Vol. 22, No. 1 (2013) 1-10

Vibrational spectra and density functional theoretical calculations on the NLO crystal DL-Valinium trifluoroacetate

D Manimaran^a, I Hubert Joe^a*, Daisy Bhat^b and V K Rastogi^b,c

^aCentre for Molecular and Biophysics Research, Department of Physics, Mar Ivanios College, Thiruvananthapuram-695 015, India.

^bR D Foundation Group of Institutions, NH-58, Kadrabad (Modinagar ), Ghaziabad, India

^cIndian spectroscopy society, K.C 68/1, Old Kavi Nagar, Ghaziabad- 201 002, U.P, India.

Good optical quality single crystal of DL-Valinium trifluoroacetate (VLTFA) was grown by slow evaporation technique. The grown crystal was characterized by FT-IR and FT-Raman spectra and analyzed. The DFT computations were performed at B3LYP level with 6-31G(d,p) basis set to derive molecular structural parameters, vibrational wavenumbers, intensities, atomic charges distribution of VLTFA molecule. Vibrational analysis was used to investigate O-H …O=C and N–H…O=C hydrogen bonding interactions. Mulliken population analysis, hyperpolarizability and HOMO-LUMO energy gap are calculated by density functional theory. © Anita Publications. All rights reserved.

Total Refs: 33

DSC and optical texture studies of a nematic liquid crystal mixture

Rajbir Singh*, Jitendra Kumar** and K K Raina***

¹Department of Physics, Meerut College, Meerut-250 001, India
²Department of Applied Sciences, IIMT Engineering College, Meerut-250 001,
***School of Basic and Material Sciences, Thapar Institute of Engineering and Technology, Patiala-147 004, India

Phase transition measurements have been taken using differential scanning calorimeter (DSC) and optical texture techniques of a nematic liquid crystal mixture (E-201) during heating cycle. The thermodynamic parameters such as the enthalpy (ΔH), entropy (ΔS) latent heat and heat capacity (Cp) have been determined. The optical texture of nematic liquid crystal mixture depends on the temperature and magnitude of the dc voltage applied to the cell geometry. © Anita Publications. All rights reserved.
Keywords: DSC, Nematic liquid crystal mixture, Optical Texture.

References

1. Bahadur B (ed), Liquid Crystals: Applications and Uses, Vol 1-3, (World Scientific, Singapore), 1995.
2. Bahadur B (ed), Liquid Crystals: Applications and Uses, R, Vol 1, (New Jersy, USA, World Scientific), 1990.
3. Barrall E M (II), Johnson J F, in Liquid Crystals and Plastic Crystals, Vol 2, (eds) G W Gray, D A Winsor, (Chichester: Ellis, Horwood), 1974.
4. Shukla J P, Agarwal V K, Ali J A, Arora V P, National Academy Science Letters, 15(1992)377.
5. Demus D, Goodby J, Gray J W, Spiees H W, Vill V, Handbook of Liquid Crystals, Vol 1 & Vol 2, (Weinheim, New York, Chichester, Toronto, Singapore: Wiley-VCH), 1998.
6. Srivastava S L, Dhar R, Mukherjee A, Mol Cryst Liq Crys, 287(1996)139.
7. Anand P P, Singh Rajbir, Agarwal V K, Ind J Pure & Appl Phys, 38(2000)281.
8. Arora V P, Kumar Anil, Agarwal V K, National Academy Science Letters, 26(2003).
9. Agarwal V K, Khamis K M, Arora V P, Ind J Pure & Appl Phys, 26(1988)614. 
10. Bonvallet G A, Differential Scanning Calorimetric Study of the Nematic Liquid Crystal 5CB, (Physics Department, The College of Wooster, Wooster, Ohio 44691), 1999, p 1-4.
11. Arora V P, Agarwal V K, J Phys Soc Jpn, 45(1978)1360.
12. Demus D, Hahannand H G, Kuschel F, Mol Cryst Liq Cryst, 44(1978)61. .
13. Cheng J, Meyer R B, Phys Rev A, 92(1974)744.
14. Gathania A K, Raina K K, Field induced in liquid crystal mixture, (Department of Applied Sciences, Adesh Institute of Engg and Technology Faridkot & School of Basic and Applied Sciences, Thapar Institute of Engineering and Technology, Patiala), p 1-4.
15. Singh R, Anand P P, Agarwal V K, Arora V P, Raina K K, Indd J Phys,78(2004)583.