The photoinduced polymerization of electron-rich heteroaromatic pentacycles (ERHPs), such as thiophene derivatives and pyrrole derivatives, is challenging owing to the inherent stability of their aromatic structure. The resultant polymers are organic semiconductor materials that are widely used in both organic electronic and bioelectronic devices. Here we report an efficient hydrogen-atom transfer (HAT) photocatalyst, which is the dimerization product (1,2-bis(4-(2-hydroxyethoxy)phenyl)ethane-1,2-dione) of an acyl radical generated by the photolysis of Irgacure 2959, and its use for the dehydrogenation of coupled ERHPs formed in an acidic environment. The dehydrogenation occurs via a double HAT process, enabling the photopolymerization of ERHPs. This reaction also allows us to fabricate three-dimensional (3D) conductive pathways in hydrogels. The hydrogel can be printed to form free-standing 3D conductive structures of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate with a precision of 220 nm, markedly surpassing structures built using previous methods (>10 µm). The approach introduces opportunities for precision engineering of 3D electrodes with the possibility of expanding applications in organic electronics and bioelectronics.

富电子杂芳族五环化合物（ERHP）（例如噻吩衍生物和吡咯衍生物）的光诱导聚合由于其芳香结构的固有稳定性而具有挑战性。所得聚合物是广泛用于有机电子和生物电子器件的有机半导体材料。在这里，我们报道了一种高效的氢原子转移（HAT）光催化剂，它是由酰基自由基产生的二聚产物（1,2-双（4-（2-羟基乙氧基）苯基）乙烷-1,2-二酮） Irgacure 2959 的光解，及其用于酸性环境中形成的偶联 ERHP 脱氢的用途。脱氢通过双 HAT 过程发生，从而实现 ERHP 的光聚合。该反应还使我们能够在水凝胶中制造三维 (3D) 导电通路。该水凝胶可以打印形成独立的聚(3,4-乙撑二氧噻吩)：聚苯乙烯磺酸盐3D导电结构，精度为220 nm，明显超过使用以前的方法构建的结构(>10 µm)。该方法为 3D 电极的精密工程带来了机会，并有可能扩大在有机电子和生物电子领域的应用。