Exploiting earth-abundant iron-based metal complexes as high-performance photosensitizers demands long-lived electronically excited metal-to-ligand charge-transfer (MLCT) states, but these species suffer typically from femtosecond timescale charge-transfer (CT)-state quenching by low-lying nonreactive metal-centered (MC) states. Here, we engineer supermolecular Fe(II) chromophores based on the bis(tridentate-ligand)metal(II)-ethyne-(porphinato)zinc(II) conjugated framework, previously shown to give rise to highly delocalized low-lying ³MLCT states for other Group VIII metal (Ru, Os) complexes. Electronic spectral, potentiometric, and ultrafast pump–probe transient dynamical data demonstrate that a combination of a strong σ-donating tridentate ligand and a (porphinato)zinc(II) moiety with low-lying π*-energy levels, sufficiently destabilize MC states and stabilize supermolecular MLCT states to realize Fe(II) complexes that express ³MLCT state photophysics reminiscent of their heavy-metal analogs. The resulting Fe(II) chromophore archetype, FeNHCPZn, features a highly polarized CT state having a profoundly extended ³MLCT lifetime (160 ps), ³MLCT phosphorescence, and ambient environment stability. Density functional and domain-based local pair natural orbital coupled cluster [DLPNO-CCSD(T)] theory reveal triplet-state wavefunction spatial distributions consistent with electronic spectroscopic and excited-state dynamical data, further underscoring the dramatic Fe metal-to-extended ligand CT character of electronically excited FeNHCPZn. This design further prompts intense panchromatic absorptivity via redistributing high-energy absorptive oscillator strength throughout the visible spectral domain, while maintaining a substantial excited-state oxidation potential for wide-ranging photochemistry––highlighted by the ability of FeNHCPZn to photoinject charges into a SnO₂/FTO electrode in a dye-sensitized solar cell (DSSC) architecture. Concepts enumerated herein afford opportunities for replacing traditional rare-metal–based emitters for solar-energy conversion and photoluminescence applications.

利用地球上大量的铁基金属络合物作为高性能光敏剂需要长寿命的电子激发金属到配体的电荷转移（MLCT）状态，但是这些物质通常遭受飞秒时标电荷转移（CT）状态的淬灭通过低洼的非反应性金属居中（MC）状态。在这里，我们基于双（三齿-配体）金属（II）-乙炔-（卟啉）锌（II）共轭骨架设计了超分子Fe（II）生色团，先前证明它们会引起高度离域的低洼³MLCT规定了其他VIII族金属（Ru，Os）配合物。电子光谱，电位计和超快泵浦探针瞬态动力学数据表明，强大的σ供体三齿配体和（卟啉）锌（II）部分与低的π*能级结合在一起，足以破坏MC状态和稳定超分子MLCT状态以实现Fe（II）配合物，该配合物表现出^3种MLCT状态光物理特性，让人联想到其重金属类似物。生成的Fe（II）生色团原型FeNHCPZn具有高度极化的CT状态，具有^3个MLCT寿命（160 ps），³MLCT磷光，和周围环境稳定。密度泛函和基于域的局部对自然轨道耦合簇[DLPNO-CCSD（T）]理论揭示了三态态波函数空间分布与电子光谱和激发态动力学数据一致，进一步强调了剧烈的铁金属扩展配体电子激发的FeNHCPZn的CT特性。该设计通过在可见光光谱域内重新分配高能吸收振荡器强度，从而进一步增强了强烈的全色吸收率，同时为广泛的光化学保持了相当大的激发态氧化电势-FeNHCPZn将电荷光注入电荷到SnO _2中的能力突显了这一点。染料敏化太阳能电池（DSSC）结构中的/ FTO电极。本文列举的概念为取代传统的基于稀土的发光体提供了机会，可用于太阳能转换和光致发光应用。