MX chain interactions in binary metallomesogenic mixtures of Pt(II) and Pt(IV) complexes

AEI 55

Rachel J. Allenbaugh, rja@bu.edu, Chemistry Department, Boston University, Metcalf Center for Science and Engineering, 590 Commonwealth Ave, Boston, MA 02215-2521 and Cynthia K. Schauer, Department of Chemistry, University of North Carolina at Chapel Hill, CB #3290 Venable and Kenan Laboratories, Chapel Hill, NC 27599-3290.

The supramolecular ordering of liquid crystalline phases provides a unique method for templating weaker transition metal interactions utilizing the microphase separation of the mesophase.  Novel optical and electronic properties would be expected from mixtures of d8 and d6 metallomesogens forming one-dimensional MII…X-MIV-X structures via so-called MX chain interactions.  We undertook to determine if MX chain interactions could be engendered in a liquid crystalline phase from binary mixtures of platinum mesogens.  Analysis of PtLnCl2 and PtLnCl4 (Ln = dialkyl-2,2΄-bipyridine-4,4΄-dicarboxylate) complexes and binary PtII/PtIV mixtures via differential scanning calorimetry, polarizing optical microscopy, and NMR spectroscopy will be presented.  The structure of the PtIV mesophase will be discussed in light of the rarity of PtIV metallomesogens.  Phase diagrams and analysis of the PtLnCl2/PtLnCl4 mesophase structure through variable temperature X-ray diffractometry will be presented, and evidence for formation of PtII…Cl-PtIV interactions in a liquid crystalline phase will be discussed.