Isonicotinic acid anthracen-9-ylmethylene-hydrazide (AI), prepared from anthracene-9-carboxaldehyde and isoniazid, exhibited mechano-responsive luminescent emissions; for instance, gentle pressing of the weakly emissive crystals of AI (λ em 527 nm) produced a yellow-green emissive material (λ em 540 nm). Also, the mechano-luminescent emissions of AI could be easily switched "off" upon exposure to N,N-dimethylformamide. Contrastingly, under the same conditions, benzoic acid anthracen-9-ylmethylene-hydrazide (AB) did not exhibit mechano-responsive luminescent emissions. On the basis of UV−vis, fluorescence, Fourier transform infrared spectroscopy, and powder X-ray diffraction (XRD) studies, we suggest that mechano-luminescent emissions of AI were triggered by mechanically induced deformations in the lattice, which affected the intermolecular interactions and aromatic stacking behavior. Again, the mechano-luminescent emissions of AI were switched off when mixed with oxalic acid, although accompanied by a concomitant change in color, from yellow-green to red. Single crystal XRD studies provided vital insights into the interactions of AI with oxalic acid, highlighting the role of hydrogen bonding and anion-mediated aromatic-π interactions.

No abstract

Agriculture is the main source of livelihood in Assam and it contributed over 19 per cent to state domestic product (SDP) in 2010-11. But the farmers are still suppressed class even after seven decades of Independence. This may be for various reasons. In Assam Majority farmers are from tribal population where their living standard is very low. So, the present study reveals the Socioeconomic Status and expenditure pattern of Tribal Farmers of sonitpur district of Assam. The study area has been chosen Thelamara circle of the district. The data has been collected on the basis of personal interview by survey method to each of the farmer through a predetermined questionnaire. A total sample of 80 farmers has been collected purposively from four different villages of the circle. The study revealed that Tribal farmers are very poor farmers with low literacy and knowledge about agricultural methods in comparison to non Tribal farmers.

No abstract