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Observation of the Properties of a Single Unit of a Limited CDW Structure in a Pt II /Pt IV Host–Guest Binary System Based on a Square‐Shaped Complex
Author(s) -
Hirahara Eri,
Takaishi Shinya,
Yamashita Masahiro
Publication year - 2009
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.200900114
Subject(s) - crystallography , chemistry , platinum , ethylenediamine , raman spectroscopy , valence (chemistry) , stereochemistry , resonance (particle physics) , single crystal , inorganic chemistry , physics , atomic physics , biochemistry , organic chemistry , optics , catalysis
A macrocyclic tetranuclear platinum(II) complex [Pt(en)(4,4′‐bpy)] 4 (NO 3 ) 8 ( 1 ⋅(NO 3 ) 8 ; en=ethylenediamine, 4,4′‐bpy=4,4′‐bipyridine) and a mononuclear platinum(IV) complex [Pt(en) 2 Br 2 ]Br 2 ( 2 ⋅Br 2 ) formed two kinds of Pt II /Pt IV mixed valence assemblies when reacted: a discrete host–guest complex 1 ⋅ 2 ⋅Br 10 ( 3 ) and an extended 1‐D zigzag sheet 1 ⋅( 2 ) 3 ⋅Br 8 (NO 3 ) 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 M II /M IV complexes. The intervalence interaction indicates the presence of an isolated {Pt II ⋅⋅⋅XPt IV X⋅⋅⋅Pt II } 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 Pt II –Pt IV distances were observed.