Elaboration of a convenient route towards donor-substituted pyrazoles from heteropropargyl precursors is challenging due to a number of thermodynamically favorable side reactions (e.g., ...acetylene-allene isomerization and Glaser homocoupling). In this work, Sonogashira cross-coupling conditions of 4-
-butylphenyl propargyl ether with benzoyl chloride followed by tandem Michael addition/cyclocondensation with hydrazine into 3,5-disubstituted pyrazole (kinetic control), as well as cycloisomerization conditions of ketoacetylene intermediate into 2,5-disubstituted furan (thermodynamic control), were established through a variation of the catalyst loading, solvent polarity, excess of triethylamine, and time of reaction. During the optimization of process parameters, a number of by-products represented by a monophosphine binuclear complex (PPh
PdI
)
with two bridging iodine atoms and diyne were identified and isolated in the pure form. The quantum-chemical calculations and solution-state
H/
C NMR spectroscopy suggested that the 5(3)-(4-
-butylphenyloxy)methoxy-3(5)-phenyl-1
-pyrazole exists in the tautomeric equilibrium in a polar methanol solvent and that individual tautomers could be characterized in case aprotic solvents employed. The pyrazole features a unique tetramer motif in the crystal phase formed by alternating 3(5)-phenyl-1
-pyrazole tautomers, which was stabilized by N-H···N bonds and stacking interactions of pyrazole rings, whereas pyrazole dimers were identified in the gas phase.
A series of four new Dy12 dodecanuclear clusters based on azobenzene derivative ligands of salicylic acid (L1–L4) has been synthesized and characterized in the crystalline phase using X-ray ...diffraction on single crystal and powder, IR spectroscopy, elemental analysis, and DSC–TGA methods. It was revealed that all obtained clusters exhibit the formation of the similar metallic cluster nodes, as vertex-sharing heterocubanes, obtained from four Dy3+ cations, three bridging hydroxyl groups, and O atoms from the salicylic ligands. The coordination geometry around the Dy(III) centers has been carefully analyzed. Whereas Dy12-L1 and Dy12-L2 with L1 and L2 containing Me and OMe groups in para positions of the phenyl rings, respectively, form similar porous 3D diamond-like molecular networks due to CH−π interactions, for Dy12-L3 with L3 bearing NO2-electron-withdrawing group, the generation of 2D molecular grids assembled by π–π staking is observed, and for Dy12-L4 with L4 bearing phenyl substituent, 3D hexagonal channels have been generated. The complexes Dy12-L1, Dy12-L2, and Dy12-L3 exhibit a zero-field slow magnetic relaxation effect. After UV irradiation of Dy12-L1, a decrease of the magnetic anisotropy energy barrier displaying the possibility of control over magnetic properties by the external stimulus has been observed.
New fluorescent systems for photocatalysis, sensors, labeling, etc., are in great demand. Amphiphilic ones are of special interest since they can form functional colloidal systems that can be used in ...aqueous solutions. A new macrocycle platform for click chemistry and its adduct with o-propargylfluoresceine was synthesized and characterized using modern physical techniques. Nanosized solid lipid nanoparticles (SLNs) from the calixarene-fluoresceine adduct were synthesized through the solvent injection technique and well-characterized in the solution and in solid state using light-scattering and microscopy methods. The maximum fluorescence intensity of the SLNs was found to be in the pH range from 7 to 10. The Förster resonance energy transfer (FRET) efficiency from SLNs to rhodamine 6g was found to be 97.8%. Finally, pure SLNs and the FRET system SLNs-Rh6G were tested in model photocatalytic ipso oxidative hydroxylation of phenylboronic acid under blue LED light. The SLNs-Rh6G system was found to be the best, giving an almost qualitative phenol yield, which was shown by HPLC-UV analysis.
A series of new 2-hydroxy-3-methoxybenzylidenethiazolo3,2-
pyrimidines with different aryl substituents at the 5 position are synthesized and characterized by
H/
C NMR and IR-spectroscopy and ...mass-spectrometry, as well as single crystal X-ray diffraction (SCXRD). It was demonstrated that the type of hydrogen bonding can play a key role in the chiral discrimination of these compounds in the crystalline phase. The hydrogen bond of the O-H...N type leads to 1D supramolecular heterochiral chains or conglomerate crystallization in the case of the formation of homochiral chains. The hydrogen bond of O-H...O type gave racemic dimers, which are packed into 2D supramolecular layers with a parallel or angular dimers arrangement. Halogen bonding of the N...Br or O...Br type brings a new motif into supramolecular self-assembly in the crystalline phase: the formation of 1D supramolecular homochiral chains instead 2D supramolecular layers. The study of cytotoxicity against various tumor cells in vitro was carried out. It was found that 2-hydroxy-3-methoxybenzylidenethiazolo3,2-
pyrimidines with 3-nitrophenyl substituent at C5 carbon atom demonstrated a high efficiency against M-HeLa (cervical adenocarcinoma) and low cytotoxicity against normal liver cells.
A series of new thiazolo3,2-
pyrimidines different by aryl substituents in 2 and 5 positions are synthesized and characterized in solution as well as in the crystalline phase using
H and
C NMR-, ...IR-spectroscopies, mass-spectrometry methods, and single crystal X-ray diffraction (SCXRD). The SCXRD study revealed the role of intermolecular H-bonding in the formation of supramolecular architectures (racemic monomers, centrosymmetric racematic dimers, or homochiral 1D chains) of obtained thiazolo3,2-
pyrimidines derivatives depending on solvents (aprotic DMSO or protic EtOH) used upon the crystallization process. Moreover, the in vitro study of cytotoxicity toward different tumor cells showed their high or moderate efficiency with moderate cytotoxicity against normal liver cells which allows to consider the obtained thiazolo3,2-
pyrimidine derivatives as promising candidates for application as antitumor agents.
Three zinc-based coordination complexes were selectively generated in the crystalline phase using a new flexible molecular "tweezers" calix4arene derivative ligand decorated with two appended ...carboxylic moieties and benzyl spacers (
3
-4H). Through the control of the metal/ligand ratio and the synthetic conditions, the coordination sphere around the zinc cations was found to be different, which influenced the nuclearity of the obtained complexes. The mononuclear complex (
3
-3H)
2
-Zn(DMF)
2
was obtained, while two partially deprotonated ligands (
3
-3H)
−
cap the metallic cation, leading to a nontubular "8"-shaped structure with a metal/ligand ratio equal to 1/2. The dinuclear (
3
-2H)
2
-Zn
2
py
4
complex displays a tubular structure with a metal/ligand ratio equal to 1/1, where two zinc cations act as a linear metal linker between two (
3
-2H)
2−
species, which adopts a cone conformation. Finally, the third trinuclear coordination complex (
3
-2H)
4
-Zn
3
(OH
2
) was obtained using (
3
-4H) and the highly coordinating sulfonylcalix4arene (
4
-4H), exhibiting a 3/1/1 metal/
3
/
4
ratio. Thus, it has been demonstrated that under self-assembly conditions, the nuclearity of the new complexes based on zinc cations and calix4arene dicarboxylate (
3
-4H) can be tuned using different synthetic conditions: nature of solvent, crystallization method, use of a highly coordinating ligand (
4
-4H).
Three zinc-based coordination complexes were selectively generated in the crystalline phase using a new flexible molecular "tweezers" calix4arene derivative ligand decorated with two appended carboxylic moieties and benzyl spacers ((
3
-4H)).
1st generation dendrimers containing polar hydroxyl and both 1st and 2nd generation dendrimers with oxyethyl groups were obtained using a convergent approach and CuAAC reaction. Three types of ...dendrimer nuclei were utilized: the macrocyclic nucleus of calix4arene bearing 2/4 dendron and 2/4 alkyl fragments and the non-macrocyclic analog of calixarene bearing a one dendron/alkyl fragment. Nanoparticle tracking analysis reveals self-organization of the obtained dendrimers in aqueous solution into submicron/nanoparticles with sizes of 80–250 nm. The lowest CAC values in the series are possessed by tetra-alkyl substituted calix4arenes (1.6–1.8 μM), while the low molecular weight analog of calixarenes possesses a CAC one to two orders of magnitude larger (44–350 μM). When the obtained dendrimers were used as stabilizers of palladium nanoparticles, the formation of spherical palladium nanodendrites (50–60 nm) consisting of metal Pd and PdO was determined using TEM and SAED. The micellar effect of using stabilized palladium particles with dendrimers at concentrations higher than their CAC in the catalysis of Suzuki reactions and nitro aromatics reduction is shown. In the p -nitrophenol reduction reaction, the catalytic activity of the obtained systems (the maximum k app in series was 0.47 min −1 ) exceeds many known Pd-based systems.
A series of new manganese complexes of general formula 32-Mn4Xn, displaying a highly-reproducible MnII2MnIII2 cluster core formation, was observed when tetra-
p
-adamantylcalix4arene 3 was used in ...combination with N,N′-chelating auxiliary ligands, such as bipy (32-Mn4(bipy)2, bipy = 2,2′-bipyridyl) and phen (32-Mn4(phen)2, phen = 1,10-phenanthroline), as well as with DMF/H
2
O solvent molecules (32-Mn4(dmf)4, 32-Mn4(dmf)2(H2O)2), acting as O-donor coligands, in the crystalline phase. Single-crystal X-ray diffraction revealed that the involvement of auxiliary ligands in coordination with Mn-ions results in the distortion of their coordination sphere and leads to the controlled compression of the {Mn
4
}-cluster core of complexes. Moreover, the appearance of adamantyl groups at the upper rim of the macrocyclic backbone of 3 influences the crystalline self-assembly of obtained clusters, providing a preferable “side-to-head” orientation of the cluster molecules within the crystal, leading to the observation of relatively higher {Mn
4
}⋯{Mn
4
} distances than those revealed for the earlier reported calix4arene supported {Mn
4
} clusters. All 32-Mn4Xn clusters demonstrated ferromagnetic interactions between the metal atoms within the cluster core independent of the nature of the O-donor or N-donor auxiliary ligands.
Giant octahedral M
coordination cages were prepared
self-assembly of sulfonylcalix4arene-supported tetranuclear M(II) clusters (M = Co, Ni) with hybrid linker based on tris(dipyrrinato)cobalt(III) ...complexes appended with peripherical carboxylic groups. Due to intrinsic and extrinsic porosity, the obtained solid-state supramolecular architectures demonstrated good performance as adsorbents for the separation of industrially important gases mixtures.
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