π-conjugation in these systems. For the phosphine derivatives, the sum of angles about phosphorus is 308–309°, typical of a pyramidal configuration. As a result, π-electronic interaction between boron and phosphorus is probably weak and a large angle exists between the ground-state and excited-state dipole moments. Related arguments also apply to the ferrocenyl boranes. The large β value ( − 24 × 10−30 esu) measured
我们报告的5π电子共轭
二苯基膦基二茂铁和di
MESitylboranes(合成和表征ë)-Ph 2 PCHCHB(
MES)2(图3a)中结晶,空间群P 2 1 2 1 2 1,并显示出粉末二次谐波(S
HG)效率χ (2),大约等于
尿素的效率。第一超极化分子,β,的图3a中,Ph 2 PCCB(
MES)2(图5a),(ë) - (η-C 5 H ^ 5)的Fe(η-C 5 H ^ 4)CHCHB(
MES)2(3B)和(η-C 5 H ^ 5)的Fe(η-C 5 H ^ 4)CCB(
MES)2(图5b)进行了测量,其值是可与小型有机化合物媲美。通过分析化合物3a,b,5a,b的晶体和分子结构,已经检查了它们的基态电荷转移相互作用。重要的是,
乙烯基从BC 3平面旋转出3a的16.8°和5a的12.0°,而异族基团通常相对于
硼价平面旋转50–70°。这表明最佳的π-共轭是沿着所