- Spin Crossover vs. High-Spin Iron(II) Complexes in N4S2 Coordination Sphere Containing Picolyl-Thioether Ligands and NCE (E=S, Se and BH3) Co-Ligands
-
To study the effect of the chelate ring size on the magnetic properties of thioether-based iron(II) metal complexes, two ligands have been envisaged, synthesised and characterised. The two ligands correspond to the bidentate benzylpicolylthioether (PySBn) and tetradentate 2,3-bis(((2-pyridylmethyl)thio)methyl)quinoxaline (QuinoxS). Five iron(II) complexes have been synthesised, containing either two bidentate ligands or one tetradentate ligand, and two N-bond NCE co-ligands (E=S, Se or BH3): trans-[FeII(PySBn)2(NCE)2] (1 a–b) and cis-[FeII(QuinoxS)(NCE)2] (2 a–c), a for E=S, b for E=Se and c for E=BH3. The iron(II) complexes have been characterised by standard techniques, X-ray crystallography (except for complex 1 a) and VT-magnetic measurements in the solid state. X-ray crystallography showed that all the complexes are isolated in the high spin (HS) state, based on the relatively long Fe?L bond lengths, Fe?N>2.0 ? and Fe?S≈2.5–2.6 ?. VT-magnetic measurements demonstrated that complexes 1 a and 2 a-c are stabilised in the HS-state, showing orbital contribution to g and zero field splitting. However, complexes 1 b shows a relatively abrupt, hysteretic, and incomplete at the low-end spin conversion, with T1/2↓=92, T1/2↑=98 K and ΔT1/2=6 K at 5 K min?1, moreover, the hysteresis loop is scan rate dependent increasing up to 11 K at 10 K min?1. An analysis of structural and electronic parameters has been performed to rationalise the differing magnetic properties of the metal complexes, such as metallacycle size, bond lengths and angles, and cis- vs. trans-coordination mode. A comparison with the literature-reported spin crossover iron(II) complexes in N4S2 coordination sphere containing NCE co-ligands has been conducted as well, finding that, as previously reported, the Fe?N?C(E) bond angle is diagnostic for determining the spin lability of the metal complexes, and in addition we have found that the N?C(E) bond length is too useful.
- Plaza-Lozano, Diego,Conde-Gallardo, Agustín,Olguín, Juan
-
-
Read Online
- Fluorescent molecule for recognizing copper ions, preparation method and application
-
The invention discloses a fluorescent molecule for recognizing copper ions, a preparation method and application. Polycyclic aromatic hydrocarbons such as naphthalene rings or anthracene rings are used as initial raw materials; through a series of optimized organic synthesis reaction (substitution and addition), after the connection with different recognition sites, molecular clamp body tweezer host compounds with different recognition performance can be obtained. The fluorescent molecule can be used for copper ion detection and solves the problems that the existing molecule device is difficult to effectively recognize object molecules.
- -
-
Paragraph 0099; 0108; 0109; 0110
(2019/02/04)
-
- Fluorescent molecule for identifying mercury ions as well as preparation method and application
-
The invention discloses a fluorescent molecule for identifying mercury ions as well as a preparation method and application. Polycyclic aromatic hydrocarbons including a naphthalene ring or an anthracene ring and the like are used as starting raw materials and different identification sites are connected through a series of organic synthetic reaction (including substitution and addition) to obtainmolecular-tweezers-shaped main body compounds with different identification properties. The fluorescent molecule can be used for detecting the mercury ions and the problem that guest molecules cannotbe easily effectively identified through an existing molecule device is solved.
- -
-
Paragraph 0108; 0110; 0111; 0112
(2019/01/08)
-
- The reactions of pyridinyl thioesters with triiron dodecacarbonyl: Their novel diiron carbonyl complexes and mechanistic investigations
-
Reaction of Fe3(CO)12 with pyridinyl thioester ligand PyCH2SCOCH3 (L1, Py = pyridin-2-yl) produced complex, [Fe2(κ-COCH3)(μ-SCH2Py)(CO) 5] (1) (PyCH2S = pyridin-2-ylmethanethiolate). When complex 1 reacted with PPh3, a monosubstituted complex, [Fe 2(κ-COCH3)(μ-SCH2Py)(CO) 4PPh3] (2), was derived. Reaction of the same precursor with analogous thioester ligand PyCH2SCOPy (L2) generated three novel diiron complexes, [Fe2(κ-Py)(μ-SCH 2Py)(CO)5] (3), [Fe2(κ-Py)′(μ- SCH2Py)(CO)5] (4), and [Fe2(κ-Py)(μ- SCH2Py)(CO)6] (5). Complexes 3 and 4 are structural isomers. Complex 5 could be converted into complex 4 but the conversion from complex 5 to the isomer 3 was not observed. All the five complexes were fully characterised using FTIR, NMR, and other techniques. Their structures were determined using X-ray single crystal diffraction analysis. The oxidative formation of complexes 1, 3, 4, and 5 involved C-S and/or C-C bonds cleavages. To probe possible mechanisms for these cleavages, DFT calculations were performed. From the calculations, viable reaction pathways leading to the formation of all the isolated products were delineated. The results of the theoretic calculations also allowed rationalisation of the experimental observations.
- Long, Li,Xiao, Zhiyin,Zampella, Giuseppe,Wei, Zhenhong,De Gioia, Luca,Liu, Xiaoming
-
p. 9482 - 9492
(2012/09/05)
-
- 4-(Pyridin-2-yl)thiazol-2-yl thioglycosides as bidentate ligands for oligosaccharide synthesis via temporary deactivation
-
This study focusses on a new concept for oligosaccharide synthesis based on 4-(pyridin-2-yl)thiazol-2-yl thioglycosides that can either act as effective glycosyl donors or can be deactivated by stable bidentate complexation with palladium(ii) bromide. The Royal Society of Chemistry.
- Pornsuriyasak, Papapida,Rath, Nigam P.,Demchenko, Alexei V.
-
supporting information; experimental part
p. 5633 - 5635
(2009/04/13)
-
- Complexation and (templated) synthesis of rhenium complexes with cyclodextrins and cyclodextrin dimers in water
-
Several small, lipophilic rhenium complexes form inclusion complexes with native β-cyclodextrin (β-CD) and β-CD dimers. Association constants larger than 109M-1 were obtained using dimers. The use of β-CD also enabled the synthesis of these rhenium complexes in water, in excellent yields, through complexation of the otherwise insoluble corresponding ligands. The influence of the reaction time and temperature on the configuration of the reaction products has been investigated in depth for one of these complexes. Using a β-CD dimer, it proved possible to specifically template the formation of one configuration. The strength of the complexes of the rhenium complexes in cyclodextrin dimers may allow radiolabeling of biomolecules.
- Van Bommel, Kjeld J. C.,De Jong, Menno R.,Metselaar, Gerald A.,Verboom, Willem,Huskens, Jurriaan,Hulst, Ron,Kooijman, Huub,Spek, Anthony L.,Reinhoudt, David N.
-
p. 3603 - 3615
(2007/10/03)
-
- Inhibition of human cytomegalovirus protease N(o) with monocyclic β- lactams
-
Monocyclic β-lactams have been identified as potent and selective inhibitors of the human cytomegalovirus protease (HCMV) N(o). Two series of these inhibitors are described, a peptidyl series of compounds and non- peptidic molecules featuring lower molecular weights. The SAR work that lead to the discovery of these inhibitors, together with their synthesis is also disclosed.
- Deziel,Malenfant
-
p. 1437 - 1442
(2007/10/03)
-
- A new strategy for the synthesis of phosphorothioates of 2′-deoxyriboligonucleotides
-
2-Picoline thiol, a new reagent, has been indigenously prepared and a new strategy has been followed for the sulphurization of phosphate bond in nucleotide monomer. The 2-picolylthiophosphorobis-(triazolide) has been prepared using phosphite triester approach and treated with protected nucleosides to get phosphorothioate synthons. The two dimers, d(GpT) and d(TpT) have been synthesised in very good yields using these synthons. The removal of 2-methylpyridyl group at the end of synthesis is achieved with 1,1,3,3-tetramethylguanidinium-4-nitrobenzaldoxime in dioxane-water.
- Kumar, Prabhat,Misra
-
p. 1000 - 1004
(2007/10/03)
-
- PENEM DERIVATIVES AND ANTIMICROBIAL AGENT CONTAINING THE SAME
-
A penem derivative represented by the following formula (I): wherein R1represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkylthio group, a substituted or unsubstituted alkenylthio group, a substituted or unsubstituted aralkylthio group, a substituted or unsubstituted arylthio group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted heterocyclic thio group, a substituted or unsubstituted acylthio group, a mercapto group or a hydrogen atom, and R2represents a hydrogen atom or a carboxyl-protecting group; or a pharmacologically acceptable salt thereof. The compound (I) exhibits strong antibacterial activities, and especially, shows strong activities against MRSA. It is therefore useful not only as a general antibacterial agent but also as an antibacterial agent for MRSA against which no general antibacterial agents are recognized to be effective.
- -
-
-
- Synthesis and Biological Activity of trans-(+/-)-N-Methyl-2-(3-pirydyl)-2-tetrahydrothiopyrancarbothioamide 1-Oxide (RP 49356) and Analogues: A New Class of Potassium Channel Opener
-
The synthesis and biological activity of trans-(+/-)-N-methyl-2-(3-pyridyl)-2-tetrahydrothiopyrancarbothioamide 1-oxide (8a, RP 49356) and analoques is reported.These compounds constitute a new structural class of K+-channel opener.The effects of changes in the pyridyl group, thioamide, and thiane ring on in vitro K+-channel opening activity are discussed.A 3-pyridyl or 3-quinolyl group, a small N-alkyl thioamide function, and a thiane oxide ring, in which the sulfoxide is in a trans relationship to thioamide, are preferred for activity.Selected compounds were tested intravenously in the normotensive anaesthetized rat for hypotensive effects, and the activities reflect their in vitro K+-channel opening activity.This led to further evaluation of compound 8a and the selection of the (-)-enantiomer 8b (RP 52891) for development as an antihypertensive and antianginal agent.
- Brown, Thomas J.,Chapman, Robert F.,Cook, David C.,Hart, Terance W.,McLay, Iain M.,et al.
-
p. 3613 - 3624
(2007/10/02)
-
- ALKYLAMIDE DERIVATIVES WITH H2-RECEPTOR ANTAGONISTIC AND CYTOPROTECTIVE ACTION
-
Alkylamide derivatives having the formula, These compounds have a strong antiulcer action depend on histamine H 2-receptor antagonistic action and a cytoprotective action upon gastric mucous membrance.
- -
-
-
- Carbapenem antibiotics
-
Disclosed are novel carbapenem derivatives characterized by a 2-substituent of the formula STR1 in which A represents a C1 -C6 straight or branched chain alkylene group; R5 represents an optionally substituted aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, aryl, araliphatic, heteroaryl, heteroaraliphatic, heterocyclyl or heterocyclyl-aliphatic radial and STR2 represents a nitrogen-containing aromatic heterocycle attached to the alkylene group A at a ring carbon atom and quaternized by substituent R5. Such derivatives are useful as potent antibacterial agents.
- -
-
-
- Synthesis and Antisecretory and Antiulcer Activities of Derivatives and Analogues of 2-(2-Pyridyl)tetrahydrothiophene-2-carbothioamide
-
New thioamide derivatives of 2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (29) and related compounds (in which the tetrahydrothiophene ring was replaced by tetrahydrothiopyran, tetrahydrofuran, 1,3-dithiane, or 1,3-oxathiane and where the pyridine ring was repleaced by other nitrogen heterocycles) were synthesized and tested for their antisecretory and antiulcer activities.These thioamides were prepared according to one of the following methods: (i) reaction of an isothiocyanate with the carbanion of the corresponding cyclic precursor (for secondary thioamides); (ii) reaction of ammonia or an amine with the dithio ester prepared from the same precursor (for primary, secondary, and tertiary thioamides).These thioamides were evaluated by the Shay method to measure their antisecretory activity and by the stress-induced-ulcer method to test their antiulcer activity.Structure-activity relationships are discussed.N-Methyl-2-(2-pyridyl)tetrahydrothiophene-2-carbothioamide (R.P. 40749,30) exhibited activities that were at least 10 times higher than those reported for cimetidine.
- Aloup, Jean-Claude,Bouchaudon, Jean,Farge, Daniel,James, Claude,Deregnaucourt, Jean,Hardy-Houis, Monique
-
-
- ACTIVITE ESTEROLYTIQUE DE COMPOSES ASSOCIANT UNE FONCTION THIOL ET UNE BASE HETEROCYCLIQUE. EXEMPLES DE PROCESSUS BIFONCTIONNEL
-
The synthesis of 19 compounds associating a thiol function and a basic heterocycle (i.e. benzimidazole, pyridine, thiazole) is described.Their esterolytic activity towards para nitrophenyl acetate (PNPA) is compared with that of simple monofunctional thiols.The influence of the substituents and of the nature of the basic heterocycle shows that the apparition of a cooperative effect depends both on the relative pKa values (thiol and heterocyclic) and on the possibility of proton exchange via the heterocyclic moiety.Examples of bifonctional process are reported in the case of benzimidazolylmethanethiol compounds, due to a basic assistancce on the neutral form of the thiol function.
- Brembilla, Alain,Roizard, Denis,Lochon, Pierre
-
p. 577 - 588
(2007/10/02)
-
- Heterocyclic Quinonoid Chromophoric Systems : Part V - Synthesis of 3,4-Phthaloyl-2-thiaquinolizine
-
Condensation of α-mercaptomethylpyridine with 1,4-naphthoquinone, 2-chloro-1,4-naphthoquinone and 2,3-dichloro-1,4-naphthoquinone leads to a number of quinonoid derivatives including the desired 2-α-pyridylmethylmercapto-1,4-naphthoquinone (XVI) and its 3-chloro derivative (XI).Cyclization of XVI and XI gives 3,4-phthaloyl-2-thiaquinolizine (I) which represents a new heterocyclic quinonoid chromophoric system.Plausible mechanisms for the formation of the different heterocyclic quinones are discussed.Interaction of 1,4-naphthoquinone with 1-mercaptomethylisoquinoline affords 8,9-benzo-3,4-phthaloyl-2-thiaquinolizine (XXI).The thiaquinolizines undergo sulphur extrusion on heating to m.p. or on treatment with alkaline dithionite to yield the corresponding 2,3-phthaloylpyrrocolines.
- Shah, J. N.,Tilak, B. D.
-
-
- Studies on Tertiary Amine Oxides. LXVII. Reactions of Aromatic N-Oxides with 3-Arylrhodanines in the Presence of Acetic Anhydride
-
Quinoline 1-oxides 1 readily react with 3-arylrhodanines 2 in the presence of acetic anhydride to afford 3-aryl-5-(2-quinolyl)rhodanines 3 in high yields.These products resist hydrolysis under both alkaline and acidic conditions, but are oxidized to quinaldinic acid 1-oxide 4 with 30percent hydrogen peroxide in hot acetic acid.Besides isoquinoline 2-oxide 5, pyridine 1-oxide 7a also react in the same way to give 3-aryl-5-(2-pyridyl)rhodanines 8, although the reactivity of γ-picoline 1-oxide 7b is considerably lower.Contrary to 3, 3-phenyl-5-(2-pyridyl)rhodanine 8a is successfully hydrolyzed with boiling 48percent hydrobromic acid to 2-pyridinemethanethiol 10 in 57percent yield.
- Yousif, Mohammed M.,Saeki, S.,Hamana, M.
-
p. 305 - 309
(2007/10/02)
-