Self-assembly of three 1,1'-biphenyl-2,2',6,6'-tetracarboxamides 2a-2c differing each from the other by substitution at the amidic nitrogens (R = H, ethyl and 1-(R)-phenylethyl, respectively) was investigated by single crystal X-ray diffraction analysis. It was found that the unsubstituted tetracarboxamide 2a gives rise to infinite hydrogen-bonded 2D network composed from chiral cyclotetrameric squares (D4 symmetry). Such self-assembling pattern is suppressed by alkyl substitution in 2b and 2c, which disfavours formation of intermolecular amide-amide hydrogen bonds.
使用单晶X射线衍射分析研究了三种1,1'-联苯-2,2',6,6'-四酰胺2a-2c的自组装,它们在酰胺氮原子上的取代基不同(R = H,乙基和1-(R)-苯乙基)。发现未取代的四酰胺2a形成无限氢键化的手性四聚体正方形(D4对称性)的二维网络。在2b和2c中,烷基取代抑制了分子间酰胺-酰胺氢键的形成,从而抑制了这种自组装模式的形成。