The title N-heterocyclic carbene derivative, C(23)H(33)N(4) (+)·Cl(-), has been synthesized and characterized by elemental analysis, (1)H and (13)C NMR, IR spectroscopy and a single-crystal X-ray diffraction study. Ions of the title compound are linked by three C-H⋯Cl inter-actions. The seven-membered 1,3-diazepane ring has a form inter-mediate between twist-chair and twist-boat.