Pillared honeycomb nanoarchitectures formed on solid surfaces by the self-assembly of lipid-packaged one-dimensional Pt complexes

摘要

A highly lipophilic polyion complex[Pt(en)2][PtCl2(en)2](1)4(en, 1,2-diaminoethane) is prepared from one-dimensional mixed valencePtII/PtIV complex and newly designed chiralamphiphile 1. The powdery sample showed purple color, which is a resultof the mixed valence absorption of the linear chlorobridgedcomplex (PtII-Cl-PtIV-Cl-)n. Whenthe lipid complex is dispersed in dichloromethane, purple-coloreddispersion is obtained at 0°C, whereas the color disappears afterheating the solution to 21°C. The observed thermochromism isreversible with respect to the temperature changes and is ascribed tothe reversible dissociation and reassembly of the self-assemblinginorganic wires. Casting of the 0°C-purple dispersion on solidsubstrates affords honeycomb nanostructures in addition to thenanowires with the width of about 20 nm. The honeycomb patterns seem tobe templated by the condensed water droplets that are formed andaligned on the rapidly evaporating dichloromethane solution. On theother hand, more regular honeycomb structures are exclusively obtainedby casting the 21°C-colorless solution. These observationsindicate that the ordered honeycomb structures are obtainable onsolid surfaces by the self-assembly of molecularly dispersed components[Pt(en)2](1)2 andtrans-[PtCl2(en)2](1)2.Very interestingly, formation of double-layered honeycomb nanostructureis observed by scanning electron microscopy. The unit hexagons andpillars of the honeycombs are made of nanowires that are hierarchicallyassembled from the lipid-packaged PtII/PtIVcomplexes. The surface self-organization of lipophilic inorganiccomplexes has a potential to fabricate novel nanoarchitectures withconjugated electronic structures.