Growth of Morpholin-4-ium hydrogen tartrate single crystal for optical limiting application

Abstract

A new third order nonlinear optical single crystal of Morpholin-4-ium hydrogen tartrate has been grown by the slow evaporation method. The lattice parameters and crystalline purity of this orthorhombic crystal were measured by single crystal X-ray diffraction and powder X-diffraction technique respectively. The optimized geometry shows that the morpholinium ring exist in a chair form where tartrate anions are linked via NH⋯O hydrogen bonds, forming chains. These chains are linked via NH⋯O and OH⋯O hydrogen bonds, involving the morpholinium cation. The vibrational spectral investigation predicts that the red shifting of OH and NH stretching wavenumbers are due to OH⋯O and NH⋯O intermolecular interactions, respectively which are also evident form NBO analysis. The photoluminescence spectrum shows luminescence at the blue region with an appreciable lifetime leading to applications in blue OLEDs. Third order nonlinear optical properties like self-defocusing, saturable absorption and optical limiting at 532 nm are identified by Z-scan analysis. The laser damage threshold (LDT) energy have been measured by using Nd:YAG laser of wavelength 532 nm. The field dependent nature of first and second order hyperpolarizabilities and luminescence properties suggest that MHT crystal is a potential candidate for OLED and nonlinear optical applications.