title: From Mesomorphic Phosphine Oxide to Clustomesogens Containing Molybdenum and Tungsten Octahedral Cluster Cores.
abstract: New clustomesogens (i.e., metal atom clusters containing liquid crystalline (LC) materials) have been obtained by grafting neutral cyanobiphenyl (CB)- or cholesteryl-containing tailor-made dendritic mesomorphic triphenylphosphine oxide ligands on luminescent (M6 Cl(i) 8 )(4+) octahedral cluster cores (M=Mo, W). The LC properties were studied by a combination of polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray powder diffraction analyses. While the organic ligands showed various mesophase types ranging from nematic, SmA columnar (SmACol ), SmA, and SmC phases, it turned out that the corresponding clustomesogens formed layered phases (SmA) over a wide range of temperatures that depend on the nature and density of mesogenic groups employed. Intrinsic luminescence properties of the cluster precursors are preserved over the entire range of LC phase existence.
authors.affiliation: Université de Rennes 1, UMR "Sciences Chimiques de Rennes", UR1-CNRS 6226, Equipe Chimie du Solide et Matériaux, Campus de Beaulieu, CS 74205, 35042 Rennes Cedex (France). viorel.circu@chimie.unibuc.ro.|Department of Inorganic Chemistry, University of Bucharest, Dumbrava Rosie 23, Bucharest 020464, sector 2 (Romania). viorel.circu@chimie.unibuc.ro.
authors.forename: Viorel
authors.initials: V
authors.lastname: Cîrcu
authors.affiliation: Université de Rennes 1, UMR "Sciences Chimiques de Rennes", UR1-CNRS 6226, Equipe Chimie du Solide et Matériaux, Campus de Beaulieu, CS 74205, 35042 Rennes Cedex (France). yann.molard@univ-rennes1.fr.
authors.forename: Yann
authors.initials: Y
authors.lastname: Molard
authors.affiliation: Université de Rennes 1, UMR "Sciences Chimiques de Rennes", UR1-CNRS 6226, Equipe Chimie du Solide et Matériaux, Campus de Beaulieu, CS 74205, 35042 Rennes Cedex (France).
authors.forename: Maria
authors.initials: M
authors.lastname: Amela-Cortes
authors.affiliation: Université de Bordeaux and CNRS, CRPP, UPR8641, 33600 Pessac (France).
authors.forename: Ahmed
authors.initials: A
authors.lastname: Bentaleb
authors.affiliation: Université de Bordeaux and CNRS, CRPP, UPR8641, 33600 Pessac (France).
authors.forename: Philippe
authors.initials: P
authors.lastname: Barois
authors.affiliation: Université de Rennes 1, UMR "Sciences Chimiques de Rennes", UR1-CNRS 6226, Equipe Chimie du Solide et Matériaux, Campus de Beaulieu, CS 74205, 35042 Rennes Cedex (France).
authors.forename: Vincent
authors.initials: V
authors.lastname: Dorcet
authors.affiliation: Université de Rennes 1, UMR "Sciences Chimiques de Rennes", UR1-CNRS 6226, Equipe Chimie du Solide et Matériaux, Campus de Beaulieu, CS 74205, 35042 Rennes Cedex (France). stephane.cordier@univ-rennes1.fr.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Cordier
keywords: cluster compounds; liquid crystals; molybdenum; phosphine oxide; tungsten