Platinum diimine bis(acetylilde) and platinum terpyridyl acetylide complexes for photo-induced charge separation

Platinum diimine bis(acetylide) and platinum terpyridyl acetylide chromophores display bright solution luminescence and longed lived excited states which arise from a Metal-to-Ligand Charge Transfer transition (3MLCT). This thesis explores the design, synthesis, and photophysical study of Pt(II) diimine bis(acetylide) and Pt(II) terpyridine acetylide complexes for use in multi-component systems for light-to-chemical energy conversion.; Chapters 2 and 3 discuss the synthesis and characterization of a series of luminescent Pt(diimine)(C≡C-p-C6H 4CHO)2 complexes (where the diimine = bipyridine, phenanthroline, or its derivatives). One of the most luminescent complexes, Pt(dpphen)(C≡C- p-C6H4CHO)2 (where dpphen = 4,7-diphenylphenanthroline), was easily derivatized by Schiff base chemistry with a series of donors having the formula p-NH2-C6H4-X (where X = NMe2, OMe, or H) to form Donor-Chromophore (D-C) dyads in excellent yields. All of the dyads have been structurally characterized by single crystal X-ray diffraction analysis, and the emission of the dyads is significantly quenched in all solvents. While the synthetic connection to make the dyads is facile, photolysis experiments suggest that the imine linkage is photochemically unstable.; Chapter 4 discusses the triad [Pt(pytpy)(p-C≡C-C 6H4CH2(PTZ)](PF6)2 (where pytpy = 4-(pyridinium)-4-N-(methylphenyl)-2,2':6 ',2″-terpyridine and PTZ = phenothiazine) which was prepared along with the related Donor-Chromophore (D-C) dyads [Pt(ttpy)( p-C≡CC6H4CH2(R)]PF6 (where ttpy = 4'-p-tolyl-2,2 ':6',2″-terpyridine and R = phenothiazine (PTZ), R = 2-(methoxy)phenothiazine (MPZ), R = 2-(trifluoromethyl)phenothiazine (TPZ), R = 2-(chloro)phenothiazine (CPZ)), and the Chromophore-Acceptor (C-A) dyad [Pt(Pytpy)(p-C≡CC 6H5)](PF6)2. The luminescence of the triad is completely quenched in fluid solution which indicates electron transfer quenching is occurring to generate a charge separated state. Cyclic voltammetry confirms the one electron oxidation of the donors and the one electron reduction of the acceptor demonstrating its potential usefulness in light-to-chemical energy conversion.; Chapter 5 discusses a novel Pt(II) terpyridine complex which incorporates nicotinamide into the terpyridyl ligand system. This complex [Pt(Nttpy)Cl](PF 6)2 (where Nttpy = 4'-(p-nicotinamide-N-methylphenyl)-2,2 ':6',2″-terpyridine) was observed to be brightly emissive in the solid state and demonstrated vapochromic behavior when exposed to certain organic solvents. The nature of this vapochromic behavior has been elucidated through steady state emission experiments and analysis of this complex's crystal packing which was determined through single crystal X-ray diffraction analysis.