Synthesis and Structure of Potassium and Barium Complexes With Diphenylphosphinothioicamido Ligand Containing Ba-S Direct Bonds

• Published in: Phosphorus, sulfur, and silicon and the related elements sulfur, and silicon and the related elements, 2014-11, Vol.189 (11), p.1624-1632
• Main Authors: Kottalanka, Ravi K., Naktode, Kishor, Anga, Srinivas, Panda, Tarun K.
• Format: Article
• Language: English
• Subjects: Barium; Crystals; Diffraction; Diphenylphosphinothioicamine; Ligands; metallacycle; Potassium; Sulfur
• ISSN: 1042-6507; 1563-5325
• DOI: 10.1080/10426507.2013.818998

We report the syntheses and structures of homoleptic diphenylphosphinothioicamido potassium and barium complexes of the molecular formula [{K(THF) 2 Ph 2 P(S)N(CHPh 2 )} 2 ] (2)] and [Ba(THF) 2 {Ph 2 P(S)N(CHPh 2 )} 2 ] (3)], respectively. The potassium complex 2 can be obtained in good yield by the treatment of diphenylphosphinothioicamine [Ph 2 P(S)NH(CHPh 2 )] (1) and potassium bis(trimethylsilyl)amide in tetrahydrofuran (THF). However, the barium complex 3 was prepared by two synthetic routes; first by the silylamide route where the barium bis-trimethylsilyl amide [Ba{N(SiMe 3 ) 2 } 2 (THF) 2 ] was treated with 1 in 1:2 molar ratio in THF to afford 95% of the product via the elimination of hexamethyldisilylamine. In the second method, potassium complex 2 was treated with barium diiodide in THF to yield the same product 3 in 85% yields. In the solid state, the potassium complex 2 is dimeric and form highly strained polymetallacyclic motif through the coordination of nitrogen, phosphorus, and sulfur atoms of the diphenylphosphinothioicamido moieties. The solid state structures of 2 and 3 were established by single-crystal X-ray diffraction analysis. In the molecular structure of barium complex 3, the barium adopts a pseudo-octahedral geometry and a direct barium sulfur bond is observed.