Easily processed metal-free phosphorescent luminophores with a fast rate of phosphorescence are emerging as promising materials for advanced optoelectronics. Alkylation of modified Vitamin B6 vitamer (pyridoxine) affords a family of pyridinium-derived ionic pairs 1–7 exhibiting variable anion-π interactions in the solid state. Such a noncovalent cation-anion network promotes tunable room-temperature phosphorescence (RTP, λ_em = 510-565 nm) in crystalline materials stemming from anion(I^-)-π(pyridinium⁺) charge transfer. Systematic X-ray structural and computational studies manifest the key role of the anion(I^-)-π(pyridinium⁺) distance to the spin-orbit coupling, hence the observed RTP. For the studied pyridinium salts with RTP, the radiative rate constants (k_r) reach up to 0.9–1.3×10⁵ s⁻¹ which are competitive with those of many noble metal emitters. Ion pair 2 reached an RTP with a quantum yield of 93% and was successfully demonstrated as an excellent X-Ray scintillating dye in neat film. The demonstrated strategy of attaining intense RTP in small metal-free accessible molecules, i.e., atom-photon economy, represents a new twist in designing efficient and sustainable photofunctional molecular materials.