Observation of the Properties of a Single Unit of a Limited CDW Structure in a PtII/PtIV Host–Guest Binary System Based on a Square‐Shaped Complex |
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| Authors: | Eri Hirahara Shinya Takaishi Dr. Masahiro Yamashita Prof. Dr. |
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| Affiliation: | 1. Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo 113‐8656 (Japan);2. Department of Chemistry, Graduate School of Science, Tohoku University, 6‐3 Aramaki‐Aza‐Aoba, Aoba‐ku, Sendai 980‐8578 (Japan), Fax: (+81)?222‐176‐548 |
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| Abstract: | A macrocyclic tetranuclear platinum(II) complex [Pt(en)(4,4′‐bpy)]4(NO3)8 ( 1 ?(NO3)8; en=ethylenediamine, 4,4′‐bpy=4,4′‐bipyridine) and a mononuclear platinum(IV) complex [Pt(en)2Br2]Br2 ( 2 ?Br2) formed two kinds of PtII/PtIV mixed valence assemblies when reacted: a discrete host–guest complex 1 ? 2 ?Br10 ( 3 ) and an extended 1‐D zigzag sheet 1 ?( 2 )3?Br8(NO3)6 ( 4 ). Single crystal X‐ray analysis showed that the dimensions of the assemblies could be stoichiometrically controlled. Resonance Raman spectra suggested the presence of an intervalence interaction, which is typically observed for quasi‐1‐D halogen‐bridged MII/MIV complexes. The intervalence interaction indicates the presence of an isolated {PtII???X? PtIV? X???PtII} moiety in the structure of 4 . On the basis of electronic spectra and polarized reflectance measurements, we conclude that 4 exhibits intervalence charge transfer (IVCT) bands. A Kramers–Kronig transformation was carried out to obtain an optical conductivity spectrum, and two sub‐bands corresponding to slightly different PtII–PtIV distances were observed. |
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| Keywords: | charge transfer host– guest systems mixed valence platinum supramolecular chemistry |
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