Molecular Bridges for 2D Nanomaterials

The exceptional electronic, optical, and chemical properties of nanomaterials are often compromised when individual building blocks are assembled into macroscopic devices, where poorly defined interfaces govern charge transport, mechanical integrity, and functional performance. Cross‐linking has emerged as a powerful strategy for engineering these interfaces by introducing molecular bridges that couple neighboring nanostructures and control their structural and electronic interactions. Although this concept has been explored in nanoparticle assemblies, its translation to 2D materials remains in its early stages. In this perspective, we propose molecular cross‐linking as a unifying framework for interfacial engineering across nanomaterial systems, highlighting how linker chemistry governs spacing between nanomaterials, charge transport, mechanical behavior, and chemical functionality. By comparing molecular bridging strategies in metal nanoparticles, quantum dots, transition‐metal dichalcogenides, graphene oxide, and MXenes, we review how different binding motifs and types of linkers give rise to distinct structure‐property relationships. Building on our recent demonstration of hydrogen‐bonded diamine bridging in Ti 3 C 2 T x MXenes, we propose molecular junction engineering as a general design principle for 2D materials. We envision that a programmable molecular interface will enable next‐generation hybrid materials with tunable charge‐transport characteristics, mechanics, and chemical functionality, extending far beyond MXenes to a broad class of molecularly engineered 2D systems.