%0 Journal Article %T Effect of Ni Doping on the Growth and Properties of Mn-L-Histidine Hydrochloride Monohydrate Crystals %A J. Sai Chandra %A P. N. V. V. L. Prameela Rani %A V. Parvathi %A Y. Sunandamma %J International Journal of Inorganic Chemistry %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/716819 %X The main focus of this work had been to grow good quality crystals from amino acids and amino acid-based materials for nonlinear optics (NLO) applications. For the first time, a series of amino acid complexes doped with transition metal ions were grown in our laboratory from aqueous solutions by slow evaporation technique. Ni(II) ion doped Manganese L-Histidine hydrochloride monohydrate (Ni(II)-MnLHICl) crystals were grown on the same lines and were characterized by powder X-ray diffraction (XRD), optical absorption, electron paramagnetic resonance, and infrared absorption studies. From Powder XRD, the unit cell lattice parameters were calculated as £¿nm, £¿nm and £¿nm. From electron paramagnetic resonance (EPR) spectra, isotropic ¡°g¡± factor and spin hamiltonian parameter A all were calculated as 2.0439 and , respectively. From optical absorption studies, crystal field splitting value ( ) and the interelectron repulsion parameters B and C were calculated for Ni2+ and Mn2+ as £¿cm£¿1, £¿cm£¿1, £¿cm£¿1 and £¿cm£¿1, £¿cm£¿1, £¿cm£¿1, respectively. The presence of various functional groups and the modes of vibrations were confirmed by FTIR studies. 1. Introduction Doping is a well-chosen and widely accepted technique for incorporating the required physical properties in a bulk material for technological applications [1¨C3]. The technique has been extensively explored to modify the properties like electrooptical (photoluminescence), conductivity and crystal growth [4]. It has also been demonstrated that metal ion dopants are the most versatile in modifying the properties of a compound [5]. Metal amino acid interactions have been widely studied because of their biological importance. Metal amino acid complexes constitute very important model systems in order to understand the electronic properties of metal ions in biologically important macromolecules [6]. Amino acid complexes doped with transition metal ions are suitable model systems for understanding the basic aspects of role of metals in proteins [7, 8]. L-Histidine is an optically active ¦Á-amino acid in its laevo-form and is a tridentate ligand that has an imidazole ring, amino, and carboxylate groups. It is also a protein-forming amino acid playing a fundamental role in several biological mechanisms including the formation of hemoglobin and is being used in the treatment of allergic diseases and anemia [9]. Complexes of amino acids with metal ion dopants combine the advantage of organo amino acid with that of inorganic metal ions [10]. Multidentate complexes of amino acids with metal ion dopants are at present %U http://www.hindawi.com/journals/ijic/2013/716819/