Pyrene appended terpyridine derivatives as electrochemiluminescence material for OLEDs: Characterization of photo-physical, thermal and electrochemical properties

Three new terpyridine appended pyrene derivatives (Pyr-Tp, Pyr-Ph-Tp, and Pyr-Bp-Tp) have been synthesized by condensation and Suzuki-Miyaura reaction. The photo-physical, electro-chemical and thermal properties of these compounds have been investigated in detail. DFT studies have been carried out to understand the structure-property relationships at the molecular level. Synthesized fluorophores displayed high quantum yield (70-96%) of fluorescence due to triplet to singlet intramolecular energy transfer, delayed fluorescence and positive solvatochromism indicating the presence of intra-molecular charge transfer excited state. In addition, they have high thermal decomposition temperature (Td: 390-450°C), melting temperature (Tm: 180-220°C) and further with suitable oxidation and reduction potentials makes them favourable molecules for OLED fabrications.

Photoinduced electron transfer between a donor and an acceptor separated by a capsular wall

The efficient photoinduced electron transfer from a stilbene derivative incarcerated within a negatively charged organic nanocapsule to positively charged acceptors (methyl viologen and a pyridinium salt) adsorbed outside and the back electron transfer were controlled by supramolecular effects

Experimental study of end-capped acceptors influencing the photo-physical, electrochemical and thermal parameters of A-D-π-D-A type small molecular electron donors

385-392We have designed A-D-π-D-A type three new small molecular donor materials denoted as FD-IND, FD-DCV and FD-NBR, which have been synthesised and their photo-physical, electrochemical and thermal properties explored. The synthesised materials have fluorene as “π-spacer,” dithieonopyrrole as “Donor” (D) and various “Acceptor” (A) units are 1,3-indanedione (IND), dicyanovinylene (DCV) and N-butyl rhodanine (NBR). All these three materials have good solubility (~30 mg/mL) in most common organic solvents and have relatively broad absorption in the visible region covering the range of 300-650 nm with two primary absorption bands. The absorption bands located at shorter wavelength region are ascribed to a localized aromatic π-π* transition of the A-D-π-D-A system, while the bands at longer wavelength are mainly attributed to an ICT transition. All the compounds exhibit excellent thermal stabilities in the range of 260-373°C. Cyclic voltammetry data provided HOMO values as −5.26, −5.32 and −5.32 eV for FD-NBR, FD-DCV and FD-IND respectively. LUMO values estimated from HOMO values and optical band gap are −3.27, −3.22 and −3.37 eV for FD-NBR, FD-DCV and FD-IND respectively. Therefore, these are potential molecules for organic solar cells

Experimental study of end-capped acceptors influencing the photo-physical,electrochemical and thermal parameters of A-D-π-D-A type small molecularelectron donors

We have designed A-D-π-D-A type three new small molecular donor materials denoted as FD-IND, FD-DCV andFD-NBR, which have been synthesised and their photo-physical, electrochemical and thermal properties explored.The synthesised materials have fluorene as “π-spacer,” dithieonopyrrole as “Donor” (D) and various “Acceptor” (A) unitsare 1,3-indanedione (IND), dicyanovinylene (DCV) and N-butyl rhodanine (NBR). All these three materials have goodsolubility (~30 mg/mL) in most common organic solvents and have relatively broad absorption in the visible regioncovering the range of 300-650 nm with two primary absorption bands. The absorption bands located at shorter wavelengthregion are ascribed to a localized aromatic π-π* transition of the A-D-π-D-A system, while the bands at longer wavelengthare mainly attributed to an ICT transition. All the compounds exhibit excellent thermal stabilities in the range of 260-373°C.Cyclic voltammetry data provided HOMO values as −5.26, −5.32 and −5.32 eV for FD-NBR, FD-DCV and FD-INDrespectively. LUMO values estimated from HOMO values and optical band gap are −3.27, −3.22 and −3.37 eV forFD-NBR, FD-DCV and FD-IND respectively. Therefore, these are potential molecules for organic solar cells

Pyrene appended terpyridine derivatives as electrochemiluminescence material for OLEDs: Characterization of photo-physical, thermal and electrochemical properties

1564-1574Three new terpyridine appended pyrene derivatives (Pyr-Tp, Pyr-Ph-Tp, and Pyr-Bp-Tp) have been synthesized by condensation and Suzuki-Miyaura reaction. The photo-physical, electro-chemical and thermal properties of these compounds have been investigated in detail. DFT studies have been carried out to understand the structure-property relationships at the molecular level. Synthesized fluorophores displayed high quantum yield (70-96%) of fluorescence due to triplet to singlet intramolecular energy transfer, delayed fluorescence and positive solvatochromism indicating the presence of intra-molecular charge transfer excited state. In addition, they have high thermal decomposition temperature (Td: 390-450°C), melting temperature (Tm: 180-220°C) and further with suitable oxidation and reduction potentials makes them favourable molecules for OLED fabrications

The search for the 'next' euphoric non-fentanil novel synthetic opioids on the illicit drugs market: current status and horizon scanning

Purpose: A detailed review on the chemistry and pharmacology of non-fentanil novel synthetic opioid receptor agonists, particularly N-substituted benzamides and acetamides (known colloquially as U-drugs) and 4-aminocyclohexanols, developed at the Upjohn Company in the 1970s and 1980s is presentedMethod: Peer-reviewed literature, patents, professional literature, data from international early warning systems and drug user fora discussion threads have been used to track their emergence as substances of abuse.Results: In terms of impact on drug markets, prevalence and harm, the most significant compound of this class to date has been U-47700 (trans-3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide), reported by users to give short-lasting euphoric effects and a desire to re-dose. Since U-47700 was internationally controlled in 2017, a range of related compounds with similar chemical structures, adapted from the original patented compounds, have appeared on the illicit drugs market. Interest in a structurally unrelated opioid developed by the Upjohn Company and now known as BDPC/bromadol appears to be increasing and should be closely monitored.Conclusions: International early warning systems are an essential part of tracking emerging psychoactive substances and allow responsive action to be taken to facilitate the gathering of relevant data for detailed risk assessments. Pre-emptive research on the most likely compounds to emerge next, so providing drug metabolism and pharmacokinetic data to ensure that new substances are detected early in toxicological samples is recommended. As these compounds are chiral compounds and stereochemistry has a large effect on their potency, it is recommended that detection methods consider the determination of configuration

Oxidation of thioketens by singlet oxygen and ozone

Di-t-butylthioketen ( 1 ) readily reacts with singlet oxygen to yield unexpected products (based on the behaviour of other heterocumulenes) and reacts with ozone to give, quantitatively, the corresponding sulphoxide ( 2

Generation of stable and persistent carbocations from 4-vinylanisole within zeolites

Stable and ultrastable carbocations from 4-vinylanisole are spontaneously generated within zeolites; these reactive intermediates are stable for several weeks within the confined environments of zeolites.NRC publication: Ye

Oxidation of thioketens by singlet oxygen and ozone

Di-t-butylthioketen (1) readily reacts with singlet oxygen to yield unexpected products (based on the behaviour of other heterocumulenes) and reacts with ozone to give, quantitatively, the corresponding sulphoxide (2)

Oxidations of thio ketones by singlet and triplet oxygen

Oxidation of di-tert-butyl thioketone (1) and 2,2,4,4-tetramethylcyclobutylth ioketone (2) by singlet oxygen yields the corresponding sulfine and ketone; in the case of 1 the sulfine is the major product, whereas in 2 it is the ketone. 1,2,3-Dioxathietane has been suggested as the precursor for the ketones, and the zwitterionic/diradid peroxide is believed to be a common primary intermediate for both sulfine and ketone. Steric influence is felt both during primary interaction between singlet oxygen and thioketone and during the partitioning of the peroxide intermediate. Steric interaction is suggested as the reason for variations in the product distribution between 1 and 2. Singlet oxygen is also generated through energy transfer from the triplet state of thioketones. These excited states also directly react with oxygen to yield ketone