Aminoalkyl-H-phosphinic acids, also called aminoalkylphosphonous acids, are investigated as biologically active analogues of carboxylic amino acids and/or as valuable intermediates for synthesis of other aminoalkylphosphorus acids. Their synthesis has been mostly accomplished by phospha-Mannich reaction of a P-H precursor, an aldehyde and an amine. The reaction is rarely clean and high-yielding. Here, reaction of H3PO2 with secondary amines and formaldehyde in wet AcOH led to aminomethyl-H-phosphinic acids in nearly quantitative yields and with almost no by-products. Surprisingly, the reaction outcome depended on the basicity of the amines. Amines with pK a > 7-8 gave the desired products. For less basic amines, reductive N-methylation coupled with oxidation of H3PO2 to H3PO3 became a relevant side reaction. Primary amines reacted less clearly and amino-bis(methyl-H-phosphinic acids) were obtained only for very basic amines. Reaction yields with higher aldehydes were lower. Unique carboxylic-phosphinic-phosphonic acids as well as poly(H-phosphinic acids) derived from polyamines were obtained. Synthetic usefulness of the aminoalkyl-H-phosphinic was illustrated in P-H bond oxidation and its addition to double bonds, and in selective amine deprotection. Compounds with an ethylene-diamine fragment, e.g. most common polyazamacrocycles, are not suitable substrates. The X-ray solid-state structures of seventeen aminoalkyl-phosphinic acids were determined. In the reaction mechanism, N-hydroxyalkyl species R2NCH2OH and [R2N(CH2OH)2]+, probably stabilized as acetate esters, are suggested as the reactive intermediates. This mechanism is an alternative one to the known phospha-Mannich reaction mechanisms. The conditions can be utilized in syntheses of various aminoalkylphosphorus compounds.

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• časopisecké články MeSH

Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments. Our experimental data are reproduced by numerical simulations of the NV spin interaction with gadolinium complexes covering the NDs. Considering the versatile engineering options provided by polymer chemistry, the underlying mechanism can be expanded to detect a variety of physiologically relevant species and variables.

• MeSH
• biosenzitivní techniky metody   MeSH
• časové faktory MeSH
• koncentrace vodíkových iontů MeSH
• konfokální mikroskopie MeSH
• kvantová teorie MeSH
• nanodiamanty chemie   ultrastruktura   MeSH
• nanotechnologie metody   MeSH
• optické zobrazování metody   MeSH
• oxidace-redukce MeSH
• reprodukovatelnost výsledků MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nanodiamanty MeSH

The luminescence lifetimes of europium(III) complexes with new monophosphorus acid derivatives of H(4)dota were measured by means of time-resolved laser-induced luminescence spectroscopy in H(2)O and D(2)O. The hydration numbers of these complexes were estimated using different empirical equations [Horrocks and Sudnick (1979) J. Am. Chem. Soc. 101 (1979) 334; Choppin and Barthelemy(1989) Inorg. Chem. 28, 3354-3357; Choppin and Bünzli Lanthanide probes in life, chemical and earth sciences. Theory and practice (1989); Kimura and Kato J. Alloys Comp. 275-277 (1998) 806; Parker (1999) J. Chem. Soc., Perkin Trans. 2, 493-503; Supkowski and Horroks (2002) Inorg. Chim. Acta. 340, 44-48]. It was shown that all the relationships gave similar results with a satisfactory precision. The hydration numbers of complexes of H(3)do3a and H(4)dota agreed with the literature values. One water molecule is coordinated in complexes of the new ligands. The results showed that the Choppin formula based on measurements only in H(2)O can be satisfactorily used for estimation of the hydration numbers.

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• časopisecké články MeSH