不同溴取代对多溴联苯醚分子平面结构的影响

发布时间：2019-03-25 13:27

【摘要】：多溴联苯醚(PBDEs)同系物有209种,溴取代数和位置不同,对其空间结构稳定性有影响,PBDEs分子平面可能会发生扭转,继而影响它们的物理化学性质,因此研究最稳定的存在构型及溴取代对PBDEs平面结构的影响尤为重要.本文以多溴联苯醚为研究对象,通过Gaussian03软件在B3LYP/6-31G*水平下运用量子化学方法分别对PBDEs进行强制平面结构优化和非平面结构优化,并对数据进行分析得出Br取代对PBDEs分子结构的影响.结果表明,所考察的PBDEs均为非平面结构更稳定,即Br取代会引起PBDEs平面结构扭转.从分子的量子化学参数分析,非平面结构优化的PBDEs的醚键键角(θ_(C—O—C))变小,1,1'位键长(R_(C1—O)、R_(O—C1'))和6,6'位键长(R_(C6—*)、R_(C6'—*))增大,偶极距μ值增大,但二面角(D)大小与R_(C6—*)、R_(C6'—*)无明显变化规律.
[Abstract]:There are 209 kinds of (PBDEs) congeners of polybromobiphenyl ether, the number and position of bromine substituents are different, and the stability of spatial structure is affected. The molecular plane of PBDEs may be twisted, which will affect their physicochemical properties. Therefore, it is very important to study the effect of the most stable existing configuration and bromine substitution on the plane structure of PBDEs. Taking PBDEs as the research object, the forced plane structure optimization and non-plane structure optimization of PBDEs were carried out by means of quantum chemistry method under the level of B3LYP6 / 31g * with Gaussian03 software, and the structure optimization of the forced plane and the non-planar structure of PBDEs were carried out by quantum chemistry. The effect of Br substitution on the molecular structure of PBDEs was obtained by analyzing the data. The results show that the non-planar structure of PBDEs is more stable, that is, Br substitution will cause the torsion of the plane structure of PBDEs. From the quantum chemical parameters of the molecule, it is found that the ether bond angle (胃 _ (C-O-C) of the non-planar structure-optimized PBDEs decreases and the 1,1'- position bond length (R _ (C1) O) decreases. R _ (O _ (C _ 1') and 6, 6'- bit bond length (R _ (C _ 6 ~ *), R _ (C _ (C _ 6) *) increase, dipolar distance 渭 value increases, but dihedral angle (D) size and R _ (C _ 6c ~ *), RC _ (C _ 6) did not change obviously.
【作者单位】：华侨大学化工学院;
【基金】：国家自然科学基金(21207043)资助~~
【分类号】：O621.13

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