Materials Chemistry and Physics 129 (2011) 433–438 Contents lists available at ScienceDirect Materials Chemistry and Physics j ourna l ho me pag e: www.elsevier.com/locate/matchemphys Studies on crystal growth and physical properties of 2-amino-5-chloropyridine single crystal T. Suthan a , N.P. Rajesh a,∗ , C.K. Mahadevan b , G. Bhagavannarayana c a Centre for Crystal Growth, SSN College of Engineering, Kalavakkam 603 110, India b Physics Research Centre, S.T. Hindu College, Nagercoil 629 002, India c C.G.C. Section, National Physical Laboratory, New Delhi 110 012, India a r t i c l e i n f o Article history: Received 10 June 2010 Received in revised form 8 April 2011 Accepted 11 April 2011 PACS: 61.66.Hq 81.10. 74.25.Gz 81.70.Pg 77.22.Gm Keywords: A. Organic compounds B. Crystal growth C. Differential thermal analysis (DTA) D. Dielectric properties a b s t r a c t Organic 2-amino-5-chloropyridine single crystals have been grown by slow evaporation technique suc- cessfully. The grown crystal was confirmed by single and powder X-ray diffraction studies. The presence of functional groups was identified by Fourier transform infrared (FTIR) study. High resolution X-ray diffraction (HRXRD) analysis indicates the crystalline perfection of the grown crystal. UV–Vis–NIR anal- ysis was performed to examine the optical property of the grown crystal. The thermal property of the grown crystal was studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The dielectric measurements were carried out and the results indicate an increase in dielectric and con- ductivity parameters with the increase of temperature at all frequencies. The Vicker’s hardness study reveals that the grown crystal is in soft nature. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Researchers are giving an appreciable attention to grow organic single crystals for technological applications. Microelectronics industry needs replacement of dielectric materials in multilevel interconnect structures with new low dielectric constant (ε r ) mate- rials, as an interlayer dielectric (ILD) which surrounds and insulates interconnect wiring. Lowering the ε r values of the ILD decreases the RC delay, lowers power consumption and reduces ‘crosstalk’ between nearby interconnects [1]. Silica has the ε r value ≈ 4.0, in part as a result of Si–O bonds. Although several innovative devel- opments have been made for the development of new low ε r value materials to replace silica, there is still a need for new ε r value dielectric materials. Porosity is an unwanted problem encountered with the polycrystalline and thin film materials [1]. In this context, materials in the single crystal form would be very much interesting. The 2-hydroxy-4-methoxybenzophenone [2], KDP added with urea [3] and l-arginine [4], l-arginine acetate [5] and l-arginine oxalate [5] are the reported low dielectric constant materials. In this series, ∗ Corresponding author. Tel.: +91 044 27474844; fax: +91 044 27474844. E-mail addresses: rajeshnp@hotmail.com, rajeshnp@ssn.edu.in (N.P. Rajesh). the 2-amino-5-chloropyridine crystal is expected to be a candidate for the low dielectric constant material. There are several meth- ods for crystal growth. Solution methods, namely slow cooling or slow evaporation of solutions, are commonly used for the growth of organic molecular crystals. The 2-amino-5-chloropyridine is a non- hygroscopic simple organic material and its molecular formula is C 5 H 5 ClN 2 . Single crystal of this material cannot be grown using the Bridgman technique because weight loss occurs before melting point. In this reason, slow evaporation method is adopted to grow this crystal. In this present study 2-amino-5-chloropyridine single crystal was successfully grown by the slow evaporation method and the grown crystal was analyzed by single crystal X-ray diffraction study, powder XRD, FTIR, HRXRD, UV–Vis–NIR, TG/DTA, dielectric and microhardness measurements. 2. Experimental The 2-amino-5-chloropyridine was commercially purchased from sigma Aldrich with 98% purity; it has a molecular weight of 128.56. The solubility study reveals that 2-amino-5-chloropyridne was not soluble in water and dissolved in organic solvent. In this study so we chose acetone as the solvent. The solubility curve of 2-amino-5-chloropyridine obtained by the gravimetric method is shown in Fig. 1 and it shows that solubility increases with temperature. The purity of the mate- rial was further improved by successive recrystallization process. The recrystallized salt was used for the preparation of saturated solution at room temperature. 0254-0584/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.matchemphys.2011.04.038