Photoinduced charge transfer in push-pull pyrazoline-based chromophores - Relationship between molecular structure and photophysical, photovoltaic properties.

The manuscript describes the effect of molecular structure on the photophysical and photovoltaic properties of the pyrazoline-based donor-branched-π-system-acceptor compounds decorated with two end groups: phenyl or thiophene. Although the absorption to the first singlet excited state is strongly allowed, the emission quantum yield is low in all studied solvents. This behaviour was explained by the existence of two non-radiative deactivation channels: the back electron transfer process, especially operated in polar solvents, and internal conversion realized as the rotation of flexible rotors (cyano, keto phenyl or thiophene).

Synthesis of Nonsymmetrically Substituted 2,3-Dialkoxyphenazine Derivatives and Preliminary Examination of Their Cytotoxicity.

Fourteen new 2,3-dialkoxyphenazine derivatives with two different alkoxy groups bearing R and R alkyl chains, defined as -CHCH(CH) and -(CH)CH for = 1, 2, 4, 6, 8, and 10, were prepared regioselective synthesis. The applied synthetic protocol is based on the following reactions: the Buchwald-Hartwig coupling of a nonsymmetrically substituted 4,5-dialkoxy-2-nitroaniline with a 1-bromo-2-nitrobenzene derivative featuring additional -butyl, trifluoromethyl or two methoxy groups; the reduction of bis(2-nitrophenyl)amine; and a final step of tandem-like oxidation that leads to the preparation of a heterocyclic phenazine system. The regioselectivity of these steps and the molecular structure of the compounds under investigation were confirmed by nuclear magnetic resonance and additionally by single-crystal X-ray diffraction performed for some examples of and phenazine series.

Ab Initio Study of H-Bond Dynamics in Three-Component Crystals Comprising (DABCOH ) Polycationic Chains.

In this work, the dynamic character of hydrogen-bond (H-bond) networks in two three-component crystals comprising polycationic chains was described. The first studied system was 1,4-diazabicyclo[2.2.

Near-Infrared Photoactive Aza-BODIPY: Thermally Robust and Photostable Photosensitizer and Efficient Electron Donor.

We report herein the synthesis of aza-BODIPY substituted with strongly electron-donating p-(diphenylamino)phenyl substituents (p-Ph N-) at 3,5-positions. The presence of p-Ph N- groups lowers the energy of the singlet excited state (E ) to 1.48 eV and induces NIR absorption with λ at 789 nm in THF.

Synthesis, Photophysics and Redox Properties of Aza-BODIPY Dyes with Electron-Donating Groups.

A series of novel aza-BODIPY dyes substituted with p-(dimethylamino)phenyl groups were synthesized and their spectral and electrochemical properties were compared. In particular, the impact of p-(Me N)Ph- groups on these characteristics was of consideration. For two aza-BODIPYs studied, a near-IR absorption band was observed at circa λ =796 nm.

A proposal for coherent nomenclature of multicomponent crystals.

Here a new, systematic, unambiguous and unified nomenclature for multicomponent materials is presented. The approach simplifies naming schemes of extraordinary co-crystals containing multiple building blocks with different charges. Although the presented examples of cytosine compounds cannot cover all possibilities, they clearly show that the new nomenclature is flexible and can be easily extended to other multicomponent materials.

Unmasking the Mechanism of Structural Para- to Ferroelectric Phase Transition in (NH)SO.

New nontoxic and biocompatible ferroelectric materials are a subject undergoing intense study. One of the most promising research branches is focused on H-bonded organic or hybrid ferroelectrics. The engineering of these materials is based on mimicking the phase transition mechanisms of the well-known inorganic ferroelectrics.

Self-assembly of long-chain quaternary ammonium cations in a hybrid inorganic-organic material with one-dimensional polymeric tribromidoplumbate(II).

catena-Poly[benzyldecyldimethylammonium [plumbate(II)-tri-μ-bromido]], {(C(19)H(34)N)[PbBr(3)]}(n), crystallizes as an inorganic-organic hybrid following monoclinic space-group symmetry P2(1)/c. The structure consists of extended chains running along the [001] direction and built of [PbBr(3)](-) units. These inorganic chains are separated by interdigitated ammonium cations which form hydrophilic layers through weak C-H···Br interactions.