Molecular Organization of 2,1,3-Benzothiadiazoles in the Solid State

Derivatives of 2,1,3-benzothiadiazole
(1) are widely
used in many areas of science and are particularly valuable as components
of active layers in various thin-film optoelectronic devices. Even
more effective benzothiadiazoles are likely to result if a deeper
understanding of their preferred patterns of molecular association
can be acquired. To provide new insight, we have analyzed the structures
of compounds in which multiple benzothiadiazole units are attached
to well-defined planar and nonplanar molecular cores. Our results
show that molecular organization can be controlled in complex structures
by using directional S···N bonding of benzothiadiazole
units and other characteristic interactions. Moreover, the observed
structures are distinctly different from those of analogous arenes.
Replacing benzene rings in arenes by thiadiazoles thereby provides
a strategy for making new compounds with extended systems of π-conjugation
and unique patterns of molecular organization, including the ability
to co-crystallize with the fullerenes C60 and C70.

2,1,3-苯并噻二唑（2,1,3-benzothiadiazole）衍生物(1)已被广泛应用于诸多科学研究领域，尤其作为各类薄膜光电器件活性层的核心组分，具备极高的应用价值。若能更深入地解析其分子组装的偏好模式，有望开发出性能更为优异的苯并噻二唑类化合物。为获取全新的研究视角，我们针对多个苯并噻二唑单元连接至结构明确的平面与非平面分子核的化合物展开了结构分析。研究结果表明，通过调控苯并噻二唑单元的定向S···N成键作用及其他特征性分子间相互作用，可实现复杂结构中分子排布方式的精准调控。此外，观测得到的晶体结构与同类芳烃的结构存在显著差异。将芳烃中的苯环替换为噻二唑环，可为构建具有扩展π共轭体系与独特分子组装模式的新型化合物提供可行策略，这类化合物还可与富勒烯（fullerenes）C₆₀及C₇₀实现共结晶。