Click derived organosilane assembled with nano platform for the detection of Cu2+ ions: Biological evaluation and molecular docking approach

Metal ions have active roles in biochemical, industrial, and environmental processes. The design and development of new rapid sensing materials with advanced reasonable, compelling, and convenient, techniques are urgent. Here in this work, we design and develop sensor with the facile amalgamation of the pyrene-based organosilane (5) through a click silylation approach silicon composite for selective detection of Cu²⁺ ions. Physicochemical and keen methods are employed to perceive the resultant hybrid nanoparticles (H-NPs), and these nanocomposites similarly displayed a strong affection for Cu²⁺ ions. In addition, the identification restrictions while utilizing 5 and H-NP's towards Cu²⁺ found in this study are far lower than the WHO rules for drinking water. Further, organosilane (5) shows good antibacterial and antioxidant activity. The antibacterial effects of triazole-based organosilane (5), are evaluated with a molecular docking study with Escherichia coli (IJZQ) was conducted. The selected ligand was revealed to have a reasonable docking score with a binding energy of -8.40 kcal mol^-1.

Development of piperazine conjoined 1,2,3-triazolyl-γ-propyltriethoxysilanes: Fluorometric detection of Cr3+ ions and computational study

Chromium is essential for some biochemical processes, and excess is a big concern that shows adverse effects on human health and the environment. Therefore, it is urgent to design new sensors to detect chromium ions rapidly. The present study discusses the synthesis of piperazine conjoined 1,2,3-triazolyl-γ-propyltriethoxysilanes (4a-4b) and development of 4a as fluorescence turn-on sensor for the detection of Cr³⁺ ions. The mechanistic insights reveal to the restricted CN rotation and inhibited intramolecular charge transfer (ICT) process. In addition, Job's plot and Benesi-Hildebrand plot justify the 1:1 binding affinity with a binding constant of 9.96 × 10⁵ M^-1 for [ligand 4a + Cr³⁺] complex and the limit of detection for Cr³⁺ ions is observed as 6.06 × 10^-8 M. The fluorescence spectral changes, ¹H NMR spectra and DFT studies provide evidences for ligand 4a and Cr³⁺ ions interactions. Further, the reversibility of the ligand 4a from [ligand 4a + Cr³⁺] complex on the addition of EDTA can be used in the construction of molecular logic gate where Cr³⁺ and EDTA are considered as inputs and the fluorescence intensity at 398 nm as output. Further, compounds 4a-4b were then evaluated for their antibacterial activity against bacterial strains (Escherichia coliand Staphylococcus aureus), revealing a modest activity. The binding mode of ligand 4a to Staphylococcus aureus (PDB ID - 3U2K) and Escherichia coli (PDB ID - 5Z4O) was investigated using an in-silico molecular docking technique, which revealed that the triazole ring and silanyl group are involved in hydrogen bonding with proteins and may be the cause of the ligand's antibacterial activity. The ligand 4a demonstrated a high affinity for binding within the active sites of proteins with binding energies of -7.97 kcal/mol (3U2K) and -8.68 kcal/mol (5Z4O).

Copper(II) Ion Promoted Reverse Solvatochromic Response of the Silatrane Probe to Spectral Shifts: Preferential Solvation and Computational Approach

The unique solvatochromic attitude of an analyte owing to its coordination with metal ions in solvents of different polarities is challenging. Herein, we introduce two new solvatochromic 4-(pentan-3-yl) benzaldehyde-based triazolyl silatrane probes (5 and 6). The solvatochromic behavior of both probes 5 and 6 was studied using Reichardt's E (30) and the Kamlet-Taft empirical scale by UV-visible spectra in 14 solvents (hydrogen-bond donor (HBD) and non-HBD), and the results show that probes 5 and 6 exhibit reverse solvatochromism. Probe 5 witnessed an enhancement in this behavior upon coordination with the Cu²⁺ ion in MeCN/MeOH solvents due to the intramolecular charge transfer (ICT) process. Interestingly, the binding of probe 5 with Cu²⁺ ions resulted in an instant color change in MeCN and MeOH from pale yellow to light blue and brown-red, respectively, which can be easily detected by the "naked eye". A solvatochromic study of the complex 5-Cu²⁺ in binary mixtures of polar aprotic and polar protic solvents (MeCN/MeOH) discloses that the latter are more preferred over polar aprotic solvents in the solvation microsphere. The entire metal coordination process of probe 5 toward the Cu²⁺ ion can be visualized and was further evaluated by UV-vis/fluorescence spectral titrations, Fourier transform infrared (FT-IR) spectroscopy, and theoretical calculations employing density functional theory (DFT) and time-dependent-DFT (TD-DFT). The proposed analytical approach is believed to play a crucial role in the solvatochromic study of higher coordinated silicon compounds, which may be utilized to develop a solvent-dependent sensor.

Synthesis and X-ray characterization of antipyrine-tethered organosilanes and their magnetic nanoparticles: potent anti-oxidants and receptors for Sn(ii) ions

This study focuses on the synthesis and X-ray characterization of antipyrine-tethered organosilanes for their potential applications in the fields of material science, pharmaceuticals and chemosensing.

Kinetic investigation of the cyclopropanation process of fullerene C60 by halogenmethyl ketones under the conditions of the Bingel reaction

The kinetics of the Bingel reaction with halogenmethyl ketones and C₆₀ fullerene has been studied in streaming mode by sampling the reaction mixture at different time intervals and separating the components using HPLC.

First report of silver ion recognition via a silatrane-based receptor: excellent selectivity, low detection limit and good applicability

This study involves the synthesis of a silatrane-based receptor using Knoevenagel condensation and click chemistry approach for the recognition of silver ions in aqueous solution.

A strategic approach to the synthesis of ferrocene appended chalcone linked triazole allied organosilatranes: Antibacterial, antifungal, antiparasitic and antioxidant studies

A series of ferrocene appended chalcone allied triazole coupled organosilatranes (FCTSa 7-FCTSa 12) were synthesised with the aim of amalgamating the pharmacological action of the constituting moieties into a single molecular scaffold. All the synthesised silatranes were well characterized by various spectroscopic techniques like IR, ¹H NMR, ¹³C NMR and elemental analysis. Organosilatranes were then evaluated for their biological alacrity against bacterial and fungal strains compared with the standard drugs Rifampicin and Amphotericin B respectively. The ferrocene conjugates were found to be only moderately effective against the tested microbes. However, the organosilatranes conceded excellent efficacy against parasite G. lamblia with FCTSa 11 arraying the leading results. On the other hand against another parasite T. vaginalis, FCTSa 8 has emerged as an outstanding composite. Further, Total Antioxidant Assay (TAA) with 2,2'-azino-bis-3-(ethylbenzothiazoline-6-sulphonic acid) revealed FCTSa 10 to be the best claimant for radical scavenging activity. Along these lines, introducing some different substituents in the synthesised hybrids may act as a useful strategy for increasing the biological profile of the drugs.

Role of alkyl silatranes as plant growth regulators: comparative substitution effect on root and shoot development of wheat and maize

BACKGROUND

The present investigation reports the stimulating effects of different substituted alkyl silatranes (3a-3e) on the early seedling growth of wheat (Triticum aestivum) and maize (Zea mays). Seeds of these plants were exposed to six different concentrations (0, 10, 50, 100, 200 and 500 µmol L^-1 ). The results revealed that different substitutions (3a-3e) had different effects on root and shoot elongation. Silatranes (3a-3e) were synthesized employing microwave irradiation by a solvent-mediated transesterification reaction, thereby reducing reaction times from several hours under conventional reflux conditions to 15 min under microwave irradiation.

RESULTS

It was of interest that the effect of these silatranes did not show a dose-dependent relationship but an optimum concentration, which was 100 µmol L^-1 for maize and 200 µmol L^-1 for wheat. γ-Aminopropyl silatranes (3b and 3e) gave the best results in maize, whereas γ-chloropropyl silatrane (3a) was most efficient for wheat at these optimum concentrations.

CONCLUSION

All the synthesized silatranes were effective in promoting root and shoot growth of wheat and maize. Furthermore, an efficient green microwave methodology was successful for the synthesis of silatranes. These observations pave the way for silatranes as efficient plant growth regulators for crops. © 2018 Society of Chemical Industry.

Chalcone scaffolds as photofunctional hybrid material of indolin-2-one-functionalized siloxy framework for optical sensing of Cu2+

The present article is about the synthesis of an indolin-2-one chalcone-based photofunctional hybrid for the selective and sensitive detection of Cu²⁺.

Molecular keypad controlled circuit for Ce(iii) and NO3− ions recognition by μw synthesized silicon-embedded organic luminescent sensor

This report demonstrates the mimicking of an electronic circuit diagram towards Ce(iii) ion sensing response supported by molecular keypads. The probe naphthyl based triazole linked silatrane (NTS) was efficiently synthesized using a series of microwave mediated reactions. The luminescent sensor NTS was explored for the ion sensing response towards Ce(iii) ions using DMSO and DMSO : H₂O 4 : 1 (v/v) as solvent media, respectively. The role of water in Ce(iii) ion sensing was detected as ‘turn-off’ response that contradicts the ‘turn-on’ with DMSO. Further, the sensing of NO₃⁻ ions by NTS–Ce(iii) ensemble was associated with blue shift on absorption maxima. These mimicking response studies were sketched as circuit diagrams assisted by molecular keypad behaviour as IMPLICATION output logic gate.

This report demonstrates the mimicking of an electronic circuit diagram towards Ce(iii) ion sensing response supported by molecular keypads.

Heteroaryl chalcone allied triazole conjugated organosilatranes: synthesis, spectral analysis, antimicrobial screening, photophysical and theoretical investigations

A series of heteroaryl tethered triazole conjoined organosilatranes were synthesized and studied for their solvatochromism experimentally and theoretically followed by antimicrobial screening.

Chalcomer assembly of optical chemosensors for selective Cu2+ and Ni2+ ion recognition

The o-, m- and p-isomeric units of chalconyl triazole-based, caged organosilicon complexes were efficiently synthesized and explored for their cationic chemosensing activities.

Synthetic approach towards ‘click’ modified chalcone based organotriethoxysilanes; UV-Vis study

The efficient linkage of a conjugate chalcone to n-propyltriethoxysilanes via a 1,2,3-triazole is reported. The synthesis involves a Claisen–Schmidt condensation followed by a copper(i) catalyzed azide–alkyne cycloaddition (CuAAC) reaction.

Discrete complexes immobilized onto click-SBA-15 silica: controllable loadings and the impact of surface coverage on catalysis

Azidopropyl functionalized mesoporous silica SBA-15 were prepared with variable azide loadings of 0.03-0.7 mmol g(-1) (~2-50% of maximal surface coverage) through a direct synthesis, co-condensation approach. These materials are functionalized selectively with ethynylated organic moieties through a copper-catalyzed azide alkyne cycloaddition (CuAAC) or "click" reaction. Specific loading within a material can be regulated by either the azide loading or limiting the alkyne reagent relative to the azide loading. The immobilization of ferrocene, pyrene, tris(pyridylmethyl)amine (TPA), and iron porphyrin (FeTPP) demonstrates the robust nature and reproducibility of this two-step synthetic attachment strategy. Loading-sensitive pyrene fluorescence correlates with a theoretically random surface distribution, rather than a uniform one; site-isolation of tethered moieties ~15 Å in length occurs at loadings less than 0.02 mmol g(-1). The effect of surface loading on reactivity is observed in the oxygenation of SBA-15-[Cu(I)(TPA)]. SBA-15-[Mn(II)(TPA)]-catalyzed epoxidation exhibits a systematic dependence on surface loading. A comparison of homogeneous, site-isolated and site-dense complexes provides insight into catalyst speciation and ligand activity.

Deposition of dense siloxane monolayers from water and trimethoxyorganosilane vapor

A convenient, laboratory-scale method for the vapor deposition of dense siloxane monolayers onto oxide substrates was demonstrated. This method was studied and optimized at 110 °C under reduced pressure with the vapor of tetradecyltris(deuteromethoxy)silane, (CD(3)O)(3)Si(CH(2))(13)CH(3), and water from the dehydration of MgSO(4)·7H(2)O. Ellipsometric thicknesses, water contact angles, Fourier transform infrared (FTIR) spectroscopy, and electrochemical capacitance measurements were used to probe monolayer densification. The CD(3) stretching mode in the FTIR spectrum was monitored as a function of the deposition time and amounts of silane and water reactants. This method probed the unhydrolyzed methoxy groups on adsorbed silanes. Excess silane and water were necessary to achieve dense, completely hydrolyzed monolayers. In the presence of sufficient silane, an excess of water above the calculated stoichiometric amount was necessary to hydrolyze all methoxy groups and achieve dense monolayers. The excess water was partially attributed to the reversibility of the hydrolysis of the methoxy groups.