Homogeneous Alloy-like Organic Single Crystals Based on Nonplanar 8‑Hydroxyquinoline Metallic Complexes: A Novel Pathway to Supramolecular Crystals with an Arbitrarily Adjustable Stoichiometric Ratio

Binary organic crystals play critical roles in ambipolar transistors, solar cells, and light-emitting devices. However, these crystals are currently limited to a few planar materials and fixed stoichiometric ratios. Here, a new strategy of binary organic crystals was demonstrated by preparing alloy-like organic single crystals. Binary crystals based on nonplanar 8-hydroxyquinoline metallic complexes were successfully self-assembled through a solution pathway at room temperature. Structural analyses exhibit that the samples are rod-shaped homogeneous mixed crystals. We show that the stoichiometric ratio of the crystals can be arbitrarily adjusted by changing the ratio of the component materials. The charge-transfer (CT) interaction and photophysical properties were also studied. Our strategy of organic crystals may facilitate the development of binary or solid-solution organic crystals with precisely adjusted structures and physical properties.