Cu3(BTB)2: Multilayer, MOF, or Hybrid?

Metal organic frameworks (MOF) are highly porous crystalline structures that are most commonly studied in the powder form. However, they may also be studied as surface anchored MOFs (surMOF). The growth mechanism of the iconic MOF-14 system has been studied extensively as a surMOF using atomic force microscopy and ellipsometry, which indicate a Van der Merwe growth mechanism. Given this growth mechanism and the unit structure of MOF-14 as a powder, it is of interest to determine if the surMOF-14 has a multilayer structure, framework structure, or a hybrid structure. To investigate the structure, the growth mechanisms of the system on different self-assembled monolayers (SAMs) was studied. In addition, ammonia exposure was conducted to determine if the MOF-14 system behaves similarly to either the MHDA multilayer system or the HKUST-1 surMOF. Results indicate that changing the SAM does not have a major effect on changing the growth mechanism of surMOF-14. Preliminary results indicate the surMOF-14 does not respond in a way similar to that of the MHDA multilayer system or the HKUST-1 surMOF