Themed collection ChemComm 60th Anniversary Historic Papers from India

What is a weak hydrogen bond? With hydrogen bonds becoming increasingly important, the special features of the weaker varieties of this interaction are outlined in this review. The C–H⋯O hydrogen bond is significant not only in the crystal structures of small organic molecules but also in the large biological macromolecules. The spin-off in rational drug design and lead optimisation is highlighted.

From Saridon to Entresto: the journey of pharmaceuticals from the first drug–drug combination of propyphenazone and pyrithyldione in 1937 (left) to the most recent monosodium sacubitril and disodium valsartan in 2015 (right).

Recent advancements in luminescent materials containing polyhedral boron clusters are summarised in this review article.

In this review article we provide an overview of the recent developments made in small molecule-based turn-off fluorescent sensors for nitroaromatic explosives with special focus on organic and H-bonded supramolecular sensors.

Our Feature Article details the physiological role of amyloid beta (Aβ), elaborates its toxic effects and outlines therapeutic molecules designed in the last two years targeting different aspects of Aβ for preventing AD.

A review of the recent advancement in the development of organic materials with efficient phosphorescent emission features is presented.

Spectrophotometric monitoring of nitrophenol reduction to aminophenol in the presence of nanoparticle catalysts becomes a universal reaction to test a nanocatalyst.

Here we describe the various strategies for the synthesis of imidazo[1,2-a]pyridines.

This article summarizes the recent developments in the construction of multicomponent molecular hollowed-out cages through the metal–ligand coordination-driven self-assembly process, with a focus on the decreasing relevance of the use of templates.

The combination of isomorphous solids gives rise to continuous solid solutions and solids in which the adhesive interactions outweigh the cohesive ones lead to cocrystals. With weak adhesive, strong cohesive and a geometric misfit, the product is eutectic.

Organocatalysts have gained importance because of their green chemistry perspective and this would be largely fulfilled if the reaction solvent also possesses this property. Water satisfies this objective. We describe the reactions carried out by organocatalysts in water and the features required for the catalysts to work well in the solvent.

This feature article discusses the structure–activity relation of various cationic liposomes for DNA/si-RNA/oligonucleotide delivery, the liposome and lipoplex characterizations, cytotoxicity and the biological applications of the lipid-based gene delivery vehicles.

In bulk water, solvation occurs in <1 ps. Solvation dynamics of water confined in biological systems (biological water) is 100–1000 times slower. This feature article illustrates the ultraslow component and its implications.

We examine the emerging chemical and structural trends in the field of inorganic–organic framework structures and discuss some of the nascent applications of this vast and exciting class of materials.

In recent years, the crystal engineering of coordination polymers has attracted the enormous interest of chemists due to the potential applications. This review covers the coordination networks of prototypical bridging ligand 4,4′-bipyridine with various transition metals.

B-doped graphene electrocatalyses the reduction of CO₂ to formic acid/formate with a high faradaic efficency.

Novel graphene quantum dot-doped polyaniline composites are visualized as supercapacitor electrode materials that show excellent specific capacitance value and good cyclic stability.

A new triazine functionalized hexagonally ordered covalent organic polymer (TRITER-1) with a high BET surface area (716 m² g⁻¹) has been synthesized via the Schiff-base condensation reaction between a triamine and terephthaldehyde. TRITER-1 shows an excellent CO₂ uptake capacity of 58.9 wt% at 273 K and 5 bar pressure.

A new luminescent metal–organic framework has been synthesized and explored as a dual functional fluorescent sensor to detect picric acid and Pd²⁺.

Quantum dots of single-/few-layered MoS₂ with tunable sizes, obtained through a unique electrochemical exfoliation process, show excellent electrocatalytic activity towards hydrogen evolution reactions.

We report the successful incorporation of bifunctional (acid/base) catalytic sites in the crystalline organocatalytic porous COF (2,3-DhaTph). Due to the presence of acidic (catachol) and basic (porphyrin) sites, 2,3-DhaTph shows significant selectivity, reusability, and excellent ability to perform the cascade reaction.

A new ultrafast and highly sensitive ‘turn-off/turn-on’ biosensing approach that combines the intrinsic peroxidase-like activity of gold nanoparticles (GNPs) with the high affinity and specificity of a ssDNA aptamer is presented.

Dynamic covalent chemistry has been utilized to synthesise a fluorescent [3+2] self-assembled nanoscopic organic cage. The reduced analogue of this cage is also highly fluorescent and was further exploited for the remarkably high selective detection of explosive picric acid (PA).

A dramatic improvement in pseudocapacitance is found for MOF derived CeO₂ with a value of 1204 F g⁻¹ at 0.2 A g⁻¹.

The high color contrast reversible mechanochromic and aggregation induced emissive tetraphenylethene substituted phenanthroimidazoles are reported. The incorporation of a cyano group into phenanthroimidazole (3b) improves thermal stability and enhances the AIE property.

Aqueous phase selective and sensitive nitro explosive detection by a porous luminescent metal–organic framework.

Gold nanoparticles immobilized into a stable covalent organic framework have been synthesized via the solution infiltration method. The as-synthesized Au(0)@TpPa-1 catalyst shows high recyclability and superior reactivity for nitro reduction reaction than HAuCl₄·3H₂O.

A spirobenzopyran-quinoline (SBPQ) based sensor was synthesized which selectively detects trivalent ions viz. Al³⁺, Fe³⁺ and Cr³⁺ through a fluorescence turn on signal.

A benchmark result demonstrating 99 823 μmol h⁻¹ g⁻¹_catalyst of H₂ produced using the lowest photocatalyst amount of 0.1 g L⁻¹.

GO@ZIF-8 hybrid nanocomposites show tunable nanoscale morphology depending on the GO content. The GO content also controls the porosity and CO₂ uptake capacity. GO@ZIF-8 hybrid nanocomposite acts as a precursor for in situ generation of GO@ZnS nanocomposite.

For ratiometric “naked eye” detection of CN⁻, an ESIPT exhibiting benzothiazole receptor (BHI) is designed having one aldehyde group ortho and the other aldehyde para to the OH group respectively.

MoS₂–MWCNT (1 : 1) hybrids prepared by dry grinding act as a superior anode in Li ion batteries (1214 mA h g⁻¹, 60 cycles).

Highly fluorescent carbon dots with 26% quantum yield have been prepared by hydrothermal carbonization of orange juice at comparatively mild temperature and in less time.

A fluoranthene based fluorescent chemosensor for the detection of picric acid at the parts per billion level was evaluated. Static fluorescence quenching was the dominant process by intercalative π–π interaction between fluoranthene and nitroaromatics.

Regioselective oxidative cyclization of aromatic acids with alkynes in the presence of a ruthenium catalyst providing isocoumarin derivatives was investigated.

A novel quinoline–coumarin (QC) fluoroionophore shows differential fluorescence turn on response to Zn²⁺ and overall ratiometric selectivity for Al³⁺ in aqueous media based on an ICT mechanism. QC exhibits preferential dual-mode selectivity for Al³⁺ as confirmed by ratiometric displacement of Zn²⁺ from the [QC + Zn²⁺] complex.

Poly(ethylene glycol) upon microwave irradiation produced small and highly fluorescent and non-cytotoxic carbon dots which were useful for cell labelling.

A new series of porphyrin based porous organic polymers has been synthesized using an extended aromatic substitution reaction between pyrrole and aromatic di-aldehydes and the materials have very high BET surface areas and excellent CO₂ capture (~19 wt%) property.

Graphene oxide is reported as a highly efficient and cost-effective organocatalyst for the aza-Michael addition of amines to activated alkenes.

A highly luminescent micrometre-sized Zn(II) metal–organic framework (MOF) of a new π-electron rich tricarboxylate dispersed in ethanol is demonstrated as a selective sensory material for the detection of nitroaromatic explosives via a fluorescence quenching mechanism.

Two new crystalline polymorphs and an amorphous phase of curcumin, the most active chemical ingredient of turmeric, are reported. The new Form 2 has higher solubility and dissolution rate compared to the known commercial form.

The amino functionalized Zeolitic Tetrazolate Framework (ZTF-1) shows high CO₂ (273 K) uptake due to the presence of free –NH₂ group and tetrazole nitrogen.

A novel 3D framework of Mg(II), {Mg(DHT)(DMF)₂}_n, having permanent porosity has been synthesized and unveils ligand-based multicolor emission based on excited state proton transfer (ESIPT) of the organic linker.

A pyrrolidine constrained bipyridyl-dansyl (ionophore-fluorophore) conjugate with triazole linker was prepared through click chemistry. The fluoroionophore serves as a selective ratiometric and colorimetric chemosensor for Al³⁺ based on internal charge transfer.

Raman spectra and electronic properties of graphene are markedly affected on interaction with electron-donor and -acceptor molecules.

A new chemosensor which can detect Hg²⁺ in water and Hg²⁺/Cu²⁺ in acetonitrile and its application as a molecular keypad lock using Cu²⁺ and F⁻ as ionic inputs are demonstrated.

Organic molecular crystals are soft. Why some of them bend rather than break is explained.

HClO₄–SiO₂ efficiently catalyzes the acetylation of phenols, thiols, amines, and alcohols at room temperature under solvent free conditions. Excellent results are obtained during the direct acetylation of alcohols with HOAc.

This communication reports the generation of an Au–nanoparticle polyaniline composite with H₂O₂ used as both oxidising and reducing agent; the composite thus generated has enhanced electrical conductivity.

Ultrasound has promoted Suzuki cross-coupling reactions of halobenzenes with phenyl boronic acid at ambient conditions using the ionic liquid [bbim][BF₄] with methanol as co-solvent without a phosphine ligand.