High‐Yield Syntheses of Sodium, Potassium, and Thallium Hydrotris[3,5‐bis(trifluoromethyl)pyrazolyl]borates and the X‐ray crystal structure of {hydrotris[3,5‐bis(trifluoromethyl)pyrazolyl]borato} thallium(I)

Abstract

An improved synthesis of 3,5-bis(trifluoromethyl)pyrazole (1) is described. This compound was used for the high-yield syntheses of the tris(pyrazoly1)borates Nd[HB(3,5-(CF3),-pz),1 (2a) and the corresponding potassium salt, 2b, starting from 1 and NaBH, and KBH,, respectively. A convenient route to the corresponding thallium(1) salt, 2c, using thallium(1) acetate and either 2a or 2b in CHCI,, is also described. The sodium (3a), potasium (3b), and thallium (3c) salts of bis(pyrazoly1)borate [H,B(3,5-(CF3),-pz),]-were also prepared. The above pyrazolylborates were characterized by 'H-, I3C-, I9F-, and "B-NMR spectroscopy. The X-ray crystal structure of the thallium derivative 2c was determined. The compound crystallizes in the monoclinic space group P2,/rn with a = 8.248(9) A, b = 15.034(12)& c = 9.243(8)A,p = 100.10(7)O,Z = 2. TheTI-atomadoptsapyramidalgeometry with respect to the three N-atoms. However, two TI-N distances (2.725(7) A) are longer than the third (2.675(10) A).

New copper(I) phosphane complexes of dihydridobis(3-nitro-1,2,4-triazolyl)borate ligand showing cytotoxic activity

“…In particular poly(pyrazolyl)borate copper derivatives, synthesized in order to model various properties of copper-containing natural products, have been discussed in a review devoted to the structure and function of copper proteins [23]. Very little has been done on poly(pyrazolyl)borate systems bearing electron withdrawing substituents [24][25][26][27][28][29][30][31]. The electron withdrawing substituents in polyfluorinated ligands [32] commonly improve oxidation resistance, thermal stability, and solubility of metal complexes.…”

Deposition of Conductive Ru and RuO2 Thin Films Employing a Pyrazolate Complex [Ru(CO)3(3,5‐(CF3)2‐pz)]2 as the CVD Source Reagent

“…All reactions were performed in air using anhydrous solvents or solvents treated with an appropriate drying reagent. The pyrazole ligand (3,5-(CF 3 ) 2 -pz)H was prepared according to the method reported in the literature [33].…”

Synthesis and structures of Co bis-trifluoromethylpyrazolate complexes

“…Solvents were dried prior to use by distillation from sodium benzophenone ketyl anion under nitrogen. The compounds 3,5-bis(trifluoromethyl)pyrazole 3,5-(CF 3 ) 2 -PzH, 25 [Co(PMe 3 ) 4 ], 26 and [Co(PMe 3 ) 3 Cl] 25 were prepared as previously described. Trimethylphosphine (97%), sodium hydride, and n-butyl lithium (1.6 M in hexane) were purchased from Aldrich and used without further purification.…”