Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6 Canada.
Chemistry. 2012 May 29;18(22):6781-7. doi: 10.1002/chem.201103421. Epub 2012 Apr 18.
A series of new substituted 1,3-bis(2-pyridylimino)isoindolines--1,3-bis(2-pyridylimino)-5,6-bis(2,6-diisopropylphenoxy)isoindoline (2b), 1,3-bis(2-pyridylimino)-5,6-bis(4-tert-butylphenyl)isoindoline (2c), and 1,3-bis(2-pyridylimino)-5-tert-butylisoindoline (2d)--were synthesized and structurally characterized by single-crystal X-ray diffraction. The birefringence (Δn) of the crystals of unsubstituted 1,3-bis(2-pyridylimino)isoindoline (2a), 2b, 2c, and 2d were measured and found to vary greatly, with Δn values of 0.0654(3), 0.0629(17), 0.588(10), 0.701(12), respectively. A structure-property relationship for the birefringence values of 2a-2d was outlined and indicated that the anisotropy of the polarizability of the molecules plays a crucial role in the birefringence of the crystals. The greatest birefringence values are achieved when the molecules are oriented in a face-to-face configuration intermolecularly, and along the crystallographic face being measured.
一系列新的取代的 1,3-双(2-吡啶基亚氨基)异吲哚啉-1,3-双(2-吡啶基亚氨基)-5,6-双(2,6-二异丙基苯氧基)异吲哚啉(2b)、1,3-双(2-吡啶基亚氨基)-5,6-双(4-叔丁基苯基)异吲哚啉(2c)和 1,3-双(2-吡啶基亚氨基)-5-叔丁基异吲哚啉(2d)被合成并通过单晶 X 射线衍射进行了结构表征。未取代的 1,3-双(2-吡啶基亚氨基)异吲哚啉(2a)、2b、2c 和 2d 的晶体的双折射(Δn)被测量，并发现变化很大，Δn 值分别为 0.0654(3)、0.0629(17)、0.588(10)、0.701(12)。概述了 2a-2d 的双折射值的结构-性质关系，并表明分子的极化率各向异性在晶体的双折射中起着至关重要的作用。当分子在分子间以面对面的构型取向并且沿着被测量的晶面取向时，实现了最大的双折射值。
