The various potential applications of supramolecular gels in the fields of sensors, electrooptics, template self-assembly, morphology control, drug delivery, etc. have attracted much attention in recent years. The synthesis of smart supramolecular gels, which respond to external stimuli, such as temperature, light, pH, mechanical stress, sonication, chemicals, and so on, has remained a major challenge.

Lixin Wu, Vivian Yam, and co-workers, Jilin University and The University of Hong Kong, respectively, China, have synthesized, characterized, and investigated a series of six cholesterol-/estradiol-appended alkynylplatinum(II) complexes with tridentate N-donor ligands, based on 2,6-bis(1-alkylpyrazol-3-yl)pyridine. They found that three are capable of forming smart supramolecular gels, which are responsive to both thermal and mechanical stimuli.

With mainly metallogels responsive to thermal stimulus reported so far, this new class of cholesterol-appended alkylplatinum(II) complexes shows promising properties.

• Cholesterol-/Estradiol-Appended Alkynylplatinum(II) Complexes as Supramolecular Gelators,
  Yongguang Li, Elizabeth Suk-Hang Lam, Anthony Yiu-Yan Tam, Keith Man-Chung Wong, Wai Han Lam, Lixin Wu, Vivian Wing-Wah Yam,
  Chem. Eur. J. 2013.
  DOI: 10.1002/chem.201301510