Crystals of cobalt(III) salts dinitro(triethylenetetramine)cobalt(III) dichromate [Co(trien)(NO₂)₂]₂Cr₂O₇ (1) and dinitro(triethylenetetramine)cobalt(III) thiocyanate [Co(trien)(NO₂)₂]SCN (2) have been synthesized to investigate [Co(trien)(NO₂)₂]⁺ cation as a promising host to capture dichromate and thiocyanate anions. The characterization of the newly synthesized compounds was accomplished by elemental analysis and spectroscopic techniques (IR, UV/visible and ¹H-NMR) and solubility product measurement. The asymmetric unit of complex 1 has a half dichromate anion and one [Co(trien)(NO₂)₂]⁺ cation while that of complex 2 has one thiocyanate anion and one [Co(trien)(NO₂)₂]⁺ cation as divulged by X-ray structure determination. The structural investigation exhibited that the crystal lattice was stabilized by second sphere hydrogen bonding interactions such as N–H_trien...O (dichromate), C–H_trien...O (dichromate), N–H_trien...N (thiocyanate) and C–H_trien...N (thiocyanate) interactions resulting in the formation of supramolecular assemblies. The complexes 1 and 2 were further examined for antibacterial activity and the findings unveiled moderate activity against gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa species. These complexes were also scrutinized for anti-proliferative activity against malignant PANC-1 cells using MTT cell survival analysis. Complex 1 exhibited remarkable anticancer activity whereas complex 2 has comparatively lesser anticancer potential