Publications by authors named "Armand Budzianowski"

15 Publications

  • Page 1 of 1

Comprehensive Characterisation of the Ketoprofen-β-Cyclodextrin Inclusion Complex Using X-ray Techniques and NMR Spectroscopy.

Molecules 2021 Jul 5;26(13). Epub 2021 Jul 5.

Falsified Medicines and Medical Devices Department, National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland.

Racemic ketoprofen (KP) and β-cyclodextrin (β-CD) powder samples from co-precipitation (), evaporation (), and heating-under-reflux () were analysed using X-ray techniques and nuclear magnetic resonance (NMR) spectroscopy. On the basis of NMR studies carried out in an aqueous solution, it was found that in the samples obtained by methods and there were large excesses of β-CD in relation to KP, 10 and 75 times, respectively, while the sample obtained by method contained equimolar amounts of β-CD and KP. NMR results indicated that KP/β-CD inclusion complexes were formed and the estimated binding constants were approximately 2400 M, showing that KP is quite strongly associated with β-CD. On the other hand, the X-ray single-crystal technique in the solid state revealed that the ()-KP/β-CD inclusion complex with a stoichiometry of 2:2 was obtained as a result of heating-under-reflux, for which the crystal and molecular structure were examined. Among the methods used for the preparation of the KP/β-CD complex, only method is suitable.
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http://dx.doi.org/10.3390/molecules26134089DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8271474PMC
July 2021

"Clicking" fragment leads to novel dual-binding cholinesterase inhibitors.

Bioorg Med Chem 2021 Jul 7;42:116269. Epub 2021 Jun 7.

National Medicines Institute, Chełmska 30/34, 00-725 Warsaw, Poland; National Centre for Nuclear Research, 05-400 Otwock-Świerk, Poland.

Cholinesterase inhibitors are potent therapeutics in the treatment of Alzheimer's disease. Among them, dual binding ligands have recently gained a lot of attention. We discovered novel dual-binding cholinesterase inhibitors, using "clickable" fragments, which bind to either catalytic active site (CAS) or peripheral anionic site (PAS) of the enzyme. Copper(I)-catalyzed azide-alkyne cycloaddition allowed to effectively synthesize a series of final heterodimers, and modeling and kinetic studies confirmed their ability to bind to both CAS and PAS. A potent acetylcholinesterase inhibitor with IC = 18 nM (compound 23g) was discovered. A target-guided approach to link fragments by the enzyme itself was tested using butyrylcholinesterase.
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http://dx.doi.org/10.1016/j.bmc.2021.116269DOI Listing
July 2021

Some mechanistic aspects regarding the Suzuki-Miyaura reaction between selected -substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine.

Beilstein J Org Chem 2018 11;14:2384-2393. Epub 2018 Sep 11.

Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.

Atropisomers are very interesting stereoisomers having axial chirality resulting from restricted rotation around single bonds and are found in various classes of compounds. Substituted arylpyridines are an important group of them. A regio- and atropselective Suzuki-Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied. Reactions with various amounts of -substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw conclusions about the order of substitution. Also, the observed selectivity in the case of -methoxyphenylboronic acid suggested an additional metal -chelation effect in the transition state, apparently not present in the -chloro analogues. The rotational barrier in selected atropisomers was determined on the basis of HT NMR and thermal epimerisation experiments. The structure of most presented atropisomeric derivatives of 2,6-dimethylpyridine was confirmed by single-crystal X-ray analysis. Racemic chiral, differently substituted atropisomers were also examined by H NMR spectroscopy in the presence of a chiral solvating agent. This regio- and atropselectivity may be generally applicable to other arylpyridine systems. A regio- and atropselective Suzuki-Miyaura cross-coupling process has been observed, giving an efficient access to a class of atropisomeric compounds. An opposite selectivity using a differently -substituted phenylbornic acid was observed.
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http://dx.doi.org/10.3762/bjoc.14.214DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142784PMC
September 2018

High-Pressure Behavior of Silver Fluorides up to 40 GPa.

Inorg Chem 2017 Dec 15;56(23):14651-14661. Epub 2017 Nov 15.

Center of New Technologies, University of Warsaw , ul. Banacha 2C, 02-097 Warsaw, Poland.

A combined experimental-theoretical study of silver(I) and silver(II) fluorides under high pressure is reported. For Ag, the CsCl-type structure is stable to at least 39 GPa; the overtone of the IR-active mode is seen in the Raman spectrum. Its AgF sibling is a unique compound in many ways: it is more covalent than other known difluorides, crystallizes in a layered structure, and is enormously reactive. Using X-ray diffraction and guided by theoretical calculations (density functional theory), we have been able to elucidate crystal structures of high-pressure polymorphs of AgF. The transition from ambient pressure to an unprecedented nanotubular structure takes place via an intermediate orthorhombic layered structure, which lacks an inversion center. The observed phase transitions are discussed within the broader framework of the fluorite → cotunnite → NiIn series, which has been seen for other metal difluorides.
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http://dx.doi.org/10.1021/acs.inorgchem.7b02528DOI Listing
December 2017

AgSO meets AgSO: the second example of metal-ligand redox isomerism among inorganic systems.

Dalton Trans 2016 Nov;45(45):18202-18207

Faculty of Chemistry, University of Warsaw, Pasteur 1, 02093 Warsaw, Poland.

Valence (redox) isomerism based on electron exchange between a metal and a ligand is immensely rare in purely inorganic systems, with only one documented case, that of PbS which adopts two polymorphic forms corresponding to Pb(iv)(S) and Pb(ii)(S). Here we have taken advantage of metathetic reactions using salts of weakly coordinating anions and we have prepared for the first time Ag(i)SO, silver(i) peroxydisulphate. The title compound crystallizes in the non-centrosymmetric Cc space group with partial disorder of the anionic sublattice. Ag(i)SO is a highly thermally unstable diamagnetic and colourless valence isomer of the antiferromagnetic and black Ag(ii)SO, described by us in the past.
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http://dx.doi.org/10.1039/c6dt03283dDOI Listing
November 2016

Crystal and electronic structure, lattice dynamics and thermal properties of Ag(I)(SO3)R (R = F, CF3) Lewis acids in the solid state.

Dalton Trans 2012 Feb 19;41(7):2034-47. Epub 2011 Dec 19.

ICM, University of Warsaw, Pawińskiego 5a, 02-106, Warsaw, Poland.

Trifluoromethansulfonate of silver(I), AgSO(3)CF(3) (abbreviated AgOTf), extensively used in organic chemistry, and its fluorosulfate homologue, AgSO(3)F, have been structurally characterized for the first time. The crystal structures of both homologues differ substantially from each other. AgOTf crystallizes in a hexagonal system (R3 space group, No.148) with a = b = 5.312(3) Å and c = 32.66(2) Å, while AgSO(3)F crystallizes in a monoclinic system in the centrosymmetric P2(1)/m space group (No.11) with a = 5.4128(10) Å, b = 8.1739(14) Å, c = 7.5436(17) Å, and β = 94.599(18)°, adopting a unique structure type (100 K data). There are two types of fluorosulfate anions in the structure; in one type the F atom is engaged in chemical bonding to Ag(I) and in the other type the F atom is terminal; accordingly, two resonances are seen in the (19)F NMR spectrum of AgSO(3)F. Theoretical analysis of the electronic band structure and electronic density of states, as well as assignment of the mid- and far-infrared absorption and Raman scattering spectra for both compounds, have been performed based on the periodic DFT calculations. AgSO(3)F exhibits an unusually low melting temperature of 156 °C and anomalously low value of melting heat (ca. 1 kJ mol(-1)), which we associate with (i) disorder of its anionic sublattice and (ii) the presence of 2D sheets in the crystal structure, which are weakly bonded with each other via long Ag-O(F) contacts. AgSO(3)F decomposes thermally above 250 °C, yielding mostly Ag(2)SO(4) and liberating SO(2)F(2). AgOTf is much more thermally stable than AgSO(3)F; it undergoes two consecutive crystallographic phase transitions at 284 °C and 326 °C followed by melting at 383 °C; its thermal decomposition commences above 400 °C leading at 500 °C to crystalline Ag(2)SO(4) and an unidentified phase as major products of decomposition in the solid state.
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http://dx.doi.org/10.1039/c1dt11747eDOI Listing
February 2012

Thermal and chemical decomposition of di(pyrazine)silver(II) peroxydisulfate and unusual crystal structure of a Ag(I) by-product.

Dalton Trans 2012 Jan 19;41(2):396-402. Epub 2011 Sep 19.

ICM, The University of Warsaw, Żwirki i Wigury 93, 02-089, Warsaw, Poland.

High purity samples of a [Ag(pyrazine)(2)]S(2)O(8) complex were obtained using modified synthetic pathways. Di(pyrazine)silver(II) peroxydisulfate is sensitive to moisture forming [Ag(pyrazine)(2)](S(2)O(8))(H(2)O) hydrate which degrades over time yielding HSO(4)(-) derivatives and releasing oxygen. One polymorphic form of pyrazinium hydrogensulfate, β-(pyrazineH(+))(HSO(4)(-)), is found among the products of chemical decomposition together with unique [Ag(i)(pyrazine)](5)(H(2)O)(2)(HSO(4))(2)[H(SO(4))(2)]. Chemical degradation of [Ag(pyrazine)(2)]S(2)O(8) in the presence of trace amounts of moisture can explain the very low yield of wet synthesis (11-15%). Attempts have failed to obtain a mixed valence Ag(II)/Ag(I) pyrazine complex via partial chemical reduction of the [Ag(pyrazine)(2)]S(2)O(8) precursor with a variety of inorganic and organic reducing agents, or via controlled thermal decomposition. Thermal degradation of [Ag(pyrazine)(2)]S(2)O(8) containing occluded water proceeds at T > 90 °C via evolution of O(2); simultaneous release of pyrazine and SO(3) is observed during the next stages of thermal decomposition (120-285 °C), while Ag(2)SO(4) and Ag are obtained upon heating to 400-450 °C.
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http://dx.doi.org/10.1039/c1dt10744eDOI Listing
January 2012

Na[Li(NH2BH3)2]--the first mixed-cation amidoborane with unusual crystal structure.

Dalton Trans 2011 May 15;40(17):4407-13. Epub 2011 Mar 15.

Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland.

We describe the successful synthesis of the first mixed-cation (pseudoternary) amidoborane, Na[Li(NH(2)BH(3))(2)], with theoretical hydrogen capacity of 11.1 wt%. Na[Li(NH(2)BH(3))(2)] crystallizes triclinic (P1) with a = 5.0197(4) Å, b = 7.1203(7) Å, c = 8.9198(9) Å, α = 103.003(6)°, β = 102.200(5)°, γ = 103.575(5)°, and V = 289.98(5) Å(3) (Z = 2), as additionally confirmed by Density Functional Theory calculations. Its crystal structure is topologically different from those of its orthorhombic LiNH(2)BH(3) and NaNH(2)BH(3) constituents, with distinctly different coordination spheres of Li (3 N atoms and 1 hydride anion) and Na (6 hydride anions). Na[Li(NH(2)BH(3))(2)], which may be viewed as a product of a Lewis acid (LiNH(2)BH(3))/Lewis base (NaNH(2)BH(3)) reaction, is an important candidate for a novel lightweight hydrogen storage material. The title material decomposes at low temperature (with onset at 75 °C, 6.0% mass loss up to 110 °C, and an additional 3.0% up to 200 °C) while evolving hydrogen contaminated with ammonia.
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http://dx.doi.org/10.1039/c0dt01491eDOI Listing
May 2011

Structural polymorphism of pyrazinium hydrogen sulfate: extending chemistry of the pyrazinium salts with small anions.

Acta Crystallogr B 2010 Aug 12;66(Pt 4):451-7. Epub 2010 Jul 12.

ICM, The University of Warsaw, Pawińskiego 5a, 02-106, Warsaw, Poland.

Two polymorphs (alpha, beta) of pyrazinium hydrogen sulfate (pyzH(+)HSO(4)(-), abbreviated as PHS) with distinctly different hydrogen-bond types and topologies but close electronic energies have been synthesized and characterized for the first time. The alpha-polymorph (P2(1)2(1)2(1)) forms distinct blocks in which the pyzH(+) and HSO(4)(-) ions are interconnected through a network of NH...O and OH...O hydrogen bonds. The beta-form (P1) consists of infinite chains of alternating pyzH(+) and HSO(4)(-) ions connected by NH...O and OH...N hydrogen bonds. Density functional theory (DFT) calculations indicate the possible existence of a hypothetical polar P1 form of the beta-polymorph with an unusually high dipole moment.
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http://dx.doi.org/10.1107/S0108768110019580DOI Listing
August 2010

Anomalous protonic-glass evolution from ordered phase in NH...N hydrogen-bonded dabcoHBF4 ferroelectric.

J Phys Chem B 2008 Dec;112(51):16619-25

Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.

Dielectric properties, spontaneous polarization, and phase transitions of the NH+...N bonded ferroelectric dabcoHBF4 (i.e., 1,4-diazabicyclo[2.2.2]octane tetrafluoroborate, [C6H13N2]+ BF4-) have been related to one-dimensional arrangement of the cations and to their conformational properties. The onset of conformational transformation lowering the symmetry of the cations, rearrangement of the anions, and proton disordering in NH+...N hydrogen bonds, linking the cations into linear chains, lead to a ferroelectric-ferroelectric phase transition at T23 = 153 K. A weak coupling between the protonic and anionic sites in dabcoHBF4 results in the formation of distinct phase-diagram regions: the high-temperature paraelectric phase with disordered protons, the intermediate ferroelectric phase with the protons ordered, and the low-temperature ferroelectric phase where the protons become disordered again. The lowest temperature phase remains ferroelectric owing to the ionic displacements, while the protons assume the glass state. In this phase the H+ transfers involve local formation of neutral, monocationic, and dicationic species. Such an anomalous formation of protonic glass state from the ordered phase depends on the subtle structural features pertaining to the proton transfers in bistable hydrogen bonds. In paraelectric phase I, between the mp and T12 = 374 K, the anions are orientationally disordered, the protons are disordered in the hydrogen bonds and the cations rotate about the [z] direction; in ferroelectric phase II below T12, the protons and cations order, the dabco cations assume a planar conformation of ethylene bridges, and the anions exhibit a residual temperature-dependent gradual ordering (two 80:20 occupied sites of the anion are still observed at 332 K); and in ferroelectric phase III below T23, the cations assume left- and right-twisted propeller conformations and the anions are ordered but the protons become disordered in the hydrogen bonds.
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http://dx.doi.org/10.1021/jp801316aDOI Listing
December 2008

Competing hydrogen-bonding patterns and phase transitions of 1,2-diaminoethane at varied temperature and pressure.

Acta Crystallogr B 2006 Dec 14;62(Pt 6):1078-89. Epub 2006 Nov 14.

Faculty of Crystal Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.

1,2-diaminoethane has been in-situ pressure- and temperature-frozen; apart from two known low-temperature phases, Ialpha and II, three new phases, Ibeta, Igamma and III, have been observed and their structures determined by X-ray diffraction. The measurements at 0.1 MPa were carried out at 274, 243 and 224 K, and 296 K measurements were made at 0.15 GPa (phase Ialpha), at 0.3 and 1.1 GPa (phase Ibeta), at 1.5 GPa (phase Igamma), and at 0.2, 0.3 and 0.5 GPa (phase III). All these phases are monoclinic, space group P2(1)/c, but the unit-cell dimension of phases Ialpha and III are very different at 296 K: aIalpha=5.078 (5), bIalpha=7.204 (8), cIalpha=5.528 (20) A, betaIalpha=115.2 (2) degrees at 0.15 GPa, and aIII=5.10 (3), bIII=5.212 (2), cIII=7.262 (12) A, betaIII=111.6 (4) degrees at 0.2 GPa, respectively; in both phases Z=2. An ambient-pressure low-temperature phase II has been observed below 189 K. Discontinuities in the unit-cell dimensions and in the N...N distance mark the isostructural transition between phases Ialpha and Ibeta at 0.2 GPa, which can be attributed to a damping process of the NH2 group rotations. In phase Igamma the unit-cell parameter a doubles and Z increases to 4. The molecule has inversion symmetry in all the structures determined. 1,2-Diaminoethane can be considered as a simple structural ice analogue, but with NH...N hydrogen bonds and with the H-atom donors (four in one molecule) in excess over H-atom acceptors (two per molecule). Thus, the transformations of 1,2-diaminoethane phases involving the conformational dynamics affect the hydrogen-bonding geometry and molecular association in the crystal. The 1,2-diaminoethane:1,2-dihydroxyethane mixture has been separated by pressure-freezing, and a solid 1,2-diaminoethane crystal in liquid 1,2-dihyroxyethane has been obtained.
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http://dx.doi.org/10.1107/S010876810602982XDOI Listing
December 2006

Pressure tuning between NH...N hydrogen-bonded ice analogue and NH...Br polar dabcoHBr complexes.

J Phys Chem B 2006 May;110(20):9755-8

Faculty of Chemistry, Adam Mickiewicz University, Poznań, Poland.

At normal conditions 1,4-diazabicyclo[2.2.2]octane hydrobromide [C(6)H(13)N(2)](+.)Br(-) forms centrosymmetric crystals, space group Pm2, NH(+)...N hydrogen-bonded linear polycationic chains with disordered protons in the structure. As in H(2)O ice Ih, the protons in [C(6)H(13)N(2)](+.)Br(-) crystals remain disordered at low temperatures. Above 0.4 GPa the [C(6)H(13)N(2)](+.)Br(-) crystals transform into a new polar NH(+)...Br(-) hydrogen bonded complex, space group Cmc2. It has been crystallized in-situ in a diamond anvil cell and its structure determined by X-rays. The low-pressure triggering of this transformation indicates that it is a possible source of defects in the real structure at normal conditions, where, along with disproportionation defects, they can be responsible for anomalous dielectric properties, including relaxor-like behavior of NH...N hydrogen-bonded compounds.
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http://dx.doi.org/10.1021/jp061234tDOI Listing
May 2006

Pressure-frozen benzene I revisited.

Acta Crystallogr B 2006 Feb 17;62(Pt 1):94-101. Epub 2006 Jan 17.

Faculty of Crystal Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland.

The crystal structure of benzene, C6H6, in situ pressure-frozen in phase I, has been determined by X-ray diffraction at 0.30, 0.70 and 1.10 GPa, and 296 K. The molecular aggregation within phase I is consistent with van der Waals contacts and electrostatic attraction of the positive net atomic charges at the H atoms with the negative net charges of the C atoms. The C-H...aromatic ring centre contacts are the most prominent feature of the two experimentally determined benzene crystal structures in phases I and III, whereas no stacking of the molecules has been observed. This specific crystal packing is a likely reason for the exceptionally high polymerization pressure of benzene. The changes of molecular arrangement within phase I on elevating the pressure and lowering the temperature are analogous.
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http://dx.doi.org/10.1107/S010876810503747XDOI Listing
February 2006

Coupling of the lactone-ring conformation with crystal symmetry in 6-hydroxy-4,4,5,7,8-pentamethyl-3,4-dihydrocoumarin.

Acta Crystallogr B 2002 Feb 24;58(Pt 1):125-33. Epub 2001 Jan 24.

Faculty of Chemistry, Adam Mickiewicz University, 60-780 Poznań, Grunwaldzka 6, Poland.

Conformational disorder and inversions of the lactone ring induce structural transformations in the crystals of 6-hydroxy-4,4,5,7,8-pentamethyl-3,4-dihydrocoumarin, C14H18O3. The onset of ordering of the lactone ring at 300 K proceeds continuously, changes the space group from P2(1)/m to P2(1)/c and doubles the unit cell; the abrupt inversion of the lactone rings at 225 K changes the crystal translational symmetry in the (010) plane. The mechanism combining the molecular conformation and dynamics with the crystal structure, its symmetry, and phase transitions is presented.
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http://dx.doi.org/10.1107/s0108768101017955DOI Listing
February 2002
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