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At room temperature, many organic compounds can emit light not only from singlet excited states but also from triplet excited states. This phenomenon is known as room-temperature phosphorescence (RTP). RTP has numerous potential applications in various areas, including industry, medicine, and daily life. RTP materials can be used in white light-emitting, memorising, sensing, bioimaging, semiconducting, 3D printing, microfluidic visualisation, quantum computing, X-ray detection, etc. They have advantages over fluorescent and metal-based phosphorescent materials. They are characterized by different emission spectra, longer lifetimes, and higher environmental sensitivity. However, challenges related to the tuning of emission colours, realization of dual emission, and meeting application-specific requirements still need to be overcome. Various molecular design strategies and synthetic approaches have been developed to overcome these challenges and to develop efficient RTP materials. This review article discusses recent advances in the synthesis and properties of RTP materials, focusing on emission colours and applications. Theoretical and experimental approaches for the development of organic room temperature phosphorescence compounds exhibiting blue, green, red, and white emissions for many potential applications are analysed and classified.

The IR absorption spectra of the recently synthesized series of benzoyl-containing thianthrene derivatives were studied in the context of their structural identification. Geometry optimizitation of the ground singlet state by density functional theory (DFT) calculations with the gradient and Hessian search were performed for thianthrene molecule in the framework of the C2v symmetry restriction. The excited singlet and triplet states of thianthrene were found to be distorted along the b3u vibrational mode of the D2h point group, as well as the ground state, which leads to the non-planar batterfly-like structure (C2v). But the excited states require additional symmetry reduction; they are closer to planarity but have no symmetry elements. Optimized ground states structure for the thianthrene-benzoyle molecule and its four derivatives with fluoro-substituents and different substitution positions were analysed through complete assignment of all their vibrational modes and comparison with experimental infrared absorption spectra. A good agreement between experimental data and DFT calculated IR spectra provides additional structural support to results of the X-ray diffraction analysis of all synthesized compounds. The Hirshfeld surfaces analysis of the crystalline 3-fluorobenzoylthianthrene (T3F) was performed in order to analyze intermolecular interactions in T3F crystal. It indicates the presence of weak CH...F, CH...S and CH...O intermolecular contacts, stabilizing the crystal structure of T3F. The CH...O interactions appear in the IR spectrum of T3F crystal as two vibrational modes with frequencies 3084 and 3078 cm-1. The intermolecular interactions CH...F and CH...S do not affect the IR spectrum of T3F.

Because of the contradiction of the efficiencies of fluorescence (FL) and room temperature phosphorescence (RTP) under ambient conditions, achievement of the molecular design of efficient monomolecular white emission resulting from the overlapping of FL and RTP is attractive but very challenging. With the aim of obtaining efficient white emission from a single organic molecule, phenyl-(thianthren-2-yl)-methanone and its tan derivatives with halogen atoms are developed. Single-molecular white emitters are investigated by experimental and theoretical approaches including steady-state and time-resolved spectroscopy, X-ray analyses, and density functional theory calculations. Photoluminescence quantum yields (PLQYs) of white emission of the molecular dispersion of phenyl-(thianthren-2-yl)-methanone in the rigid host ZEONEX at room temperature are significantly enhanced from 19 to 84% after the removal of oxygen. Based on the results of X-ray analysis of the single crystal, the high PLQY values are partly attributed to the absence of pi-pi intermolecular interactions and the low number of weak van der Waals intermolecular stacking due to the strong bending of heterocyclic thianthrene moiety and the high dihedral angle between thianthrene and benzoyl groups. The structural peculiarities of the newly synthesized thianthrene derivatives may result in the development of even more efficient organic monomolecular white emitters.

Chemistry as a science about spin and electric charge of micro particles which provide driving forces of atomic interactions and molecular structure transformations fits pretty well to the modern Quantum Infor-mation Science (QIS) requirements. Today's computers operate only electric current signals in the semicon-ductor networks but the electron-spin properties are not exploited in a large extend. Spintronics provides spin-polarized currents and manipulates magnetic spin interactions; it uses mostly solid state chemistry of heavy elements. But a rich organic chemistry of solvents and fin films offers a great potential for molecular elec-tronics and quantum computing. Photo-excited organic complexes of the "chromophore-radical" type provide good promise for many technological applications in molecular spintronics and electronics, including QIS technology. The doublet state photo excitation of stable organic radical being delocalized onto the linked anthracene molecule within picoseconds and subsequently evolved into a quartet state for big radicals (a pure high spin state) of the mixed radical-triplet character presents a sensible spin-optical interface for qubit in quantum computing. This high-spin state is coherently addressable with EPR microwaves even at room tem-perature, with the optical read-out induced by intersystem crossing (ISC) to emissive triplet state. Such inte-gration of radical luminescence and high-spin states EPR provides the organic materials involvement into emerging QIS technologies.