Biswajit SadhuBhabha Atomic Research Centre | BARC · Health Physics Division
Biswajit Sadhu
M.Sc, M.Tech, Ph.D
About
49
Publications
12,145
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
433
Citations
Citations since 2017
Introduction
I am a computational chemist and data analyst. I have expertise in topological data analysis, machine learning methods. My research interest lies on understanding the basic and fundamental aspects of chemical processes. I use a range of techniques including but not limited to quantum mechanics, molecular dynamics, metadynamics along with graph theoretic analyses tools for the research projects. I am passionate about exploring new data analysis methods, and open to collaborative projects.
Additional affiliations
January 2023 - December 2028
February 2020 - present
May 2018 - July 2018
Education
January 2013 - March 2017
October 2011 - December 2012
Publications
Publications (49)
Recent work [Mirth et al., J. Chem. Phys. 154, 114114 (2021)] has demonstrated that sublevelset persistent homology provides a compact representation of the complex features of an energy landscape in 3 N-dimensions. This includes information about all transition paths between local minima (connected by critical points of index ≥1) and allows for di...
Recent work (J. Chem. Phys. 154, 114114) has demonstrated that sublevelset persistent homology provides a compact representation of the complex features of an energy landscape in $3N$-dimensions. This includes information about all transition paths between local minima (connected by critical points of index > 1), and allows for differentiation of e...
A phenomenological model has been developed for the mechanism of action of phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. The "Dispersion by Competitive Intermolecular Interaction" model (DCI) explicitly considers the strength and prevalence of different intermolecular interactions that influence the...
A phenomenological model has been developed for the mechanism of action of phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. Unlike the qualitative “cosolvent” and “cosurfactant” paradigms previously discussed in the literature, the new “Dispersion by Competitive Interaction” model (DCI) explicitly consi...
A phenomenological model has been developed for the mechanism of action of phase modifiers as additives that control aggregation phenomena within water-in-oil emulsions. Unlike the qualitative “cosolvent” and “cosurfactant” paradigms previously discussed in the literature, the new “Dispersion by Competitive Interaction” model (DCI) explicitly consi...
A set of new oxidovanadium(IV) complexes, [VO(4-NO2C6H4CH = CHCONHO)2] (1), [VO(4-NO2C6H4CH = CHCONHO)2(2–CNC5H4N)] (2) and [VO(4-NO2C6H4CH = CHCONHO)2(4-CNC6H4NH2)] (3), have been synthesized and characterized by different analytical techniques (magnetic susceptibility, molar conductivity, elemental analysis) and spectroscopic techniques, viz. FTI...
Amphiphile self-assembly in non-polar media is often enhanced by polar co-solutes. This is observed within many biphasic separations processes, where amphiphiles mediate transport of water and acid into organic solution. A myriad of competitive intermolecular interactions have thus far prevented a fundamental understanding of the individual and dua...
Amphiphile self-assembly in non-polar media is often enhanced by polar co-solutes. This is observed within many biphasic separations processes, where amphiphiles mediate transport of water and acid into organic solution. A myriad of competitive intermolecular interactions have thus far prevented a fundamental understanding of the individual and dua...
Amphiphile self-assembly in non-polar media is often enhanced by polar co-solutes. This is observed within many biphasic separations processes, where amphiphiles mediate transport of water and acid into organic solution. A myriad of competitive intermolecular interactions have thus far prevented a fundamental understanding of the individual and dua...
Hypothesis: Amphiphile self-assembly in non-polar media is often enhanced by polar co-solutes, as observed upon amphiphile mediated transport of water and acid into organic solution. Such co-extraction precludes understanding the individual roles of polar solutes upon self-assembly. Using this liquid-liquid extraction (LLE) system as a test-bed, we...
Hypothesis: Amphiphile self-assembly in non-polar media is often enhanced by polar co-solutes, as observed upon amphiphile mediated transport of water and acid into organic solution. Such co-extraction precludes understanding the individual roles of polar solutes upon self-assembly. Using this liquid-liquid extraction (LLE) system as a test-bed, we...
The title complex [PdCl(L)] (1), is obtained from the reaction of SCS pincer ligand HL (where, HL = N,N'-di-tert-butylbenzene-1,3-dicarbothioamide) with lithium tetrachloropalladate (II) in methanol. The compound 1 is characterized by elemental analysis, FTIR, ¹H, and ¹³C-NMR spectroscopy, UV-Vis spectroscopy, powder X-ray diffraction and X-ray cry...
Real solutes are often highly influenced by the local, and sometimes extended, implicit and explicit interactions that they have with solvent. From a modeling and simulation perspective, solvent effects can be accounted in a number of different ways, each with their own bias toward the incorporation of correct physics. In turn, these methods influe...
Although the self-assembly of amphiphiles is well-studied in aqueous solutions, much less is understood about the fundamental driving forces and structure property relationships in non-polar media. In recent work [Journal of Physical Chemistry B, 2020, 124, 10822.] the authors have studied a series of malonomide-based amphiphiles that are relevant...
The self-assembly of amphiphiles is often modified by the presence of co-solutes and significant study has examined this behavior in aqueous systems. Much less is known about the role of polar co-solutes upon amphiphile aggregation within non-polar media, however such conditions are relevant to a variety of industrial processes - not the least of w...
The self-assembly of amphiphiles is often modified by the presence of co-solutes and significant study has examined this behavior in aqueous systems. Much less is known about the role of polar co-solutes upon amphiphile aggregation within non-polar media, however such conditions are relevant to a variety of industrial processes - not the least of w...
Although the self-assembly of amphiphiles is well-studied in aqueous solutions, much less is understood about the fundamental driving forces and structure property relationships in non-polar media. In recent work [Journal of Physical Chemistry B, 2020, 124, 10822.] the authors have studied a series of malonomide-based amphiphiles that are relevant...
Although the self-assembly of amphiphiles is well-studied in aqueous solutions, much less is understood about the fundamental driving forces and structure property relationships in non-polar media. In recent work [Journal of Physical Chemistry B, 2020, 124, 10822.] the authors have studied a series of malonomide-based amphiphiles that are relevant...
The need for efficient macrocyclic ligands that can sequester U(VI) has gained immense importance due to the increased applications of U(VI) in various sectors, including but not limited to nuclear energy. Structural attributes such as number and type of donor centers ("hard" and "soft") of ligands are essentially the key components for providing t...
The need for efficient macrocyclic ligands that can sequester U(VI) has gained immense importance due to the increased applications of U(VI) in various sectors, including but not limited to nuclear energy. Structural attributes such as number and type of donor centers ("hard" and "soft") of ligands are essentially the key components for providing t...
![Optimized structures of [Cs⁺·CC6] complex in the absence and presence...](publication/352442964/figure/fig5/AS:11431281185048124@1693516165546/Optimized-structures-of-CsCC6-complex-in-the-absence-and-presence-of-nitrate-counter_Q320.jpg)
Due to the long half-life of 137Cs (t 1/2 ∼ 30 years), the selective extraction of cesium (Cs) from high level liquid waste is of paramount importance in the back end of the nuclear fuel cycle to avoid long term surveillance of high radiotoxic waste. As 1,3-di-octyloxycalix[4]arene-crown-6 (CC6) is suggested to be a promising candidate for selectiv...
p>The oxidovanadium(IV) complex [VO(HL)<sub>2</sub>] ( 1 ) (where, HL = 4-nitrocinnamohydroxamate; 4-NO<sub>2</sub>C<sub>6</sub>H<sub>4</sub>CH=CHCONHOH) has been synthesized by the condensation reaction of VOSO<sub>4</sub>∙5H<sub>2</sub>O and potassium 4-nitrocinnamohydroxamate in methanol-water medium. The complex is characterized by elemental an...
The title complex [PdCl(L)] (1), is obtained from the reaction of SCS pincer ligand HL (where, HL = N,N'-di-tert-butylbenzene-1,3-dicarbothioamide) with lithium tetrachloropalladate (II) in methanol. The compound 1 is characterized by elemental analysis, FTIR, 1H, and 13C-NMR spectroscopy, UV-Vis spectroscopy, powder X-ray diffraction and X-ray cry...
A relativistic density functional theory (DFT) study is reported which aims to understand the complexation chemistry of An4+ ions (An = Th, U, Np, and Pu) with a potential decorporation agent, 5‐LIO(Me‐3,2‐HOPO). The calculations show that the periodic change of the metal binding free energy has an excellent correlation with the ionic radii and suc...
Soft donor ligands often provide higher selectivity for actinides(III) over chemically similar lanthanides(III), e.g., in the AmIII-EuIII pair. Frequently, the origin of such selectivity is associated with an increased covalency in actinide-ligand bonding. However, the relationship between the degree of covalency and ion selectivity has yet to reac...
During civil, nuclear or defense activities, internal contamination of actinides in humans and mitigation of their toxic impacts are of serious concern. Considering the health hazards of thorium (Th) internalization, an attempt was made to examine the potential of ten rationally-selected compounds/formulations to decorporate Th ions from physiologi...
In the context of mitigating the biological effects of internal radionuclide contamination and for efficient decorporation, the design and development of efficient chelators for lanthanide and actinide metal ions has become a central issue. Pioneering work of Raymond and coworkers (Chem. Rev. 2003, 103, 4207-4282) led to development of siderophore...
Selective separation of toxic heavy metals such as uranyl can be accomplished using ligands with stereognostic hydrogen bonding interactions to uranyl oxo group was proposed by Raymond and co-workers (T. S. Franczyk, K. R. Czerwinski and K. N. Raymond, J. Am. Chem. Soc., 1992, 114, 8138-8146). Recently, several ligands which possessing this weak in...
Bacterial NaK ion channel is distinctly different from other known ion channels due to its inherent non-selective feature. One of the unexplored and rather interesting feature is its ability to permeate divalent metal ions (such as Ca²⁺ and Ba²⁺) apart from monovalent alkali metal ions. Several intriguing questions on energetics and structural aspe...
Selective extraction of a radionuclide in the presence of other interfering ions is one of the vital steps in the back-end-of-the-nuclear fuel cycle. The presence of interfering cations (such as Ca2+) in the radioactive waste and involvement of multiple separation steps are known to be bottlenecks in the efficient Sr2+ extraction. Here, using free...
A plethora of chemical reactions is redox driven processes. The conversion of toxic and highly soluble U(VI) complexes to nontoxic and insoluble U(IV) form are carried out through proton coupled electron transfer by iron containing cytochromes and mineral surfaces such as machinawite. This redox process takes place through the formation of U(V) spe...
Rationale:
Mandelic acid is a complexing agent employed for the liquid chromatographic separation of actinides. However, the types of species and the structural details of the uranyl-mandelate complexes are still unknown. Understanding the nature of these complex species would provide better insight into the mechanism of their separation in liquid...
Recently, Auramine O (AuO), has been projected as a fluorescent fibril sensor, and it has been claimed that AuO has an advantage over the most extensively utilized fibril marker, Thioflavin-T (ThT), owing to the presence of an additional large red shifted emission band for AuO, which was observed exclusively for AuO in the presence of fibrillar med...
The geometric structures and electron transfer properties of type 1 Cu proteins are reasonably understood at the molecular level (E. I. Solomon and R. G. Hadt, Coord. Chem. Rev., 2011, 255, 774-789, J. J. Warren, K. M. Lancaster, J. H. Richards and H. B. Gray, J. Inorg. Biochem., 2012, 115, 119-126). Much understanding of type 1 copper electron tra...
The selective separation of uranyl ions from an aqueous solution is one of the most important criteria for sustainable nuclear energy production. We report herein a known, but unexplored extractant, tetraalkyl urea, which shows supreme selectivity for uranium in the presence of interfering thorium and other lanthanide ions from a nitric acid medium...
Electrospray ionization mass spectrometry (ESI-MS) technique was used to find out the type of species of uranyl with α-hydroxyisobutyric acid in positive and negative ion modes. It was found that the singly charged monomeric and doubly charged dimeric species were present in soft ionization conditions. The molecular level understanding on the struc...
![Table 9 . Energy Decomposition Analysis b (kcal mol −1 ) of M·CB[5]...](profile/Biswajit-Sadhu/publication/289530758/figure/tbl1/AS:645352260632578@1530875377555/Energy-Decomposition-Analysis-b-kcal-mol-1-of-MCB5-Complexes-M-3-Am-Eu-in_Q320.jpg)
Achieving an efficient separation of chemically similar Am3+/Eu3+ pair in high level liquid waste treatment is crucial for managing the long-term nuclear waste disposal issues. The use of sophisticated supramolecules in a rigid framework could be the next step toward solving the long-standing problem. Here, we have investigated the possibility of s...
Ion channels, such as potassium channels are known to discriminate ions to achieve remarkable selective transportation of K(+) over Na(+) through the membrane. Recently reported NaK ion channel, in contrary, seems to be an exception, as it is observed to permeate most of the group IA alkali metal cations and hence suggested to be nonselective in na...
Designing new and innovative receptors for the selective binding of radionuclides is central to nuclear waste management processes. Recently, a new multi-topic ion-pair receptor was reported which binds a variety of cesium salts. Due to the large size of the receptor, quantum chemical calculations on the full ion-pair receptors are restricted, thus...
The migration of potentially harmful radionuclides, such as, Cesium (Cs(137)) and Strontium (Sr(90)) in soil is governed by the chemical and biological reactivity of soil components. Soil organic matter (SOM) that can be modeled through fulvic acid (FA) is known to alter the mobility of radionuclide cations, Cs(+) and Sr(2+). Shedding light on the...
The effect of successive alkylation of the Cα atom adjacent to the carbonyl group in N,N-dialkyl amides (i.e., di(2-ethylhexyl)acetamide (D2EHAA), di(2-ethylhexyl)propionamide (D2EHPRA), di(2-ethylhexyl)isobutyramide (D2EHIBA), and di(2-ethylhexyl)pivalamide (D2EHPVA)) on the extraction behavior of hexavalent uranium (U(VI)) and tetravalent thorium...
Straight chain amide N,N-dihexyloctanamide (DHOA) has been found as a promising alternative extractant to tri-n-butyl phosphate (TBP) for the reprocessing of irradiated uranium and thorium based fuels. Unlike TBP, DHOA displays preferential extraction of Pu(IV) over U(VI) at higher acidities (≥ 3 M HNO3) and poor extraction at lower acidities. Dens...
Small angle neutron scattering (SANS) studies were carried out to compare the aggregation behavior of 1.1 M solutions of tributyl phosphate (TBP) and N,N-dihexyl octanamide (DHOA) dissolved in different deuterated diluents viz. n-dodecane, chloroform and benzene during the extraction of Th(IV) from nitric acid medium. The scattering data was treate...
2-(4'-pyridyl)benzimidazole (4PBI) can exist in several states of protonation, having three basic nitrogen atoms. The equilibria involving these states, in ground as well as in excited states, are found to be affected significantly by cyclodextrins (CDs). The formation of inclusion complexes of this compound with all three varieties of cyclodextrin...
Questions
Questions (5)
I often have confusion over proper definition of these two terms orbital mixing and orbital overlap. In case of energy decomposition analysis (EDA), we often get substantial orbital contribution in the metal-ligand bond, which not always correspond to better degree of overlap of orbitals but sometime point towards the orbital mixing contribution. In this context, it becomes confusing to understand these two aspects intuitively. Any comments on this aspect will be appreciated.
(IO3)- non bonding parameter for molecular dynamics simulation...
