Physicochemical Studies on Thienyl Chalcone Derivative for Nonlinear Optical Application

Single crystals of 1-(5-chlorothiophen-2-yl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one (CTTMP) having nonlinear optical property have been grown by slow evaporation technique. The functional groups were identified by FT-IR and NMR techniques. The mechanical property of the crystals was studied using Vicker's microhardness tester and the load dependence hardness was observed. The material is dimensionally stable up to 112°C. The dielectric properties of the crystals were determined using semiconductor characterization system. The optical limiting behavior of the crystal was studied using Z-scan technique. 1. Introduction Nonlinear optical (NLO) materials play an important role in fields like photonics and optoelectronics [1]. Such materials find application in technologies such as optical computing and optical communication [2, 3]. Recently, much focus has been given to organic NLO materials for applications in field of photonics [4] due to their large nonlinear response, good optical limiting behavior, fast switching time, and convenient optimization routes through molecular design compared to the currently used inorganic materials [5]. Chalcone derivatives are one of the interesting groups of materials as they are exhibiting high NLO coefficients and good crystallizability [6]. The intramolecular charge-transfer feature available in the chalcone allows us to design new molecules substituted for donor or acceptor groups, which gives an understanding of structure-property relationship [7]. Several chalcone compounds are reported to crystallize in noncentrosymmetric crystal pattern and provide necessary configuration for NLO activity with two planar benzene rings connected through a conjugated double bond and a carbonyl moiety [8, 9]. Most of the work reported on these chalcones is on second order nonlinear efficiency [10, 11]. The strong delocalization of -electrons in these systems is responsible for high molecular polarizability and their remarkable third order nonlinearities. However the third order nonlinear efficiency of Donor- -Acceptor- -Donor (D- -A- -D) type of molecules with centrosymmetric crystal structure is not found in the literature. Recently, we have reported crystal structures and second or third order nonlinear optical properties of few chalcone derivatives having thienyl group [12, 13]. We have also reported synthesis and crystal structure of 1-(5-chlorothiophen-2-yl)-3-(2,4,5-trimethoxyphenyl) prop-2-en-1-one derivative [14]. However, physicochemical property of this derivative has not been investigated. In order to find the