52411-33-3

New azo-azomethine dyes, L1-L3, with N 2S2O2 donor set of atoms have been synthesized via condensation reaction of 1,2-bis(2-aminophenylthio)ethane with 5-(4-X-phenyl)-azo-salicylaldehyde (X = Cl, OMe and Me). The new dyes were characterized by IR, UV-Vis, 1H NMR and fluorescence spectroscopy as well as mass spectrometry and elemental analysis. Mononuclear nickel(II) complexes of the dyes have been also prepared. The crystal structure of [NiL1]·0.5H2O was determined by single-crystal X-ray diffraction. The thermal analysis data indicate that all prepared dyes, L1-L3, are thermally stable up to 320 C. The fluorescence behavior of the prepared complexes have been also investigated and compared to those of L1-L3.

Macrocyclic diamides have been synthesized by the condensation of 1,4-bis(2-aminophenyl)-1,4-dioxa(dithia)butanes with the diacid chlorides of glutaric, diglycolic, and thiodiglycolic acids under conditions of high dilution.Subsequent reduction with diborane led to the corresponding macrocyclic diamine containing atoms of oxygen and (or) sulfur.Structural assignments were made using data of mass spectrometry and IR, PMR, and 13C NMR spectra.

The diamine reagent 1,2-bis(2-aminophenylthio)ethane is no longer commercially available but is still required for the synthesis of the bismaleimide resin, APO-BMI, used in syntactic foams. In this work, we examined the hydrolysis of benzothiazole followed by reaction with dichloroethane or dibromoethane. The deprotonation of 2-aminothiophenoI followed by reaction with dibromoethane was also investigated and later optimized for scale-up by scrutinizing all aspects of the reaction conditions, work-up, and recrystallization. On bench-scale, the optimized procedure consistently produced a 75-80% overall yield of finely divided, high purity product (>95%). The material was also produced on both a 100 Ib scale and a 200 Ib scale using the optimized process, giving high quality material in excellent yield.

A new class of zirconium and hafnium complexes coordinated by linear dianonic tetradentate NSSN ligands is reported. The ligands feature two amide functions coupled with two thioether groups linked by a central flexible ethane bridge and two lateral rigid phenylene bridges and differ for the substituents on the aniline nitrogen atoms, i.e., isopropyl, cyclohexyl, or mesityl substituents: NSSN-iPr, NSSN-Cy, or NSSN-Mes. They were prepared by reacting 2-aminothiophenol with dibromoethane to afford the NSSN ligands without substituents on the aniline nitrogen atoms, which were subsequently alkylated through a reductive amination of acetone or cyclohexanone or palladium-catalyzed cross-coupling reaction with mesityl bromide. The corresponding zirconium and hafnium complexes 1-5 were obtained through a transamination reaction between the neutral ligands and Zr(NMe2)4 or Hf(NMe2)4 [(NSSN-iPr)Zr(NMe2)2 (1), (NSSN-Cy)Zr(NMe2)2 (2), (NSSN-Mes)Zr(NMe2)2 (3), (NSSN-iPr)Hf(NMe2)2 (4), and (NSSN-Cy)Hf(NMe2)2 (5)]. They were characterized in solution by NMR spectroscopy and in solid state by X-ray diffraction analysis (except for 3). All complexes present an octahedral coordination geometry with a fac-fac ligand wrapping and a cis relationship between the other two monodentate ligands. The catalytic performances of 1-5 in the ring-opening polymerization of cyclic esters were investigated. Complex 1 was the most active: its polymerization activity was superior to those generally displayed by zirconium complexes featuring OSSO ligands and compared well with those of the most active group 4 complexes operating in a toluene solution.

Reactions of 1,2-di(o-aminophenylthio)ethane with 3-ethoxy-2-hydroxybenzaldehyde yield the new hexadentate N2S2O2 donor thioether Schiff base 1,2-bis(2-((2-(thio)phenylimino)methyl)-6-ethoxyphenol)ethane (H2L). Ni(II), Zn(II), Cd(II), and Hg(II) complexes of this ligand were prepared. Of these complexes, [NiL]·2H2O has been structurally characterized by X-ray crystallography. The coordination geometry around Ni(II) was described as octahedral. Zn(II), Cd(II), and Hg(II) complexes and the Schiff base ligand have been characterized by CHN analyses, molar conductivity, UV-vis, FT-IR, 1H, and 13C NMR spectroscopy.

A metal ion sensing fluorophore L that exhibits a large two-photon absorption cross-section has been synthesized in good yields. The influences of different metal ion inputs, on the one- and two-photon spectroscopic properties of L, have been investigated. The ligand itself does not show any fluorescence although in presence of a metal ion like Zn(II), Cd(II), Mg(II) or Ca(II), a ～25 time enhancement of fluorescence is observed. The ligand with symmetrical "donor-acceptor-acceptor-donor" characteristics exhibits a large two-photon absorption cross-section measured by femtosecond open-aperture Z-scan technique at 880 nm. However, presence of any of the above metal ions lowers its two-photon absorption cross-section (δ) to different extents at 880 nm. Theoretical calculation carried out in DFT formalism on the ligand and its Zn(II) complex corroborate experimental results.

This paper aimed at synthesizing symmetrical Schiff base ligands derived from the primary amine 1,2-bis(2-aminophenylthio)ethane condensed with 7-formyl-8-hydroxyquinoline and 2-hydroxy-1-naphthaldehyde. The synthesised ligands were used for preparing metal complexes with the iron triad metals. The symmetrical tetradentate (N2O2) Schiff base ligands SL1 and SL2 forms mononuclear complexes with square planar geometry in case of Co(II) and Ni(II) complexes, while an octahedral geometry was obtained for the Fe(III) complexes. The molar conductance quantification showed that the complexes were non-ionic. In vitro antimicrobial potential examination of the free ligands indicated weak activity and the corresponding complexes showed enhanced activity. Moreover, the In vivo molluscicidal potential of the tested chemicals showed good activity against the tested land snails. Ligands showed activity at concentration of 1000 ppm while their metal complexes show activity at concentration of 500 ppm. The highest activity (LC50) of complexes was shown at concentration of 5000 ppm.

Nickel complexes with non-innocent ligands generated by one-electron reduction of octahedral Schiff base nickel(ii) complexes with hemilabile ligands exhibited excellent catalytic activities of over 5000 TONs through a metal-ligand cooperation mechanism for hydrogen evolution from water under visible light irradiation.

Bis(6-amino-1,2-dihydropyridine-3,5-dicarbonitriles) containing thioether linkages are prepared via the condensation of bis(cyanoacetamides) with α-substituted cinnamonitriles in the presence of piperidine. The target compounds can also be obtained via a three-component reaction of bis(cyanoacetamides) with two equivalents of both aldehydes and malononitrile in ethanol containing piperidine as a base.

A zinc oxide catalyzed solvent-free mechanochemical process has been developed for the rapid construction of C-S bonds by using a nucleophilic substitution reaction (SN2 mechanism) that involves a variety of thiols and phenacyl/ benzyl/alkyl bromides. Notable advantages of this method in-clude its broad substrate scope, clean reaction profile, safety, scalability, high product yields at ambient conditions, and the recyclability of the catalyst. Furthermore, the prepared compounds are valuable building blocks for the synthesis of various biologically active molecules.

Disclosed are flexible polyamines, flexible amine-terminated polyformal adducts, flexible-amine-terminated polythioether adducts, compositions comprising flexible polyamines and isocyanate-terminated prepolymers, and compositions comprising flexible amine-terminated adducts and isocyanate-terminated prepolymers. Uses of the compositions as sealants, and particularly as aerospace sealants, are also disclosed.

A series of hexadentate ligands, H2Lm (m = 1-4), [1H-pyrrol-2-ylmethylene]{2-[2-(2-{[1H-pyrrol-2-ylmethylene]amino}phenoxy) ethoxy]phenyl}amine (H2L1), [1H-pyrrol-2-ylmethylene]{2- [4-(2-{[1H-pyrrol-2-ylmethylene]amino}phenoxy)butoxy]phenyl}amine (H 2L2), [1H-pyrrol-2-ylmethylene][2-({2-[(2-{[1H-pyrrol-2- ylmethylene]amino}phenyl)thio]ethyl}thio)phenyl]amine (H2L 3) and [1H-pyrrol-2-ylmethylene][2-({4-[(2-{[1H-pyrrol-2-lmethylene] amino}phenyl)thio]butyl}thio) phenyl]amine (H2L4) were prepared by condensation reaction of pyrrol-2-carboxaldehyde with {2-[2-(2-aminophenoxy)ethoxy]phenyl}amine, {2-[4-(2-aminophenoxy)butoxy]phenyl} amine, [2-({2-[(2-aminophenyl)thio]ethyl}thio)phenyl]amine and [2-({4-[(2-aminophenyl)thio]butyl}thio)phenyl]amine respectively. Reaction of these ligands with nickel(II) and copper(II) acetate gave complexes of the form MLm (m = 1-4), and the synthesized ligands and their complexes have been characterized by a variety of physico-chemical techniques. The solid and solution states investigations show that the complexes are neutral. The molecular structures of NiL3 and CuL2, which have been determined by single crystal X-ray diffraction, indicate that the NiL 3 complex has a distorted octahedral coordination environment around the metal while the CuL2 complex has a seesaw coordination geometry. DFT calculations were used to analyse the electronic structure and simulation of the electronic absorption spectrum of the CuL2 complex using TDDFT gives results that are consistent with the measured spectroscopic behavior of the complex. Cyclic voltammetry indicates that all copper complexes are electrochemically inactive but the nickel complexes with softer thioethers are more easily oxidized than their oxygen analogs.

A series of cyclic and acyclic diamido-bis-sulfide ligands were synthesized by N-acylation of 1,2-bis(2-aminophenylthio)ethane and 1,4-bis(2- aminophenylthio)butane with acetic, malonic, and 3,3'-dithiodipropionic acid chlorides or esters. The complexation of obtained ligands with CuII, NiII, and CoII salts in solution and on the gold electrode surface was studied. The formation of complexes of these ligands with copper(II) chloride in DMF is irreversible and accompanied by deprotonation of the amide nitrogen atoms.

Novel bifunctional chelating agents bearing an aromatic rigid backbone have been synthesized and characterized on the basis of spectroscopic techniques. These macrocyclic multidentate chelating agents were conjugated with monoclonal antibody which forms stable complexes with 99mTc with high radiochemical purity.

A rapid and convenient synthetic methodology for the cyclocondensative transformation of various alkylsulfanylphenylamines with bromoacetyl bromide by supporting on KF-alumina in ionic liquids [bmim] [Br] and [bmim][BF 4] has been developed to obtain 3-oxo-1,4-benzothiazine in good yields. The product is easily obtained by extraction with ethyl acetate and concentrating under vacuum. Easy recovery of ionic liquid and use in consecutive reactions is also reported.

Reactions of divalent metal salts of Co, Ni and Zn with 1,2-di(salicylaldimino-o-phenylthio)ethane (H2L1) and 1,2-di(naphthaldimino-o-phenylthio)ethane (H2L2), having N2O2S2 cores, and 1,2-di(O-salicylaldimino-o- hydroxyphenyl)ethane (H2L3), having a N2O 4 core, have been explored. Out of the three ligands and the nine products obtained from the corresponding reactions, two ligands and seven products were crystallographically characterized. However, all the ligands and the products were characterized by analytical and spectral methods. Reaction of H2L1 and H2L2 with Co(II) salts results in oxidative cleavage of the C-S bond to produce a CO(III) product bound to two dissimilar tridentate ligands formed as a result of the cleavage. The reaction of H2L1 and H2L2 with Co(III)acac in the presence of methanolic NaOH also shows cleavage of the C-S bond to give compounds similar to those obtained by reacting H2L 1 and H2L2 with Co(II) salts in the absence of additional external base. However, the reaction of Co(II) salt with H 2L3 did not lead to any C-O bond cleavage; rather it produced an octahedral CO(II) complex of the hexadentate H2L 3. Reactions of all these three ligands with Ni(II) salt resulted in octahedral complexes of the corresponding hexadentate ligands. In the case of Zn(II), while H2L3 with a N2O4 core resulted in an octahedral complex, H2L1 and H 2L2, both with a N2O2S2 core, produced pseudo-octahedral complexes whose Zn-S bond lengths are rather long. The conformations of both the 5-membered and 6-membered chelate rings formed in the products were evaluated. The extent of distortion exhibited in the geometry of these octahedral complexes was computed and appropriately compared.

The synthesis of new calix(aza), calix(aza-thia) crowns and bisbromoacetamides is reported in good yields.

Some complexes of dibenzyltin(IV) salts with two N2S2 donor ligands have been prepared and a number of reactions, viz. addition, replacement and cyclisation reactions were performed and studied.The complexes and their derivatives have been characterised and found to possess octahedral geometry on the basis of physicochemical studies.

Complexes of some diphenyltin(IV) salts with N2S2 donor ligands have been prepared and characterized on the basis of analytical, IR and 1H NMR spectral studies.The reactivity of these complexes with various reagents has also been studied.

The syntheses and reactions of sulfur coordinated ruthenium centers with CO, PR3, (R = Me, ), N2H4 and N2 are investigated.Reaction of with lithium-o-methylthiobenzenethiolate yields cis-, with Li2-o-benzenedithiolate the cis-(2-)-ion is obtained, which can be isolated either as the NMe4 salt or reacted further with 1,2-C2H4Br2 to give cis-, (dttd(2-) = 2,3,8,9-Dibenzo-1,4,7,10-tetrathiadecane(2-)).In all three complexes the CO ligands are relatively inert to substitution; refluxing of (2-) in EtOH in the presence of excess PMe3, however, and subsequent alkylation with 1,2-C2H4Br2 yields . is obtained from and Li2-dttd, the synthesis of which is also described.In the PMe3 ligands are inert, but in 3)2(dttd)> one P3 ligand is easily substituted by CO or N2H4 yielding 3)dttd> or 3)dttd> respectively; 3)2(dttd> is obtained from 3)3Cl2> and H2-dttd.The complexes are characterized by elemental analyses, IR, 1H NMR and mass spectroscopy. - Key words: Ruthenium Sulfur Carbonyl Phosphine Hydrazine Complexes