Complexes Cu Mes MIC Naph Cz, Cu Mes MIC p-An Cz, Cu Mes MIC 3,5-CF3Ph Cz, Cu Mes MIC Naph NPh2, and Cu Mes MIC NPh2 were crystallized by slow diffusion of diethyl ether in acetonitrile solutions and their structures were confirmed by single crystal X-ray diffraction. As illustrated in Figure , all the complexes exhibit linear geometries (C1-Cu1-N1 angles = 174 -178º) with similar Cu1-C1 (1.863-1.879(2) Å) and Cu1-N1 (1.858-1.875(2) Å) bond lengths that are consistent with the reports by Thompson and Liu. 63 t BuOK (1.1 equiv.) Likewise, the C1-N1 bond lengths range between 3.717-3.743 Å, which are also similar to previously-reported the linear Cu I complexes. The most notable differences are the angles defined by the carbene central ring and the amides planes. ). The angles for the diphenylamide (DMA) complexes are defined using the triazole MIC ring and the Cu-N-C-C plane of both phenyl rings of the DPA and their values (22.9 and 19.3º for Cu Mes MIC Naph NPh2, 28.1 and 27.2º for Cu Mes MIC 3,5-CF3Ph NPh2) are larger than those for the corresponding carbazole (6.0º for Cu Mes MIC Naph Cz, 20.5º for Cu Mes MIC 3,5-CF3Ph Cz). Moreover, it appeared that the presence of the electron-withdrawing bis(trifluoromethyl) groups on the aryl ring leads to larger angles between the carbene and the carbazolide (Cu Mes MIC 3,5-CF3Ph Cz > Cu Mes MIC p-An Cz > Cu Mes MIC Naph Cz) or the diphenylamide (Cu Mes MIC 3,5-CF3Ph NPh2> Cu Mes MIC Naph NPh2), despite no obvious steric reasons for this phenomenon. The absence of a steric origin is bolstered by the fact that the angles between the triazole ring and the arene planes show no clear electronic trends and range between 41.0-48.7º across all five complexes (Table ), while the triazole-mesityl planes angles are all close to orthogonal (68.8-88.5º). Thus, based on the X-ray structures, we expect long-range  interactions between the 2p orbitals of the carbazolide and the MICs that are more similar to the interactions described by Thompson than those that exist in the systems of Liu. 63