IJSRST184111 | Received : 21 Dec 2017 | Accepted : 04 Jan 2018 | January-February-2018 [(4)2: 42-45] © 2018 IJSRST | Volume 4 | Issue 2 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X Themed Section: Science and Technology 42 Structure, Spectroscopic Measurement of 4-(Diethoxymethyl) benzaldehyde S. P. Saravanan 1 , A. Sankar 2 , K. Parimala 3 1 Department of Chemistry, Vivekanandha Arts and Science College for Women, Sankari, Tamil Nadu, India 2 Department of Chemistry, Kandaswami Kandar's College, P.Velur, Tamil Nadu, India 3 Department of Physics, Vivekanandha College of Arts and Sciences for women (Autonomous), Tiruchengode, Tamil Nadu, India ABSTRACT The structural of 4-(Diethoxymethyl)benzaldehyde (DTMB) are determined by B3LYP method with 6-311++G** basis set. The fundamental vibrations are analyzed with the help of FT-IR (4000-400 cm-1) and FT-Raman (3500- 100 cm-1) spectra. The theoretically calculated vibrational frequencies are compared with experimental FT-IR and FT-Raman frequencies. The 1H and 13C NMR spectra have been analyzed and compared with theoretical 1H and 13C NMR chemical shifts calculated by gauge independent atomic orbital (GIAO) method. Keywords: DTMB, NMR, B3LYP I. INTRODUCTION Benzaldehyde does not possess α-hydrogen, therefore, benzaldehyde cannot form enolate (enol) reaction intermediates. This precludes intermolecular aldol condensation reactions. The electronic character of phenyl ring is perfectly suited for the benzoin condensation. Electron donating substituents on the phenyl ring inhibit benzoin condensation because the carbanion intermediate is destablized. Conversely, electron withdrawing groups on the phenyl ring stabilize the analogous carbanion and subsequent nucleophilic addition reaction will not occur. Benzaldehyde is the simplest aromatic aldehyde and the substitution of a functional group in benzaldehyde changes the spectra markedly. The vibrational spectra of benzaldehyde and its derivatives have been extensively investeated by many earlier researchers [1, 2]. In the present study 4-(Diethoxymethyl)benzaldehyde have been discussed. II. EXPERIMENTAL DETAILS The compound under investigation namely 4- (Diethoxymethyl)benzaldehyde (DTMB) is purchased from Sigma-Aldrich chemicals, U.S.A with spectroscopic grade and it was used as such without any further purification. The band width on half height is 3.0 nm. 13C (100 MHz: CDCl3) and 1H (400 MHz: CDCl3) nuclear magnetic resonance (NMR) spectra were recorded on a Bruker HC 400 instrument. Chemical shifts for protons are reported in parts per million scales (δ scale) downfield from tetramethylsilane (TMS). III. COMPUTATIONAL DETAILS Quantum chemical calculations (QCC) were carried out for DTMB with Gaussian 09W program package [3] using the Becke’s three-parameter (B3) hybrid functional with Lee-Yang-Parr (LYP) correlation functional [4, 5] with the standard 6-311++G** basis set. We have scaled the numbers with standard scaling factor 0.965. The Raman activities (S i ) calculated by the Gaussian 09W program was converted to relative Raman intensities (I i ) using the following relationship derived from the intensity theory of Raman scattering [6, 7].       KT hc S f I i i i i i / exp 1 4 0         (1) where ν 0 is the laser exciting wavenumber in cm -1 (in this work, we have used the excitation wavenumber ν 0 = 9398.5 cm -1 , which corresponds to the wavelength of 1064 nm of a Nd:YAG laser), ν i is the vibraional wavenumber of the i th normal mode (cm -1 ), while S i is the Raman scattering activity of the normal mode ν i , f (is a constant equal to 10 -12 ) is a suitably chosen common