New Fluorescent Dye for the Detection of Zn in Living Cells and Fixed Sections of the Rat Pancreas.

We report the synthesis and characterization of a new 4-methoxyphenyl-2,2'-bipyridine-based ligand, such as 12, bearing dipicolylaminomethyl core as a receptor unit, as a probe for the fluorescence "turn-on" detection of Zn. Thus, in the presence of Zn the probe 12 exhibited a fluorescence enhancement with a Stokes shift of ~ 180 nm and photoluminescence quantum yields value of ~ 1.0.

Mechanosynthesis of Polyureas and Studies of Their Responses to Anions.

Polyureas (PUs) have already found wide practical applications, and various methods of their synthesis have been reported. In this manuscript, we wished to report the very first mechanochemical approach towards aromatic PUs via reactions between isomeric 2,2'-, 3,3'-, and 4,4'-diaminobiphenyls and triphosgene under solvent-free conditions following ball-milling. By using this synthetic approach, both PUs and azomethine-capped Pus were obtained.

Polymers and Polymer-Based Materials for the Detection of (Nitro-)explosives.

Methods for the remote detection of warfare agents and explosives have been in high demand in recent times. Among the several detection methods, fluorescence methods appear to be more convenient due to their low cost, simple operation, fast response time, and naked-eye-visible sensory response. For fluorescence methods, a large variety of fluorescent materials, such as small-molecule-based fluorophores, aggregation-induced emission fluorophores/materials, and supramolecular systems, have been reported in the literature.

One-pot Synthesis and Photophysical Studies of Α-cycloamino-substituted 5-aryl-2,2'-bipyridines.

A series of α-cycloamine substituted 2,2'-bipyridines 3ae'-3ce' was obtained via the one-pot approach based on ipso-substitution of a cyano-group in 1,2,4-triazines, followed by aza-Diels-Alder reaction in good yields. Photophysical properties, including fluorosolvatochromism, were studied for 3ae'-3ce' and were compared with α-unsubstituted 2,2'-bipyridines. In addition, dipole moments differences in ground and excited states were calculated by both Lippert-Mataga equation and DFT studies and were compared to each other.

TM-Free and TM-Catalyzed Mechanosynthesis of Functional Polymers.

Mechanochemically induced methods are commonly used for the depolymerization of polymers, including plastic and agricultural wastes. So far, these methods have rarely been used for polymer synthesis. Compared to conventional polymerization in solutions, mechanochemical polymerization offers numerous advantages such as less or no solvent consumption, the accessibility of novel structures, the inclusion of co-polymers and post-modified polymers, and, most importantly, the avoidance of problems posed by low monomer/oligomer solubility and fast precipitation during polymerization.

Synthesis and Photophysical Properties of α-(-Biphenyl)-Substituted 2,2'-Bipyridine-Based Push-Pull Fluorophores.

A series of new α-(-biphenyl)-substituted 2,2'-bipyridines were obtained through the combination of the ipso-nucleophilic aromatic substitution of the C5-cyano group, aza-Diels-Alder and Suzuki cross-coupling reactions, starting from 5-cyano-1,2,4-triazines. For the obtained compounds, photophysical and fluorosolvatochromic properties were studied. Fluorophores and demonstrated unexpected AIEE activity, while and showed promising nitroexplosive detection abilities.

Sustainable Solvent-Free Diels-Alder Approaches in the Development of Constructive Heterocycles and Functionalized Materials: A Review.

The Diels-Alder reaction (DAR) is found in myriad applications in organic synthesis and medicinal chemistry for drug development, as it is the method of choice for the expedient synthesis of complex natural compounds and innovative materials including nanomaterials, graphene expanses, and polymeric nanofibers. Furthermore, the greatest focus of attention of DARs is on the consistent reaction procedure with stimulus yields by highly stereo- and regioselective mechanistic pathways. Therefore, the present review is intended to summarize conventional solvent-free (SF) DARs for the expedient synthesis of heterocyclic compounds and materials.

Assessment on facile Diels-Alder approach of α-pyrone and terpenoquinone for the expedient synthesis of various natural scaffolds.

The development of highly facile synthetic procedures for the expedient synthesis of complex natural molecules is always in demand. As this aspect, the Diels-Alder reaction (DAR) has a versatile approach to the synthesis of complex natural compounds and highly regio-/stereoselcetive heterocyclic scaffolds. Additionally, α-pyrone and terpenoquinone are two versatile key intermediates that are prevalent in various bioactive natural compounds for instance, (±)-crinine, (±)-joubertinamine, (±)-pancratistatin, (-)-cyclozonarone, and 8-ephipuupehedione, etc.

Studies on the interactions of 5-R-3-(2-pyridyl)-1,2,4-triazines with arynes: inverse demand aza-Diels-Alder reaction versus aryne-mediated domino process.

The interactions between substituted 5-R-3-(pyridyl-2)-1,2,4-triazines with in situ generated substituted aryne intermediates have been studied. The reaction afforded either inverse demand (ID) aza-Diels-Alder products or 1,2,4-triazine ring rearrangement (domino) products as major ones depending on the nature of both the substituents at the C5 position of the 1,2,4-triazine core or in the aryne moiety. The structures of the key products were confirmed based on X-ray data.