Synthesis and properties of Zn<sup>2+</sup>/Cd<sup>2+</sup>-directed self-assembled metallo-supramolecular polymers based on 1,4-diketo-pyrrolo[3,4-c]pyrrole (DPP) derivatives
作者:Xuegang Chen、Kai Guo、Fanchao Li、Li Zhou、Hongbin Qiao
DOI:10.1039/c4ra10685g
日期:——
New building blocks based on 1,4-diketopyrrolo[3,4-c]pyrrole (DPP), 2,5-bis(2-ethylhexyl)-3,6-bis(5-[p-(2,2':6′,2′′-terpyridine-4′-yl) phenyl]thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (M1) and 2,5-bis(2-ethylhexyl)-3,6-bis(4-[p-(2,2′:6′,2′′-terpyridine-4′-yl) phenyl]phenyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (M2) were synthesized by the Suzuki Pd-catalyzed cross-coupling reaction. Under moderate conditions, directed self-assembly polymerizations by the transition metal ions Zn2+ and Cd2+, respectively, were carried out. The metallo-supramolecular polymers P1Zn, P1Cd, P2Zn and P2Cd were obtained and fully characterized. The supramolecular polymers P2Zn and P2Cd, containing DPP modified by a phenyl unit, showed absorption maxima at about 504 and 506 nm in films. In contrast, the polymers P1Zn and P1Cd, in which the thiophene moiety-modified DPP was introduced, exhibited strong and broad visible absorption over 300–800 nm with maxima at about 601 and 598 nm and shoulder peaks at about 665 and 671 nm, respectively. The low band gaps estimated from CV of 1.52, 1.51, 1.58 and 1.58 eV for P1Zn, P1Cd, P2Zn and P2Cd, respectively, are also reported.
基于 1,4-二酮吡咯并[3,4-c]吡咯 (DPP)、2,5-双(2-乙基己基)-3,6-双(5-[p-(2,2':6′,2′′-叔吡啶-4′-基)苯基]噻吩-2-基)吡咯并[3,4-c]吡咯-1,4(2H,5H)-二酮(M1)和 2,5-双(2-乙基己基)-3,6-双(4-[p-(2,2′:通过铃木钯催化的交叉偶联反应合成了 2,5-双(2-乙基己基)-3,6-双(4-[p-(2,2′: 6′,2′′-叔吡啶-4′-基)苯基]苯基)吡咯并[3,4-c]吡咯-1,4(2H,5H)-二酮(M2)。在温和的条件下,过渡金属离子 Zn2+ 和 Cd2+ 分别进行了定向自组装聚合。得到了金属超分子聚合物 P1Zn、P1Cd、P2Zn 和 P2Cd,并对其进行了全面表征。含有苯基单元修饰的 DPP 的超分子聚合物 P2Zn 和 P2Cd 在薄膜中的最大吸收波长分别为 504 纳米和 506 纳米。相比之下,引入了噻吩分子修饰的 DPP 的聚合物 P1Zn 和 P1Cd 在 300-800 纳米波长范围内表现出强烈而宽广的可见光吸收,最大值分别约为 601 纳米和 598 纳米,肩峰约为 665 纳米和 671 纳米。根据 CV 值估算,P1Zn、P1Cd、P2Zn 和 P2Cd 的低带隙分别为 1.52、1.51、1.58 和 1.58 eV。