http://ore.immt.res.in/handle/2018/4 2026-08-16T13:59:31Z http://ore.immt.res.in/handle/2018/4001 Sterically Crowded Hexaterpyridyl-BODIPY: A Multiresponsive Far-Red Emissive AIE-Active Probe for Zn(II) Recognition and Biological Applications Behera, K. C.; Das, Suprava Sterically crowded aggregation-induced emission (AIE)-active fluorophores provide a powerful approach to constructing multifunctional platforms for sensing and bioimaging. Herein, we describe the rational design and synthesis of a highly crowded hexaterpyridyl-functionalized BODIPY, obtained through hexabromination of the BODIPY core followed by Suzuki-Miyaura coupling with terpyridyl boronic acid derivatives. Spectroscopic characterization confirms the structure, while the installation of six terpyridine units at the alpha/beta positions generates substantial steric crowding, leading to pronounced AIE behavior, far-red emission, cooperative metal-ion coordination, and efficient cellular imaging. Systematic aggregation studies in THF/water mixtures reveal significant fluorescence enhancement correlated with the formation of well-defined spherical nanoaggregates, as confirmed by TEM and SEM analyses. The hexaterpyridyl-BODIPY further exhibits selective Zn(II) recognition with distinct fluorescence responses. Comparative studies with alpha,alpha- and beta,beta-diterpyridyl analogs emphasize the critical role of multiligand steric crowding in tuning aggregation, photophysical properties, and biological performance. Notably, the hexaterpyridyl derivative shows efficient cellular uptake, bright intracellular fluorescence, excellent biocompatibility in normal and cancer cell lines, and enhanced phototoxicity compared to its counterparts. DFT calculations elucidate the structure-property relationships, establishing a versatile molecular design strategy that integrates AIE, metal-ion sensing, and bioimaging within a single BODIPY scaffold. 2026-01-01T00:00:00Z http://ore.immt.res.in/handle/2018/4000 Effect of Co/Y co-doping concentrations on the tailoring structure and optical properties of ZnO nanostructures Sawyasasin, D.; Gajendiran, J.; Kasilingam, T.; Gnanam, S.; Thennarasu, G.; Ramasamy, B.; Jeyanthi, C. E. Undoped and 0.01, 0.03 and 0.05 mol% concentrations of Co/Y co-doped ZnO nanostructures were attempted by solid-state method. In this study, to investigate experimentally how Co/Y co-doping concentrations impact the crystalline structure, surface particle dimension, and optical characteristics of ZnO nanostructures. Hexagonal structure was found in the XRD pattern of undoped ZnO. However, distortion in the hexagonal structure were noticed in the ZnO by introducing co-dopant concentrations (Co/Y) from 0.01 to 0.05 mol% in the XRD pattern. Non-uniform size with agglomerated spherical, coalescence with spherical, porous structure with smaller size spherical, and highly porous with well dispersed spherical particles were noticed for the undoped, 0.01, 0.03 and 0.05 mol% of Co/Y co-doped ZnO in the SEM studies. FT-IR spectra indicate that the Zn-O vibrational shift towards to the lower wavenumber with an increasing Co/Y dopant concentrations in the ZnO. Raman spectra were studied to understand the structural confirmation of the synthesized compounds. The molecular elements, chemical composition, elemental oxidation states and its corresponding binding energy of the synthesized undoped ZnO and Co/Y-doped ZnO were recorded from the EDX/mapping and XPS studies. Optical absorption spectra were evaluated for the synthesized compounds and their optical band gap (Eg = 1.76 to 1.46 eV) results narrowing in the ZnO by increasing co-dopant concentrations from 0.01 to 0.05 mol% when compared to the undoped ZnO (Eg = 3.16 eV). The PL emission bands (UV and visible portion) and colour coordinates (x, y) position values were slightly tuned under the impact of co-dopant concentrations in the synthesized ZnO nanostructures. 2026-01-01T00:00:00Z http://ore.immt.res.in/handle/2018/3998 Harnessing dispersed metal ions in salt-solution quenched ceria nanorods for promoting electrocatalytic activity towards alkaline oxygen reduction reaction Das, D.; Ping, T.; Annadata, H. V.; Bahadur, J.; Jena, B. K.; Gupta, S. K.; Sudarshan, K. Defect engineering, particularly through the creation of oxygen vacancies, combined with transition-metal incorporation, offers an effective route to tailor the catalytic properties of metal oxides. In this study, we report, for the first time, the simultaneous modulation of defects and the dispersion of transition-metal ions on ceria nanorods via quenching in ice-cold salt solutions to improve Oxygen Reduction Reaction (ORR) electrocatalysis in alkaline media. Hydrothermally synthesized ceria nanorods with high surface area and mesoporous architecture were quenched in Co2+, Ni2+, Cu2+, and Zn2+ salt solutions and comprehensively characterized using structural, morphological, and surface-sensitive techniques. Positron annihilation lifetime spectroscopy revealed a nearly balanced distribution of oxygen vacancies and vacancy clusters in the bulk and surface regions of the Zn2+-quenched catalyst (Zn-Q). Furthermore, Extended X-ray Absorption Fine Structure (EXAFS) and wavelet-transformed EXAFS analyses identified a distinct neighboring Zn-Ce interaction in Zn-Q, indicating a unique mode of Zn incorporation compared with the other quenched catalysts. The synergistic effects of defect modulation and transition-metal dispersion were subsequently correlated with ORR activity. Salt-solution quenching enhanced the half-wave potential and shifted the ORR pathway from a two-electron to a four-electron pathway. Among the investigated catalysts, Zn-Q exhibited the most favorable combination of thermodynamic and kinetic ORR descriptors, delivering the highest four-electron selectivity with minimal peroxide generation. These findings demonstrate a simple, cost-effective strategy for engineering high-performance ceria-based ORR electrocatalysts through concurrent defect modulation and transition-metal dispersion, without the addition of noble-metal components. 2026-01-01T00:00:00Z http://ore.immt.res.in/handle/2018/3997 Report on Rare Earth Phosphate Minerals from the Daitari Iron Ore Province, Singhbhum Craton, Eastern India Sahoo, J. K.; Mishra, P.; Angadi, S.; Khaoash, S.; Mohapatra, B. K. Rare-earth phosphate minerals have been reported in the Banded Hematite Jasper (BHJ) of the Daitari Iron Ore Province, Singhbhum Craton, eastern India, through electron-microscope study, supported by electron microprobe analysis. The Rare Earth Element (REE) minerals identified are monazite and xenotime, occurring as discrete, micron-size (7-30 mu m) anhedral grains within hematite-jasper bands. The monazite grains are enriched in Light Rare Earth Elements (LREEs), with Ce2O3 (29-32 wt%), La2O3 (27-31 wt%), and Nd2O3 (similar to 1 wt%), whereas xenotime is dominated by Heavy Rare Earth Elements (HREEs), notably Y2O3 (45-49 wt%), Er2O3 (4-10 wt%), and Dy2O3 (2-3 wt%). Both phases contain abundant P2O5 (20-38 wt%) and traces of Th and U. The micro-structural and compositional results of the phosphate minerals indicate that the phosphate-rich fluid was possibly derived from some adjacent source, which was later subjected to diagenesis and low-grade metamorphism. These phosphate minerals sequester a significant proportion of the REE in the BHJ of the present set-up. The Daitari BHJ thus represents a potential micro-reservoir of REE-bearing phosphates within the Archaean Banded Iron Formation (BIF) regime of the Singhbhum Craton. 2026-01-01T00:00:00Z