Water is vital for sustenance of all forms of life. Hence, water pollution is a universal crisis of survival for all forms of life and a hurdle for sustainable development....

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A pair of enantiomeric tetrahedral complexes (Λ-[Zn­(L)2] and Δ-[Zn­(L)2]) comprised of the achiral ligand methyl-3-hydroxy-3-phenyl-2-propenedithioate (L) have been synthesized by spontaneous resolution. Two chiral inducers, viz., d-(−)- and l-(+)-tartaric and mandelic acids, have been employed to achieve bulk homochirality and extend the generality of the present work. The work highlights the achievement of bulk homochirality using readily available chiral inducers in the synthesis of a spontaneously resolving chiral tetrahedral zinc­(II) complex using achiral starting materials. These findings are established by 30 sets of single-crystal X-ray diffraction data with refined Flack parameters and circular dichroism spectroscopy.

New functionalized homoleptic dithiocarbamates of the form [M(L) 2 ] (M = Ni(II), L = L1, N-(3-methoxybenzyl)-N-(methylbenzyl)dithiocarbamate (1), L3, N-(3,4,5-trimethoxybenzyl)-N-(3-methylpyridyl)dithiocarbamate (3), L4, N-(4-methoxybenzyl)-N-benzyldithiocarbamate (4); Pd(II), L2, N-(N 0 -methyl-2-pyrrole)-N-benzyldithiocarbamate (2)) have been synthesized and characterized by microanalysis and their structures have been investigated using X-ray crystallography. All the four structures are centrosymmetric with the metal located in a square plane with minor distortions, Pd(II) greater than Ni(II). The crystal structures of 1 and 2 revealed the existence of unique intermolecular C-HÁ Á ÁM (Ni, Pd) anagostic interactions between the methylene hydrogen atom on the ligand substituents and the metal centres and these enable the formation of 1-D polymeric chains. Particularly, geometric parameters (PdÁ Á ÁH-C = 2.61 Å; +PdÁ Á ÁH-C = 1731) for the C-HÁ Á ÁPd interactions in 2 are at the border of anagostic and hydrogen bonding. By contrast, 4 shows interactions between the methylene hydrogen atom and the CS 2 Ni ring rather than the metal alone, while the interaction in 3 is intermediate between the two aforementioned types. These interactions are not shown in solution as revealed by their 1 H NMR studies. DFT calculations have been performed to analyse these rare interactions. 1, 3 and 4 are weakly conducting, s rt = 10 À10 -10 À12 S cm À1 , and show semiconductor behaviour in the 313-373 K range.