Metallogels based on platinum complexes display drastic color and emission changes during the gel-to-sol phase transition. Their gel-like properties, which respond to external stimuli such as concentration or temperature, make them interesting as soft matter in smart materials. However, platinum metallogels that display both liquid crystalline and photochromic properties are rare.

Vivian Yam and co-workers, University of Hong Kong, have designed, synthesized and characterized a series of multifunctional luminescent platinum(II) bipyridine complexes. Three of the complexes were shown to exhibit stable thermotropic metallogels in organic solvents. One of these complexes also displayed lamellar liquid crystalline behavior. In contrast to typical thermotropic metallogels, one of the complexes could form metallogels in dodecane and was very stable towards external stimuli.

_{Image: (c) Wiley-VCH}

• Synthesis, Characterization, and the Photochromic, Luminescence, Metallogelation and Liquid-Crystalline Properties of Multifunctional Platinum(II) Bipyridine Complexes
  Y. Li, A. Y.-Y. Tam, K. M.-C. Wong, W. Li, L. Wu, Vivian W.-W. Yam,
  Chem. Eur. J. 2011.
  DOI: 10.1002/chem.201003738