Cesium hydridotris(trifluoromethyl)borate, Cs[(CF3)3BH]

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Materials Science

Background:

• Trifluoromethyl substituted boron compounds are of interest due to their unique electronic properties.
• The synthesis and characterization of novel boron hydride anions are crucial for advancing coordination chemistry.

Purpose of the Study:

• To synthesize and characterize a new cesium trifluoroborate hydride salt, Cs[(CF3)3BH].
• To investigate the stability and reactivity of the [(CF3)3BH]- anion.
• To elucidate the molecular structure and electronic properties of the synthesized compound.

Main Methods:

• Synthesis of Cs[(CF3)3BH] from Cs[(CF3)3BNH2] using H2NOSO3H.
• Single-crystal X-ray diffraction for structural determination.
• Spectroscopic characterization including IR, Raman, and multinuclear NMR.
• Density Functional Theory (DFT) calculations for vibrational assignments and charge analysis.

Main Results:

• Isolation of pure Cs[(CF3)3BH], stable up to 300°C.
• The [(CF3)3BH]- anion demonstrates high stability in concentrated HCl and low reactivity as a hydride.
• Clean reactions with halogens (F2, Cl2, Br2) yielding corresponding haloborates.
• Detailed crystal structure and spectroscopic data obtained, supported by DFT calculations.

Conclusions:

• The strong electron-withdrawing effect of CF3 groups significantly reduces the reactivity of the hydride in [(CF3)3BH]-.
• Cs[(CF3)3BH] represents a stable and synthetically versatile boron hydride species.
• The study provides valuable insights into the structure-property relationships of fluorinated boron compounds.