Synthesis and structural analysis of Bis(2-hydroxyphenyl) phenylamine, PhN(o-C6H4OH)2: Comparison with Tris(2-hydroxyphenyl)amine N(o-C6H4OH)3
作者:Bryte V. Kelly、Joseph M. Tanski、Mary Beth Anzovino、Gerard Parkin
DOI:10.1007/s10870-005-5360-0
日期:2005.12
The molecular structures of N(o-C6H4OH)3, PhN(o-C6H4OH)2, andp-TolN(o-C6H4OMe)2 have been determined by X-ray diffraction, thereby indicating several structural differences. For example, whereas the nitrogen in N(o-C6H4OH)3 is pyramidal with ΣC–N–C = 348.3∘, the nitrogen atoms in PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 are trigonal planar with ΣC–N–C = 359.9∘ and ΣC–N–C = 360.0∘, respectively. The phenyl andp-tolyl groups of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 lie close to the trigonal plane, while theo-C6H4OH ando-C6H4OMe groups are almost orthogonal to this plane. The coplanar and orthogonal orientations of the aryl groups of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 are in marked contrast to those of the phenyl groups within Ph3N, which exhibit dihedral angles in the range 38–52∘ and approximateD3 symmetry. The observed structures of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 may be rationalized in terms of maximizing delocalization of the nitrogen lone pair into the phenyl andp-tolyl groups, while minimizing unfavorable overlap with theo-C6H4OH ando-C6H4OMe groups due to the presence of π-donatingortho-substituents; the orthogonal orientation of theo-C6H4OH ando-C6H4OMe groups is also one that minimizes unfavorable steric interactions between theortho-substituents.
通过 X 射线衍射测定了 N(邻-C6H4OH)3、PhN(邻-C6H4OH)2 和p-TolN(邻-C6H4OMe)2 的分子结构,从而发现了它们在结构上的一些差异。例如,N(o-C6H4OH)3 中的氮原子呈金字塔形,ΣC-N-C = 348.3∘,而 PhN(o-C6H4OH)2 和 p-TolN(o-C6H4OMe)2 中的氮原子呈三棱锥平面,ΣC-N-C = 359.9∘和 ΣC-N-C = 360.0∘。PhN(o-C6H4OH)2 和 p-TolN(o-C6H4OMe)2 的苯基和对甲苯基靠近三棱锥平面,而邻-C6H4OH 和邻-C6H4OMe 基几乎与该平面正交。PhN(o-C6H4OH)2 和 p-TolN(o-C6H4OMe)2 中芳基的共面和正交方向与 Ph3N 中苯基的共面和正交方向形成鲜明对比,后者的二面角范围为 38-52∘,对称性近似于 D3。观察到的 PhN(邻-C6H4OH)2 和 p-TolN(邻-C6H4OMe)2 的结构可以从以下角度进行合理解释:最大限度地将氮孤配对分散到苯基和 p-tolyl 基团中,同时最大限度地减少由于存在 π 供氧邻取代基而与邻-C6H4OH 和邻-C6H4OMe 基团的不利重叠;Theo-C6H4OH 和 Co-C6H4OMe 基团的正交方向也能最大限度地减少正取代基之间不利的立体相互作用。