Single-molecule switches are a promising technology which can result in advances in nanoscale memristors and neuromorphic computing. While resistance-switching memristor-like phenomena induced by voltage bias have been documented in molecular junctions, the fundamental mechanisms governing these processes are not yet fully understood. IV-traces measured of 5 different rigid conjugated molecules (1-SAc, 2-SMe, 3-meta, 4-Hmeta, 5-Hpara) in a mechanically controlled break junction consist of complex features such as small conductance peaks which cannot be explained using the single-level model. Resistance-switching phenomena is studied to disentangle switches caused by mechanical origin related to the positioning of the molecule within the break junction, and those caused by a hypothetical proton-hopping mechanism which is expected to be a cause for switches in 4-Hmeta and 5-Hpara molecules. In this study, the molecule is modelled as a dipole consisting of 2 coupled sites with capacitive coupling, resulting in more accurate fits of the IV-traces compared to when using the single-level model. These small conductance peaks are found to be related to a very strong coupling Γ to the electrodes or a large coupling τ between the 2-sites within the dipole model. The dipole model is found to be insufficient to explain the entire shape of these IV traces and are found to be only partially able to fit the entire trace. Model inadequacies of the proposed dipole model are discussed extensively. Corrections to the dipole model are suggested such as in the form of a parallel resistance and inclusion of non-rectangular tunnelling barriers. The results of the curve fits using the dipole model point towards a step towards uncovering the origin of the memristive behaviour found in these IV-traces. ... Read more