A Reversible Polymorphic Phase Change Which Affects the Luminescence and Aurophilic Interactions in the Gold(I) Cluster Complex, [μ₃-S(AuCNC₇H₁₃)₃](SbF₆)

Crystallographic examination of [μ3-S(AuCNC7H13)3](SbF6) shows that it undergoes a reversible phase change from orthorhombic to monoclinic upon cooling. At 190 K, the structure shows that two cations self-associate to form a pseudo-octahedral array of six gold atoms connected by both intra- and interionic aurophilic interactions. On cooling, the clusters become less symmetric, and in one, the interionic Au···Au separations increase, while they decrease in the second cluster. The luminescence of crystalline [μ3-S(AuCNC7H13)3](SbF6) shows corresponding changes in emission, with two emissions of similar lifetimes but with different excitations at 77 K, but only a single emission at 298 K. In contrast, [μ3-S(AuCNC6H11)3](PF6), which has a similar structure to that of the high-temperature form of [μ3-S(AuCNC7H13)3](SbF6), does not undergo a phase change or change in its luminescence upon cooling

A Reversible Polymorphic Phase Change Which Affects the Luminescence and Aurophilic Interactions in the Gold(I) Cluster Complex, [μ₃-S(AuCNC₇H₁₃)₃](SbF₆)

Crystallographic examination of [μ3-S(AuCNC7H13)3](SbF6) shows that it undergoes a reversible phase change from orthorhombic to monoclinic upon cooling. At 190 K, the structure shows that two cations self-associate to form a pseudo-octahedral array of six gold atoms connected by both intra- and interionic aurophilic interactions. On cooling, the clusters become less symmetric, and in one, the interionic Au···Au separations increase, while they decrease in the second cluster. The luminescence of crystalline [μ3-S(AuCNC7H13)3](SbF6) shows corresponding changes in emission, with two emissions of similar lifetimes but with different excitations at 77 K, but only a single emission at 298 K. In contrast, [μ3-S(AuCNC6H11)3](PF6), which has a similar structure to that of the high-temperature form of [μ3-S(AuCNC7H13)3](SbF6), does not undergo a phase change or change in its luminescence upon cooling

A Reversible Polymorphic Phase Change Which Affects the Luminescence and Aurophilic Interactions in the Gold(I) Cluster Complex, [μ₃-S(AuCNC₇H₁₃)₃](SbF₆)

Crystallographic examination of [μ3-S(AuCNC7H13)3](SbF6) shows that it undergoes a reversible phase change from orthorhombic to monoclinic upon cooling. At 190 K, the structure shows that two cations self-associate to form a pseudo-octahedral array of six gold atoms connected by both intra- and interionic aurophilic interactions. On cooling, the clusters become less symmetric, and in one, the interionic Au···Au separations increase, while they decrease in the second cluster. The luminescence of crystalline [μ3-S(AuCNC7H13)3](SbF6) shows corresponding changes in emission, with two emissions of similar lifetimes but with different excitations at 77 K, but only a single emission at 298 K. In contrast, [μ3-S(AuCNC6H11)3](PF6), which has a similar structure to that of the high-temperature form of [μ3-S(AuCNC7H13)3](SbF6), does not undergo a phase change or change in its luminescence upon cooling

Crystallization and Interconversions of Vapor-Sensitive, Luminescent Polymorphs of [(C₆H₁₁NC)₂Au^I](AsF₆) and [(C₆H₁₁NC)₂Au^I](PF₆)

The remarkable, vapor-induced transformation of the yellow polymorphs of [(C₆H₁₁NC)₂Au^I]­(AsF₆) and [(C₆H₁₁NC)₂Au^I]­(PF₆) into the colorless forms are reported along with related studies of the crystallization of these polymorphs. Although the interconversion of these polymorphs is produced by vapor exposure, <i>molecules of the vapor are not incorporated into the crystals</i>. Thus, our observations may have broad implications regarding the formation and persistence of other crystal polymorphs where issues of stability and reproducibility of formation exist. Crystallographic studies show that the colorless polymorphs, which display blue luminescence, are isostructural and consist of linear chains of gold­(I) cations that self-associate through aurophilic interactions. Significantly, the yellow polymorph of [(C₆H₁₁NC)₂Au^I]­(AsF₆) is not isostructural with the yellow polymorph of [(C₆H₁₁NC)₂Au^I]­(PF₆). Both yellow polymorphs exhibit green emission and have the gold cations arranged into somewhat bent chains with significantly closer Au···Au separations than are seen in the colorless counterparts. Luminescence differences in these polymorphs clearly enhance the ability to detect and monitor their phase stability