Approaches to the construction of intrinsically acentric chromophoric NLO materials: chemical elaboration and resultant properties of self-assembled multilayer structures

This contribution reports on the chemical generality of processes employed to construct self- assembled chromophoric multilayer materials with high second-order optical nonlinearities. These robust materials can be assembled on a variety of amorphous and single crystal substrates. Furthermore, there is significant breadth in the scope of coupling layer reagents and chromophore precursors that can be employed. These elaborations lead to enhancements in multilayer construction efficiency as does the use of in situ SHG measurements to directly monitor the assembly process. The chromophoric layers undergo facile ion exchange and the chromophore `capping' step in the construction process has been streamlined. Although these multilayer assemblies are chemically rather inert, they can be etched with HF solutions.