Simple molecular structures capable of emitting over the entire visible range are still a challenge. Planar molecular structures have the drawback of fluorescence quenching in the solid state thus limiting their application fields. Combining long range excimer/exciplex emissions with a compound emission have been used to get white light. In this work, a series of new coumarin derivatives having a planar structure have been synthesized and characterized. The effects of systematic variation in alkyl chain functionalization providing morphological variations that permit interesting solid state emitting properties have been discussed simultaneously with electrochemical behavior and OLED (organic light emitting diode) device applications. Carbon chains containing 0-16 carbon atoms have been studied in order to conclude the results that systematic changes in alkyl group substitution can be utilized as a tool to tune the emitting color of these planar coumarins. Alkyl chains were introduced by O-acylation and O-benzoylation reaction on the hydroxyl group of parent coumarin 5. Thus the present strategy is also helpful in establishing a template to control the unproductive interchromophore electronic couplings.Solid state fluorescence properties support the crystal studies. Theoretical studies are also in agreement with experimental data. Electroluminescence of Device 2 with a turn on voltage (V on ) around 5-6 V having s-CBP doped with 1% of 8 having alkyl substitution of 2-carbons is found to exhibit white emission with CIE co-ordinates of (0.29, 0.34) which is close to white emission while the alkyl substitution of 14-carbons (compound 17) in Device 7 (V on ¼ 7 V) exhibited green emission. Thus a strategy helpful to tune the electroluminescence has been discussed.

A Cd(ii)-based metal–organic framework (MOF) has been demonstrated to have trifunctional properties, namely as an efficient and selective adsorbent for dyes, a visible-light-active photocatalyst for the degradation of dyes and a photocatalyst for Cr(vi) reduction.

The successful commercialization of fuel cells and electrolyzer is limited to the cost and instability issues associated with electrocatalysts (platinum/platinum-based catalysts) used. Hence, there is critical challenge to develop stable, non-platinum-based catalysts with multifunctionality and better durability that can efficiently replace platinum. While a sufficient number of bifunctional catalysts are now known in the literature, development of trifunctional catalyst is rarely reported. Herein, we report the development of nitrogen-doped graphitized carbon-encapsulated Ni nanoparticles-based catalyst (Ni-NC700) from an easy derivable Ni­(II)-dimeric complex. Microstructural studies reveal that the catalyst annealed at 700 °C has 4–5 layers of graphene sheets forming a shell surrounding the Ni nanoparticles. This catalyst exhibits outstanding trifunctional catalytic performance with onset potential of 0.86, 1.52, and −0.02 V (vs RHE) for oxygen reduction reaction, oxygen evolution reaction, and hydrogen evolution reaction, respectively. The long-term accelerated durability test and methanol tolerance test confirm better stability and durability of this catalyst than those of the benchmark Pt/C. The development of N-doped graphitized carbon shell-encapsulated Ni nanoparticles from a small binuclear Ni­(II) complex will open a new horizon for the synthesis of efficient electrocatalysts with trifunctionality.

This report deals with the fabrication and utilization of a novel 2D zinc-based metal−organic framework (MOF) {[Zn(PA 2− )(4,4′-bpy)]-(H 2 O)} n (where PA = pamoic acid and 4,4′-bpy = 4,4′-bipyridine). The Zn-MOF has been synthesized via a solvothermal method and emanates green fluorescence. As Cr(VI) is a fatal and carcinogenic ion, it is extremely important to discern and remove it from nature. The bright green fluorescence of Zn-MOF can be quenched upon interaction with a Cr 2 O 7 2− ion, which implies the MOF's applicability as a Cr(VI) detector through turn-off fluorescence signaling. On the contrary, among various strategies to remove Cr(VI), the photocatalytic reduction of Cr(VI) to Cr(III) is acknowledged as the most effective one. Delightfully, apart from being a Cr(VI) sensor, this same Zn-MOF can be further recruited as a photocatalyst to convert Cr(VI) to Cr(III). The catalytic reduction is triggered by natural sunlight, acidic pH, and a hole scavenger. In addition, good stability and reusability of the Zn-MOF satisfies the quest for a potential photocatalyst for conversion of Cr(VI) to Cr(III). The limit of detection for fluorometric recognition of Cr(VI) was found to be 4.12 μM, and almost a complete reduction of toxic Cr(VI) ion was achieved.

A new thermoreversible organogel based on diketopyrrolopyrrole dye (DPP-NCO) is reported for the first time and evolved as a new building block for the fabrication of 1D supramolecular assembly. AFM analysis illustrated that its gel state is composed of different sized 1D rods. DPP-NCO gel used as an additive in organic solar cells yields high efficiency of 7.9% owing to better nanophase separation of its active layer.