Temperature- and Mechanical-Force-Responsive Self-Assembled Rhomboidal Metallacycle

Abstract

The dianthracene-based rhomboidal organoplatinum­(II) metallacycle 1 was successfully obtained via coordination-driven self-assembly involving the combination of diplatinum­(II) acceptor 2 and dipyridyl donor 3. A dilute acetone solution of the prepared metallacycle exhibited temperature-responsive fluorescence involving a gradual red-shifted fluorescent change from cyan to yellow over a wide temperature range from 77 to 297 K. Notably, a linear correlation was observed between the emission maximum and temperature in the low-temperature region from 77 to 137 K. Additionally, the supramolecular coordination complex in the solid state showed reversible mechanochromic fluorescence behavior with an obvious color change between green and yellow. Further investigation revealed that a morphology change before and after grinding was responsible for the observed mechanofluorochromic phenomenon. These studies provide new insight into the preparation of well-defined supramolecular organoplatinum­(II) metallacycles capble of responding to multiple stimuli.

Aggregation-Enhanced Room-Temperature Phosphorescence from Au(I) Complexes Bearing Mesogenic Biphenylethynyl Ligands

“…Au-Au (aurophilic) interactions play an important role in inducing efficient luminescence from aggregates. This interaction is expressed when the distance between neighboring gold atoms falls in the range of 2.8-3.6 Å [3][4][5][6][7][8][9][10][11][12][13]. Since the emission from gold(I) complexes originate mostly from aggregates, their photophysical properties, such as emission color and intensity, are highly sensitive to changes in the aggregated structure.…”

Supramolecular Coordination Complexes as Optical Biosensors

“…The same group also reported dianthracene-based rhomboidal organoplatinum(II) metallacycle 11 which can exhibit a temperature-responsive change in fluorescence colour from cyan to yellow over a wide temperature range from 77 to 297 K in acetone medium ( Figure 5(b)). [30] Similarly, Tian and co-workers have reported AIE-active tetraphenylethylene (TPE)-based Zn(II)-coordinated metallacage 12, which showed significant increases in fluorescence intensities at a low temperature, probably due to restricted the intramolecular rotation of the TPE units ( Figure 6(a)). [31] To further investigate this observation, the authors recorded the fluorescence behaviour of the cages in the solid state under variable pressure.…”

“…Biogenic amines (BAs) are nitrogenous compounds, produced via the enzymatic decarboxylation of essential amino acids. On Reproduced from references [29] and [30] with permission from the American Chemical Society. Figure 6.…”

Metal-Organic Framework-Based Stimuli-Responsive Polymers

“…These materials have been widely used in emerging applications such as wearable electronics [31], tissue engineering [32] and self-healing coatings [33]. Materials with such behavior have been reported in Au nanoribbons [34], perovskite [35], silicon [36], and MOFs [37,38]. Specially, MOF-based MFR materials normally involve crystalline structure re-arrangement or geometry adaption by the introduction of pressure [39].…”