Solid-State Examination of Conformationally Diverse Sulfonamide Receptors Based on Bis(2-anilinoethynyl)pyridine, -Bipyridine, and -Thiophene

Utilizing an induced-fit model and
taking advantage of rotatable
acetylenic C­(sp)–C­(sp2) bonds, we disclose the synthesis
and solid-state structures of a series of conformationally diverse
bis-sulfonamide arylethynyl receptors using either pyridine, 2,2′-bipyridine,
or thiophene as the core aryl group. Whereas the bipyridine and thiophene
structures do not appear to bind guests in the solid state, the pyridine
receptors form 2 + 2 dimers with water molecules, two halides, or
one of each, depending on the protonation state of the pyridine nitrogen
atom. Isolation of a related bis-sulfonimide derivative demonstrates
the importance of the sulfonamide N–H hydrogen bonds in dimer
formation. The pyridine receptors form monomeric structures with larger
guests such as BF4– or HSO4–, where the sulfonamide arms rotate to the side
opposite the pyridine N atom.

借助诱导适配模型，并利用可旋转的乙炔基C(sp)–C(sp2)键，本研究揭示了以吡啶、2,2'-联吡啶或噻吩作为核心芳基的系列构象多变的双磺酰胺芳乙炔受体合成的固态结构。尽管联吡啶和噻吩结构在固态下似乎无法与客体分子结合，但吡啶受体能够与水分子、两种卤化物或一种各一形成2+2二聚体，具体取决于吡啶氮原子的质子化状态。相关双磺酰亚胺衍生物的分离实验表明，磺酰胺N-H氢键在二聚体形成过程中的重要性。在吡啶受体与较大客体分子如BF4–或HSO4–形成单分子结构时，磺酰胺臂旋转至与吡啶N原子相对的侧面。