The fundamental surface chemistry of relatively simple hydrocarbons is considered as one of the sources from which the fields of nanoscience and technology emerged. The seminal works about the self-assembly and development of the monolayers of Sagiv, Nuzzo, Allara, Whitesides, and many others form the basis of many functional interfaces and materials. Increasingly, complex and functional organic molecules have been used by many others to introduce surface-bound molecular machinery, optical properties, and binding sites for biomolecules, for example. The binding of molecules from the gas phase or solution onto solid support is a frequently used approach to form nano-structures and thin films. There is an excellent compatibility of many organic functional groups with diverse substrate surfaces (e.g., alkyl thiols and silanes with metallic and hydrophilic surfaces, respectively). Most thin films consist of only one molecular component. Despite many studies, control over the formation of multicomponent materials remains challenging. Different chemical and structural properties of the molecular components can cause self-sorting, phase separation, and aggregation, resulting in the formation of domains. The molecular composition of feed solutions is not always reflected in the thin film structure; similar observations were made regarding the growth of co-crystals from solutions containing more than one organic component. Control over the composition of supramolecular thin films is intriguing, since new electronic properties and other useful functionalities can arise. The use of coordination chemistry for the formation of redox-active assemblies on conductive surfaces resulted in properties that are not readily achievable with other materials. The long-range electron transfer properties of such assemblies were attributed to structural (e.g., porosity) and electronic factors.