1,4-bis[β-(2-benzoxazoly1) vinyl] benzene (BBVB) laser dye and sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS); spectroscopic investigation and DFT, NBO and TD-DFT calculations

•Excitation energy transfers from 1,4-bis[β-(2-benzoxazoly1) vinyl] benzene as a donor to Sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS).•Quenching studies in presence of Ag NPs.•The optimized BBVB laser dye, Sodium salt of meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) and BBVB/TPPS molecular structures were obtained via applying the DFT/ B3LYP/6-311G (d) method.•The calculated electronic UV–Vis absorption spectra for BBVB and BBVB/TPPS MSs in MeOH by applying the time-dependent density functional theory (TD-DFT) at CAM-B3LYP/6-311G++(3d,3p) level.