 صفحه PDF | دانلود رایگان |
Carbon-carbon bond lengths and CC vibrational frequencies are reported for the linear, all-trans unsubstituted C2nH2n+2 (nâ¯=â2â¯-â¯15), methyl capped C2nH2nMe2 (nâ¯=â2â¯-â¯13), and tert-butyl capped C2nH2n(tert-butyl)2 (nâ¯=â2â¯-5â¯) polyenes (C2h) calculated at the B3LYP/6-311++G(d,p) level. The CC/CC bond length alternation remains evident at this level for the unsubstituted and methyl capped polyenes as the chain length increases; the center-most difference in the length of the CC/CC bonds is â¼0.06â¯Ã for C30H32 and C26H26Me2. The Ag, in-phase, harmonic CC Raman frequency for the unsubstituted polyenes decreases from 1699.2â¯cmâ1 (nâ¯=â2) to 1528.9â¯cmâ1 (nâ¯=â15); the anharmonic frequency decreases from 1651.5â¯cmâ1 (nâ¯=â2) to 1547.7â¯cmâ1 (nâ¯=â8). The harmonic CC frequency for the methyl capped polyenes decreases from 1717.9â¯cmâ1 (nâ¯=â2) to 1539.6â¯cmâ1 (nâ¯=â13), and the anharmonic CC frequency decreases from 1675.0â¯cmâ1 (nâ¯=â2) to 1562.8â¯cmâ1 (nâ¯=â7).
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Journal: Chemical Data Collections - Volumes 11â12, December 2017, Pages 25-35