TY - JOUR A1 - Dolai, Malay A1 - Saha, Urmila A1 - Goswami, Juli Nanda A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Ifseisi, Ahmad A. A1 - Biswas, Surajit ED - Bhattacharya, Biswajit T1 - Nickel(II)-mediated in situ complex formation with unexpected ligand transformations: crystal structures, DFT calculations, and catalytic activity in CO2 fixation reactions N2 - Two transformed ligands, namely 1,3,5-triazapentadienato(imidoylamidinato) and N-(methoxy(pyrimidin-2-yl)(pyrimidine-2-carboxamido)methyl)pyrimidine-2-carboxamide, are reported here as the first products derived from 2-cyano pyridine/pyrimidine, respectively, under nickel metal mediation in the presence of hydroxylamine hydrochloride in situ. Two different nickel-coordinated complexes (1 and 2) were formed. Single crystal X-ray diffraction revealed that complex 1 is a mononuclear complex with tetra-coordinated square planar geometry, whereas complex 2 is a dinuclear complex with hexa-coordinated distorted octahedral geometry. The synthetic pathways of both transformed ligands are explained with the support of energy calculations of different states via density functional theory (DFT) calculations. The catalytic addition reactions of epoxides and carbon dioxide efficiently produce organic cyclic carbonates in the presence of complexes 1–2, attributed to the presence of Lewis acidic nickel and Lewis basic centers, such as free amine, imine, methoxy, or nitrogen in complexes 1 and 2. Under mild reaction conditions (1 atm CO2 pressure and 60 °C temperature), different types of epoxides (exocyclic, endocyclic, and aromatic epoxides) yield high levels of respective cyclic carbonates in the presence of both complexes 1–2 as catalysts, with tert-butylammonium bromide (TBAB) acting as a co-catalyst. The high turnover number (TON) and turnover frequency (TOF) of these catalytic reactions clearly indicate the efficacy of the two catalysts. KW - Catalytic activity in CO2 fixation reactions DFT calculations KW - Nickel(II)-complex KW - In situ complex formation KW - Crystal Structure PY - 2025 DO - https://doi.org/10.1039/d4nj01801j SN - 1369-9261 VL - 49 IS - 11 SP - 4451 EP - 4463 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Sagar A1 - Dolai, Malay A1 - Nanda Goswami, Juli A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Drew, Michael G. B. A1 - Chattopadhyay, Shouvik A1 - Sarkar, Rabi Sankar A1 - Sunil, Appu A1 - Novitchi, Ghenadie A1 - Moreno-Pineda, Eufemio A1 - Wernsdorfer, Wolfgang T1 - From strong to weak interaction: Reconciling SQUID and μSQUID-EPR data in anomalous Co(ii) dimers N2 - Magnetic molecules have been proposed as scaffolds for novel quantum technologies, ranging from quantum sensing and quantum memory to multilevel quantum bits (qudits) and fault-tolerant quantum computation. Integration of magnetic molecules into cutting-edge applications hinges on a deep understanding and tunability of their spin states. To date, the strategic manipulation of the local environment of the ion and careful selection of the magnetic core have enabled the desired tunability and scalability of the spin states. For such goals, however, extracting the anisotropic parameters that dictate the characteristics of the Spin Hamiltonian is challenging, especially for molecules consisting of multiple magnetic cores. We address these challenges by studying two cobalt(II) dinuclear systems, complicated by inherent spin–orbit coupling. We explore the magnetic properties of these systems in two temperature regimes: (i) at sub-Kelvin temperatures employing single crystals at 30 mK using a unique μSQUID-EPR technique that examines the microwave absorption peaks in the magnetisation data and their variation with field angle and frequency; and (ii) in bulk employing convectional SQUID magnetometry above 2 K i.e., χMT(T) and M(H). Unexpectedly, sub-Kelvin temperature investigations reveal a negligible interaction, whereas the SQUID data reveal a much stronger interaction between the Co(II) ions. An understanding of these data is developed based on a strong coupling model and the coupling of two moieties with a spin-effective ground state. KW - cOBALT(II)-complex KW - In situ complex formation KW - Magnetic property KW - Crystal structure PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641421 DO - https://doi.org/10.1039/D5QI01387A SN - 2052-1553 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) CY - Cambridge AN - OPUS4-64142 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pakrashy, Sourav A1 - Chakraborty, Souvik A1 - Manna, Sounik A1 - Nanda Goswami, Juli A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Mandal, Jishu A1 - Misra, Sourav A1 - Maiti Choudhury, Sujata A1 - Okla, Mohammad K. A1 - Bose, Adity A1 - Maurya, Pawan Kumar A1 - Majhi, Anjoy A1 - Dolai, Malay T1 - Inhibition of Human Colorectal Cancer by a Natural Product 7-Acetylhorminone and Interactions with BSA/HSA: Multispectral Analysis and In Silico and In Vitro Studies N2 - We have semi-synthesized a natural product 7-acetylhorminone from crude extract of Premna obtusifolia (Indian headache tree), which is active against colorectal cancer after probation through computational screening methods as it passed through the set parameters of pharmacokinetics (most important nonblood–brain barrier permeant) and drug likeliness (e.g., Lipinski’s, Ghose’s, Veber’s rule) which most other phytoconstituents failed to pass combined with docking with EGFR protein which is highly upregulated in the colorectal carcinoma cell. The structure of 7-acetylhorminone was confirmed by single crystal X-ray diffraction studies and 1H NMR, 13C NMR, and COSY studies. To validate the theoretical studies, first, in vitro experiments were carried out against human colorectal carcinoma cell lines (HCT116) which revealed the potent cytotoxic efficacy of 7-acetylhorminone and verified preliminary investigation. Second, the drugability of 7-acetylhorminone interaction with serum albumin proteins (HSA and BSA) is evaluated both theoretically and experimentally via steady-state fluorescence spectroscopic studies, circular dichroism, isothermal titration calorimetry, and molecular docking. In summary, this study reveals the applicability of 7-acetylhorminone as a potent drug candidate or as a combinatorial drug against colorectal cancer. KW - Molecular docking KW - In situ synthesis KW - ADMET PY - 2024 DO - https://doi.org/10.1021/acsabm.4c00335 VL - 7 IS - 5 SP - 3414 EP - 3430 PB - American Chemical Society (ACS) AN - OPUS4-61114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goswami, Juli Nanda A1 - Haque, Najirul A1 - Seikh, Asiful H. A1 - Bhattacharya, Biswajit A1 - Emmerling, Franziska A1 - Bar, Nimai A1 - Ifseisi, Ahmad A. A1 - Biswas, Surajit A1 - Dolai, Malay T1 - Carboxylative cyclization of propargyl alcohols with carbon dioxide for the synthesis of α-alkylidene cyclic carbonates in presence of Co(III) schiff base complex catalyst N2 - A cobalt(III) complex, [Co(L)3](DMF) (1) of Schiff base ligand HL, 2-((E)-(benzylimino)methyl)-4-bromophenol is prepared and single crystal X-ray structural analysis have also been performed. The structures of complex 1 showed hexa-coordinated mononuclear systems that adopt octahedral geometry. The complex has also exhibited the supramolecular networks through non-covalent interactions like H-bonding, C–Hπ stacking. Moreover, the complex 1 is very effective in the catalytic fixation of carbon dioxide in propergyl alcohols to produce α-alkylidene cyclic carbonates. The catalytic production of α-alkylidene cyclic carbonates have been carried out through carboxylative cyclization of propargyl alcohols using CO2 balloon of 1 atm pressure at 80 ◦C. Solvent free condition (green synthesis) made this catalytic protocol eco-friendly towards the environment. Utilizing various substrates of propargyl alcohols moderate to high percentage yield (62–95%) of respective α-alkylidene cyclic carbonates product have been isolated over this catalytic reaction. Besides, the theoretical calculations (DFT) was performed for the prediction of probable mechanism of the catalytic reaction KW - Catalytic fixation of carbon dioxide KW - Carboxylative cyclization of propargyl alcohols KW - Cobalt (III) Schiff base complex KW - X-ray crystal analysis PY - 2024 DO - https://doi.org/10.1016/j.molstruc.2023.136868 SN - 0022-2860 VL - 1296 IS - Part 1 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-58947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -