1 research outputs found
UHV-STM Investigations and Numerical Calculations of a Ruthenium β-Diketonato Complex with Protected Ethynyl Ligand: [Ru(dbm)<sub>2</sub>(acac-TIPSA)]
The quest of molecular electronic devices necessitates
addressing
model molecular systems as starting points. Among the targeted functions,
electron transfer between specific moieties inside a molecule is expected
to play a fundamental role for ultimate logical gates. Here we propose
a coordination complex exhibiting two inorganic centers (Ru and Si)
that constitutes a step toward a more complex architecture. Starting
from the complex <b>1</b> [RuÂ(dbm)<sub>2</sub>(acac-I)] (dbm
= dibenzoylmethanate ion, acac-<i>I</i> = 3-iodo-2,4-pentanedionate
ion), the complex <b>2</b> [RuÂ(dbm)<sub>2</sub>(acac-TIPSA)]
(acac-TIPSA = 3-(triisopropylsilyl)Âacetylene-2,4-pentanedionate ion)
was obtained through Sonogashira cross coupling reaction under classical
conditions. This complex <b>2</b> was characterized by elemental
analysis, IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, UV–vis,
cyclic voltammetry, mass spectroscopy as well as X-ray single-crystal
diffraction. It crystallized with empirical formula of C<sub>46</sub>H<sub>49</sub>O<sub>6</sub>Ru<sub>1</sub>Si<sub>1</sub> in a monoclinic
crystal system and space group <i>P</i>2<sub>1</sub>/<i>c</i> with <i>a</i> = 21.077(3) Å, <i>b</i> = 9.5130(7) Å, <i>c</i> = 21.8790(12) Å, β
= 94.125(7)°, <i>V</i> = 4375.5(7) Å<sup>3</sup> and <i>Z</i> = 4. Additionally, scanning tunneling microscopy
measurements at liquid He temperature and in an ultrahigh vacuum (UHV-STM)
were conducted on complex <b>2</b> on a Ag(111) surface. The
STM images, supported by adsorption and STM image calculations, demonstrate
that the molecules exist in two stable forms when adsorbed on the
metallic surface