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We report the synthesis of perylenediimide (PDI)-based donor-acceptor hybrids through dissymmetric bay functionalization of PDIs. The dissymmetric bay-functionalized di- and trisubstituted PDIs were characterized by using one- and two-dimensional NMR spectroscopy. Density functional theory calculations revealed (i) an energy gap between the HOMO and LUMO in the range 2.14-2.34 eV, beneficial for charge-transfer properties; and (ii) a twist angle between the two naphthalene units in the range 17-26°, which might be beneficial for disruption of co-facial stacking of the PDI. [ABSTRACT FROM AUTHOR]

Abstract: Here in, novel excited state intramolecular charge transfer (ESIPT)‐modulated fluorophore based on diphenylpyrimidinone DPHQ has been designed and synthesized. DPHQ shows selective 8‐fold ‘turn‐on’ fluorescence response with Cd2+/Zn2+ in buffer (containing 1% CH3CN, pH 7.2) with low detection limits of 55.7/2.7 nM accompanied with a fluorescent colour change from colourless to cyan. DPHQ–Cd2+ ensemble undergo selective fluorescence quenching with nucleoside triphosphates but it is silent to nucleoside di‐and mono‐phosphates. It can detect 58.4 nM concentration of adenosine triphosphate (ATP). The binding mode and sensing mechanism of DPHQ with Cd2+/Zn2+ was supported by the change in optical behaviors, density functional theory (DFT) calculations and Job's plot. DPHQ was successfully used for construction of ‘Set‐Reset’ memorized logic devices and OR, INHIBIT logic gates. As practical applications of DPHQ, we utilized DPHQ for detection of Cd2+/Zn2+ in blood serum and quantification of Zn2+ in tap water samples. [ABSTRACT FROM AUTHOR]

[3+2+2] Cycloaddition reactions are of key importance in organic chemistry for the synthesis of seven-membered mono- and condensed carbocycles. This review article summarises the different reports on transition-metal-catalysed [3+2+2] cycloaddition reactions since 2000. Different transitionmetals, such as Ni, Rh, Pd, Co, or Ru, which have been earlier reported for higher order [3+2+2] cycloaddition reactions are summarized in this article. The [3+2+2] cycloadditions of different functionalized substrates afford cycloheptane derivatives, 6-7,5-7 condensed bicyclic carbocycles, or 5-7-5 or 6-7-5 condensed tricyclic carbocycles. These higher order cycloaddition reactions may provide an easy route for the total synthesis of natural products, or as a preferable key synthetic step leading to final structure. [ABSTRACT FROM AUTHOR]

Acetylenic ester promoted ring opening of dienyl-thiazolidin- 4-ones and subsequent electrocyclization affords 5-phenyl-6-aryl pyridine-2-carboxylates in good to excellent yields. [ABSTRACT FROM AUTHOR]

In this work, we have designed and synthesized a perylene diimide based derivative PDI-SiHQ having an O-silylated-8-hydroxyquinoline group at the bay position. PDI-SiHQ is able to detect and differentiate CN− from F− in the presence of other anions. The electron transfer from cyanide ions to PDI-SiHQ leads to the emergence of panchromatic and NIR absorption bands due to the formation of a PDI-SiHQṖ− radical anion. In contrast, fluoride induced desilylation of PDI-SiHQ coupled with π–π aggregation results in a red-shifted absorption band at 730 nm. 1H NMR and cyclic voltammetry combined with the reversal of the PDI-SiHQṖ− radical anion to the PDI-SiHQ neutral form in the presence of NOBF4 or Cu2+ ions confirm the formation of the radical anion in PDI-SiHQ. Multi-channel UV-Vis-NIR absorption and emission bands and their reversibility with NOBF4/Cu2+ ions offer the possibility for fabrication of complex logic circuits such as complementary IMP/INH logic circuits, magnitude comparators and ‘set–reset’ flip flop memory elements. [ABSTRACT FROM AUTHOR]

Abstract: A novel, efficient and one‐pot multicomponent copper‐catalyzed amination of N‐pyridyl imines is described. This, one‐pot, multicomponent reaction, in which imine acts as a directing group by chelating to the metal core, affords a domino approach for the transformation of the commercial pyridinamines, aldehydes and azide into valuable imidazo[4, 5‐b]pyridines with wide substrate extent and diversity. [ABSTRACT FROM AUTHOR]

The detection and quantification of spermine in clinical practice is important for early diagnosis of many diseases. Chromatographic and immunoassay-based methods are commonly used. However, a fluorescence-based assay could provide real-time detection. Herein, the synthesis and aggregation properties of a dicationic perylene probe ( N1-dodecyl- N3-(4-phenyl)benzimidazolium-functionalized perylenediimide ( DAB-PDI)) used to develop a fluorescent 'turn-on' ensemble for the detection of spermine are discussed. The fluorescence of DAB-PDI (10 μ m, Φ=0.55) is efficiently quenched by negatively charged sodium dodecylsulfate (SDS) through the formation of ionic self-assembled aggregates (charge ratio of negative (N) in SDS to positive (P) in DAB-PDI (N/P)=9). This negatively charged ionic self-assembly between DAB-PDI and SDS has been characterized by using photophysical, microscopic, dynamic light scattering, isothermal titration calorimetry, and HRMS techniques. The addition of spermine to this ensemble solution results in the breakdown of the DAB-PDI-SDS ensemble owing to strong binding of spermine with SDS and, as a result, the fluorescence of DAB-PDI is recovered. This ensemble exhibits high sensitivity and selectivity for spermine detection in water, urine, and blood serum. The lowest limit of detection is 27.5 n m, which is at least about 36 times lower than that required for early diagnosis of cancer (1 to 10 μ m for urinary spermine). [ABSTRACT FROM AUTHOR]

The reactions of butadienylketene with variety of 1,4-diazabuta-1,3-dienes are studied. The reactions resulted in the formation of previously unknown functionalized cis butadienyl-4-iminomethyl-azetidin-2-ones and butenylidene-butadienyl-[2,2′-biazetidine]-4,4′- diones. Butadienyl ketene reacts in fashion with both iminic portion of 1,4- diazabuta-1,3-dienes and competitive [4+2] of 1,4-diazabuta-1,3-dienes as 4π component with butadienyl ketene as 2π component are not observed. [ABSTRACT FROM AUTHOR]

We designed and synthesized the mono bay functionalized perylenediimide (PDI) derivative PDI-DMEA which undergoes self-assembly to form a nanorod morphology. The diameter of these nanorods is in the range of 150–300 nm and the length extended up to the μm range. These nanorods on interaction with Cu2+ ions transformed into spherical aggregates having a diameter of 350–600 nm in accordance with DLS studies. In solution, PDI-DMEA shows a blue shift of the internal charge transfer (ICT) absorption band from 605 to 570 nm along with a hyperchromic effect at 570 nm, in the presence of 0.7 equivalents of Cu2+ ions. The addition of 2 equivalents of Cu2+ ions results in complete disappearance of the ICT band at 570 nm and appearance of a normal absorption band of PDI at 515 nm (a visual colour change from colourless to yellow). On the other hand PDI-DMEA shows a strong fluorescence ‘turn-on’ response at 537 and 573 nm on addition of higher equivalents of Cu2+ ions. Thus, PDI-DMEA represents several examples of molecular switches such as ‘OFF–ON–OFF’ and ‘ON–OFF–ON’ at 570/515 nm (Cu2+, absorbance), and ‘OFF–ON’ at 570 nm (Fe2+, absorbance) and 537 nm (Cu2+, fluorescence) and thus offers the possibility for developing NOR, OR, INH and TRANSFER logic and complimentary logic circuits. Moreover, PDI-DMEA and the PDI-DMEA–Cu2+ complex show fluorosolvatochromism which helps to develop a colour array for differentiating organic solvents. The detailed mechanism of interaction of Cu2+ and Fe2+ with PDI-DMEA, confocal laser scanning microscopic studies, dynamic light scattering, 1H NMR titration and reversibility are discussed. [ABSTRACT FROM AUTHOR]

Tandem aza-Michael addition of 3-amino-2-azetidinones with acetylenic esters and subsequent intramolecular amidic ring opening of the initially formed azetidin-3-ylaminoprop- or -but-2-enoic ester is described. The reaction provides a facile route for the formation of functionalized 4-oxo-4,5-dihydro-1H-pyrroles in good yields. [ABSTRACT FROM AUTHOR]