Sumit Singh Rajput
@iitbhilai.ac.in
Indian Institute of Technology Bhilai
Scopus Publications
Scholar Citations
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Scopus Publications
Devendra Kumar, Bhanendra Sahu, Subrata Dolui, Swati Singh Rajput, Md. Mehboob Alam, and Sanjib Banerjee
Elsevier BV
Swati Singh Rajput, Robert Zaleśny, and Md Mehboob Alam
American Chemical Society (ACS)
In this work, we have employed electronic structure theories to explore the effect of the planarity of the chromophore on the two-photon absorption properties of bi- and ter-phenyl systems. To that end, we have considered 11 bi- and 7 ter-phenyl-based chromophores presenting a donor−π–acceptor architecture. In some cases, the planarity has been enforced by bridging the rings at ortho-positions by −CH2 and/or –BH, –O, –S, and –NH moieties. The results presented herein demonstrate that in bi- and ter-phenyl systems, the planarity achieved via a −CH2 bridge increases the 2PA activity. However, the introduction of a bridge with the –BH moiety perturbs the electronic structure to a large extent, thus diminishing the two-photon transition strength to the lowest electronic excited state. As far as two-photon absorption activity is concerned, this work hints toward avoiding –BH bridge(s) to enforce planarity in bi- and ter-phenyl systems; however, one may use −CH2 bridge(s) to achieve the enhancement of the property in question. All of these conclusions have been supported by in-depth analyses based on generalized few-state models.
Banana Tejendra, Swati Singh Rajput, and M. Mehboob Alam
Wiley
Abstractn‐Helicenes and n‐Phenylenes are interesting examples of twisted molecules, where although the atoms are connected through conjugated ‐bonds, the ‐conjugation is largely hindered by the twisted nature of the bonds. Such structures provide a unique opportunity to study the effect of twisted ‐system on non‐linear optical properties. In this work, we studied the two‐photon absorption in donor‐acceptor substituted n‐helicenes and n‐phenylenes employing the state‐of‐the‐art RI‐CC2 method and reported a unique feature we observed in n=7 systems. We found that both 7‐helicene and 7‐phenylene systems exhibit largest two‐photon absorption than other members in their respective classes. Furthermore, using generalized few‐state model, we provided a detailed microscopic mechanism of this unique observation involving participation of different transition dipole moment vectors and their relative orientations.
S S Rajput, C Upadhyay, S Gangopadhyay, and F Fernandes
SAGE Publications
The objective of the present study is to develop a better understanding of machining performance of TiAlN coated tools during face milling of AISI 1045 medium carbon steel. The influences of three different cutting conditions (roughing, finishing, and aggressive conditions) were investigated on cutting forces, chip temperature, tool wear, surface roughness, and chip characteristics. The highest cutting forces were obtained under roughing condition, while, aggressive mode of machining (high values of cutting speed, feed, and depth of cuts) resulted in the highest chip temperature, crater, and flank wear. Material adhesion and coating delamination were predominant under roughing condition. On the other hand, aggressive condition exhibited diffusion wear causing large depth of crater and severe thermal cracks leading to fracture of the cutting edge. Attrition and abrasion wear were also evident. The results of cutting forces, chip temperature, surface roughness, and chip characteristics were correlated with those of tool wear. Results were found to be beneficial in recommending appropriate criteria for choosing different cutting conditions in face milling of AISI 1045 steel using TiAlN coated insert.
Swati Singh Rajput and Mehboob Alam
Wiley
AbstractThe aim of this work is to demonstrate the possibility of using propellane in designing a molecule that can absorb in three different wavelength regions and their nonlinear optical (NLO) activity can be fine‐tuned by varying the three wings. We considered 22 tailor‐made propellane derivatives consisting of phenyl, naphthyl, and biphenyl wings for this purpose. Using the state‐of‐the‐art linear and quadratic response methods within TD‐DFT and RI‐CC2 theories and a suitable generalized few‐state model that quantifies the effect of orientation of different transition moments on NLO properties, we discussed how and why the linear and nonlinear optical activity of propellane vary when the three wings are assembled successively to construct a full‐propellane.
S.S. Rajput, S. Gangopadhyay, T.B. Yaqub, A. Cavaleiro, and F. Fernandes
Elsevier BV
Bartosz Krajewski, Swati Singh Rajput, Marta Chołuj, Elżbieta Wojaczyńska, Andrzej Miniewicz, Md. Mehboob Alam, and Robert Zaleśny
Royal Society of Chemistry (RSC)
In this study we aim to investigate, employing electronic and vibrational-structure theories, “structure–first hyperpolarizability” relationships for a series of 16 propellanes presenting a wide palette of substituents with varying electron-accepting/donating capabilities.
Pranabendu Das, Swati Singh Rajput, Manik Das, Soumik Laha, Indranil Choudhuri, Nandan Bhattacharyya, Arindam Das, Bidhan Chandra Samanta, Md. Mehboob Alam, and Tithi Maity
Elsevier BV
S.S. Rajput, S. Gangopadhyay, A. Cavaleiro, A. AL-Rjoub, Ch. Sateesh Kumar, and F. Fernandes
Elsevier BV
A. AL-Rjoub, A. Cavaleiro, S.S. Rajput, and F. Fernandes
Elsevier BV
Kafeel Ahmad Siddiqui, Swati Singh Rajput, and Prem Lama
Springer Science and Business Media LLC