1395880-11-1Relevant articles and documents
Trans influence and steric effect on the distortions in planar NiS 4, NiS2PN, and NiS2P2 chromophores
Srinivasan, Subramaniam,Ramalingam, Kuppukkannu,Rizzoli, Corrado
, p. 1356 - 1361 (2012)
The planar diamagnetic complexes [Ni(achdtc)2] (1),[Ni(achdtc)(PPh3)(NCS)] (2), and [Ni(achdtc)(PPh 3)2]ClO4·0.5EtOAc (3) (achdtc = allylcyclohexylcarbodithioate) were prepared, characterized by elemental analysis, electronic, IR, NMR (1H, 13C, and 31P) spectroscopy and the crystal structures were determined by single-crystal X-ray crystallography. The characteristic thioureide bands occur at 1478, 1503, and 1507 cm-1 for 1, 2, and 3, respectively and the corresponding 13C chemical shifts are observed at 207.67, 204.16, and 202.31 ppm. 31P chemical shifts are observed at δ = 29.24 and 22.73 ppm for 2 and 3, respectively, indicating a strong interaction. Electronic spectral bands are observed at 480, 483, and 475 nm for 1, 2, and 3, corresponding to dz2 → dxy/dx2-y2 transitions. Ni-S distances are asymmetric. The trans influence of PPh 3 elongates the Ni-S bonds. The decrease in the S-Ni-S bite angle in 2 [78.80(16)°] and in 3 [78.36(2)°] compared to that observed in 1 [79.42(3)°] is due to the steric crowding of PPh3 around the central metal atom. A comparison of the bond parameters of compounds 1-3 shows a change in the arrangement from a planar NiS4 chromophore to distorted planar NiS2P2 chromophores. The observed distortion from planar to tetrahedral arrangement is influenced by the bulky triphenylphosphine ligand. Copyright
