Crystalline-Amorphous-Crystalline Transformation in a Highly Brilliant Luminescent System with Trigonal-Planar Gold(I) Centers.

Photoluminescent compounds showing emission color changes in response to external stimuli have received considerable attention because of their wide range of applications. Here, we report the unique photoluminescence behavior of a digold(I) coordination system with trigonal-planar Au(I) centers, [Au2(dppm)3](2+) (dppm = bis(diphenylphosphino)methane). This system shows an extremely intense phosphorescence, with a quantum yield of >95% in the solid state. Both the emission color and thermal stability vary due to changing counter ions (Cl(-) vs. OTf(-)). Of particular note is the thermal crystalline-amorphous-crystalline transformation for the chloride salt, which is accompanied by drastic emission color changes. Single-crystal and powder X-ray diffractions demonstrate that the two-step transformation is induced by the loss of water molecules of crystallization with the subsequent removal of a dppm ligand to form [Au2(dppm)2](2+), which is mechanically reverted back to [Au2(dppm)3](2+).

Proton-controlled formation and interconversion of Au(I)2Ni(II) trinuclear and Au(I)4Ni(II)3 heptanuclear complexes with mixed thiomalate and bis(diphenylphosphino)ethane.

Treatment of a newly prepared digold(i) complex, [Au2(dppe)(H2msa)2] ([H41]; dppe = 1,2-bis(diphenylphosphino)ethane, msa = thiomalate), with Ni(2+) gave two interconvertible multinuclear complexes, [Ni{Au2(dppe)(msa)2}](2-) ([2](2-)) and [Ni3{Au2(dppe)(Hmsa)2}{Au2(dppe)(msa)2}(MeOH)3] ([3]), dependent on solution acidities.

Porous molecular networks formed by the self-assembly of positively-charged trigonal building blocks at the liquid/solid interfaces.

Tris-(2-hydroxybenzylidene)triaminoguanidinium salts having six alkyl chains with proper spacing served as new molecular building blocks for the formation of porous honeycomb networks by van der Waals interaction between interdigitated alkyl chains at the liquid/graphite interfaces.

An optically resolved crystal of thiomalate: (S)-1-phenylethanaminium (R)-thiomalate.

The asymmetric unit of the optically resolved title salt, C(8)H(12)N(+)·C(4)H(5)O(4)S(-), contains a 1-phenylethanaminium monocation and a thiomalate (3-carboxy-2-sulfanylpropanoate) monoanion. The absolute configurations of the cation and the anion are determined to be S and R, respectively. In the crystal, cation-anion N-H···O hydrogen bonds, together with anion-anion O-H···O and S-H···O hydrogen bonds, construct a two-dimensional supramolecular sheet parallel to the ab plane. The two-dimensional sheet is linked with the upper and lower sheets through C-H···π interactions to stack along the c axis.