Spectral and theoretical studies of 2-naphthalenol: an organic nonlinear optical crystalline material

• Published in: Journal of Optoelectronics and Advanced Materials 2006-06, Vol.8 (3), p.1143-1147
• Main Authors: Chris, V, Oltean, M, Pirnau, A, Miclaus, V, Filip, S
• Format: Article
• Language: English
• ISSN: 1454-4164

In this work we will report a joint experimental and theoretical investigation on 2-Naphthalenol, which was shown to be a potential organic non linear optical (NLO) material [1] and has very recently been investigated by .single crystal X-ray diffraction method. Our study is aiming to get new insights into molecular structure and properties of this molecule and for this purpose we used FT-IR/ATR and FT-Raman spectroscopies, coupled with quantum chemical calculations performed in the framework of Density Functional Theory (DFT) approach, both for monomer and dimer of 2-Naphthalenol. The hybrid B3LYP exchange-correlation functional was used in conjunction with 6-31 G(d) and cc-pVDZ basis sets for geometry optimization, vibrational and polarizability and hyperpolarizability tensor calculations. Excepting the stretching OH vibration, the remaining experimental vibrational bands are reproduced with a molecular root mean square error of only 14.2 cm-1 and 14.7 cm-1 corresponding to the 6-31 G (d) and cc-pVDZ basis sets, respectively. The present calculations with the two different basis sets show the inverse relationship between the first polarizability and the corresponding HOMO-LUMO energy gap. While the dipole moment and polarizability are greater for dimer, the hyperpolarizability is significantly lower and this fact could be ascribed to the minimization of the effect of conjugation length on the second order non linear properties for this molecule.