DR. SAIKAT SARKAR
@chakdahacollege.ac.in
Associate Professor
Chakdaha College
EDUCATION
M.Sc., Ph.D.
RESEARCH, TEACHING, or OTHER INTERESTS
Inorganic Chemistry, Spectroscopy, Catalysis, Materials Chemistry
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
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...
Saikat Sarkar, Sanat Kumar Nag, Asoke Prasun Chattopadhyay, Kamalendu Dey, Sk. Manirul Islam, Avijit Sarkar, and Sougata Sarkar
Elsevier BV
E Bekyarova, S Sarkar, S Niyogi, M E Itkis, and R C Haddon
IOP Publishing
Abstract Chemistry will play an increasingly important role in the realization of graphene applications. The chemical formation of covalent carbon–carbon bonds involving the basal plane carbon atoms offers an alternative approach to the control of the electronic properties of graphene, and potentially allows the generation of insulating and semiconducting regions in graphene wafers. This review summarizes recent progress in the covalent modification of epitaxial graphene and the effect that chemistry has on the electronic and magnetic properties of the material.
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.
S. M. Islam, Anupam Singha Roy, Paramita Mondal, Sanchita Mondal, Manir Mubarak, Dildar Hossain, and Saikat Sarkar
Wiley
Three polymer-anchored metal complexes (Co, Cu, and Pd) were synthesized and characterized. The catalytic performance of these complexes was tested for the oxidation of olefins and aromatic alcohols. These complexes showed excellent catalytic activity and high selectivity. These complexes selectively gave epoxides and aldehydes from olefins and alcohols, respectively. Individually, the effect of various solvents, oxidants, substrate oxidant molar ratios, temperatures, and catalyst amounts for the oxidation of cyclohexene and benzyl alcohol were studied. Under optimized reaction conditions, 96, 81, and 71% conversions of cyclohexene and 86, 79, and 73% conversions of benzyl alcohol were obtained with Co(II), Cu(II), and Pd(II) catalysts, respectively. The catalytic results reveal that these complexes could be recycled more than five times without much loss in activity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Manirul Islam, Paramita Mondal, Sanghamitra Mukherjee, Manir Mobarak, Anupam Sigha Roy, Sanchita Mondal, and Saikat Sarkar
Wiley
BACKGROUND: Heterogenization of homogeneous catalyst has become an interesting process for the catalytic oxidation of olefins and aromatic alcohol. This may provide a new kind of catalyst that is not only friendly to the environment but also exhibits higher thermal and chemical stabilities.
RESULTS: Polymer anchored Schiff-base complexes of iron(III), copper(II) and cobalt(II) have been synthesized and characterized. The catalytic potential of these complexes has been tested for the oxidation of cyclohexene. The effect of varying solvent, oxidant, substrate oxidant molar ratio, temperature and catalyst amount has been studied. Under optimized reaction conditions 91, 88 and 81% conversion of cyclohexene was obtained with Fe(III), Cu(II) and Co(II) catalysts, respectively. Moreover, the oxidation of other substrates, such as styrene, benzylalcohol, toluene and 1-hexene were also efficiently carried out by these catalysts.
CONCLUSION: The immobilized complexes showed excellent catalytic activity along with high selectivity for the oxidation of olefins and alcohols. The catalysts can be recycled more than five times without any noticeable loss of catalytic activity. Copyright © 2009 Society of Chemical Industry
Susobhan Biswas, Golam Mostafa, Ian M. Steele, Saikat Sarkar, and Kamalendu Dey
Elsevier BV
Saikat Sarkar, Susobhan Biswas, and Kamalendu Dey
Elsevier BV
Saikat Sarkar, Susobhan Biswas, Meng-Sheng Liao, Tapas Kar, Yildirim Aydogdu, Fethi Dagdelen, Golam Mostafa, Asoke Prasun Chattopadhyay, Glenn P.A. Yap, Rui-Hua Xie,et al.
Elsevier BV
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.
Susobhan Biswas, Saikat Sarkar, Ian M. Steele, Sougata Sarkar, Golam Mostafa, Bijali Bikash Bhaumik, and Kamalendu Dey
Elsevier BV
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.
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.
Tapas Kar, Meng-Sheng Liao, Susobhan Biswas, Saikat Sarkar, Kamalendu Dey, Glenn P.A. Yap, and Kevin Kreisel
Elsevier BV
Susobhan Biswas, Saikat Sarkar, Kamalendu Dey, Bimal Jana, Tarakdas Basu, Glenn P.A. Yap, and Kevin Kreisel
Elsevier BV
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.
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.
Saikat Sarkar and Kamalendu Dey
Elsevier BV
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.
Saikat Sarkar, Yildirim Aydogdu, Fethi Dagdelen, Bijali Bikash Bhaumik, and Kamalendu Dey
Elsevier BV
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.