Research Institute for Organic Syntheses

Rybitví, Czech Republic

Research Institute for Organic Syntheses

Rybitví, Czech Republic
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Dey D.K.,Raja Peary Mohan College | Dey S.P.,Sri Krishna College of Engineering And Technology | Karan N.K.,Jadavpur University | Lycka A.,Research Institute for Organic Syntheses | And 2 more authors.
Journal of Organometallic Chemistry | Year: 2014

Three new symmetrical binuclear diorganotin(IV) complexes with the symmetrical bis-tridentate Schiff base, N,N-bis(4-oxo-4-phenylbutan-2-ylidene) oxalohydrazide, (R2Sn)2[Ph-C(O)CH-C(Me)N-NC(O)-C(O)N- NC(Me)-CHC(O)-Ph] (R = Ph: Ia; R = Me: Ib; R = n-Bu: Ic) have been synthesized by reaction with corresponding diorganotin(IV) dichloride at room temperature in methanol in presence of triethylamine. The complexes have been characterized by elemental analyses, IR, 1H, 13C, 15N and 119Sn NMR spectroscopy. Two dimensional H,H-COSY, NOESY, H,C-COSY, gs(gradient selected)-HMQC and gs-HMBC techniques were applied in order to assign proton and carbon chemical shifts unambiguously. The δ( 119Sn) values for the complexes Ia-Ic are -320.1, -181.9 and -150.7 ppm respectively, indicating pentacoordinated tin centres. The C-Sn-C angles calculated from 1J(119Sn, 13C) for Ia, 1b and Ic are found to be 135.6, 133.85 and 135.0 respectively. From the 2J(119Sn, 1H) value, the Me-Sn-Me angle for Ib is found to be 130.46. From NMR spectra a distorted trigonal-bipyramidal geometry at each tin centre is proposed. The structures of the complexes have been confirmed by single crystal X-ray diffraction analysis of one representative compound Ia. The ligand, N,N-bis(4-oxo-4-phenylbutan-2-ylidene) oxalohydrazide (H4L) coordinates to the metal centre in enolate form via the phenolic O, imino N and enolic O atoms. The X-ray structure indicates that the coordination geometry of tin atoms are intermediate between trigonal bipyramid and a square pyramid. The oxygen atoms are in axial positions while the imino nitrogen atom of the ligand and two phenyl groups occupy the equatorial sites.© 2013 Published by Elsevier B.V.


Dey D.K.,Raja Peary Mohan College | Dey S.P.,Sri Krishna College of Engineering And Technology | Lycka A.,Research Institute for Organic Syntheses | Rosair G.M.,Heriot - Watt University
Polyhedron | Year: 2011

Three new diorganotin(IV) complexes of the general formula R 2Sn[3-(OMe)-2-OC6H3CHN-NC(O)Ph] (R = Ph, Ia; R = Me, Ib; R = n-Bu, Ic) have been synthesised from the corresponding diorganotin(IV) dichlorides and the ligand, N′-(2-hydroxy-3- methoxybenzylidene)benzohydrazide in methanol at room temperature in the presence of trimethylamine. All the complexes have been characterized by elemental analysis, IR and 1H, 13C, 15N, 119Sn NMR spectra, and their structures have been confirmed by single crystal X-ray diffraction analysis of one representative compound Ia. Complex Ia crystallises in the orthorhombic system, space group Pna21 with a = 12.424(5), b = 9.911(5), c = 18.872(5) ; Z = 4. The ligand N′-(2-hydroxy-3-methoxybenzylidene)benzohydrazide (H2L) coordinates to the metal centre in the enolate form via the phenolic O, imino N and enolic O atoms. In Ia, the central tin atom adopts a distorted trigonal bipyramidal coordination geometry with the oxygen atoms in axial positions, while the imino nitrogen atom of the Schiff base and the two phenyl groups occupy the equatorial sites. The δ(119Sn) values for the complexes Ia, Ib and Ic are -327.3, -151.7 and -187.2 ppm, respectively, thus indicating penta-coordinated Sn centres in solution. © 2011 Elsevier Ltd. All rights reserved.


Cifkova E.,University of Pardubice | Holcapek M.,University of Pardubice | Lisa M.,University of Pardubice | Ovcacikova M.,University of Pardubice | And 4 more authors.
Analytical Chemistry | Year: 2012

The identification and quantitation of a wide range of lipids in complex biological samples is an essential requirement for the lipidomic studies. High-performance liquid chromatography-mass spectrometry (HPLC/MS) has the highest potential to obtain detailed information on the whole lipidome, but the reliable quantitation of multiple lipid classes is still a challenging task. In this work, we describe a new method for the nontargeted quantitation of polar lipid classes separated by hydrophilic interaction liquid chromatography (HILIC) followed by positive-ion electrospray ionization mass spectrometry (ESI-MS) using a single internal lipid standard to which all class specific response factors (RFs) are related to. The developed method enables the nontargeted quantitation of lipid classes and molecules inside these classes in contrast to the conventional targeted quantitation, which is based on predefined selected reaction monitoring (SRM) transitions for selected lipids only. In the nontargeted quantitation method described here, concentrations of lipid classes are obtained by the peak integration in HILIC chromatograms multiplied by their RFs related to the single internal standard (i.e., sphingosyl PE, d17:1/12:0) used as common reference for all polar lipid classes. The accuracy, reproducibility and robustness of the method have been checked by various means: (1) the comparison with conventional lipidomic quantitation using SRM scans on a triple quadrupole (QqQ) mass analyzer, (2) 31P nuclear magnetic resonance (NMR) quantitation of the total lipid extract, (3) method robustness test using subsequent measurements by three different persons, (4) method transfer to different HPLC/MS systems using different chromatographic conditions, and (5) comparison with previously published results for identical samples, especially human reference plasma from the National Institute of Standards and Technology (NIST human plasma). Results on human plasma, egg yolk and porcine liver extracts are presented and discussed. © 2012 American Chemical Society.


Lunak Jr. S.,University of Pardubice | Horakova P.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses | Lycka A.,University of Hradec Kralove
Dyes and Pigments | Year: 2010

A series of arylmethylidenoxindoles was synthesized by acid or base catalysed condensation of substituted aldehydes with oxindole. The products were formed as mixtures of Z- and E-isomers that were separated using column chromatography and identified by 1H and 13C NMR. The effect of substituents on absorption maxima was investigated both experimentally and theoretically, based on time dependent density functional theory. Low temperature absorption spectroscopy in a solvent glass enabled identification of the position of the 0-0 vibronic bands. The spectral features of the parent Z-benzylidenoxindole were compared to those of trans-isoindigo and trans-stilbene. Fluorescence of arylmethylidenoxindoles in solution was not observed, as E-Z isomerization represents a dominant deactivation channel after irradiation; when this geometrical isomerization was sterically hindered at low temperature solvent glass or in solid, fluorescence of planar Z-isomers was observed. © 2009 Elsevier Ltd. All rights reserved.


Hejda M.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses | Jambor R.,University of Pardubice | Ruzicka A.,University of Pardubice | Dostal L.,University of Pardubice
Dalton Transactions | Year: 2013

A set of C,N-intramolecularly coordinated boranes containing various C,N-chelating ligands L1-3 (where L1 = [o-(CHNtBu)C 6H4], L2 = [o-(CHN-2,6-iPr2C 6H3)C6H4], L3 = [o-(CH2NMe2)C6H4]); L 1-3BCl2 (for 1 L = L1, for 2 L = L2, for 5 L = L3), L1BPhCl (3) and L1BCy 2 (4) (where Cy = cyclohexyl) were synthesized and fully characterized by multinuclear NMR spectroscopy and in cases of 1 and 3-5 by the single crystal X-ray diffraction analysis. The reaction of 1-3 with the anilides ArNHLi (Ar = 2,6-Me2C6H3 or 2,6-iPr 2C6H3) proceeded via unexpected addition of anilide across the CN bond yielding 1,2,3-trisubstituted 1H-2,1-benzazaboroles 6-11, whose structures were unambiguously established by single crystal X-ray diffraction analysis (except for 11) and multinuclear NMR spectroscopy. In contrast, compounds 4 and 5 were inert towards ArNHLi. The investigation dealing with the reaction mechanism between the parent boranes 1-3 and ArNHLi revealed that amidolithiation of the CN double bond involved in the ligand backbones is the crucial step of the whole reaction. The CN double bond in 1-3 is activated by its coordination to the ortho bonded Lewis acidic boron center, which was also proven by the fact that the non-substituted ligand L1H did not react with ArNHLi under the same reaction conditions in an analogous reaction. © 2013 The Royal Society of Chemistry.


Hejda M.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses | Jambor R.,University of Pardubice | Ruzicka A.,University of Pardubice | Dostal L.,University of Pardubice
Dalton Transactions | Year: 2014

A set of 1H-2,1-benzazaboroles as B-N analogues of 1H-indene and a set of 1H-pyrrolo[1,2-c][1,3,2]diazaborolidines as B-N analogues of 1H-pyrrolizine were prepared via nucleophilic addition of selected alkyl(aryl)lithiums (MeLi, tBuLi or PhLi) to, via N→B intramolecular interactions, the activated imino CN functionality in the structure of C,N- or N,N-chelated chloroboranes. All compounds were characterized by elemental analysis and 1H, 11B, 13C and 15N NMR spectroscopy, and molecular structures of isolated compounds were on several occasions established by means of single-crystal X-ray diffraction analysis. The presence of three adjacently bonded substituents and their systematic alternation on five-membered C3BN (1H-2,1-benzazaboroles) or C2BN2 (1H-pyrrolo[1,2-c][1,3,2]diazaborolidines) rings allowed us to follow both the influence of the steric repulsion and limitations for the formation of respective annulated heterocyclic systems. This journal is © the Partner Organisations 2014.


Hejda M.,University of Pardubice | Jambor R.,University of Pardubice | Ruzicka A.,University of Pardubice | Lycka A.,Research Institute for Organic Syntheses | Dostal L.,University of Pardubice
Dalton Transactions | Year: 2014

Reduction of C,N-chelated chloroborane [2-(CH=NtBu)C6H 4]BPhCl (1) with the potassium metal afforded (3,3′)-bis(1-Ph- 2-tBu-1H-2,1-benzazaborole) (2). Compound 2 is formed via C-C reductive coupling reaction. Subsequent reduction of 2 with two equivalents of the potassium metal produced orange crystals of 1Ph-2tBu-1H-2,1-benzazaborolyl (Bab) potassium salt K(THF)(Bab) (3). Compound 3 is able to react with simple electrophiles (MeI or Me3SiCl) resulting in the formation of substituted 1H-2,1-benzazaboroles. © the Partner Organisations 2014.


Simon P.,University of Pardubice | Simon P.,Academy of Sciences of the Czech Republic | Jambor R.,University of Pardubice | Ruika A.,University of Pardubice | And 3 more authors.
Dalton Transactions | Year: 2012

NCN chelated monomeric chalcogenides, LSbE (E = S (1), Se (2), L = 2,6-bis[N-(2′,6′-dimethylphenyl)ketimino]phenyl), were synthesized and characterized with the help of elemental analysis, NMR spectroscopy and single-crystal X-ray diffraction analyses. The terminal Sb-E (E = S, Se) bonds in 1 and 2 were subjected to theoretical investigation and the results are compared with the hypothetical molecules, PhSbE (E = S, Se, Te), and earlier reported analogues. © 2012 Royal Society of Chemistry.


Svoboda T.,University of Pardubice | Jambor R.,University of Pardubice | Ruzicka A.,University of Pardubice | Jirasko R.,University of Pardubice | And 3 more authors.
Organometallics | Year: 2012

Organoantimony(III) and organobismuth(III) oxides (LMO) 2 (where L is the NCN-chelating ligand C 6H 3-2,6-(CH 2NMe 2) 2 and M = Sb (1), Bi (2)) reacted smoothly with arsenic oxides As 2O 5 and As 2O 3 to form the molecular oxides [(LM) 3(AsO 4) 2] and [(LM) 2(As 2O 5)] (where M = Sb (3, 5), Bi (4, 6)). All compounds were characterized by electrospray ionization (ESI) mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and, in the case of 5 and 6, single-crystal X-ray diffraction (XRD) analyses. Compound 3 formed two conformational isomers in a benzene or chloroform solution, as confirmed by 1H and 13C NMR spectroscopy. As in the case of 3, 5 also formed conformational isomers in a benzene solution, whereas the bismuth analogue 6 was unstable in solution. The stabilities of the three possible conformers of 5 were studied by density functional theory (DFT) calculations. © 2012 American Chemical Society.


Svoboda T.,University of Pardubice | Dostal L.,University of Pardubice | Jambor R.,University of Pardubice | Ruzicka A.,University of Pardubice | And 2 more authors.
Inorganic Chemistry | Year: 2011

Organoantimony(III) and organobismuth(III) phosphates (LM) 3(PO4)2 [M = Sb (3) and Bi (4)], containing the NCN-chelating ligand L [L = 2,6-(CH2NMe2) 2C6H3], were prepared by the simple treatment of parent oxides 1 and 2 with H3PO4. Both compounds were characterized by elemental analysis, electrospray ionization mass spectrometry, and IR and NMR spectroscopy and in the case of 3 by X-ray diffraction techniques. Compound 3 has an interesting behavior in solution, i.e., the formation of two possible conformational isomers, which was studied by 1H, 13C, and 31P NMR spectroscopy. © 2011 American Chemical Society.

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