Cu(II)-Based Nanofibrous Metallogel for Phenoxazinone Synthase-like Activity Sougata Sarkar, Pradip K. Maji, Yuichi Negishi, Soumen Dutta, Tarak N. Das, Rahul Pan, and Saikat Sarkar American Chemical Society (ACS) Metallogel formation by an individual ligand is well known, but simultaneous need of two ligands in selective metallogelation is relatively less common. In our present study, we have shown that dis...
Synthesis, spectroscopic characterization and antimicrobial studies of oxomolybdenum(v) and dioxomolybdenum(VI) complexes with NNS donor tridentate Schiff base ligands
Synthesis, characterization, and density functional study of some manganese(III) Schiff-base complexes Susobhan Biswas, Tapas Kar, Saikat Sarkar, and Kamalendu Dey Informa UK Limited Some Mn(III) complexes of N,N′-(2-hydroxy)propylenebis(acetylacetoneimine) (abbreviated to H2L1) and N,N′-(2-hydroxy)propylenebis(2-imino-3-oximino)butane (abbreviated to H2L2), [Mn(III)(Lig)(X)] (where Lig stands for the dianion of the Schiff-base ligands and X stands for CH3COO−, Cl−, Br−, I−) were synthesized. The complexes are characterized with the help of elemental analyses, magnetic moments, spectroscopic data (UV-Vis, infrared), and molecular weight determination (measured by Rast's method). The structures of the complexes were obtained using density functional theory (DFT). DFT calculation shows that 1–4 and 8 are trigonal-bipyramidal whereas 5–7 are square-pyramidal.
Transition metal complexes of Schiff base ligands of 3-formylsalicylic acid: Synthetic pathways and useful properties
Reactions of 2-(1-carboxyl-2-hydroxyphenyl)thiazolidine with chromium(III) salts leading to newer synthesis of chromium(III) complexes Susobhan Biswas, Saikat Sarkar, Bijali Bikash Bhaumik, and Kamalendu Dey Informa UK Limited Reactions of 2-(L-carboxyl-2-hydroxyphenyl)thiazolidine with different chromium(III) salts [CrCl3 · 6H2O, K3[Cr(SCN)6], NH4[Cr(NH3)2(SCN)4] · H2O, [Cr(urea)6]Cl3 · 3H2O and [Cr(CH3COO)2H2O]2] under varied reaction conditions afforded many new mixed-ligand chromium(III) complexes. The ligand is a tridentate dibasic NSO donor except for complexes 1 and 4 where two moles of the ligand are present for each molecule of complex, one functioning as a dibasic tridentate (NSO) and the other as a monobasic bidentate (NS) (phenolic OH and carboxylic COOH groups remaining uncoordinated). The complexes have been characterized by elemental analyses, magnetic susceptibilities, molar conductances, molecular weights and spectroscopic (IR, Uv-vis) data. The ligand field parameters and NSH Hamiltonian parameters suggest tetragonal geometries of the complexes.
Synthesis and characterization of oxovanadium(IV), vanadium(IV) and oxovanadium(V) complexes of tetradentate Schiff bases. Attempted preparation of vanadium-carbon bonded compounds through desilylation Saikat Sarkar, Kamalendu Dey, Susobhan Biswas, and Bijali bikash Bhaumik Informa UK Limited Condensation of 1,3-diaminopropane-2-ol with diacetylmonoxime, acetylacetone, salicylaldehyde and orthohydroxyacetophenone yielded the tetradentate Schiff bases N,N′-(2-hydroxy)propylenebis{(2-imino-3-oximino)butane} (H2dampnol), N,N′-(2-hydroxy)propylenebis(acetylacetoneimine) (H2acacpnol), N,N′-(2-hydroxy)propylenebis-(salicyalaldimine) (H2salpnol) and N,N′-(2-hydroxy)propylenebis(7-methylsalicylaldimine) (H2ohacpnol), respectively. The ligands form complexes with oxovanadium(IV), vanadium(IV) and oxovanadium(V) salts. Some mixed ligand complexes involving σ-bonded phenyl and benzyl radical along with tetradentate ligand, H2L (where, H2L stands for H2dampnol, H2acacpnol, H2salpnol or H2ohacpnol) of the types [(L)V(C6H5)2]CH3OH and [(L)V(CH2Ph)2]CH3OH have been synthesized, characterized and also provide the syntheses of some new organovanadium(IV) complexes. Silylation coupled with desilylation have been employed as a route to new organovanadium(IV) complexes. All the complexes have been characterized with the help of elemental analyses, molar conductance values, molecular weights, magnetic moments and spectroscopic (IR, UV-Vis, ESR) data.
Coordination complexes of titanium, zirconium and tin having metal-carbon bonds with dibasic NSO donor Schiff base ligand. Syntheses and characterization Saikat Sarkar, Susobhan Biswas, Kamalendu Dey, and Bijali bikash Bhaumik Informa UK Limited The reaction of 3-formylsalicylic acid with morpholine N-thiohydrazide produces 3-carboxy-2-hydroxybenzaldehyde morpholine N-thiohydrazone (H2chbmth) which remains in equilibrium in solution with its corresponding thiol form H3chbmthol having an NSO donor set of atoms. The reactions of the thiohydrazone ligand with different organometallic compounds viz. R2MCl2 (R = π-C5H5 & M = Ti/Zr; R = Me/Ph & M = Sn; R = OMe & M = Sn), (π-C5H5)2Ti(OMe)Cl2 and RMCl3 (R = Me/Ph & M = Sn; R = π-C5H5 & M = Ti) leading to the syntheses of many new organometallic derivatives have been studied. In all of the complexes the dianion of the H3chbmthol ligand functions as a dibasic tridentate NSO donor. The reactions of [(π-C5H5)Ti(Hchbmthol)Cl] and [MeSn(Hchbmthol)Cl], isolated in this study, with Me3SiE (where, E stands for NMe2 and C≡CPh) and MeSH have also been studied and many new organoderivatives of these two metal ions isolated. All the compounds under study have been characterized by elemental analyses, magnetic susceptibilities, molar conductance values, molecular weights and spectroscopic (UV-Vis, IR, 1H NMR) data. Based upon these data the geometry of the compounds has also been proposed.
Synthesis and characterization of a new thiohydrazone ligand, 3-carboxy-2-hydroxybenzaldehydemorpholine N-thiohydrazone and its metal complexes Kamalendu Dey, Saikat Sarkar, Sanjib Mukhopadhyay, Alok Kumar Mallik, Susobhan Biswas, and Bijali Bikash Bhaumik Informa UK Limited The reaction of 3-formylsalicylic acid with morpholine N-thiohydrazide in ethanol leading to the formation of a new thiohydrazone, 3-carboxy-2-hydroxybenzaldehydemorpholine N-thiohydrazone (H2chbmth) is described. This thiohydrazone ligand remained as the thio-keto form in the solid state. However, thioketo- and a small amount of the thiol-tautomeric forms (H2chbmth and H3chbmthol, respectively) remain in equilibrium in solution. The reactions of the ligand with different metal salts (in 1 : 1 molar ratio) leading to the synthesis of many new metal complexes have been studied. Depending on pH of the reaction medium and the nature of the metal salt used, the ligand is found to be monobasic tridentate, dibasic tridentate, monobasic bidentate or neutral bidentate giving complexes [Co(H2chbmth)2]X2, [X = NO3 (11), ½SO4 (13)]; [Cd(H2chbmth)(H2O)2]SO4 (21); [M(Hchbmth)X], [M = Cu(II) and X = Cl (1), NO3 (2), CH3COO (4); M = Ni(II) and X = Cl (6), NO3 (7); M = Co(II) and X = NO3 (12), CH3COO (14); M = Zn and X = Cl (17), CH3COO (18); M = Hg(II) and X = Cl (23), CH3COO (24)]; [Ni(H2chbmthol)(acac)] (9); [Co(Hchbmth)Cl]·2H2O (10), [Cu(Hchbmth)H2O]½SO4 (3); [Cu(Hchbmthol)]2 (5); [M(Hchbmthol)X], [M = Ni(II) and X = H2O (8); M = VO(II) and X = H2O (15); M = Pd(II) and X = H2O (16); M = Zn(II) and X = NH3 (19); M = Cd(II) and X = H2O (20), NH3 (22); M = Hg(II) and X = NH3 (25)]. In situ reactions of metal salts with the ligand components (i.e. 3-formylsalicylic acid and morpholine N-thiohydrazide) in ethanol resulted the same complexes. The complexes are characterized by elemental analyses, magnetic susceptibilities, molar conductances, molecular weights and spectroscopic (IR, ESR, 1H NMR and UV-visible) data.
Synthesis, characterization and coordination behavior of 2-(1-carboxyl-2-hydroxyphenyl)thiazolidine Kamalendu Dey, Saikat Sarkar, Sanjib Mukhopadhyay, Susobhan Biswas, and Bijali Bikash Bhaumik Informa UK Limited The reaction of 3-formylsalicylic acid with 2-aminoethanethiol produces 2-(1-carboxyl-2-hydroxyphenyl)thiazolidine (H2chptz) which remains in equilibrium in solution with its corresponding Schiff base, 3-carboxysalicylidenethioethanolimine (H3mcsalim) having an NSO-donor set of atoms. The reactions of the thiazolidine ligand with different metal salts leading to the synthesis of many new metal complexes and organometallic derivatives have been studied. For all the complexes the dianion of the Schiff base, H3mcsalim acts as a tridentate NSO donor ligand. The reactions of [(Hmcsalim)Ti(π-C5H5)Cl] and [(Hmcsalim)Sn(Me)Cl], isolated in this study, with Me3SiE (where, E stands for SMe, NMe2 and C≡CPh) have also been studied. The elemental analyses, magnetic susceptibilities, molar conductance values, EPR-study, CV, molecular weights and spectroscopic (UV-Vis, IR, 1H NMR) data characterize all the compounds under study. Based upon these data the geometry of the compounds has also been proposed.
Homo- and hetero-binuclear complexes of a compartmental Schiff base ligand. Synthesis and characterisation
Synthesis and characterization of some mononuclear complexes of the schiff base {N,N′-2,2′-bis(aminoethyl)-methylaminebis-(3- carboxysalicylaldimine)} Kamalendu Dey, Ranabir Bhowmick, Susobhan Biswas, Dhananjoy Koner, and Saikat Sarkar Informa UK Limited Reaction of 3‐formylsalicylic acid with diethylenetriamine yielded the Schiff base {N,N′–2,2′‐bis(aminoethyl)methylaminebis(3‐carboxysalicylaldimine)}, abbreviated as H4fsadien. The interaction of H4fsadien with CoCl2 · 6H2O, Ni(OAc)2 · 4H2O, Cu(OAc)2 · H2O, Zn(OAc)2 · 2H2O, Na2MoO4 · 2H2O, WO2(acac)2, (NH4)2[MoOCl5], (pyH)2[Mo(SCN)6], FeSO4 · 7H2O and FeCl3 · 6H2O under varied reaction conditions have been studied. The reactions of some of the new metal complexes isolated in this study have also been investigated with a view to develop new preparative methods. The Schiff base H4fsadien was found to act as a dibasic tetradentate ligand or as a dibasic pentadentate ligand, by using N2O2 or N3O2 donor sites, respectively. Elemental analyses, molecular weights, magnetic moment values, molar conductances and spectroscopic (IR, UV‐Vis and 1H NMR) data characterize the complexes. The authors are thankful to the Regional Sophisticated Instrumentation Centre, the Central Drug Research Institute, Lucknow, for elemental analyses and spectroscopic data. One of the authors (SS) is grateful to the University of Kalyani for Junior Research Fellowship.
Synthesis and characterization of some new manganese(II) complexes, manganese(III) heterochelates, and μ-dioxo-dimanganese(IV) complexes involving tetradentate Schiff bases Kamalendu Dey, Susobhan Biswas, and Saikat Sarkar Informa UK Limited Abstract Condensation of 1,3‐diaminopropane‐2‐ol with diacetylmonoxime and acetylacetone yielded the tetradentate Schiff bases N,N′‐(2‐hydroxy)propylene‐bis{(2‐imino‐3‐oximino)butane} (H2L1) and N,N′‐(2‐hydroxy)propylene‐bis(acetylacetoneimine) (H2L2), respectively. The ligands form mononuclear manganese(II) complexes of the type [Mn(II)(L1)] (1) and [Mn(II)(L2)] (3), which are used for the formation of the manganese(III) heterochelates of the type [Mn(III)(L)(L‐L)] (where H2L = H2L1 or H2L2; L‐L = anion of acetylacetone or salicylaldehyde). Cationic heterochelates of the type [Mn(L)(L‐L)]ClO4 where H2L = H2L1 or H2L2 and L‐L = ethylenediamine and N,N′‐propylene‐bis(benzaldimine) (L3) have been synthesized by the reactions of bis(acetylacetonato)manganese(II) or bis(salicylaldehydato)manganese(II) with the preformed Schiff bases or by the reactions of [Mn(II)(L1)] or [Mn(II)(L2)] with L‐L in absolute alcohol under reflux. Some of the complexes, synthesized here, may be used as precursors in the synthesis of higher nuclearity manganese complexes. Air oxidation of [Mn(II)(L1)] (1) and [Mn(II)(L2)] (3) in DMF yielded the dark‐brown µ‐dioxo‐bis‐[N,N′‐(2‐hydroxy)propylene‐bis{(2‐imino‐3‐oximino)butane}]dimangenese(IV) (2) and µ‐dioxo‐bis[N,N′‐(2‐hydroxy)propylene‐bis{(acetylacetoneimine)}]dimangenese(IV) (4) complexes, respectively. All of the complexes have been characterized with the help of elemental analyses, molar conductance values, molecular weights, magnetic moments, and spectroscopic (IR, UV‐VIS, ESR) data.
Synthesis, characterization and reactions of metal complexes of 2-(1-formyl-ferrocene)thiazoline and 2-methyl-2-(1-ferrocene)thiazoline