Abstract
Charge transfer complexes (CTCs) are created when an electron donor
reacts with an electron acceptor. Then, a new compound (CTC) is produced
by forming hydrogen bonds or charge transfer. This review examines the
production, features, and reported CTCs. This highlights recent
advancements in utilizing CTCs across different sectors and explores
their potential in upcoming uses, as well as the obstacles that must be
overcome to create new CTCs and investigate their uses. These complexes
have the characteristics of distinctive molecules that differ from
traditional ionic, covalent, and coordination bonding. The review
opening part summarizes CTCs, highlighting the connection between donors
and acceptors in creating new molecular structures. Furthermore, this
paper delves into applying density functional theory in examining
intermolecular CTCs, emphasizing estimating structures, binding
energies, and CT transitions. The review also discusses the different
types of CTCs, such as protonic CTCs or hydrogen-bonded charge-transfer
(HB-CT) complexes, and the thermodynamics involved in the process, which
governs the relationship between the donor and the acceptor. Moreover,
the paper emphasizes the diverse uses of CTCs in biological fields,
thermoelectrics, photoconductors, light detectors, photocatalysts,
material science, medicine, optoelectronic devices, NLO materials,
chemo-sensors, electrical conductors, surface chemistry, molecular
nanodevices, and photographic technology among other applications.