Determination of molar ratio of primary secondary and tertiary amines in polymers by applying derivatization and NMR spectroscopy

Liu, Qing; Zhu, Marcel

doi:10.1016/j.polymertesting.2016.10.013

Cited by 17 publications

(4 citation statements)

References 15 publications

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“…The content of grafted units was calculated from 1 H NMR spectra (Figure S3) of TFA-derivatized samples dissolved in DMSO-d 6 [39]. The integral intensities of the 1H NMR signal at 10.4 ppm (protons at tertiary nitrogen atoms) were compared with the integral intensities of the all C-H protons within 0.8–4.6 ppm except for those of DMSO, keeping in mind the average length of the grafted oligoamines.…”

Section: Methodsmentioning

confidence: 99%

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

et al. 2018

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Amine containing polymers are extensively studied as special carriers for short-chain RNA (13–25 nucleotides), which are applied as gene silencing agents in gene therapy of various diseases including cancer. Elaboration of the oligonucleotide carriers requires knowledge about peculiarities of the oligonucleotide–polymeric amine interaction. The critical length of the interacting chains is an important parameter which allows us to design sophisticated constructions containing oligonucleotide binding segments, solubilizing, protective and aiming parts. We studied interactions of (TCAG)n, n = 1–6 DNA oligonucleotides with polyethylenimine and poly(N-(3-((3-(dimethylamino)propyl)(methyl)amino)propyl)-N-methylacrylamide). The critical length for oligonucleotides in interaction with polymeric amines is 8–12 units and complexation at these length can be accompanied by “all-or-nothing” effects. New dimethylacrylamide based polymers with grafted polyamine chains were obtained and studied in complexation with DNA and RNA oligonucleotides. The most effective interaction and transfection activity into A549 cancer cells and silencing efficiency against vascular endothelial growth factor (VEGF) was found for a sample with average number of nitrogens in polyamine chain equal to 27, i.e., for a sample in which all grafted chains are longer than the critical length for polymeric amine–oligonucleotide complexation.

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Section: Methodsmentioning

confidence: 99%

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

et al. 2018

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“…It shows downfield signals at 9.050–9.135 ppm due to the secondary amine –NH group present in the dye. 39 A sharp downfield singlet is also observed at 6.826 ppm, which corresponds to the hydroxyl (–OH) group bonded to the naphthalene ring present in the structure. 40 The compound spectrum also shows multiplet signals in the 7.488–8.527 ppm range due to aromatic protons.…”

Section: Resultsmentioning

confidence: 99%

“…5. The spectrum showed downfield signals at 9.050-9.135 ppm due to de-shielded protons of the secondary amine -NH group present in the dye (Liu and Zhu 2016). A sharp downfield singlet is also observed at 6.826 ppm which corresponds to the -OH group bonded to the naphthalene ring present in the structure (Zhao et al 2011).…”

Section: H 1 -Nmr and C 13 -Nmr Analysismentioning

confidence: 95%

Development of functional cotton fabric by simultaneous dyeing and finishing with a novel bioactive reactive dye

et al. 2023

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“…The approximate chemical ratio of primary and secondary amines, as shown in Figure 2b, was calculated using the resulting 1 H NMR data. [47] Notably, at first, isocyanates exhibited higher reactivity toward primary amines than to secondary amines, initiating the reaction for u-PEI10. Subsequent reactions involved more secondary amines, ultimately resulting in a complete reaction with u-PEI30.…”

Section: Resultsmentioning

confidence: 99%

Bifunctional Urea–Polyethyleneimine‐Mediated Surface Engineering in SnO₂ Electron‐Transport Layer for Efficient and Stable Organic Solar Cells

Kim,

Lee,

et al. 2024

Solar RRL

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Because of its high conductivity, wide bandgap, and excellent photostability, tin oxide (SnO2) has long been recognized as an electron transport layer (ETL) in organic solar cells (OSCs). However, the energy‐level mismatch between the work function (WF) of SnO2 and the lowest unoccupied molecular orbital level of Y‐series non‐fullerene acceptors (NFAs), along with the abundance of surface defects on SnO2, have limited its widespread application as ETLs in OSCs. Herein, we introduce a novel approach utilizing urea‐functionalized polyethyleneimine (PEI) materials called u‐PEIs for modifying SnO2. This modification, which serves dual purposes of WF modulation and surface‐defect passivation, can mitigate the energy barriers of SnO2/Y‐series NFA and increase the conductivity of the SnO2 film. PM6:Y6‐based OSCs with u‐PEI‐modified SnO2 (SnO2:u‐PEI) ETLs exhibited a remarkable efficiency of 16%, which significantly exceeded that (13.5%) achieved with bare SnO2‐based OSCs, along with outstanding photo‐ and thermal‐ stability. This study confirms the efficacy of urea‐functionalized PEI for efficient and stable OCSs, paving the way for SnO2 applications.This article is protected by copyright. All rights reserved.

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Determination of molar ratio of primary secondary and tertiary amines in polymers by applying derivatization and NMR spectroscopy

Cited by 17 publications

References 15 publications

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

Development of functional cotton fabric by simultaneous dyeing and finishing with a novel bioactive reactive dye

Bifunctional Urea–Polyethyleneimine‐Mediated Surface Engineering in SnO₂ Electron‐Transport Layer for Efficient and Stable Organic Solar Cells

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Determination of molar ratio of primary secondary and tertiary amines in polymers by applying derivatization and NMR spectroscopy

Cited by 17 publications

References 15 publications

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

Design of Oligonucleotide Carriers: Importance of Polyamine Chain Length

Development of functional cotton fabric by simultaneous dyeing and finishing with a novel bioactive reactive dye

Bifunctional Urea–Polyethyleneimine‐Mediated Surface Engineering in SnO2 Electron‐Transport Layer for Efficient and Stable Organic Solar Cells

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Bifunctional Urea–Polyethyleneimine‐Mediated Surface Engineering in SnO₂ Electron‐Transport Layer for Efficient and Stable Organic Solar Cells