The methodical study of trinuclear copper(I) metal complexes phosphorescent vapochromic chemosensor via metal-metal interactions for sensing various volatile organic compounds has piqued the interest of many researchers. Herein, we highlighted the performance of chemosensors trinuclear copper(I) pyrazolate complexes (2Pz1‒2Pz5) with different molecular design short alkyl side chains from the respective pyrazole ligands. The synthesized complexes had demonstrated a high phosphorescent sensing capacity of various alcohol derivatives. Due to weak metal-metal interactions, the complexes give emission bands centered around 553-644 nm at an excitation of 280 nm. We found that the only 2Pz3 chemosensors showed quenching phenomena with a significant decrease in its emission intensity of 100% for exposure in 5 minutes with irreversible performance. Interestingly, we also found that the shifting of the emission center due to the disruption of metal-metal interaction performed by chemosensor 2Pz5 resulting in the best detection performance of methanol and ethanol (∆λ= 60 nm) and propanol (∆λ = 22 nm) showing autonomous recovery within 15 minutes. Based on the findings, the specific balance, such as rigidity and amphiphilicity in the molecular design of chemosensors, is important for the detection of vapors via supramolecular interactions.

Column gravity chromatography suffered from several drawbacks such as time-consuming and need a large amount of eluents. Herein we reported an efficient technique for effective separation of amphiphilic trinuclear gold(I) pyrazolate complex ([Au3Pz3]C10TEG) with high polarity based on size-exclusion principle of chromatographic technique. Based on the size-exclusion limit, [Au3Pz3]C10TEG having a larger size with molecular weight of 4011.39 Da (4030.40 Da when added Na+) was successfully eluted and collected firstly from its impurities after being recycled for 2 times. In the chromatogram for first cycle, an intense peak upon excitation at 220 nm for [Au3Pz3]C10TEG was observed at retention time of 58 mins, while small peaks due to the presence of impurities was observed in the range between 73 to 85 mins. In the second cycle, the impurities were flushed away before [Au3Pz3]C10TEG was successfully collected at retention time of 170 mins in the third cycle. The columns were a set of polystyrene/divinylbenzene (PS/DVB) JAIGEL-1H and -2.5H connected in series having exclusion limit of 1 X 103 and 2 X 104 in which chloroform was used as the eluent at flow rate of 3.5 mL min-1. As a result, the visual appearance of dark-yellowish [Au3Pz3]C10TEG was successfully purified to give pale-yellowish product. Moreover, differential scanning calorimetry thermogram showed that extra shoulder from impurities at 6.13 °C in the first endothermic peak of [Au3Pz3]C10TEG at 0.76 °C was completely removed. Hence, it can be concluded that size-exclusion chromatography can be used as an effective purification method with much more convenience and small consumption of solvents.

We highlight that columnar assembly of self-assembled templates was successfully utilized using sol-gel technique of mesostructured silica for the quality improvement of transparent mesoporous film nanocomposites with a hexagonal structure through appropriate heat treatment methods and self-assembled templates in the removal of organic components. In contrast to the reported mesostructured silica film nanocomposites containing columnar assembly of trinuclear gold(I) pyrazolate complex ([Au3Pz3]C10TEG/silicahex) with calcination at 450 °C, mesostructured silica film nanocomposites from self-assembled template of triphenylene bearing amphiphilic decoxy triethylene glycol side chains (TPC10TEG/silicahex) can be completely collapsed upon calcination at 450 °C. This hexagonal structure can be only preserved with calcination at 250 °C although intensity of its main diffraction peak of d100 at 2θ of 3.70° was significantly decreased. On the other hands, thermal hydrogen reduction at the same temperature was found to be the best heat treatment to preserve the quality of mesoporous silica film nanocomposites with decreasing in intensity of diffraction peak up to 30%. Such phenomenon might be caused by slow decomposition of organic components with the presence of hydrogen gas upon heating to shrinkage the silica wall from interpenetration of ethylene glycol segments of the side chains and to open bonding of benzene ring from the core.