Cryst. Res. Technol. 45, No. 3, 299 – 302 (2010) / DOI 10.1002/crat.200900509 © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Optical properties of 2-aminopyridinium nitrato silver K. P. Bhuvana* 1 , S. Robinson Jebas 2 , and T. Balasubramanian 3 1 SRM Valiammai Engineering Colege, SRM Nagar, Kattankulathur, Chennai – 603203, India 2 X-ray Crystallography Laboratory, Universiti sains Malaysia, Penang, Malaysia 3 Department of Physics, National Institute of Technology, Tiruchirappallai – 620 015, India Received 19 August 2009, revised 9 December 2009, accepted 22 December 2009 Published online 15 January 2010 Key words optical materials, crystal structure, optical properties. Crystals of 2-aminopyridinium nitrato silver have been synthesized by slow evaporation method. Grown crystals have been subjected to FTIR, Single crystal X-Ray diffraction and UV-Visible studies in order to investigate the structural and optical properties of the crystal. The FTIR spectrum reveals the presence of the functional group that corresponds to both 2-aminopyridine and silver nitrate, suggesting the formation of the compound, 2-aminopyridinium nitrato silver. From XRD it is observed that the crystal crystallizes in the structure of monoclinic with the space group of P2 1 /c. The optical transmittance spectrum shows the maximum transparency of about 95% in the visible region is in consistent with the wide band gap, estimated as 4.738 eV. The optical constants n and k has also been determined from the transmittance data. The static dielectric constant is found to be 0.851. The wide band gap and the less dielectric constant suggest the suitability of this compound material for photoconductive applications. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 Introduction Organic light-emitting diodes (OLEDs) using phosphorescent dopants have attracted much attention due to their high external quantum efficiency [1-4]. Recently it has been reported that a new photosensitive material has been realized by the mixtures with Pyridine [5]. Pyridine and their organic complexes exhibit a large amount of florescence in crystalline environment [6]. As such, pyridine compounds are considered to be an optical material. Earlier we have reported the optical properties of the derivatives of 2-Aminopyridine and its suitability for the fabrication of optical devices [7,8]. We have made a trial to enhance the optical properties further by chelating the metal binding within the compound. Out of all the metals, noble metals like silver have been extensively attracted for wide applications because of their unique optical and electrical properties apart from high conductivity and good stability [9-11]. In this work, we have incorporated the silver binding with 2-Aminopyridine in order to improve the optical properties of the organic material. Several reports propose that the silver doping enhances the optical properties [12]. This work is focused towards the achievement of a suitable inorganic complex for the optoelectronic applications. 2 Experimental The crystals of 2-aminopyridinium nitrato silver have been synthesized by slow evaporation. Solutions of 2- Aminopyridine (0.282 g dissolved in ethanol) and Silver nitrate (0.169 g dissolved in 20 ml of ammonia solution) have been mixed in the molar ratio of 3:1 and warmed with reflux at the temperature of 60 °C for 2 h. Pale yellow crystals of 2-aminopyridinium nitrato silver have been observed over a period of two weeks. ____________________ * Corresponding author: e-mail: kpusha27@gmail.com