Brocorens Patrick, Lazzaroni Roberto, Brédas Jean-Luc
Service de Chimie des Matériaux Nouveaux, Université de Mons-Hainaut, Place du Parc, 20, B-7000 Mons (Belgium).
J Phys Chem B. 2005 Oct 27;109(42):19897-907. doi: 10.1021/jp0520493.
The parameters that influence the conformation of poly(propylene imine) dendrimers were investigated by molecular simulations using molecular mechanics and simulated annealing methods. Dendrimers with two types of peripheral units able to communicate via hydrogen bonding-amine and amide moieties-were considered in order to study the role that secondary interactions among the end groups have in the spatial organization of the dendritic branches. Radial atomic density profiles and radial atomic probability distributions were used to extract global properties, such as the degree of packing of the branches, the distribution of the monomers throughout the molecular volume, and the extent and characteristics of the surface region. Information was also obtained about the nature, location, and extent of formation of the hydrogen bonds, as well as their evolution with dendrimer generation and their assembly into networks. The analyses were supported by a detailed investigation of the first two generations, with an emphasis on the relationship between hydrogen bonding and the compactness and stability of the molecules; this allowed us to account for the generational evolution of hydrogen bonding that is experimentally observed in several poly(propylene imine) dendrimers.
通过使用分子力学和模拟退火方法的分子模拟，研究了影响聚（丙烯亚胺）树枝状大分子构象的参数。为了研究端基之间的二级相互作用在树枝状分支空间组织中的作用，考虑了具有两种能够通过氢键相互作用的外围单元（胺基和酰胺基团）的树枝状大分子。径向原子密度分布和径向原子概率分布用于提取全局性质，如分支的堆积程度、单体在整个分子体积中的分布以及表面区域的范围和特征。还获得了有关氢键的性质、位置和形成程度的信息，以及它们随树枝状大分子代数的演变及其组装成网络的信息。通过对前两代的详细研究支持了这些分析，重点是氢键与分子的紧密性和稳定性之间的关系；这使我们能够解释在几种聚（丙烯亚胺）树枝状大分子中实验观察到的氢键的代际演变。
