Growth and Characterization of Potassium Di Chromate Doped L-Alanine Crystal

Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Growth and Characterization of Potassium Di Chromate Doped L-Alanine Crystal 1 D. Prasanna1, N.Karthikeyan2, Dr. P. Elangovan 1 1 – PG & Research Department of Physics, Pachaiyappa’s College, Chennai, Tamil Nadu, India 2 – Department of Physics, Prist University, Thanjavur, India DOI 10.2412/mmse.28.63.937 provided by Seo4U.link

Keywords: L-alanine, amino acid, potassium, single crystal.

ABSTRACT. L-alanine is a neutral, genetically coded amino acid. Single crystals of L-alanine have been grown from buffered aqueous solutions and characterized as to their optical quality via waveforms distortion analysis, electro optical response and harmonic generation efficiency. L-alanine was first crystallized by BERNAL and later by SIMPSON et al.

DESTRO et al. who refined the structure. By using slow evaporation method to prepare seed crystal and the preparation methods, properties and characteristic reactions of amino acids were discussed. A brief study of L-lysine monohydrochloride has been made. And various properties and uses of L-alanine have been studied.

Introduction. Crystals are ordered arrangements of atoms (or molecules). A material in crystalline form has special optical and electrical properties, in many cases improved properties over materials with randomly arranged atoms or molecules (also said to be amorphous or glassy). Crystal growth is a controlled phase transformation to solid phase, either from solid or liquid or gaseous phase. The growth units, namely the atoms, or molecules, diffuse to the growth site from the mother phase, when given sufficient time to get orderly arranged on the lattice Since crystal growth has a vital and fundamental part of materials science and engineering, crystals of suitable size and perfection are required for fundamental data acquisition and for practical devices such as detectors, integrated circuits and for other millions and millions of applications.

Experimental Synthesis of L-Alanine. Potassium phthalimide reacts with l-bromo-l-methyl propyl ester which gives an esterified phthalimide. Then hydrolysis takes place formine an acid. For release of amino acid, aqueous HCl is added. Thus, the acid is released forming L-alanine (P. Chattopadhyay).

© 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Fig. 1. Formation of L-alanine Seed preparation. Preparation of LAKDC: LAKDC synthesis at room temperature with known solubility is prepared as follows: đ?‘…đ?‘œđ?‘œđ?‘š đ?‘‡đ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’

L-alanine + Pottasium dichromate ⇒

LAKDC

Amount of LAKDC Required:

X = (P/P+Q) x Solubility of the compound at particular temperature Prepration of Mixed Salt (LAKDC): here x = 0.2 L-Alanineď‚Ž Molecular weight in grams x Molar ratio = P Pottasium di chromateď‚Ž Molecular weight in grams x Molar ratio = Q Total Molecular weight = P+Q Preparation of Seed. Slow evaporation method was employed in preparing the seed. In this method, 4.084 grams of ADP which is in crystal form is powdered and doped with 45.91568 grams of TGS which is in powder form is taken in 200ml beaker. This has been dissolved in 125ml of doubly distilled water and poured into a Pettidish. The Petri dish is covered with a plastic paper with few small holes to enable evaporation of solvents and kept in an undisturbed place. After a week seeds are produced in the Pettidish and the fine seeds of good morphology were selected for crystal growth.

Preparing the Solution. Making up the solution is the most time consuming step. There appear to cut for obtaining a solution precisely equilibrated at a desired temperature, but it may be helpful to MMSE Journal. Open Access www.mmse.xyz

Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

mention some common pitfalls. A precisely saturated solution can never be make simply by combining the necessary amount of water and salts as determined by solubility curves, 1.Because an astonishingly larger amount of published solubility date is not accurate.2.heating to complete dissolution introduces gross errors.

Growth of Crystal by Slow Evaporation. The prepared saturated solution (salt about 200ml) is taken in a 500ml beaker. A precisely fine seed crystal tied in a nylon thread is inserted in the solution.

It is seen carefully that the crystal seed is centered in the solution. So that the crystal growth takes is covered by a thin plastic paper with fine holes for evaporation of the solvent and the whole apparatus is placed undisturbed periodic to ensure the growth of the crystal.

Harvesting the Grown Crystal. Crystals grown of suitable size are harvested carefully from the beaker. Crystal obtained from mixed crystals is shown below (Fig. 2):

Fig. 2. Pottasium di chromate doped L-Alanine.

Characterization Studies.

Powder X-Ray Diffraction Analysis: The aim of the study is to determine the cell parameters of ferroelectric L-Alanine doped TGS crystals grown from solution. The grown crystal was powdered and the powder was distributed uniformly on a glass plate. The glass plate with powder was mounted on the sample holder. Monochromatic intense X-ray of wavelength 1.540598 (CuK) was used. The powder specimen of the crystal can be considered to be a collection of randomly oriented tiny crystals.

The diffracted rays from the powder are detected by means of a detector and it is amplified.The d values were calculated from the observed 2 values corresponding to the peaks using Bragg's equation. The observed `d' values were then compared with the d values of the JCPDS data.

Table 1. Structure of L-alanine.

Compound

a

B

α

c

β

γ

Structure

Pure lalanine

6.032

12.343

5.784

90

90

90

Orthorhomic

l-alanine doprd K2Cr2O7

5.382

6.211

12.213

90

90

90

Orthorhomic

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Fourier Transform Infrared (FTIR) Spectral Studies: The stretching and bending modes of vibrations exhibited by the L-Alanine doped TGS compound was analysed using FTIR. The FTIR spectrum was recorded between 400-4000 cm-1 and show in Fig.2.The observed mode are found to be as follows, the peak observed at about 3165 cm-1 due to NH3 asymmetric stretching is clearly indicates the presence of NH3 group in amine functionality. The broad band observed at about 1708 cm-1 in L-Alanine is C = O stretching the medium strong band in 1628 cm-1 is more available group of C = C stretching vibration. The strong NH3(NH3) vibration was observed at the wave number 1505 cm–1. The peak observed at about 1425 cm-1 is CH2 scissoring. The peak observed at about 1307 cm-1 is assigned as CH2 wagging, and the peak at 1126 cm-1 is due to CH2twisting. The peak 906 cm1 is assigned to C-O-C stretching and the peak 865 cm-1 in assigned as SO4 symmetric stretching. The rocking of O-C-O bending mode of band is assigned at wave number 645 cm-1.

l-alanine doped K2Cr2O7 ll 100.0

LA+K2Cr2O7

95

456

90 1959

85 80

2031 2291 2248

75

486

70 65 772

60 918 2111

55

1151

649

50 %T 45

2505

1235 849

40 35

1013 1113

30

1518 1508

25

2853 2601 2811 2782 2936 2730 2987

20 15 10

539 1455

1594 1618

3083

1411 1306 1361

5 0.0 4000.0

3600

3200

2800

2400

2000

1800 cm-1

1600

1400

1200

1000

800

600

450.0

Fig. 3. FTIR Spectrum L-Alanine doped K2Cr2O7.

UV-VIS-NIR Spectral Studies. The band gap energy value of 4.76 eV indicates that the material is a high band gap energy dielectric compound. The grown crystalline material is found to be optically transparent from UV to near IR.

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Fig. 4. UV-VIS-NIR absorbance spectrum of L-Alanine doped K2Cr2O7.

Thermal Analysis: Thermal properties of the LAKDC were revealed from the TG/DTA analysis.

The above figures show the TG/DTA curve of the sample. Both the curves show the melting point of LAKDC is 213°C. The TGA curve shows that the material has high thermal stability; it is stable up to300.1°C. The TGA curve shows that the major decomposition takes place after 397.1°C. The DTA line shows two exothermic peaks 300°C and 400°C. Around 99.4% of the material decomposes at 397°C.Finally the pyridine moiety goes out from the material and only .6% remains as residue at 800°C. 30.00

120.0

20.00 100.0

102.8% 507.5Cel 5.52uV

10.00

80.0

60.0 -10.00

TG %

DTA uV

0.00

40.0

-20.00

-30.00

20.0

-40.00 0.0

300.4Cel -47.00uV -50.00 100.0

200.0

300.0

400.0 Temp Cel

500.0

600.0

700.0

800.0

Fig. 5. Thermal analysis of L-Alanine doped K2Cr2O7.

Summary. Slow evaporation method was employed in preparing the seed. The preparation methods, properties and characteristic reactions of amino acids were discussed.

A brief study of L-lysine monohydrochloride have been made. And various properties and uses of Lalanine have been studied. Some of the properties of L-alanine are: colourless crystal; soluble in water; slightly soluble in alcohol; insoluble in ether; optically active and it is nontoxic.

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

The fundamental requirement for infrared activity, leading to absorption of infrared radiation, is that there must be a net change in dipole moment during the vibration for the molecule or the functional group under study. The FT-IR spectrum confirms the presence of molecules in grown crystals and the frequency bonding between them. The UV-VIS-NIR spectrum recorded for the grown L-Alanine doped K2Cr2O7 crystalline material. The fundamental absorption peak cut off wavelength occur at 260 nm. This indicates that the crystal is transparent from near UV to near IR including complete visible portion of Electromagnetic spectrum. Thermal properties of the LAKDC were revealed from the TG/DTA analysis.

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[4] Fundamentals of Analytical Chemistry, 3rd. edition, Saunders Golden Sunburst Series, Holt, Rinehart and Winston, Philadelphia, 1976.

[5] Mohd. Shkir, I.S. Yahia, A.M.A. Al-Qahtani, Bulk monocrystal growth, optical, dielectric, third order nonlinear, thermal and mechanical studies on HCl added L-alanine: An organic NLO material, Mater. Chem. Phys. 184 (2016), 12-22, DOI 10.1016/j.matchemphys.2016.07.052 [6] P.P.Sahay, R.K.Nath and S.Tiwari, Optical properties of thermally evaporated CdS thin films, Crystal. Res. Technology, vol.42 (3), pp. 275-280, 2007.

[7] D. Rayan Babu, D. Jayaraman R. Mohan Kumar R. Jayavel, Growth and characterization of nonlinear optical L-alanine tetrafluoroborate (L-AlFB) single crystals, Journal of Crystal Growth, 245, 2002, 121-125, DOI 10.1016/S0022-0248(02)01708-6

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