A novel conjugated octylcarbazole ornamented 3-phenothiazinal, 10-(9-octyl-9H-carbazol-3-yl)-10H-phenothiazine-3-carbaldehyde (OCPTC) was synthesized and fully characterized by 1H-NMR, 13C-NMR, elemental and single crystal XRD analyses. The optimized geometrical structure, vibrational frequencies and NMR have been computed with M06-2X method using 6-31+G(d,p) basis set. Total electronic energies and HOMO-LUMO energy gaps in gas phase are discussed. The geometrical parameters of the title compound obtained from single crystal XRD studies have been found in accord with the calculated (DFT) values. The experimental and theoretical FT-IR and NMR results of the title molecule have been investigated. The experimentally observed vibrational frequencies have been compared with the calculated ones, which are in good agreement with each other. Single crystal X-ray structural analysis of OCPTC, evidences the ‘‘butterfly conformation’’ of phenothiazine ring with nearly perpendicular orientation of the carbazole structural motif to the phenothiazine moiety.