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The article presents the results of research conducted in the years 2020– 2021 on the influence of agrotechnical processes on the growth and productivity of the plum of the Super President variety grafted on two rootstocks, Corcoduş (cherry plumor myrobalan plum) and Cubani-86. Scientific data are presented on the diameter of the trunk, the height of the trees, the width of the crowns, the average and total length of the annual growths, the surface of the leaves and the content of pigments in the leaves and fruit productivity in the years 4-5 of tree vegetation.

Palladium nanoparticles entrapped in porous aromatic frameworks (PAFs) or covalent organic frameworks may promote heterogeneous catalytic reactions. However, preparing such materials as active nanocatalysts usually requires additional steps for palladium entrapment and reduction. This paper reports as a new approach, a simple procedure leading to the self-entrapment of Pd nanoparticles within the PAF structure. Thus, the selected Sonogashira synthesis affords PAF-entrapped Pd nanoparticles that can catalyze the C-C Suzuki-Miyaura cross-coupling reactions. Following this new concept, PAFs were synthesized via Sonogashira cross-coupling of the tetraiodurated derivative of tetraphenyladamantane or spiro-9,9'-bifluorene with 1,6-diethynylpyrene, then characterized them using powder X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, X-ray photoelectron spectroscopy, high-resolution scanning transmission electron microscopy, and textural properties (i.e., adsorption-desorption isotherms). The PAF-entrapped Pd nanocatalysts showed high catalytic activity in Suzuki-Miyaura coupling reactions (demonstrated by preserving the turnover frequency values) and stability (demonstrated by palladium leaching and recycling experiments). This new approach presents a new class of PAFs with unique structural, topological, and compositional complexities as entrapped metal nanocatalysts or for other diverse applications.

We report herein our attempt to synthesize an analog of indacenedithiophene (IDT) based on a tetraphenylhexyl substituted, covalently bridged syn-terthienyl unit. Instead of the expected compound the adopted synthetic route led to the formation of an unexpected, new naphtho[2,3-b]thiophene derivative. The structure of this compound was fully characterized by NMR and HRMS as well as single crystal X-ray diffraction and its electronic properties have been analyzed by UV-vis absorption spectroscopy and cyclic voltammetry. A possible mechanism for the formation of this compound is also proposed on the basis of detailed theoretical investigations.

Single-crystal X-ray diffraction studies on Halogen-Bonded Organic Frameworks (XBOF) formed by N---I contacts of 2,2′,7,7′-tetrapyridyl-9,9′-spirobifluorene with pentafluoroiodobenzene or the isome...

In the context of helical chirality, bridging of biphenyl units leads to banister-type compounds and the stability of the resulted atropisomers may increase dramatically if suitable changes are performed in the linker unit that coils around the biphenyl moiety. A rigorous density functional theory (DFT) study was conducted for macrocycles containing rigid oxime ether segments connected to the biphenyl backbone in order to determine how the rotation barriers are influenced by the presence of either a flexible oligoethyleneoxide or a more rigid m–xylylene component in the macrocycle. The calculated values for the racemization barrier were in good agreement with those obtained experimentally and confirm the benefit of introducing a more rigid unit in the macrocycle on the stability of atropisomers. Solid-state data were obtained and computed data were used to assess the contribution brought by supramolecular associations observed in the lattice to the stabilization of the crystal structure. Beside introducing rigidity in the linker, complexation of flexible macrocycles with alkali metal ions is also contributing to the stability of atropisomers, leading to values for the racemization barrier matching that of the rigid macrocycle. Using diethylammonium cation as guest for the macrocycle, a spectacular increase in the barrier to rotation was observed for the resulted pseudo[2]rotaxane.

A new class of axially-chiral o,o′-bridged biphenyls containing etheroxime chains was obtained in good yields by the macrocyclisation reaction of o,o′-diformylbiphenyl dioxime with several ditosylated or dibrominated reagents. In all cases the enantiomers of the compounds were separated by HPLC using a chiral column (Chiralpack IC) and the stability of the enantiomers (barriers of racemisation) was investigated employing chiral HPLC or chiral Dynamic HPLC techniques. A slight influence on the barrier to rotation was noticed when the enantiomerisation was performed in the presence of suitable alkali cations.

Indacenodithiophene (IDT) is a major building block for the design of advanced functional π-conjugated polymers and nonfullerene electron-acceptor materials for organic photovoltaics. Preliminary results of a synthetic approach aiming at the modulation of the electronic properties of IDT-based acceptors by modification of the mode of linkage of the thiophene rings with the median phenyl ring are presented. The synthesis of three acceptor-donor-acceptor (A-D-A) structures corresponding to the different possible modes of thiophene-phenyl connection (1–3) is described and their electronic properties are discussed on the basis of the results of UV–Vis absorption spectroscopy, cyclic voltammetry and theoretical calculations.

The synthesis of a dyad involving a small arylamine-dicyanovinyl push-pull system as donor block and C60 fullerene as acceptor, connected by a flexible insulating linker formed by esterification of a β-hydroxymethylthiophene spacer is described. Unlike previously reported parent dyads with linkers connected at the 2-position of the thienyl spacer, this mode of connection allows the preservation of a free carbaldehyde group and thus the possibility to modulate the energy levels of the push-pull donor block. The electronic properties of the new dyad are analyzed by UV–Vis absorption spectroscopy, cyclic voltammetry, and theoretical calculations. A preliminary evaluation of this compound as active material for single-material organic solar cells is reported and discussed with reference to the mode of linkage of donor and C60 blocks.

We report herein our attempt to synthesize an analog of indacenedithiophene (IDT) based on a tetraphenylhexyl substituted, covalently bridged

The synthesis of a series of four donor-π-acceptor (D-π-A) compounds involving pyrene derivatized with hexylcyanoacetate acceptor groups connected by phenyl or thienyl π-conjugating spacers is described. The electronic properties are characterized by UV–Vis absorption spectroscopy, cyclic voltammetry theoretical calculations and solvatochromism experiments. The results indicate that the thienyl connectors leads to D-π-A systems with smaller optical gaps and stronger internal charge transfers attributed to the combined effects of the lower resonance energy of thiophene, the smaller twist angles between the pyrene block and the π-connector and the deformability of the thiophene ring.

The high-yield synthesis and the structural investigation of a new cryptand with C3 symmetry, exhibiting 2,4,6-triphenyl-1,3,5-triazine central units and pyridine-based bridges, are reported. The structure of the compound was investigated by single crystal X-ray diffractometry, NMR (nuclear magnetic resonance), HRMS (high resolution mass spectrometry) measurements, and theoretical calculations. The study of supramolecular behavior in solid state revealed the association of cryptand molecules by C-H---&pi, and &pi, &pi, contacts. Moreover, theoretical calculations indicated the high binding affinity of the cryptand for various organic molecules as guests.

International audience

International audience; Supramolecular assemblies of 2,7-dipyridylfluorene with diiodotetrafluorobenzene isomers were obtained by mechanochemical synthesis, and their structures were determined by single crystal X-ray diffraction. The contribution of specific noncovalent interactions between different building blocks to the stability and solid-state packing behaviors of the supramolecular catemers was evaluated by theoretical methods, which confirm the geometries and interactional bonding observed in single crystal X-ray diffraction structures.

The aromatic nucleophilic substitution reaction based synthesis of a three-armed cryptand displaying 2,4,6-triphenyl-1,3,5-triazine units as caps and pyridine rings in the bridges, along with NMR, MS and molecular modelling-based structural analysis of this compound are reported. Appropriate NMR and molecular modelling investigations proved the formation of 1:1 host–guest assemblies between the investigated cryptand and some polynuclear aromatic hydrocarbons or their derivatives.

Background High antimicrobial efficacy of short tryptophan-and arginine-rich peptides makes them good candidates in the fight against pathogens. Substitution of tryptophan and arginine by histidine could be used to modulate the peptides efficacy by optimizing their structures. Methods The peptide (RRWWRWWRR), reported to showed good antimicrobial efficacy, was used as template, seven new analogs being designed substituting tryptophan or arginine with histidine. The peptides' efficacy was tested against E. coli, B. subtilis and S. aureus. The cytotoxicity and hemolytic effect were evaluated and the therapeutic index was inferred for each peptide. Atomic force microscopy and molecular simulation were used to analyze the effects of peptides on bacterial membrane. Results The substitution of tryptophan by histidine proved to strongly modulate the antimicrobial activity, mainly by changing the peptide-to-membrane binding energy. The substitution of arginine has low effect on the antimicrobial efficacy. The presence of histidine residue reduced the cytotoxic and hemolytic activity of the peptides in some cases maintaining the same efficacy against bacteria. The peptides' antimicrobial activity was correlated to the 3D-hydrophobic moment and to a simple structure-based packing parameter. Conclusion The results show that some of these peptides have the potential to become good candidates to fight against bacteria. The substitution by histidine proved to fine tune the therapeutic index allowing the optimization of the peptide structure mainly by changing its binding energy and 3D-hydrophobic moment. General significance The short tryptophan reach peptides therapeutic index can be maximized using the histidine substitution to optimize their structure.

This work is focused on self-assembled monolayers (SAMs) fabrication, using two types of Au surfaces, by subsequent attachment of different layers in order to develop a stable platform consisting of covalent multilayer functionalized gold surfaces. The key step in the construction of SAMs is the covalent linkage to the gold surface, via an amino-thiol derivative, of a cyclooctyne unit exhibiting strained triple bonds which react fast (catalysts are not needed) and quantitatively with organic azides and enable the introduction of various chemical functionalized entities on the gold surface. The versatility of the system is demonstrated by the reaction of the cyclooctyne decorated gold surface with an azide functionalized terpyridine followed by step by step complexation with Fe(II) and another terpyridine unit resulting into a multilayer covered gold surface. The Au surfaces were characterized by XPS to determine the chemical composition of the resulting SAMs. SPR was applied for real-time monitoring of the molecular interactions that occurred on the Au surface for each deposited layer. DPN was used to direct pattern the terpyridine-ink on a pre-functionalized AuIDE electrode. The AFM topology resulted from DPN and PEIS demonstrated metal-coordinating ligand of Fe(II)-Terpy.

Two rigid tetrahedral organic linkers derived from adamantane have been employed in constructing a 3-D, 4-fold interpenetrated framework featuring a PtS topology, [CuL1(H2O)2](BF4)2·8H2O (1) (L1 = 1,3,5,7-tetrakis{4-(4-pyridyl)phenyl}adamantane), and a 2-fold interpenetrated grid-like coordination polymer, [Mn(hfac)2(L2)0.5] (2) (L2 = 1,3,5,7-tetrakis(4-cyanophenyl)adamantane).

The synthesis of two dyads involving small arylamine-based push-pull systems as donor block and C60 fullerene as acceptor connected by a flexible insulating linker formed by esterification is described. After analysis of their electronic properties by cyclic voltammetry and UV–Vis absorption spectroscopy, the potential of these molecules as active material for single-material organic solar cells has been evaluated in simple devices of direct structure. Both dyads lead to modest conversion efficiencies of ∼0.40% due essentially to poor fill factors. These results are discussed in terms of insufficient nano-phase separation of the donor and acceptor blocks and of fall of hole-mobility of the donor block consecutive to the linking to C60.

Single material organic solar cells (SMOSCs) are based on ambivalent materials containing electron donor (D) and acceptor (A) units capable to ensure the basic functions of light absorption, exciton dissociation, and charge transport. Compared to bicomponent bulk heterojunctions, SMOSCs present several major advantages such as considerable simplification of cell fabrication and a strong stabilization of the morphology of the D/A interface, and thus of the cell lifetime. In addition to these technical issues, SMOSCs pose fundamental questions regarding the possible formation, and dissociation of excitons on the same molecular D–A architecture. SMOSCs are developed with various approaches, namely “double‐cable” polymers, block copolymers, oligomers, and molecules that differ by the donor platform: polymer or molecule, the nature of A, the D–A connection, and the intra‐ and intermolecular interactions of D and A. Although for several years the maximum efficiency of SMOSCs has remained limited to 1.0–1.5%, impressive progress has been recently accomplished leading to SMOSCs with 4.0–5.0% efficiency. Here, recent advances in the synthesis of D–A materials for SMOSCs are presented in the broader context of the chemistry of organic photovoltaic materials in order to discuss possible directions for future research.

The synthesis, structure, and properties of crown ether macrocycles, cyclophanes, and cryptands exhibiting 1,3-dioxane are discussed. The role of the saturated heterocycles for the preorganization of the substrates and for the monitoring of the dynamics of these complex molecules is revealed.

New indeno[1,2-c]pyran-3-ones bearing different substituents at the pyran moiety were synthesized and their photophysical properties were investigated. In solution all compounds were found to be blue emitters and the trans isomers exhibited significantly higher fluorescence quantum yields (relative to 9,10-diphenylanthracene) as compared to the corresponding cis isomers. The solid-state fluorescence spectra revealed an important red shift of λmax due to intermolecular interactions in the lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra.

The adsorption of aqueous monuron and metals by coffee waste as a low-cost material is reported using batch experiments. Coffee waste with minimal processing and coffee waste pyrolyzed at 500°C were used for the adsorption of monuron. For metals, only the unpyrolyzed coffee waste was used. Monuron was determined by high-performance liquid chromatography with diode array detection, and metals were determined by inductively coupled plasma-mass spectrometry. The specific surface areas of the adsorbent materials were calculated using the Brunauer–Emmett–Teller equation. The removal rates of monuron and metals were determined quantitatively.

The formation of highly ordered supramolecular architectures via cooperative C(aliphatic)–H·anion contacts between β-HCH and various anions (Cl−, Br−, I− and HSO4−) was investigated by single crystal X-ray diffractometry, molecular modelling, ESI-MS and 1H-NMR titrations.

Cryptands with 2,4,6-triphenyl-1,3,5-triazine and/or 1,3,5-triphenylbenzene aromatic units and oligoethyleneoxide loops were synthesized in good yields, in a two-step procedure, by reacting the corresponding triphenols with ditosylated oligoethyleneglycols. The structures of the cryptands were elucidated by NMR spectroscopy and HRMS measurements. The complexation of aromatic diamines or alkali cation guests were investigated by NMR and ES(+)-MS experiments.

The CuAAC synthesis and the characterization of new rigid nucleobase-decorated tetrapodands exhibiting 1,3,5,7-tetraphenyladamantane and 9,9′-spirobifluorene central units are reported. 1,3,5,7-Tetraphenyladamantane and 3,3′,6,6′-tetrasubstituted 9,9′-spirobifluorene derivatives are tetrahedral building blocks, while the derivatives of 2,2′,7,7′-tetrasubstituted 9,9′-spirobifluorene can lead to 2D architectures.

Macrocycles emerged as an important class of useful compounds with multiple applications ranging from selective complexation of different anions, cations or neutral molecules to the development of new sensors, materials with improved properties and biologically active compounds. In this review we focus our discussion on the synthesis and structural analysis of macrocycles containing dibenzoheterocycles with sulphur and/or nitrogen atoms in the central six-membered ring (i.e. 10H-phenothiazine, 9,10-dihydroacridine or acridane, acridone, thianthrene, phenoxathiine, acridine, phenazine). We further highlight selected application of these compounds as host molecules, DNA intercalating agents or enzyme inhibitors.

Suzuki–Miyaura cross coupling reaction was used for access to new macrocycles exhibiting oligoethyleneoxide bridges and embedding bithiophene, terthiophene or 3,7-bis(thiophen-2-yl)-N-ethyl-10H-phenothiazine units. The synthesis was performed under various reaction conditions and different coupling types in order to establish the correlation between yields and employed solvents and bases. The structure of the compounds was supported by single crystal X-ray diffractometry, NMR, and MS experiments.

We describe herein the synthesis and characterization of new rigid nucleobase-decorated tripodands. The synthetic strategy involves the use of new azide functionalized nucleobases (adenine, thymine, and uracil). ES(+)-MS studies of hydrogen-bonding self-association as well as associations with complementary nucleosides are also reported.

A series of novel 2,5-disubstituted 1,3,4-oxadiazin-6-ones and their N-aroylhydrazone precursors were synthesized and characterized by NMR and UV–Vis spectroscopy. The electronic properties of 2-aryl-5-phenyl-1,3,4-oxadiazin-6-ones are mainly dependent on the 2-aryl substituent and their absorption maxima exhibit a red shift in dichloromethane. Single crystal X-ray diffraction on four acylhydrazones indicated the isolation of isomer with Z configuration of the C N double bond. Intermolecular interactions through strong H-bonding and C H⋯π contacts serve to link the molecules into a three-dimensional supramolecular network.

Cryptands with di-yne units were obtained in good yields by the acetylenic homocoupling reaction of tripodands possesing terminal ethynyl units on the pendant arms. The coupling reactions also led to isomeric bismacrocylic compounds, and the shifting of the process toward the products of intramolecular or intermolecular coupling reactions was influenced by the structure of tripodands and by the coupling reaction conditions.

Various cryptands based on 1,3-dioxane decorated 1,3,5-trisubstituted-benzene building blocks, connected by different chains (exhibiting ester, ether, or triazol groups) to several units with C3 symmetry, are reported. The structure of the compounds was investigated by single crystal X-ray diffraction, NMR, and MS. The role of the 1,3-dioxane units was targeted to ensure the preorganization of the substrate for the macrocyclization reactions on one side, and for easier NMR assignment of the structure of the cryptands on the other side.

The synthesis, structure, and properties of crown ether macrocycles, cyclophanes, and cryptands exhibiting 1,3-dioxane are discussed. The role of the saturated heterocycles for the preorganization of the substrates and for the monitoring of the dynamics of these complex molecules is revealed.