Tetracyanoquinodimethanido Derivatives of (Terpyridine)‐ and (Phenanthroline)metal Complexes − Structural and Magnetic Studies of Radical‐Ion Salts

Abstract

Several derivatives of formulae [M(terpy)2

Coarse and Fine Tuning of the Electronic Energies of Triimineplatinum(II) Square-Planar Complexes

“…6 One of the strategies to circumvent this electrochemical mismatch is to use the anionic form of the organic acceptor as a counterion for the cationic complexes [Pt(tbtrpy)X] + while ultimately targeting solar cells based on SnO 2 , 7 whose conduction band lies at lower energy than the reduction potential of the stable nitrile radical anions. In analogy to similar inorganic-organic hybrid materials, the [Pt(tbtrpy)X] + TCNQadducts might also exhibit interesting conducting 8 and magnetic 9 S4, SI). 11 Neither compound exhibits Pt‚‚‚Pt interactions.…”

“…One of the strategies to circumvent this electrochemical mismatch is to use the anionic form of the organic acceptor as a counterion for the cationic complexes [Pt(tbtrpy)X] + while ultimately targeting solar cells based on SnO 2 , whose conduction band lies at lower energy than the reduction potential of the stable nitrile radical anions. In analogy to similar inorganic−organic hybrid materials, the [Pt(tbtrpy)X] + TCNQ - adducts might also exhibit interesting conducting and magnetic applications. This Communication represents our first contribution in this ongoing expansion, in which we report the syntheses, crystal structures, absorption, and electrochemical properties of several [Pt(tbtrpy)X]Y complexes and we demonstrate that a systematic variation of X and Y results in coarse and fine tuning of the electronic energies.…”

Importance of Vibronic Effects in the UV–Vis Spectrum of the 7,7,8,8-Tetracyanoquinodimethane Anion

“…Metal–organic complexes with 7,7,8,8-tetracyanoquinodimethane (TCNQ – ) as counterion form solid-state materials consisting of supramolecular stacks that strongly absorb light in the whole visible range. − The metal–organic moiety absorbs in the near-UV and short-wavelength visible range of the absorption spectrum, and the strong absorption is extended to longer wavelengths by the TCNQ – anion leading to black absorber materials suitable for solar cell applications. − However, despite absorbing over the entire visible spectrum, the TCNQ – anion does not exhibit any electronic transitions in the visible region. , Here we investigate whether vibronic effects arising from quantum nuclear motion can explain this conundrum.…”

Computational Studies of the Electronic Absorption Spectrum of [(2,2′;6′,2″-Terpyridine)–Pt(II)–OH] [7,7,8,8-Tetracyanoquinodimethane] Complex

“…Platinum–terpyridine complexes have interesting spectroscopic properties with strong light absorption in the near-ultraviolet (UV) and short-wavelength visible (vis) regions. The absorption has been assigned to spin-allowed metal-to-ligand transitions, whereas the luminescence is due to spin-forbidden phosphorescence transitions. − Chen et al reported that [Pt(tbtrpy)X]Y complexes with tbtrpy = 4,4′,4″- t Bu 3 -2,2′;6′,2″-terpyridine, t Bu is tert -butyl, X = NCS – , OH – , or thiolates (ArS – ), Y = Cl, OH, BF 4 , or 7,7,8,8-tetracyanoquinodimethane (TCNQ) form supramolecular stacks in the solid state . In the solid state, the [Pt(tbtrpy)X] moiety probably donates an electron to Y forming an ionic [Pt(tbtrpy)X]Y complex with a formal oxidation state of Pt(II), − because the electron affinities of TCNQ and the other Y moieties are very large. ,− The supramolecular stacks have suitable properties for solar cell applications, ,− , because they strongly absorb light in a wide energy range of the visible spectrum. , The strong absorption is further extended to the near-infrared (NIR) region when TCNQ is used as ligand Y.…”

“…9 In the solid state, the [Pt(tbtrpy)X] moiety probably donates an electron to Y forming an ionic [Pt(tbtrpy)X]Y complex with a formal oxidation state of Pt(II), 9−11 because the electron affinities of TCNQ and the other Y moieties are very large. 9,12−14 The supramolecular stacks have suitable properties for solar cell applications, 2,[6][7][8]10 because they strongly absorb light in a wide energy range of the visible spectrum. 9,10 The strong absorption is further extended to the near-infrared (NIR) region when TCNQ is used as ligand Y.…”