Perylene bisimide (PBI) dyes are known as red, maroon and black pigments, whose colors depend on the close π−π stacking arrangement. However, contrary to the luminescent monomers, deep-red and black PBI pigments are commonly non- or only weakly fluorescent due to (multiple) quenching pathways. Here, we introduce N-alkoxybenzyl substituted PBIs that contain close π stacking arrangement (exhibiting d_π−π ≈ 3.5 Å, and longitudinal and transversal displacements of 3.1 Å and 1.3 Å); however, they afford deep-red emitters with solid-state fluorescence quantum yields (Φ_F) of up to 60%. Systematic photophysical and computational studies in solution and in the solid state reveal a sensitive interconversion of the PBI-centred locally excited state and a charge transfer state, which depends on the dihedral angle (θ) between the benzyl and alkoxy groups. This effectively controls the emission process, and enables high Φ_F by circumventing the common quenching pathways commonly observed for perylene black analogues.

苝双酰亚胺 (PBI) 染料被称为红色、栗色和黑色颜料，其颜色取决于紧密的π−π堆叠排列。然而，与发光单体相反，深红色和黑色 PBI 颜料由于（多个）淬灭途径通常不发荧光或仅发微弱荧光。在这里，我们介绍了N -烷氧基苄基取代的 PBI，其包含紧密的 π 堆叠排列（表现出d _π−π ≈ 3.5 Å，以及 3.1 Å 和 1.3 Å 的纵向和横向位移）；然而，它们提供了具有固态荧光量子产率 ( Φ _F) 高达 60%。溶液和固态的系统光物理和计算研究揭示了以 PBI 为中心的局部激发态和电荷转移态之间的敏感相互转换，这取决于苄基和烷氧基之间的二面角 ( θ ) 。这有效地控制了发射过程，并通过绕过苝黑类似物常见的常见猝灭途径来实现高Φ _F。