An hybrid metal-organic framework formulated as 3[2(CH6N3)+.Cl4 Mn(II)] has been synthesized by reflux condensation method of reacting guanidinium carbonate with manganese chloride. From synthesized material, good quality of single crystals have been harvested by solvent evaporation technique and characterized by single crystal XRD (SCXRD), DT-TGA analysis, UV–visible spectroscopy and Z-Scan. SCXRD investigation establishes that grown crystal crystallizes in the monoclinic crystal system with space group P 21/c. The crystal structure features strong metal-organic frameworks through Mn-Cl bonds, it limits its coordination for three adjacently connected octahedrons and making a closed metal-chlorine volume. Thermal properties have been examined by differential thermal (DT) and thermogravimetric analysis (TGA). Temperature and frequency-dependent dielectric properties have been investigated by LCR meter. The existence of third order nonlinear optical susceptibility and intensity tunable optical limiting responses have been confirmed by the Z-scan technique. © 2020 The Physical Society of the Republic of China (Taiwan)