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This article is a part of a scientific project focused on obtaining a new type of composite materials that are characterized by singlet oxygen generation upon irradiation with red light, which can be used as antibacterial agents. The composite material is nanoscale graphite oxide (GO) particles covalently bonded to an axially substituted zirconium phthalocyanine complex. For this purpose, two phthalocyanine zirconium complexes, axially mono-substituted with 4-aminosalicylic or 4-aminophthalic acids, were prepared and measured in terms of structure, morphology, and spectroscopic properties. The zirconium phthalocyanines are photosensitizers, and the axial ligands are bridging links connecting the complexes to the GO carrier (due to their terminal amino groups and carboxyl groups, respectively). The axial ligand in zirconium phthalocyanine complexes has a strong influence on the stability and optical properties of composite materials and, consequently, on reactive oxygen species (ROS) generation. In this paper, the effect of composite components (4-aminophthalato or 4-aminosalicylato substituted zirconium phthalocyanine complex as a photosensitizer and graphite oxide as a carrier and modulator of the action of active components) on ROS generation for potential antibacterial use is discussed.

We present studies on bioactive silica-based glass nanoparticles showing photoluminescence. The sol–gel or solvothermal route was used for syntheses. Lanthanides, zinc oxide or phthalocyanine complexes ensured light emission. The structural, morphological, and optical properties were examined. During the bioactivity tests, when particles were immersed in SBF, ions release to the medium and hydroxyapatite formation were analyzed. Composites with graphite oxide were described as well. The systems are promissing for monitoring structural changes of the glass immersed in biological fluids, bioimaging or photodynamic therapy. Research was performed within Polish–Ukrainian Joint Exchange Project and NSC grants 2016/23/B/ST5/024830, 2016/22/E/ST5/00530.

Graphene oxide (GO) undergoes a rapid gelation process in the presence of ammonium hydroxide and formic acid at room temperature which is promoted by ultrasonication. Infrared and X-ray ph ...

In this work, the synthesis of a group of photoactive materials based on zirconium(IV) phthalocyanine out-of-plane substituted with two fragments of L-arginine is described. The studied group contained the phthalocyanine (Pc) complex, complex immobilized on graphite oxide (GO) flakes, composite of GO-Pc with silver nanoparticles, and GO-Pc being a component of dental filling cement. The structural, compositional, morphological, and optical properties of the materials were studied using, among others, scanning electron microscopy, X-ray diffractometry, and optical spectroscopies (UV–Vis absorption, FTIR, Raman, and photoluminescence). The photoactivity of all materials was confirmed when they were exposed to broadband red light, observed as reactive oxygen species generation that was the highest for the Pc complex, lower for the GO-Pc samples, and the lowest but still present, in the case of GO-Pc-modified cement. The bioactivity of the GO-Pc and GO-Pc-Ag samples was tested against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa) bacteria strains showing the highest action against S. aureus and a slight impact of the light irradiation. The comparison of cytotoxicity tests performed for GO-Pcs with Pc complexes substituted with different ligands showed that the GO with L-arginine derivative of PcZr had the lowest toxicity.

Two complexes of bis(aminobenzoato)zirconium(IV) phthalocyanine and their graphite oxide-based composites were synthesized and characterized in respect of their photochemical properties. Structures of phthalocyanines were confirmed by Mass and infrared spectroscopies. The absorption and photoluminescence spectra were investigated to show various behavior of the complexes in different media (dimethyl sulfoxide and saline). Optical technique (monitoring variation of absorption spectra of diphenylisobenzofuran used as an indicator) was used to prove the generation of reactive oxygen species (ROS) by under light irradiation in the range of the first biological window. The photoactivity of the materials was compared and discussed in terms of their potential ability to be used in biomedical applications, for example, as photosensitizers in photodynamic therapy.

In search of an effective antibacterial agent that is useful in photodynamic therapy, new derivatives of zirconium(IV) phthalocyanine (ZrPc) complexes were obtained and linked to graphite oxide flakes. In the syntheses of ZrPc derivatives, two bis-axially substituted ligands with terminal amino group and different lengths of linear carbon chain (C4 in 4-aminobutyric acid or C11 in 11-aminoundecanoic acid) were used. The optical properties (absorption and photoluminescence spectra) of ZrPcs and the composites were examined. Broadband red&ndash, near-infrared lamp was tested as an external stimulus to activate ZrPcs and the composites. Optical techniques were used to show generation of singlet oxygen during irradiation. Considering the application of graphite oxide-based materials as bacteriostatic photosensitive additives for endodontic treatment of periapical tissue inflammation, the antibacterial activity was determined on one Escherichia coli strain isolated directly from an infected root canal of a human tooth and one strain with silver and antibiotic resistance. Looking at the obtained results, modified levels of activity toward different bacterial strains are discussed.

A nanosilica-supported dual acidic ionic liquid on the basis of 1-methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate was synthesized and used as an efficient, green, non-corrosive, non-toxic, heterogeneous, and reusable catalyst for the synthesis of some new and known substituted flavanones. The synthesis was done by the condensation of 2'-hydroxyacetophenone with different aldehydes and the subsequent cyclization of the resulting 2'-hydroxychalcone in the presence of the catalyst. High yields of the products, short reaction times, and solvent-free conditions characterize this new method.

Two convenient green protocols for the synthesis of β-amino ketones have been developed which involve one-pot aza-Michael-type and Mannich-type reactions of a series of aldehydes, ketones, and amines in the presence of a catalytic amount of the magnetic solid sulfonic acid catalyst, Fe3O4@SiO2@Me&Et-PhSO3H, at room temperature. The catalyst can be reused four times without loss of activity.

An acidic nanocatalyst SBA-15-SO3H with a high surface area and high acid content was readily synthesized, characterized, and effectively used in the synthesis of some new and known pyrido[2,3-d:6,5-d′]dipyrimidine derivatives by condensation reaction of 6-aminouracil and different aldehydes under solvent-free conditions. The catalyst was reused for 6 runs without significant loss of its activity. Short reaction times, high yield of the products, solvent-free conditions, and use of a robust and reusable catalyst are worthwhile advantages of the present method.

Generally ionic liquids have gained increasing attention in organic synthesis as catalyst and solvent. However, there are some drawbacks, including the difficulties in the product purification, ionic liquid recycling, and use of excess amounts of the expensive ionic liquid when the ionic liquid is used in the organic reactions. In addition, the high viscosity of ionic liquids can lead to mass transfer limitations in fast chemical reactions. These problems can be overcome by the use of supported ionic liquid phases. In this article, a simple, efficient and green method has been developed for the synthesis of bisphenolic antioxidants by the reaction of 2-tert-butyl-4-methylphenol and aldehydes in the presence of nanosilica supported dual acidic ionic liquid (NSSDAIL) as robust and reusable catalyst under solvent-free conditions. Three different NSSDAILs were synthesized and characterized using SEM, BET, IR, and XRD techniques. High yields of the products, short reaction times, use of a non corrosive, non to...

New β-acetamido ketone derivatives are synthesized through a one-pot, four-component reaction of benzaldehyde, dimedone, acetyl chloride, and acetonitrile in the presence of cellulose sulfuric acid as an efficient reusable catalyst. The procedure offers advantages in terms of good yields, short reaction times, mild reaction conditions, and reusability of the catalyst.

1,8-Dioxo-octahydroxanthenes have been synthesized good yields via a reaction of aldehydes and dimedone in the presence of cellulose sulfonic acid as a heterogeneous catalyst under solvent-free condition.

A nanosilica-supported dual acidic ionic liquid on the basis of 1-methyl-3-(4-sulfobutyl)imidazolium hydrogen sulfate was synthesized and used as an efficient, green, non-corrosive, non-toxic, heterogeneous, and reusable catalyst for the synthesis of some new and known substituted flavanones. The synthesis was done by the condensation of 2'-hydroxyacetophenone with different aldehydes and the subsequent cyclization of the resulting 2'-hydroxychalcone in the presence of the catalyst. High yields of the products, short reaction times, and solvent-free conditions characterize this new method.

Two convenient green protocols for the synthesis of β-amino ketones have been developed which involve one-pot aza-Michael-type and Mannich-type reactions of a series of aldehydes, ketones, and amines in the presence of a catalytic amount of the magnetic solid sulfonic acid catalyst, Fe3O4@SiO2@Me&Et-PhSO3H, at room temperature. The catalyst can be reused four times without loss of activity.

3,4,6-Trisubstituted 2-pyridone derivatives have been synthesized in good to excellent yields through a condensation reaction of various 1,3-diketones with amides in the presence of 1,4-Diaza-bicyclo[2,2,2]octane (DABCO) at reflux temperature.

New β-acetamido ketone derivatives are synthesized through a one-pot, four-component reaction of benzaldehyde, dimedone, acetyl chloride, and acetonitrile in the presence of cellulose sulfuric acid as an efficient reusable catalyst. The procedure offers advantages in terms of good yields, short reaction times, mild reaction conditions, and reusability of the catalyst.

DABCO is shown to be an efficient catalyst for the synthesis of pyridone derivatives of type (III) or (V) from 1,3-diketones and amides.