The behavior of two classes of dynamic crystals, crystals whose properties change in response to an external stimulus will be discussed. Colorless, blue luminescent crystals of the gold box, [Au₆(Triphos)₄Cl](SbF₆)₅7(CH₃C₆H₅) (Triphos is Ph₂P(CH₂)₂PPh(CH₂)₂PPh₂), become orange luminescent upon grinding. X-ray crystal structures of both the starting box and the product, a chloro-bridged helicate have been determined. The process involves a significant amount of bond making and breaking, yet a rather simple process can account for the chemical change that occurs within the solid. The second part of the talk will focus upon crystals of the two-coordinate cation, [Au^I(cyclohexyl isocyanide)₂]⁺. The structure and properties of crystals containing [Au^I(cyclohexyl isocyanide)₂]⁺ depend significantly upon the non-coordinating anion present. The influence of that anion on the sensitivity of crystals to organic vapors, temperature, and mechanical pressure will be discussed.

Mechanical transformation of the Au<sub>6</sub> box into the chloro-bridged helicate

Mechanical transformation of the Au₆ box into the chloro-bridged helicate

Kamran Ghiassi

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