Mesomorphic Metallo-Dendrimers Based on the Metal−Metal Bonded Ru<SUB>2</SUB>(CO)<SUB>4</SUB> Sawhorse Unit

Chem. Mater., 20 (4), 1340–1343, 2008. 10.1021/cm7018845
Web Release Date: January 8, 2008

Mesomorphic Metallo-Dendrimers Based on the Metal−Metal Bonded Ru₂(CO)₄ Sawhorse Unit

Stéphane Frein,^† Mathieu Auzias,^† Aline Sondenecker,^† Ludovic Vieille-Petit,^† Boris Guintchin,^† Natacha Maringa,^† Georg Süss-Fink,^† Joaquín Barberá,^‡ and Robert Deschenaux^*^†

Institut de Chimie, Université de Neuchâtel, Avenue de Bellevaux 51, Case postale 158, 2009 Neuchâtel, Switzerland, and Química Orgánica, Facultad de Ciencias-Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain

Received July 17, 2007

Revised Manuscript Received October 22, 2007

Abstract:

Dinuclear ruthenium complexes containing the stable metal−metal bonded Ru₂(CO)₄ sawhorse unit with two dendritic carboxylato bridges have been synthesized and characterized. All complexes Ru₂(CO)₄(O₂CR)₂L₂ (R = R¹, R², R³) containing cyanobiphenyl-based poly(arylester) dendrons of first (R¹), second (R²), and third (R³) generation and triphenylphosphine, pyridine, or 4-picoline ligands L proved to be mesomorphic, giving rise to smectic A or smectic A and nematic phases. The supramolecular organization within the smectic A phase is governed by the nature and structure of the mesogenic units and dendritic core. Such materials are of interest for the design of catalytically active anisotropic fluids.

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