Coordination behaviour of new dipyridylpyrazole ligands towards ZnCl2and PdCl2fragments. Crystalline structural characterization and multinuclear NMR studies as evidence of linkage and conformational isomers
Coordination behaviour of new dipyridylpyrazole ligands towards ZnCl<sub>2</sub>and PdCl<sub>2</sub>fragments. Crystalline structural characterization and multinuclear NMR studies as evidence of linkage and conformational isomers
Because the molecular shape is a factor determinant in the organisation of molecules in the liquid crystal phase, we were interested in solving the crystalstructure of representative examples of the mentioned compounds, such as 1 and 6. So, the X-ray crystalstructure of [HpzR(12)py] 1 shows the presence of dimeric units through N–H⋯N hydrogen bonds, which conform to an elongated molecular shape containing
新型吡啶官能化的吡唑化合物[Hpz R(n)py ](R(n)= C 6 H 4 OC n H 2 n +1 ; n = 12,14,16,16,18; 1-4)及其相应的银配合物[Ag(上HPZ R(ñ)PY)2 ] [A]([A] = NO 3 -,BF 4 - ; 5-12)已被合成和表征。所有这些,除了1与非同晶型相关的R(n)-单取代化合物相反,它们是表现出单向或对映SmA中间相的液晶材料。由于分子形状是决定液晶相中分子组织的因素,因此我们有兴趣解决上述化合物的代表性实例(例如1和6)的晶体结构。因此,[Hpz R(12)py ] 1的X射线晶体结构显示通过N–H⋯N氢键形成二聚体单元,该氢键符合包含双链长度的细长分子形状。另一方面,[Ag(Hpz R(14)py)2 ] [NO 3] 6还证明了“ U”形阳离子实体的Ag-Ag键合二聚体。这些二聚体显示出四个链,两个被两个交替,