Kolandaivelu Saminathan

Cyclo­hexyl­ammonium picrate

In the crystal structure of the title salt, C6H14N+·C6H2N3O7−, picrate anions lie parallel to one another with a relative orientation of nearly 120°. The protonated N atom of the cation makes one linear and two bifurcated hydrogen bonds with three neighbouring picrate ions. The centrosymmetrically related anions and cations form hydrogen-bonded graph-set motifs of R42(8) and R44(12) alternately along the [010] direction.

Trans effect of triphenylphosphine on Ni–S bonds in solid state and DFT/B3LYP optimized structure: Synthesis, spectral and structural studies on (bis(2-ethylhexyl)dithiocarbamato-S,S′)(thiocyanato-N)(triphenylphosphine)nickel(II)

GRAPHICAL ABSTRACT ABSTRACT The compounds [Ni(behdtc)2] (1) and [Ni(behdtc)(NCS)(PPh3)] (2) (where behdtc = bis(2-ethylhexyl)dithiocarbamate) were synthesized and characterized by elemental analyses, electronic, IR, and NMR (1H and 13C) spectroscopy. UV-vis spectral data are consistent with the formation of square-planar nickel complexes. The N13CS2 carbon signal for [Ni(behdtc)(NCS)(PPh3)] is observed at 204.4 ppm with an upfield shift of about 3.8 ppm compared with that found in [Ni(behdtc)2] (208.2 ppm). The observed shielding in [Ni(behdtc)(NCS)(PPh3)] indicates the effect of PPh3 on the mesomeric drift of electron density toward nickel through the thioureide C-N bond. This observation is supported by the higher νC-N values observed in the IR spectrum of the complex 2. A single crystal X-ray analysis of complex 2 proved four coordinated nickel in a distorted square-planar arrangement with a S2NP donor set. A significant asymmetry in the Ni–S bond in 2 (2.1690(10) and 2.2234(10)Å) supports the less effective trans effect of SCN− over PPh3. Molecular electrostatic potential surface map shows that there are no possible sites for nucleophilic attack and S atom of thiocyanate is preferred possible site for electrophilic attack.