Crystall ine n ickel(II) d i- i-amyl d ith iophosphate, [N i{S2P(O- i-C5H11)2}2]: Preparat ion, structure, heteronuclear (13C, 31P) CP/MAS NMR spectra, and thermal behav ior

The crystalline nickel(II) di-i-amyl) dithiophosphate (Dtph), [Ni{S2P(O-i-C5H11)2}2] (I) was isolated on a preparative scale and characterized by 13C, 31P MAS NMR, and X-ray diffraction (CIF file CCDC no. 1469369). The χ2-statistic diagrams were constructed from full 31P CP/MAS NMR spectra for calculating the 31P chemical shift anisotropy: δ aniso = δ zz –δ iso and the asymmetry parameter η = (δ yy –δ xx )/(δ zz –δ iso ). The key structural unit of I is the centrosymmetric [Ni{S2P(O-i-C5H11)2}2] molecule in which the nickel atom coordinates two Dtph ligands in the isobidentate fashion. In molecule I, each carbon, oxygen, and sulfur atom is statistically disordered over two sites with equal occupancies. However, the disorder does not affect nickel and phosphorus. These results were interpreted as the presence in I of two [Ni{S2P(O-i-C5H11)2}2] molecules rotated through 21.0(1)° (the angle between the [NiS4] chromophore planes) relative to each other around the bisecting P–Ni–P axis passing through both four-membered [NiS2P] rings. The two molecules occupy crystal lattice sites with equal probabilities. The thermal behavior of I was studied by simultaneous thermal analysis under argon. The course of the thermal destruction of the complex was established, nickel pyrophosphate (Ni2P2O7) was identified as the final product of thermal transformations.