Introduction Of Chlorine Atom Research Articles

Spectral-luminescence, redox and photochemical properties of AlIII, GaIII and InIII complexes formed by peripherally chlorinated phthalocyanines and tetrapyrazinoporphyrazines

Complexes of Al[Formula: see text], Ga[Formula: see text] and In[Formula: see text] with peripherally chlorinated phthalocyanine (Cl8PcM) and tetrapyrazinoporphyrazine (Cl8TPyzM) were prepared and studied using spectral and electrochemical methods. DFT calculations were used to reveal the peculiarities of their molecular and electronic structure. Peripheral chlorination of phthalocyanine complexes increases their electron affinity and the first reduction of [Cl8PcM] is observed at −0.25 – −0.35 V (by 0.2 – 0.3 V easier than for [PcM]). Additional azasubstitution further increases the acceptor properties of the macrocycle and [Cl8TPyzM] are reduced at −0.16 V. Among [Cl8PcM] only the Ga[Formula: see text] complex is stable to photooxidation, while among [Cl8TPyzPzM] it is the only one undergoing photoreduction. Fluorescence quantum yields ([Formula: see text] and lifetimes ([Formula: see text] as well as the ability to generate singlet oxygen ([Formula: see text] were determined. The [Formula: see text] values show typical dependence on the central metal Al > Ga >> In and are decreased upon the introduction of chlorine atoms in the peripheral and especially in the axial position. At the same time, azasubstitution in the benzene ring has a minor influence on the [Formula: see text] values but strongly shortens [Formula: see text] (from ca 6 to ca 2 ns). The Ga[Formula: see text] complexes have the highest ability to generate 1O2 and can be considered as effective photosensitizers, especially [Cl8TPyzPzGa(OH)] ([Formula: see text] = 0.87 in slightly acidified solution). Spectral properties in a strongly acid medium were also studied and it was observed that [Cl8PcM] are consequently protonated on meso-nitrogens.

A novel chlorinated small molecule donor for efficient binary and ternary all-small-molecule organic solar cells

A new acceptor-donor-acceptor (A-D-A) type small molecule donor named BTEHR-CT has been developed, taking the chlorothienyl-substituted benzodithiophene (BDT) as the central unit and 3-(2-ethylhexyl)rhodanine as the terminal group. BTEHR-CT shows a low-lying highest occupied molecular orbital (HOMO) level of −5.56 eV and the suitable molecular aggregation benefiting from the introduction of chlorine atoms, which contributes to achieving excellent photovoltaic performances. Based on an efficient non-fullerene acceptor F–2Cl, the optimized binary device exhibits a high power conversion efficiency (PCE) of 11.13% with an open-circuit voltage ( V oc ) of 0.946 V, short-circuit current densities ( J sc ) of 17.05 mA cm −2 and FF of 0.690. With the incorporation of PC 71 BM, the ternary blend film based on BTEHR-CT:F–2Cl:PC 71 BM (weight ratio of 1:0.8:0.2) shows a fibrous morphology with suitable domain size and favorable phase separation after solvent vapor annealing (SVA) treatment, leading to a superior J sc of 18.53 mA cm −2 and fill factor (FF) of 0.692, thus a higher PCE of 12.05%. To our best knowledge, the PCEs of 11.13% and 12.05% are among the highest values reported to date for non-Y series acceptors based binary and ternary all-small-molecule organic solar cells (ASM-OSCs), respectively. The results indicate that the combination of careful molecular design and suitable morphology control is an effective strategy to achieve high performances for ASM-OSCs. • A new chlorinated small molecule donor named BTEHR-CT was designed and synthesized. • BTEHR-CT exhibits excellent optical and electrochemical properties. • The binary ASM-OSCs based on BTEHR-CT:F–2Cl gave a high PCE of 11.13%. • BTEHR-CT based ternary ASM-OSCs showed a higher PCE of 12.05% with the incorporation of PC 71 BM. • The PCEs are among the highest values reported to date for non-Y series acceptors based ASM-OSCs.

Chlorine‐Substituted N‐Heteroacene Analogues Acting as Organic Semiconductors for Solution‐Processed n‐type Organic Field‐Effect Transistors

High performance solution processable n-type organic semiconductor is an essential element to realize low-cost, all organic and flexible composite logic circuits. In the design of n-type semiconducting materials, tuning the LUMO level of compounds is a key point. As a strong electron withdrawing unit, the introduction of chlorine atom into the chemical structure can increase the electron affinity of the material and reduce the LUMO energy level. Here, a series chlorine substituted N-heteroacene analogues of 6,7,8,9-tetrachloro-4,11-bis(4-((2-ethylhexyl)oxy)phenyl)-[1,2,5]thiadiazolo[3,4-b]phenazine (O4Cl), 6,7,8,9-tetrachloro-4,11-bis(4-((2-ethylhexyl)thio)phenyl)-[1,2,5]thiadiazolo[3,4-b]phenazine (S4Cl), 1,2,3,4,8,9,10,11-octachloro-6,13-bis(4-((2-ethylhexyl)oxy)phenyl)quinoxalino[2,3-b]phenazine (8Cl) and 12Cl have been synthesized and characterized. Solution-processed organic field-effect transistors (OFETs) based on these four compounds exhibit good electron mobilities of 0.04 cm2 V-1 s-1 , 0.01 cm2 V-1 s-1 , 2×10-3 cm2 V-1 s-1 and 3×10-3 cm2 V-1 s-1 , respectively, under ambient conditions. The results suggest that these chlorine substituted π-conjugated N-heteroacene analogues are promising n-type semiconductors in OFET applications.

Polarity and Ferromagnetism in Two-Dimensional Hybrid Copper Perovskites with Chlorinated Aromatic Spacers.

Two-dimensional (2D) organic–inorganic hybrid copper halide perovskites have drawn tremendous attention as promising multifunctional materials. Herein, by incorporating ortho-, meta-, and para-chlorine substitutions in the benzylamine structure, we first report the influence of positional isomerism on the crystal structures of chlorobenzylammonium copper(II) chloride perovskites A2CuCl4. 2D polar ferromagnets (3-ClbaH)2CuCl4 and (4-ClbaH)2CuCl4 (ClbaH+ = chlorobenzylammonium) are successfully obtained. They both adopt a polar monoclinic space group Cc at room temperature, displaying significant differences in crystal structures. In contrast, (2-ClbaH)2CuCl4 adopts a centrosymmetric space group P21/c at room temperature. This associated structural evolution successfully enhances the physical properties of the two polar compounds with high thermal stability, discernible second harmonic generation (SHG) signals, ferromagnetism, and narrow optical band gaps. These findings demonstrate that the introduction of chlorine atoms into the interlayer organic species is a powerful tool to tune crystal symmetries and physical properties, and this inspires further exploration of designing high-performance multifunctional copper-based materials.

Improving the performances of all-small-molecule organic solar cells by fine-tuning halogen substituents of donor molecule

A new acceptor-donor-acceptor (A-D-A) type small molecular donor named as DRTB-CT was designed and synthesized by replacing the fluorine atoms of DRTB-FT with chlorine atoms. Such a small change plays an important role in inhibiting the strong molecular crystallinity and excessive self-aggregation in donor phase due to the larger radius of chlorine atom, which leads to optimized morphology of the active layer. Based on the same nonfullerene acceptor (F–2Cl), the optimal device of DRTB-CT exhibits a higher power conversion efficiency (PCE) of 9.05% compared with that of the fluorinated molecule (7.66%), benefiting from the increased fill factor (FF, 0.568) and short-circuit current density ( J sc , 15.07 mA cm −2 ). The results indicate that the introduction of chlorine atoms is an effective strategy in developing new small molecular donors with high device performances. • A new small molecular donor named DRTB-CT with two chlorinated side chains was synthesized. • DRTB-CT exhibits better photoelectric properties compared with fluorinated counterpart. • The steric effect of large radius prevents the excessive self-aggregation in donor phases. • DRTB-CT based all-small-molecule organic solar cells gave a high PCE of 9.05%. • Introduction of chlorine atoms is favorable for designing new materials with high performances.

Dichloro Butenediamides as Irreversible Site‐Selective Protein Conjugation Reagent

AbstractWe describe maleic‐acid derivatives as robust cysteine‐selective reagents for protein labelling with comparable kinetics and superior stability relative to maleimides. Diamide and amido‐ester derivatives proved to be efficient protein‐labelling species with a common mechanism in which a spontaneous cyclization occurs upon addition to cysteine. Introduction of chlorine atoms in their structures triggers ring hydrolysis or further conjugation with adjacent residues, which results in conjugates that are completely resistant to retro‐Michael reactions in the presence of biological thiols and human plasma. By controlling the microenvironment of the reactive site, we can control selectivity towards the hydrolytic pathway, forming homogeneous conjugates. The method is applicable to several scaffolds and enables conjugation of different payloads. The synthetic accessibility of these reagents and the mild conditions required for fast and complete conjugation together with the superior stability of the conjugates make this strategy an important alternative to maleimides in bioconjugation.

Dichloro Butenediamides as Irreversible Site-Selective Protein Conjugation Reagent.

We describe maleic‐acid derivatives as robust cysteine‐selective reagents for protein labelling with comparable kinetics and superior stability relative to maleimides. Diamide and amido‐ester derivatives proved to be efficient protein‐labelling species with a common mechanism in which a spontaneous cyclization occurs upon addition to cysteine. Introduction of chlorine atoms in their structures triggers ring hydrolysis or further conjugation with adjacent residues, which results in conjugates that are completely resistant to retro‐Michael reactions in the presence of biological thiols and human plasma. By controlling the microenvironment of the reactive site, we can control selectivity towards the hydrolytic pathway, forming homogeneous conjugates. The method is applicable to several scaffolds and enables conjugation of different payloads. The synthetic accessibility of these reagents and the mild conditions required for fast and complete conjugation together with the superior stability of the conjugates make this strategy an important alternative to maleimides in bioconjugation.

Practical and Selective sp3 C-H Bond Chlorination via Aminium Radicals.

The introduction of chlorine atoms into organic molecules is fundamental to the manufacture of industrial chemicals, the elaboration of advanced synthetic intermediates and also the fine‐tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site‐selective chlorination of sp3 C−H bonds. This process exploits the ability of protonated N‐chloroamines to serve as aminium radical precursors and also radical chlorinating agents. Upon photochemical initiation, an efficient radical‐chain propagation is established allowing the functionalization of a broad range of substrates due to the large number of compatible functionalities. The ability to synergistically maximize both polar and steric effects in the H‐atom transfer transition state through appropriate selection of the aminium radical has provided the highest known selectivity in radical sp3 C−H chlorination.

Practical and Selective sp3C−H Bond Chlorination via Aminium Radicals

AbstractThe introduction of chlorine atoms into organic molecules is fundamental to the manufacture of industrial chemicals, the elaboration of advanced synthetic intermediates and also the fine‐tuning of physicochemical and biological properties of drugs, agrochemicals and polymers. We report here a general and practical photochemical strategy enabling the site‐selective chlorination of sp3C−H bonds. This process exploits the ability of protonatedN‐chloroamines to serve as aminium radical precursors and also radical chlorinating agents. Upon photochemical initiation, an efficient radical‐chain propagation is established allowing the functionalization of a broad range of substrates due to the large number of compatible functionalities. The ability to synergistically maximize both polar and steric effects in the H‐atom transfer transition state through appropriate selection of the aminium radical has provided the highest known selectivity in radical sp3C−H chlorination.

Asymmetric Synthesis of 4,4-(Difluoro)glutamic Acid via Chiral Ni(II)-Complexes of Dehydroalanine Schiff Bases. Effect of the Chiral Ligands Structure on the Stereochemical Outcome.

Four differently substituted chiral Ni(II)‐complexes of dehydroalanine Schiff base were prepared and reacted with BrCF2COOEt/Cu under the standard reaction conditions. The observed diastereoselectivity was found to depend on the degree and pattern of chlorine substitution for hydrogen in the structure of the dehydroalanine complexes. The unsubstituted complex gave the ratio of diastereomers (S)(2S)/(S)(2R) of 66/34. On the other hand, introduction of chlorine atoms in the strategic positions on the chiral ligands allowed to achieve a practically attractive diastereoselectivity of (∼98.5/1.5). Diastereomerically pure major product was disassembled to prepare 9‐fluorenylmethyloxycarbonyl (Fmoc) derivative of (S)‐4,4‐difluoroglutamic acid.

Chlorine Atom-Induced Molecular Interlocked Network in a Non-Fullerene Acceptor.

The differences between the introduction of chlorine and fluorine atoms to small-molecule acceptors were deeply investigated. From the single-crystal structures of three molecules, the Cl-substitution intervention into the molecular configuration and packing mainly lies in three aspects as follows: single molecule configuration, one direction of the intermolecular arrangement, and three-dimensional (3D) molecular packing. First, the introduction of the chlorine atom in IDIC-4Cl leads to a more planar molecular configuration than IDIC-4H and IDIC-4F because of the formation of a molecular interlocked network induced by the strong Cl···S intermolecular interactions. Second, IDIC-4Cl shows the closest π-π stacking distance and the smallest dihedral angle (0°) between adjacent molecules to form ideal J-aggregation, which should be beneficial for charge transportation between different connected molecules in this direction. Finally, the interlocked interactions between Cl and S atoms lead to a highly ordered 3D molecular packing, in which the end groups will form an ideal overlapped packing among different molecules, whereas the other two analogues with H or F show less ordered packing of their 1,1-dicyanomethylene-3-indanone ending groups. Organic solar cells based on IDIC-4Cl show the highest power conversion efficiency (PCE) of 9.24%, whereas the PCEs of IDIC-4H- and IDIC-4F-based devices are 4.57 and 7.10%, respectively.

Function and Structure of MalA/MalA', Iterative Halogenases for Late-Stage C-H Functionalization of Indole Alkaloids.

Malbrancheamide is a dichlorinated fungal indole alkaloid isolated from both Malbranchea aurantiaca and Malbranchea graminicola that belongs to a family of natural products containing a characteristic bicyclo[2.2.2]diazaoctane core. The introduction of chlorine atoms on the indole ring of malbrancheamide differentiates it from other members of this family and contributes significantly to its biological activity. In this study, we characterized the two flavin-dependent halogenases involved in the late-stage halogenation of malbrancheamide in two different fungal strains. MalA and MalA' catalyze the iterative dichlorination and monobromination of the free substrate premalbrancheamide as the final steps in the malbrancheamide biosynthetic pathway. Two unnatural bromo-chloro-malbrancheamide analogues were generated through MalA-mediated chemoenzymatic synthesis. Structural analysis and computational studies of MalA' in complex with three substrates revealed that the enzyme represents a new class of zinc-binding flavin-dependent halogenases and provides new insights into a potentially unique reaction mechanism.

Quinoline derivatives as possible lead compounds for anti-malarial drugs: Spectroscopic, DFT and MD study

In this work we report spectroscopic characterization and reactivity study by density functional theory (DFT) and molecular dynamics (MD) simulations of two quinoline derivatives. Collected computational results for the two new derivatives have been compared with the pristine quinoline in order to investigate the consequences of modifications by introduction of chlorine atoms and methyl and OH groups. Potential energy distribution (PED) analysis has been performed in order to assign principal vibrational numbers. DFT calculations have been used to obtain global and local quantum-molecular descriptors including frontier molecular orbitals, charge distribution by molecular electrostatic potential (MEP) surface, average local ionization energy (ALIE) surface, and Fukui functions. Natural bond order (NBO) analysis has been performed in order to investigate hyper-conjugative properties. To investigate sensitivity towards autoxidation and hydrolysis we have calculated bond dissociation energies (BDE) and radial distribution functions (RDF). Molecular docking study has also been performed in order to initially assess the potential of target molecules to bind with dehydrogenase inhibitor and these quinoline derivatives can be a lead compounds for developing new anti-malarial drug.

Design, synthesis and biological evaluation of novel thieno[3,2-d]pyrimidine derivatives containing diaryl urea moiety as potent antitumor agents

Two series of thieno[3,2-d]pyrimidine derivatives containing diaryl urea moiety were designed, synthesized and evaluated for their biological activity. The preliminary investigation showed that most compounds displayed good to excellent potency against four tested cancer cell lines as compared with GDC-0941 and sorafenib. In particular, the most promising compound 29a showed the most potent antitumor activities with IC50 values of 0.081 μM, 0.058 μM, 0.18 μM, and 0.23 μM against H460, HT-29, MKN-45 and MDA-MB-231 cell lines, respectively. The SAR analyses indicated that compounds with mono-halogen groups at 4-position on the terminal phenyl ring were more active than those with double-halogen groups or methyl groups. In addition, the introduction of chlorine atoms into 6,7-position of thieno[3,2-d]pyrimidine moiety led to a slight decline, but more selective activity against H460 and HT-29 cell lines.

Tyrosyl-tRNA synthetase inhibitors as antibacterial agents: Synthesis, molecular docking and structure–activity relationship analysis of 3-aryl-4-arylaminofuran-2(5 H)-ones

Thirty-five 3-aryl-4-arylaminofuran-2(5 H)-one derivatives were designed, prepared and tested for their inhibitory activity against tyrosyl-tRNA synthetase. Out of these compounds, 3-(3-bromophenyl)-4-(3,5-dichlorophenylamino)furan-2(5 H)-one ( 35) was the most active with IC 50 of 0.09 ± 0.02 μM. The structure–activity relationship revealed that introduction of chlorine atoms at both meta positions of aniline moiety significantly increased the enzyme inhibitory activity. The results of antibacterial assay revealed that the tested compounds showed good activity against Gram-positive bacteria, with 35 being the most potent with MIC 50 of 0.06 μg/mL against Staphylococcus aureus ATCC 25923. Molecular docking of 35 into S. aureus tyrosyl-tRNA synthetase active site was also performed. The inhibitor snugly fitting the active site may well explain its excellent inhibitory activity.

Hydrochlorinated derivatives of syndiotactic 1,2-polybutadiene

Chlorine-containing polymeric products with a degree of functionalization of up to 70% are synthesized through the hydrochlorination of syndiotactic 1,2-polybutadiene via carbon-carbon double bonds. The introduction of chlorine atoms into polydiene units causes substantial changes in the viscosity of polymer solutions, the flowability of the polymer melt, the glass-transition and flow temperatures, and the thermal stability of polymers. The hydrochlorinated derivatives of syndiotactic 1,2-polybutadiene demonstrate good adhesion with respect to steel and can be used in adhesive compositions.

Locking the free-rotation of a prochiral star-shaped guest molecule inside a two-dimensional nanoporous network by introduction of chlorine atoms

Two star-shaped triazatrinaphthylene (TrisK) derivatives form highly-organized nanoporous honeycomb networks when adsorbed at the n-tetradecane/HOPG interface. STM reveals that replacing three H-atoms by three Cl-atoms in the chemical structure of the TrisK skeleton results in locking the free-rotation of the guest molecules inside the pore of the host network as a result of symmetry breaking.

Chlorinated polymers based on low-molecular-weight 1,2-polybutadiene

Chlorinated polymeric products were synthesized from 1,2-polybutadiene by introduction of chlorine atoms into macromolecules at carbon carbon double bonds.

3‐Hydroxy‐quinazoline‐2,4‐dione as a Useful Scaffold to Obtain Selective Gly/NMDA and AMPA Receptor Antagonists.

AbstractFor Abstract see ChemInform Abstract in Full Text.

3-Hydroxy-quinazoline-2,4-dione as a useful scaffold to obtain selective Gly/NMDA and AMPA receptor antagonists

The synthesis and Gly/NMDA, AMPA and KA receptor binding activities of some 3-hydroxy-quinazoline-2,4-dione derivatives are reported. The binding data, together with functional antagonism studies, showed that the 3-hydroxy-quinazoline-2,4-dione moiety can be considered a useful scaffold to obtain selective Gly/NMDA and AMPA receptor antagonists. In fact, introduction of chlorine atom(s) on precise position(s) of the benzofused moiety yielded Gly/NMDA selective antagonists, while the presence of the 6-(1,2,4-triazol-4-yl) group shifted the affinity and selectivity towards the AMPA receptor.