Observation of crystallisation dynamics by crystal-structure-sensitive room-temperature phosphorescence from Au(I) complexes

The aggregation behaviour of Au(I) complexes in condensed phases can affect their emission properties. Herein, aggregation-induced room-temperature phosphorescence (RTP) is observed from the crystals of trinuclear Au(I) complexes. The RTP is highly sensitive to the crystal structure, with a slight difference in the alkyl side chains causing not only a change in the crystal structure but also a shift in the RTP maximum. Furthermore, in nanocrystals, reversible RTP colour changes are induced by phase transitions between crystal polymorphs during crystal growth from solution or the pulverisation of bulk crystals. The colour change mechanism is discussed in terms of intermolecular interactions in the crystal structure of the luminescent aggregates. The results suggest that the behaviour in nanocrystals may differ from that in bulk crystals. These insights will advance the fundamental understanding of crystallisation mechanisms and may aid in the discovery of new materials properties for solids with nano- to micrometre sizes.

Size Evolution and Composition of the Intermediate Phase During Nonclassical Protein Crystal Growth from Solution

<div>We propose here that the intermediate nucleation phase identified in a certain case</div><div>of protein crystal growth actually consists of two distinct parts; a low density and</div><div>higher density phase. A theory for crystal growth is utilized to study the formation</div><div>and growth of each phase. Within the framework of this theory the low density phase</div><div>is shown to obey a forth order kinetic law while the high density phase is zeroth order.</div><div>The combination of these two phases is shown to be a good match for X-ray diffraction </div><div>data which is indicative of its presence. The crystal growth rate is then given</div><div>in terms of the kinetic behavior of the intermediate nucleation phase. From this, the</div><div>crystal radius is estimated and shown to compare favorably with reported size data.</div><div>A method is proposed for determining the conditions that lead to protein crystals of</div><div>largest possible size.</div>

Size Evolution and Composition of the Intermediate Phase During Nonclassical Protein Crystal Growth from Solution

<div>We propose here that the intermediate nucleation phase identified in a certain case</div><div>of protein crystal growth actually consists of two distinct parts; a low density and</div><div>higher density phase. A theory for crystal growth is utilized to study the formation</div><div>and growth of each phase. Within the framework of this theory the low density phase</div><div>is shown to obey a forth order kinetic law while the high density phase is zeroth order.</div><div>The combination of these two phases is shown to be a good match for X-ray diffraction </div><div>data which is indicative of its presence. The crystal growth rate is then given</div><div>in terms of the kinetic behavior of the intermediate nucleation phase. From this, the</div><div>crystal radius is estimated and shown to compare favorably with reported size data.</div><div>A method is proposed for determining the conditions that lead to protein crystals of</div><div>largest possible size.</div>