Effect of Ni2+ Doping on the Growth and Properties of Mn-L-Histidine Hydrochloride Monohydrate Crystals

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 a=1.5301 nm, b=0.8928 nm and c=0.6851 nm. From electron paramagnetic resonance (EPR) spectra, isotropic “g” factor and spin hamiltonian parameter A all were calculated as 2.0439 and 20×10−4, respectively. From optical absorption studies, crystal field splitting value (Dq) and the interelectron repulsion parameters B and C were calculated for Ni2+ and Mn2+ as Dq=850 cm−1, B=725 cm−1, C=2640 cm−1 and Dq=915 cm−1, B=810 cm−1, C=2780 cm−1, respectively. The presence of various functional groups and the modes of vibrations were confirmed by FTIR studies