Oxidative addition to cyclometalated azobenzene platinum(II) complexes: A route to octahedral liquid crystalline materials

被引：103

作者：

Ghedini, M ^{[1
]}

Pucci, D ^{[1
]}

Crispini, A ^{[1
]}

Barberio, G ^{[1
]}

机构：

[1] Univ Calabria, Dipartimento Chim, I-87030 Arcavacata, CS, Italy

来源：

ORGANOMETALLICS | 1999年 / 18卷 / 11期

关键词：

D O I：

10.1021/om9808155

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The 4,4'-disubstituted azobenzene ligands HLa-d react with [(eta(3)-C4H7)Pt(mu-Cl)](2) to give the dinuclear cycloplatinated complexes [(La-d)Pt(mu-Cl)](2), which are easily converted to their mononuclear Pt(II) acetylacetonate derivatives [(La-d)Pt(acac)]. Oxidative addition to the square-planar Pt(II) complexes [(La-d)Pt(acac)] of electrophilic substrates such as I-2 or CH3I (RI) eventually led to the corresponding octahedral Pt(IV)[(La-d)Pt(acac)I-2] and [(La-d)Pt(acac)(CH3)I] products. Characterization by X-ray crystallography on model complexes [(L-a)Pt(acac)], [(L-a)Pt(acac)I-2], and [(L-a)Pt(acac)(CH3)I] has been carried out, showing that the I-2 or CH3I ligands are bound to the Pt(IV) center at the apical positions. The presence of two ligands in apical position led to the loss of the short intermolecular Pt- - -Pt distance of 3.311(1) Angstrom observed in the square-planar complex [(L-a)Pt(acac)]. Thermotropic mesomorphism is observed for both the Pt(II) and Pt(IV) species with clearing temperatures, mainly lower than those of the corresponding organic ligands. These products are the first examples of Pt(IV) octahedral liquid crystalline species and suggest that oxidative addition to appropriate Pt(II) precursors should be a convenient synthetic procedure for new hexacoordinated Pt(IV) mesogenic materials.

引用

页码：2116 / 2124

页数：9

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[1]

Abel E. W., 1995, COMPREHENSIVE ORGANO, V9

[2] 5-COORDINATE OLEFIN COMPLEXES OF PLATINUM(II) CONTAINING OMEGA-BONDED CARBON LIGANDS - SYNTHESIS AND CHARACTERIZATION OF [PTCLME(ETA-2-C2H4)(N-N')] COMPLEXES - MOLECULAR-STRUCTURE OF AN ADDUCT WITH A CHIRAL METAL CENTER AND OF ITS PARENT 4-COORDINATE COMPLEX [J].