Stabilization of Pd(III) states in nano-wire coordination complexes.
In spite of a long history of quasi-one-dimensional halogen-bridged complexes (MX-chains), all Pt and Pd complexes form the charge-density wave (CDW) state (-X...M(II)...X-M(IV)-X...), while all Ni complexes form Mott-Hubbard (MH) states (-X-Ni(III)-X-Ni(III)-X-), without exception. We have succeeded in stabilizing the Pd(iii) MH state for the first time by utilizing the following two methods: partial substitution with Ni(iii) ions, [Ni(1-x)Pd(x)(chxn)(2)Br]Br(2), and chemical pressure via long alkyl chains introduced as counter-anions, [Pd(en)(2)Br](C(n)-Y)(2).H(2)O. In both systems, it has been revealed that the electronic state of bromo-bridged Pd compounds are determined by the PdPd distances, in other words, CDW and MH states are stabilized when PdPd distances are longer and shorter than 5.26 A, respectively.
Yamashita
Masahiro
M
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan. yamasita@agnus.chem.tohoku.ac.jp
Takaishi
Shinya
S
D056831:Coordination Complexes / Q000737:chemistry*; D008958:Models, Molecular; D053770:Nanowires / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*
D056831:Coordination Complexes; D010165:Palladium; D009532:Nickel