Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2016.504.516IbejiC.U. AdegboyegaJ. OkaguO.D. AdelekeB.B. 1120161611Background: Conjugated systems are of great interest to chemists, particularly photochemists and spectroscopists. Benzophenone (BP), a highly conjugated compound is a well-known compound attracting keen interest from photochemist. Methodology: A comparative knowledge of the nature of ground state of dimethoxythiobenzophenone (DMTB) and dimethoxybenzophenone, their geometries, band gaps, absorption and transition properties will be a valuable contribution for further studies and practical applications. Results: The UV analysis of benzophenone (BP) in two solvents (ethanol, ε = 24.5 and n-hexane, ε = 1.88) and FT-IR correlated with Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TDDFT) of benzophenone (BP), thiobenzophenone (TBP), dimethoxybenzophenone (DMB) and dimethoxythiobenzophenone (DMTB) suggests a singlet ground state. Conclusion: The DMTB absorbs at the visible region with a lower band gap than DMB. The BP exhibits two bands: (I) A red shift from 247.6 nm (non-polar solvent) to 252.3 (polar solvent), Δλ = +4.7 nm and (II) A blue shift from 205.3 nm (non-polar solvent) to 197.7 nm (polar solvent), Δλ = -7.6 nm. This shows that band I is likely to be π→π* and band II n→π*. The DMB like BP absorbs at the UV region of the spectrum and unlike DMTB whose absorption is principally at the visible region. The DMTB showed a longer bond length of the thiocarbonyl (C=S) than carbonyl (C=O) in BP and DMB.]]>Castro, G.T., S.E. Blanco and O.S. Giordano,20005424425Metzner, P.,19991999pp: 127-181pp: 127-181Fisera, L., R. Huisgen, I. Kalwinsch, E. Langhals and X. Li et al.,199668789798Sustmann, R., W. Sicking and R. Huisgen,20031251442514434LOGKOW.,2010Benzophenone. A databank of evaluated octanol-water partition coefficient.]]>2010Ibeji, C.U., I.A. Adejoro and B.B. Adeleke,20152015Dorset, H and A. White,20002000Shao, Y., L.F. Molnar, Y. Jung, J. Kussmann and C. Ochsenfeld et al.,2006831723191Kupka, T., R. Wrzalik, G. Pasterna and K. Pasterny,20026161732Koopmans, T.,19341104104Chow, M.S., L.V. Liu and E.I. Solomon,20081051324113245Adejoro, I.A., D.C. Akintayo and C.U. Ibeji,2016113849Joshi, B.D. and P.N. Chaudhary,20139114Adeleke, B.B., K.S. Chen and J.K.S. Wan,1981208317326Ullah, H., A.H. Ali Shah, K. Ayub and S. Bilal,201311740694078Adeoye, M.D., N.O. Obi-Egbedi and I. Iweibo,20122012Anbarasan, P.M., P.S. Kumar, M. Geetha, R. Govindan, S. Manimegalai and K. Velmurugan,20102816Sundaraganesan, N., J. Karpagam, S. Sebastian and J.P. Cornard,2009731119Kosar, B., C. Albayrak, C.C. Ersanli, M. Odabasoglu and O. Buyukgungor,20129319Raj, A., K. Raju, H.T. Varghese, C.M. Granadeiro, H.I.S. Nogueira and C.Y. Panicker,200920549559Adejoro, I.A., E. Akintemi, O.O. Adeboye and C. Ibeji,20147117128