Chain‐length dependence of interlayer interaction in crystalline n‐alkanes from Raman longitudinal acoustic mode measurements
Chain‐length dependence of interlayer interaction in crystalline n‐alkanes from Raman longitudinal acoustic mode measurements
复制标题
拉曼纵向声波模式测量结晶正烷烃层间相互作用的链长依赖性
DOI：
10.1063/1.467159
复制
发表时间：
1994
影响因子：
4.4
通讯作者：
L. Mandelkern
中科院分区：
文献类型：
--
作者：
R. G. Snyder;H. L. Strauss;R. Alamo;L. Mandelkern
对链长范围为C33至C246的室温结晶正构烷烃的拉曼活性纵向声学模式（LAM）带的观测频率的分析表明，随着链变长，层间相互作用显著降低，这种相互作用通过相邻层中链端之间的振动耦合来测量。这一结论主要基于最近可用的长于100个碳的正构烷烃的LAM测量。在本分析中，正构烷烃晶体被建模为具有端对端相互作用的共线单原子链以模拟层间相互作用。根据7种正构烷烃（C48、C62、C70、C72、C94、C150和C192）的LAM-1和LAM-3谱带的观察频率，评价了一个链内力常数（F）和一个链间偶合力常数（f）。正如预期的那样，F的值基本上与链长无关。然而，f的值被发现D…
An analysis of the observed frequencies of the Raman‐active longitudinal acoustic mode (LAM) bands of room‐temperature crystalline n‐alkanes in the chain‐length range C33 to C246 indicates that, as the chains become longer, there is a significant decrease in interlayer interaction, this interaction being measured by the vibrational coupling between the ends of chains in adjoining layers. This conclusion is based mainly on LAM measurements on n‐alkanes longer than 100 carbons that have recently become available. In the present analysis, the n‐alkane crystals are modeled as collinear monatomic chains having end‐to‐end interactions to simulate interlayer interaction. One intrachain force constant (F) and one interchain coupling force constant (f ) were evaluated from the observed frequencies of the LAM‐1 and LAM‐3 bands for each of seven n‐alkanes: C48, C62, C70, C72, C94, C150, and C192. As expected, the values found for F are essentially independent of chain length. However, the values of f were found to d...