Şekercileroğlu, Emir Utku2025-08-062025-08-062025-072025-072025-08-05https://hdl.handle.net/11693/117420Cataloged from PDF version of article.Includes bibliographical references (leaves 49-56).Earth‑abundant alternatives to noble‑metal photosensitizers are urgently sought for solar‑driven catalysis and photoredox chemistry. This thesis describes the design, synthesis, and comprehensive characterization of a fully iron‑based triad that melds a pyrazine‑functionalized Fe(II) N‑heterocyclic carbene (Fe‑NHC) chromophore with two {Fe(CN)5} acceptor units. Guided by ligand‑field considerations, the strongly σ‑donating NHC scaffold raises the iron eg orbitals, while the pyrazine contributes low‑lying π* levels, collectively stabilizing the metal‑to‑ligand charge‑transfer (MLCT) manifold. Stepwise coordination of the pentacyanoiron fragments broadens the absorption cross‑section into the visible‑to‑near‑IR region and establishes an electronically coupled Fe-Fe-Fe architecture that facilitates energy transfer between metal centers. Femtosecond transient‑absorption spectroscopy reveals sub‑picosecond intersystem crossing, inter-ligand charge transfer that bridges multiple MLCT states, energy transfer between metal centers with 380nm and 500nm excitation and exhibits ~70 ps excited state lifetime with 650nm excitation, accompanied by a non‑decaying excited‑state absorption persisting beyond the 5 ns experimental window. These findings establish a modular strategy for constructing high‑performance, all‑iron photosensitizers and provide fundamental insight into inter‑metal electronic communication within polynuclear architectures.xii, 72 leaves : color illustrations, charts ; 30 cm.Englishinfo:eu-repo/semantics/openAccessIron(II) photosensitizerN-heterocyclic carbenePentacyanoironPolynuclear Fe dyadsTriadsMetal-to-ligand charge transferLigand-field engineeringEarth-abundant photochemistryEnergy transferTransient absorption spectroscopyExcited-state lifetimeThe design and photophysics of a trinuclear iron triadTamamen demirden oluşan bir triadın tasarımı ve fotofiziğiThesisB163142