The simple off-the-shelf chemical 6,7-dihydroxycoumarin (1) based copper complex (1·Cu 2+ ) has been used for the selective detection of toxic cyanide in aqueous medium. The DFT calculation confirms the binding behavior between 1 and Cu2+ (2:1) and the red shift in the UV–vis spectrum with copper ion was confirmed by the decrease in energy between HOMO–LUMO band gaps. The cyanide sensing in water was confirmed by both absorption and emission spectral studies. Cyanide ion showed 13-fold increments in fluorescent intensity in emission spectrum via displacement of copper from 1·Cu 2+ . The limit of detection of CN– in water is 5.77 μM; 1·Cu 2+ also applicable for the detection of cyanide in fresh mouse serum with detection limit of 14.4 μM. The cell images showed that 1·Cu 2+ could be used to detect intracellular CN–.

A new type of polycyclic organic superbases is reported with very high proton affinities in the gas phase and the pK(a) upto 45.8 units in acetonitrile. They have exhibited the 2nd pK(a) upto 44.4 units, which is the highest 2nd pK(a) reported till date. These organic superbases can be useful in the fixation of CO(2) released from different industrial sources.

We have performed a density functional study to examine the effect of formamide on the morphology of different alkali halide (namely LiF, NaCl, and KI) crystals. The calculations were performed both in the gas phase and aqueous phase using a continuum model (COSMO/COSMO-RS). Solvation is observed to have a major effect on the interaction energies whereas the matching of the size of the additive with the neighboring ion spacing on the lattice planes of the different alkali halides is seen to be less important. The calculated results employing the slab models show that, in the aqueous phase, formamide interacts preferentially with the {111} surface of sodium chloride (∆E ) -23.8 kcal/mol for {111} vs -0.4 and -4.3 kcal/mol for {100} and {110}, respectively). This would favor the formation of octahedral-shaped crystals as reported experimentally (Surf. Sci. 2003, 523, 307-315). On the other hand, interaction of formamide with all the surfaces of LiF are found to be repulsive in the aqueous phase while, in the case of KI, the interactions are weak (∼-2 to -5 kcal/mol) on all surfaces, i.e., no pronounced effect of formamide on morphology is expected.

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