Synthesis, spectroscopic characterization, crystal structure, Hirshfeld surface analysis, linear and NLO properties of new hybrid compound based on tin fluoride oxalate and organic amine molecule (C12N2H9)2[SnF2(C2O4)2]2H2O

•A novel hybrid compound (C12N2H9)2[SnF2(C2O4)2]2H2O was synthesized.•XRD, IR, and UV–vis spectroscopy are recorded and analyzed.•The different intermolecular interactions have been investigated using Hirshfeld surface analysis.•An inverse relationship was found between the energy gaps and the βHRS.•NLO properties are calculated with different functionals.